Hardware sensors embedded in a smartphone allow the device to become an excellent mobile navigator. A smartphone is ideal for this task because its great international popularity has led to increased phone power and since most of the necessary infrastructure is already in place. However, using a smartphone for indoor pedestrian navigation can be problematic due to the low accuracy of sensors, imprecise predictability of pedestrian motion, and inaccessibility of the Global Navigation Satellite System (GNSS) in some indoor environments. Pedestrian Dead Reckoning (PDR) is one of the most common technologies used for pedestrian navigation, but in its present form, various errors tend to accumulate. This study introduces a fuzzy decision tree (FDT) aided by map information to improve the accuracy and stability of PDR with less dependency on infrastructure. First, the map is quickly surveyed by the Indoor Mobile Mapping System (IMMS). Next, Bluetooth beacons are implemented to enable the initializing of any position. Finally, map-aided FDT can estimate navigation solutions in real time. The experiments were conducted in different fields using a variety of smartphones and users in order to verify stability. The contrast PDR system demonstrates low stability for each case without pre-calibration and post-processing, but the proposed low-complexity FDT algorithm shows good stability and accuracy under the same conditions. Over the past twenty years, several kinds of indoor navigation technologies have been developed based on various methods and theories . This tePDR is one of the most common methods for using inertial sensors to estimate two-dimensional positions for pedestrian navigation. Given an initial position, PDR uses a pedometer, step length model and heading sensor to obtain positions rather than constantly producing integral calculations like the inertial navigation system (INS). Because the model simplifies the 3D world into a 2D world, the impact of gravity projection on horizontal components in INS is eliminated in PDR. However, PDR errors accumulate with each step in a similar manner to the INS errors that accumulate over time. The estimated heading of PDR usually depends on the integration of the gyro angle rate or calculation from a magnetic field. Both of these methods, however, also have their inherent problems. It has long been understood that gyros’ readings are strongly affected by human motion because of the vibration noise and dynamic misalignment between sensor body frame and pedestrian frame, causing error drifts quickly after integration. In regard to headings based on magnetic fields, magnetic materials and environmental obstacles degrade the magnetometer’s reading, negatively influencing the accuracy of the calculated azimuth. In addition to the accuracy of the heading, most of the step length estimations derived from empirical formulas fail to accurately meet users’ various individual characteristics. For example, step length can vary by as much as 40% with different pedestrians when they are walking at the same speed, and by up to 50% across the range of walking speeds of an individual [et al. propose an integrated system comprised of PDR and beacon-type AP to maintain stable performance [Jeong-Min formance . The beaformance . They aletc. The matching algorithm first projects the navigation solution onto the passageway or corridor both to constrain the error drift and provide boundaries to avoid crossing a wall. They use the previous position, velocity and heading from the navigation solution in combination with geospatial data to perform the required mathematics, such as determining minimum distance and weighted algorithms. Once these processes have been completed, the map matching decides the most likely location of the user. However, those traditional algorithms and mathematics are more complex and time consuming when they achieve higher accuracy. Link et al. propose a novel footpath-matching algorithm that integrates their indoor maps with OSM which is thus similar to a rule-based system. To be specific, the algorithm implements the matching based on the footpath which is a route that consists of steps and corresponds with a step-by-step heading [At present, maps and geospatial data are often used as an aiding source for navigation because of their reliability. They generally consist of nodes, polylines, polygons, individual IDs and attribute data in the format of XML or computer-aided drawing (CAD) files. The map formats become more consistent because of the development of the map-matching algorithm and standards of the map database; however, the traditional generation of a numerical map is time consuming and the matching algorithm seems complex. In addition, for such a crowdsourcing map database like OpenStreetMaps (OSM), there may be inaccuracies and precision problems, since the editors are not necessarily professionals. Thus, instead of using the aforementioned maps, the proposed system uses the reliable map surveyed by the self-developed Indoor Mobile Mapping System (IMMS). The IMMS quickly obtains the indoor map in the WGS84 coordinate system with high accuracy, depending on the advanced hardware and algorithm. The map format references OSM with some self-defined attributes. The theoretical basis of the map-matching algorithm generally includes topological relation , probabi heading .a priori qualitative, uncertain and expert knowledge. Specifically, fuzzy logic expresses the input crisp system in a fuzzy set with a membership function in the fuzzifier; then, using an inference engine, it obtains the output of a corresponding fuzzy set using defined, knowledge-based rules. Finally, the defuzzifier transforms the corresponding fuzzy set into crisp values. The basic concept of the fuzzy system is illustrated in Therefore, in order to combine map information, Bluetooth beacon and PDR with lower complexity, some logic algorithms have been applied in the attempt to further improve navigation accuracy. In the real world, many decision-making tasks are too complex to be understood quantitatively, but humans succeed by flexibly using knowledge that is imprecise rather than precise . Realiziet al. estimated walking frequency and strength per step based on fuzzy logic for step length estimation in their PDR system [et al. further propose a complete fuzzy logic architecture for step length estimation with the membership functions such as step interval, human locomotion, user’s height and trajectory curvature for the knowledge-based system (KBS) [The application of fuzzy logic has dramatically increased in the last two decades, being used extensively in control theory, artificial intelligence, finance and other decision-making problems. Trawinski applied fuzzy logic based on FURIA-based and J48G-based multi-classification systems (MCSs) to improve the accuracy of a topology-based Wi-Fi signal strength fingerprint approach, where FURIA represents Fuzzy Unordered Rule Induction Algorithm and J48G is a simple decision tree . Lai et R system . Shahramem (KBS) . In looket al. propose an integrated map-matching algorithm based on fuzzy logic which combines a geometry map, probability map and the topology relation of the road network. Their fuzzy sets include three membership functions: projection distance, direction angle and comparability of trajectory [There are studies regarding fuzzy logic map matching for vehicle navigation. Haibin ajectory . Zhang aajectory . Workingajectory . Ren andajectory . Syed anajectory . Essentiet al. proposed methods based on the comparisons of RSSI and orientation information (magnetometer) to develop multiple weighted decision trees and data mining techniques for Wi-Fi fingerprinting [A decision tree is another low-complexity logic system for decision making; it consists of a hierarchical structure with a root, node and leaf, as shown in printing . There aprinting  and Zeroet al. have proposed an understandable fuzzy decision tree (FDT) based on the Iterative Dichotmiser 3 (ID3) algorithm and defined fuzzy sets for the analysis of gas in oil [Therefore, some studies combine fuzzy logic and decision tree to improve the performance of a rule-based system. Umano s in oil . In tryis in oil . Insteads in oil ,23. InspAlthough complicated algorithms, various integrations, mathematics and multi-sensor fusion do indeed significantly improve navigation accuracy, these high-complexity approaches are more time/power consuming and require higher hardware standards. In addition, external complementary signals suffer problems, such as environmental changes and maintenance costs. Other simpler algorithms usually need the adjustment of parameters based upon post/pre-processing to adapt to each user, device and environment which is inconvenient for real-time application. Therefore, developing a stable, accurate and low-complexity system is a much more attractive direction for smartphone and real-time indoor pedestrian applications. Based on this idea, a system using map-aided FDT is proposed. The system determines the user’s location based on low-complexity rules, sensor data, fewer distributed Bluetooth beacons (depending on the floor plan’s geometry). The FDT rules are trained once using experimental field data. Then these rules are fixed in the map-aided FDT system for all other new experimental field tests. In other words, after the map survey by IMMS and one experimental file is used as trained data, the proposed system has the generalization ability to work on various individuals and smartphones. The difference between the proposed system and the contrast PDR system is the additional logic rules related to the map information.There are three main advantages to this approach: (1) based on a single time training, the proposed system is versatile regarding different users, smartphones and experimental fields. In other words, the proposed system has the ability to work for new devices and individuals; in a crowd or a new environment such as a plaza ; and in corridors and a magnetic-hostile environment; (2) the system can achieve better stability without time-consuming pre/post-processing; (3) compared to traditional PDR, a low-complexity method, the proposed method is also a relatively simple while maintaining a similar level of error acceptibility without the need for continuous tuning. It is worth mentioning that for traditional PDR to achieve asimilar performance, anew tuning process is required for each users, sensor and environment.csv format file with WGS84 coordinates with some self-defined attributes. In addition, It also measures the point of interest (POI) based on the theories of photogrammetry and direct geo-referencing (DG) for the position of the installed Bluetooth beacon and its subsequent application. The coordinate of POI can be further applied to some applications such as route planning and investigation of the user’s hotspots. Those systems and software are part of an ongoing developed project at National Cheng Kung University (NCKU), as shown in IMMS was used to survey the building to generate a precise geo-referenced map, which is an important component in the proposed algorithm. The system is INS/GNSS integration and consists of GNSS, navigation-grade Inertial Measurement Unit (IMU), a panoramic camera, a power supply and an industrial computer. The use of this system reduces the time-consuming procedure for mapping a building and the result has high accuracy. A software was used to precisely estimate the trajectory of IMMS based on the Extend Kalman Filter (EKF) and Rauch-Tung-Striebel (RTS) smoother. The Non-Holonomic Constraint (NHC) and Zero Velocity Update (ZUPT) are used in the EKF. Information regarding these can be found in our previous research . AnotherRF-based Bluetooth positioning is used for both initialization and update measurements during navigation. This experiment uses two methods, proximity and bounding box, implemented individually for each beacon with different setting IDs. Both of these methods are used to obtain the initial location, but only proximity is used for the update measurement. Some proximity-type beacons have heading constraint from map knowledge; the power level is one meter and is generally placed at the POI or corridor. When the system detects the signal from the beacons, the algorithm identifies their type based on their ID, and then decides on the next action. If the signal received is from the proximity-type beacon with an RSSI value larger than the threshold, then the algorithm obtains the coordinate and heading from the map database for initialization or updating. The signal strength distribution indoors is affected by the placement of the Bluetooth beacon and the environment . To corrThe bounding box method usually has a power level higher than ten meters, depending upon the field size, and beacons are placed in the corners of the plaza. Compared to the proximity method, initialization using the bounding box method is generally less accurate because of flaws in the RSSI-distance model, but it is more flexible in a large space. In addition, the heading used in the bounding box method relies on the magnetic heading because the initial location at the plaza has no corresponding heading in the map database. When the bounding box IDs are detected and the RSSI values exceed the defined threshold, the algorithm sorts their RSSI values and chooses the top three beacons, thus determining the coordinates according to their ID in map database for further position calculation. Each beacon produces a bounding box by the use of the beacon’s location (quations :(1)xmaxx is the state vector; et al. and is shown as the following [The general PDR was developed to compare with the map-aided FDT algorithm. It has two Kalman Filters (KF) for heading and position estimation. The heading measurements are derived from gyro (ollowing :(14)Lk=A is a fuzzy set; X is a crisp set. When the x is more representative of the set A. The fuzzy decision tree shown in the The scheme for the proposed PDR system using a map-aided fuzzy decision tree is shown in The fuzzy system of step length can be seen in reference to the architecture proposed in , which iThe map engine recognizes key information from the input map, such as the direction of a corridor and where the zone of the plaza is. In general, the corridors are perpendicular to each other in a building; therefore, the type of input map can be divided into vertical or oblique. The rules in the FDT algorithm must be slightly modified after the type of map has been decided, after which the map engine generates some map point candidates with zone type attributes around the previous location based on the levels of step length.The membership probability and class of next zone type is determined by the inference engine, which uses the membership degree and level of step length and individual minimum distance. The minimum distance is determined by the previous position and the location of each zone. The weight of minimum distance is larger than step length, but step length has influence when more than one zone is close to the user. Thus, the classes of next zone type and their probabilities can be used in subsequent decision trees. The membership function of minimum distance and the fuzzy system of the next zone type are shown in The fuzzy system of moving direction is based on the magnetic heading, gyro measurement and map knowledge, which includes the next possible zone, such as the east−west corridor, as shown in Instead of using a defuzzifier to obtain a crisp value for the set of the next zone type, step length and moving direction, the decision tree directly uses levels and degree (classes and probability) of the membership functions. If the three major components  are collected, the decision tree calculates the final probability through individual branches. Each individual branch contains several nodes which decide the user’s location by multiplying the probability (degree) of each node on a specific branch. In other words, it chooses one of the locations from the four or eight candidates according to the fuzzy sets and their probability, as determined by the decision tree. The tree architecture shown in Recognize the map in order to choose the corresponding algorithm and databaseCount the step through peak detectionGenerate the map candidates around the previous locationDetermine the class and probability of step length, next neighbor zone type and moving direction with fuzzy logicChoose the most likely user’s location through the decision tree with the input of fuzzy membership value and knowledge-based rules.The sample data was collected in a departmental building in the NCKU campus by one person using smartphone HTC M7. This experiment was designed to verify and modify the architecture of FDT and related knowledge-based rules. The main architecture following the test and various refinement procedures has three groups of rules, and some rules to avoid possible exceptions during the procedure are added. Then, the defined FDT system is fixed and applied to other test fields using different smartphones with map recognition and corresponding modification (such as the position of beacon and definition of direction). In conclusion, the scheme of the proposed FDT system was implemented in the following steps:The test smartphones are of different generations and include the HTC M7, SONY Z2 and SONY Z3 . Each smartphone has its own specification of inside sensors. Four participants, three males and one female, each held a smartphone in front of the torso and walked through the experimental routes. The characteristics such as height of each participant are different. The experimental fields include three different areas: the department building at NCKU, the office floor at the Institute for Information Industry (III) building and the hall of an enterprise. The area of the tested field at NCKU is about 1000 To precisely access the performance of the proposed FDT system, we have controlled the accuracy of the initial position by using proximity only. If the user starts the navigation in the plaza, the proposed system can still estimate the initial position using the bounding method. This method was not implemented in the test because its accuracy depends on the number of beacons, geometry of the distributed beacons and the degree of complication of the environment. For further information about initialization based on the bounding box method, refer to . In ordeThe experimental results are presented in the following paragraphs. The developed Android software with proposed FDT algorithm was implemented to process the data in real time. C using the HTC M7, which is the sample data for tuning parameters and establishing knowledge rules used in the contrast PDR and proposed FDT systems, respectively. In other words, all the parameters or rules for both systems are only tuned once with HTC M7 and user C at NCKU field, and there is no further training or tuning for other smartphones, users and fields. Therefore, the other tests are designed to verify the stability and adaptability for real-time application.The contrast PDR system as well as the FDT system performs well in the sample data because of the well-tuned parameters of step length model and KF in post-processing. Due to no update operation triggered during the navigation phrase, the contrast PDR system has no ability to correct the heading. Therefore, the contrast PDR performs worse in other cases at NCKU fields. Even if we correct the initial heading, the drift continues and clearly deteriorates the trajectory. It indicates that the parameters of contrast PDR in step length model and KF are not suitable to the different users and smartphones in a magnetic-hostile environment. Thus, the contrast PDR needs new calibration of the step length for different users and a new KF tuning process for different smartphones and magnetic fields in post-processing. Unfortunately, these procedures are time consuming and not suitable for real-time indoor navigation. In contrast, the proposed map-aided FDT system performs stably in real time at all the cases without further tuning requirement.A using Sony Z2 in all fields. The figure shows that the map-aided FDT system has better stability when the field is different, regardless of user and smartphone. In addition, because the parameters of HTC M7 have been tuned with user C at NCKU, the group of HTC M7 performs better than other smartphones. It is obvious that the parameters of HTC M7 are not suitable for other smartphones which have different specifications and need individual tuning to reach optimum performance.A using three kinds of smartphones at NCKU. The NCKU cases of contrast PDR are worse because there is no initial heading correction, but the NCKU cases of FDT are better than in other fields. The group of PDR values in III has better performance than the group of PDR values in enterprise, indicating that the different characteristics between two fields need an individual tuning process. This figure shows that the map-aided FDT system has better stability even when the specification of sensors is new to this system.Ideally, the parameters and corresponding weights in KF of general PDR should be tuned for different fields and smartphones in order to compensate for the different levels of magnetic interference and differences within the sensor grade. This is because the accuracy of heading fusion depends on the accuracy of magnetometer and gyro as well as the parameters of the filter. The grade of accelerometers not only affects the pedometer but also indirectly influences the determination of step length. The model parameters of step length also depend on the characteristics of the user which needs calibration. According to these reasons, the contrast PDR system will perform poorly without individual pre-calibration and post-processing for each user, smartphone and field. However, the proposed FDT algorithm has better accuracy and stability in all cases without any further processing. It uses some simpler rules derived from one experiment and map information to mitigate the error from an inaccurate step length model and heading estimation. Therefore, the proposed map-aided FDT system provides stable average accuracy of about 1.3% based on 36 experiments in this study.In order to simplify the necessary computations and time-consuming pre/post-processing needed in a practical indoor navigation algorithm, this research proposes an FDT algorithm which significantly improves the stability of pedestrian indoor navigation with an average loop closure error of about 1.3% as well as the standard deviation of about 0.94%. Even if some algorithms can achieve higher accuracy, they usually require a lot of time in pre-calibration and post-processing for individually tuning parameters such as the contrast PDR system in this study. The proposed system has better stability and adaptability without any further tuning for different users, places and smartphones. Furthermore, some systems achieve the same stability and accuracy based upon a complex algorithm, a large amount of calculation and various integrations for real-time indoor navigation. However, the proposed FDT system only uses the rules to integrate the map information and sensor data rather than topological or graphic matching and mathematical filter. The rule-based algorithm used has relatively low complexity because of the semantic logic conditions employed and many calculations reduced.The map database and Bluetooth beacon are another important aiding source used in this study. Both the proposed FDT system and contrast PDR use the map database and Bluetooth beacon technique to enable both initialization and update measurements in real time. Although it is true that one can install more beacons to maintain navigational accuracy over a long time, the advantage of the FDT system is that it can provide acceptable accuracy even with only a small number of distributed beacons. Finally, the experiments performed for this research clearly demonstrate that the proposed FDT algorithm performs well for real-time pedestrian indoor navigation and also has high stability in different scenarios.


The crucial problem of infrared and visual image fusion is how to effectively extract the image features, including the image regions and details and combine these features into the final fusion result to produce a clear fused image. To obtain an effective fusion result with clear image details, an algorithm for infrared and visual image fusion through the fuzzy measure and alternating operators is proposed in this paper. Firstly, the alternating operators constructed using the opening and closing based toggle operator are analyzed. Secondly, two types of the constructed alternating operators are used to extract the multi-scale features of the original infrared and visual images for fusion. Thirdly, the extracted multi-scale features are combined through the fuzzy measure-based weight strategy to form the final fusion features. Finally, the final fusion features are incorporated with the original infrared and visual images using the contrast enlargement strategy. All the experimental results indicate that the proposed algorithm is effective for infrared and visual image fusion. Different imaging sensors produce images with different degrees of superiority ,6,7,8,9.The image regions in infrared images and the rich details in visual images are the spatial information. Infrared and visual image fusion should effectively combine these spatial features to produce a clear fusion result with rich details. The crucial issue of infrared and visual image fusion is how to effectively extract the image features, including the image regions and details. Combining these features into the final fusion result would produce a clear fusion image. To achieve this purpose, many algorithms have been proposed ,22,23,24Mathematical morphology has been the important theory in the field of image analysis ,30,31,32Morphological alternating filters ,27, whicBased on the analysis above, an effective algorithm for infrared and visual image fusion by using the fuzzy measure and constructed alternating operators is demonstrated in this paper. Firstly, based on the analysis of the constructed alternating operators using opening and closing based toggle operators, two types of alternating operators are used for extracting the multi-scale fusion features. Secondly, the extracted multi-scale fusion features are combined through the fuzzy measure based weight strategy to form the final fusion features. Finally, the final fusion image is produced by adjusting the contrast of the final fusion features. All the experimental results indicate that because the alternating operators could effectively extract the features for fusion and the fuzzy measure could effectively fuse the features, the proposed algorithm performs effectively for infrared and visual image fusion.f  and structuring element B . The pixel coordinates of f and B are represented by  and , respectively. Two of the basic morphological operators, dilation  in image I. Imax represents the maximum gray value of I. Based on the fuzzy valueThe fuzzy theory ,36,39 haed byγ) ,37,38, cThis measure,i could be calculated as follows:iwf represents the weight value of the bright fusion features of scale i.The weight value of the bright fusion features of each scale iwf, the final bright fusion features could be calculated as follows:By using the weight value FBFAO  represents the final bright fusion features calculated from the multi-scale bright features by using the fuzzy measureFBFAO  indicates that, the bright features with more spatial information are used with a larger weight to form the final bright fusion features. Therefore, FBFAO  would contain more spatial information, which could produce the effective fusion image with clear regions and rich details. This would produce an effective fusion result of the original infrared and visual images. Also, the final dark fusion features could be calculated as follows:idf represents the weight value of the dark fusion features of scale i. FDFAO  represents the final dark fusion features calculated from the multi-scale dark features by using the fuzzy measureFBFAO  and FDFAO  are the final bright and dark fusion features. One direct but effective way of producing fusion image based on the extracted bright and dark fusion features is the contrast adjustment strategy . To obtain an effective fusion image with good contrast, w2 and w3 should be large. Also, to keep the basic information of the original infrared and visual images, w1 should be close to 1. To be simple, we use w1 = 1.0, w2 = w3 = 2.0 in this paper. Experimental results on different types of infrared and visual images verified that the proposed algorithm using these parameters was effective.To show the effective performance of the proposed algorithm for infrared and visual image fusion, experiments comparing it with the multi-scale top-hat transform-based algorithm (MSTHT) , multi-swww.imagefusion.org. The sizes of these images range from 360 × 270 to 512 × 512. The images in the data sets are obtained under different environments. For example, the UNcamp images contain the natural and building background and the people target region is a protruding region. Also, the Dune images contain a wild background and a protruding people target region. The Navi images are obtained from the sensors located on a helicopter. Using these data sets obtained from different environments would be reasonable to verify the effectiveness of the fusion algorithms.The data sets used are standard data sets for infrared and visual image fusion, which could be downloaded from Some examples are shown below. In these examples, (a) is the original infrared image; (b) is the original visual image; (c) is the fusion result of MSTHT; (d) is the fusion result of SIDWT; (e) is the fusion result of LP; (f) is the fusion result of MSTHST; (g) is the fusion result of MSNTHT; (h) is the fusion result of MSTOOC; (i) is the fusion result of the proposed algorithm.Although MSNTHT combines the features of the original images, the details are not very rich. Moreover, the result of MSNTHT is closer to one of the original images  or the cInfrared and visual images obtained under different environments are used to verify the effective performance of the proposed algorithm. The results show that the proposed algorithm could effectively combine the image details and regions of the original images into the final fusion image, providing a clear fusion result with rich image details.To show the effective performance of the proposed algorithm through a quantitative comparison, widely used measures, including entropy ,40,41, sEntropy is a widely used measure to quantify the information content of an image. The fusion result of infrared and visual images contains the information of both original images. Thus, the entropy could be used as one measure to quantify the performance of the fusion algorithms. A large value of the entropy means the corresponding fusion result contains rich information, which indicates a good performance of the corresponding algorithm for infrared and visual image fusion.Spatial frequency is defined based on the contained spatial information in an image. Fusion of infrared and visual images would combine the image regions and details of the original images into the final fused image. The fused image has clear details and should contain more spatial information. Therefore, using spatial frequency as a quantitative measure is appropriate. A large value of the spatial frequency indicates a good performance of the corresponding algorithm for infrared and visual image fusion.Mean gradient is calculated based on the spatial gradient information. Infrared and visual image fusion should effectively combine the spatial information and produce a clear fusion result, so the mean gradient would be also an appropriate measure in the quantitative comparison. A large mean gradient value indicates a good performance of the corresponding algorithm for fusion.Q measure has been widely used to quantify the quality of an image. An effective algorithm for infrared and visual image fusion should produce a fusion image with good quality. Thus, Q measure could be also an appropriate measure to do a quantitative comparison. Also, a large value of Q measure indicates a good fusion performance.Infrared and visual images obtained under different environments are processed by different algorithms. The mean value of the entropy, spatial frequency, mean gradient and Q measure values of all the fusion results related to each algorithm is shown in Also, in In To quantitatively compare the processing times, all the algorithms are performed on images of 360 × 270 size using a computer equipped with an Intel Pentium 4, 2.6 GHz CPU and 512 MB of memory. The mean processing time of each algorithm is listed in Extracting the features of the original infrared and visual images to form a clear fusion image is a crucial task. This paper proposes an effective algorithm for infrared and visual image fusion based on the fuzzy measure and the alternating operators constructed by opening and closing-based toggle operators. The extraction of the multi-scale features of the original infrared and visual images for fusion by using two types of the constructed alternating operators is discussed in detail. Also, the extracted multi-scale features are combined through the fuzzy measure-based weight strategy to form the final fusion features. In the end, the effective fusion result is produced through importing the final fusion features into the original infrared and visual images using the contrast enlargement strategy.Because the toggle operator using opening and closing as primitives could identify the important features in the original infrared and visual images, the alternating operators could extract the features for infrared and visual image fusion well, and two types of alternating operators are used for feature extraction, which could strengthen the performance of the proposed algorithm for infrared and visual image fusion. Moreover, the strategy of combining the multi-scale features through the fuzzy measure could produce the final fusion features with rich spatial information, which would be useful for preserving the details and important regions of the original infrared and visual images in the final fused image. All of these features and the experimental results indicate that, the proposed algorithm is effective for infrared and visual image fusion, which may be also used well for other image analysis applications.


Stegosaurus is one of the most iconic dinosaurs, well-preserved fossils are rare and as a consequence there is still much that remains unknown about the taxon. A new, exceptionally complete individual affords the opportunity to describe the anatomy of Stegosaurus in detail for the first time in over a century, and enables additional comparisons with other stegosaurian dinosaurs. The new specimen is from the Red Canyon Ranch Quarry, near Shell Wyoming, and appears to have been so well preserved because it was buried rapidly in a pond or body of standing water immediately after death. The quarry is probably located in the middle part of the Morrison Formation, which is believed to be Tithonian in age in this area. The specimen is referable to Stegosaurus stenops based on the possession of an edentulous anterior portion of the dentary and elevated postzygapophyses on the cervical vertebrae. New information provided by the specimen concerns the morphology of the vertebrae, the iliosacral block and dermal armor. Several aspects of its morphology indicate the individual was not fully skeletally mature at the time of death, corroborating a previous histological study.Although  Stegosaurus is the best-known member of the clade of armored dinosaurs (thyreophorans) known as Stegosauria, or the plated dinosaurs. The stegosaurs are characterized by the possession of two parasagittal rows of hypertrophied dermal armorplates and/or spines extending from the neck to the end of the tail and range from Middle Jurassic to Early Cretaceous in age  con con2] coH 29431; ). In Dac, but thl column . Jiangjuertebrae . SixteenIn NHMUK PV R36730, cervical vertebrae get proportionately larger posteriorly along the neck, but otherwise maintain a similar morphology until the cervical-dorsal transition, between cervicals 11 and 13. In the transitional cervicals, the postzygapophyses become increasingly shorter and become elevated relative to the prezygapophyses, and the neural spines become proportionately more elongate. From dorsal 1 to dorsal 7, the vertebral centra become more elongate relative to their widths, but this decreases from dorsal 7 to dorsal 13. The dorsal neural arch pedicels becoming increasingly elongated dorsally from dorsal 1 to about dorsal 8, whereupon they maintain a similar height to dorsal 10, before become shorter until they are not elongated dorsal to the neural canal in dorsal 13. Transverse processes also become elevated to an increasing degree between dorsals 1 and about dorsal 8, but from dorsal 11 decrease in height to project laterally in dorsal 13. The parapophysis migrates dorsally from a location just dorsal to the neurocentral suture in dorsal 1 to a location at the base of the transverse process in dorsal 5. It is maintained at this location in the subsequent dorsal vertebrae.Kentrosaurus (MB R.4778). The neural arches are unfused to the intercentrum in the holotype of S. stenops, USNM 4934 ..Loricato leading : 233 to Kentrosaurus  are relatively smaller and are separated from the diapophyses by a much smaller gap than in NHMUK PV R36730. The base of the right diapophysis is preserved, but the tip is reconstructed. The diapophysis projects dorsolaterally and is L-shaped in lateral cross-section, with a short anteroventral margin and elongate posterodorsal margin  differs from that of NHMUK PV R36730 in that it is lobate in lateral view, with a rounded dorsal margin, and it bears an anteriorly directed flange about halfway up its length. It appears to project more strictly dorsally than that of NHMUK PV R36730, which is slightly posteriorly inclined.The neurocentral suture cannot be distinguished but this area is poorly preserved. In anterior view the neural canal is sub-elliptical with the long axis vertical; in posterior view it is teardrop-shaped with the apex pointing dorsally and smaller than in anterior view. The prezygapophyses are supported on stout pedicles, and the distance between the dorsal margins of the prezygapophyses and dorsal margin of the neural canal is increased in depth relative to preceding presacrals. This has the effect of increasing the height of the neural arch. In anterior view the prezygapophyses are orientated almost horizontally with their articular surfaces facing dorsally, as in D1 . In contM T7001; : figs 13M T7001; : figs 13M T7001; ; Fig 19CM T7001; ; Fig 19BD3 is similar in morphology to D2 in most respects, but differs from it in the following ways. On the centrum, a faint ridge extends from the posterior margin anteriorly for three-quarters of the length of the centrum and separates the lateral and ventral surfaces . In anteD4 is well preserved. The centrum is almost amphiplatyan with only a slight depression in the ventral part of the anterior articular surface. Both the anterior and posterior articular surfaces are sub-circular in outline . In lateIn lateral view the base of the neural arch bears a raised upwardly convex ridge forming a parabola-like structure. The area immediately below this ridge is strongly concave and merges with the lateral surface of the centrum, whereas the area above it is convex and merges dorsally into the surface of the neural arch . The neuIn anterior view the neural canal has an elongate elliptical outline with the long axis of the ellipse extending dorsoventrally; however, the neural canal narrows posteriorly so that the actual opening is considerably smaller than the fossa surrounding it . In postS. homheni (IVPP V4006), this fossa is particularly pronounced, and is bounded by sharp laminae that extend dorsally from the lateral margins of the neural canal and meet below the prezygapophyses : f: fS. steS. stenops) but not on a specimen he referred to as S. ungulatus (YPM 1858), a species considered here to be a junior synonym of S. stenops. A keel is also present in S. mjosi (DMNH 29431), S. homheni (IVPP V4006) and Huayangosaurus  or Gigantspinosaurus : f: fS. mjoCaudal (Cd) vertebrae 1–3, 20–37, and 39–45 are preserved. Caudals 4–19 were present but too poorly preserved and weathered to recover . A size Progressing posteriorly from caudal 20 to the end of the tail, the vertebral centra become proportionately smaller. Neural spines decrease in height until caudal 35, where they disappear entirely.Loricatosaurus (MHNH(BR) 001; : fHuayangosaurus, in which this flange is much smaller [The dorsal margin of the ilium posterior to the preacetabular process and dorsal to the acetabulum is rotated laterally to extend posteroventrolaterally and is hypertrophied to form a subrectangular wing-like flange that overhangs the acetabulum, obscuring it in lateral view , as in m smaller . The sacBoth ischia are present, but the right is in better condition than the left: the right ischium is complete, except for its iliac peduncle, whereas the left ischium has been skimmed with plaster on its medial and lateral surfaces, and its distal end is artificially bent medially. In lateral view, the ischium is sub-triangular in outline with the distal end, iliac peduncle and pubic peduncle forming its three corners . The dorDacentrurus armatus , that of S. mjosi (DMNH 29431), Loricatosaurus . In contrast, the anterior margins of the prepubes in S. mjosi (DNMH 29431) and Dacentrurus sp. (ML 433) are slightly expanded dorsoventrally relative to the rest of the process, while that of Dacentrurus armatus . It also expands distally in S. mjosi, (DNHM 29431) and Huayangosaurus , Loricatosaurus (NHMUK PV R3167), Kentrosaurus (MB R.4800) and Huayangosaurus , but these elements were not recovered in NHMUK PV R36730.The metatarsals are closely appressed to each other. Metatarsal 3 is the longest metatarsal, and metatarsal 4 is longer than metatarsal 2. [In proximal view, metatarsal 2 is sub-rectangular with the long axis trending anteroposteriorly. The medial and lateral surfaces are straight. It flares very slightly posteriorly, so that the posterior margin is slightly longer then the anterior margin. The dorsal surface is flat. In anterior view the element is transversely compressed with dorsal and ventral expansions. The dorsal margin of the dorsal expansion is upwardly convex. The anterior surface is sub-triangular or wedge-shaped in anterior view and wider ventrally. The articular surface for the phalanges wraps from the ventral surface onto the ventral-most part of the anterior surface. In medial view the metatarsal has a sub-quadrate outline with a long straight dorsal margin, a concave anterior margin, convex ventral margin forming the articular surface, and a straight posterior margin that slopes obliquely posterodorsally. A distinct notch separates the posterior margin from the ventral articular surface. The lateral surface is gently concave dorsoventrally forming a facet for the reception of metatarsal 3. In posterior view the metatarsal has a sub-rectangular outline with a saddle-shaped posterior surface. The dorsal margin of the bone overhangs the posterior surface and the posterior part of the articular surface for the phalanges extends onto the ventral part of the posterior surface. The articular surface for the phalanges bifurcates into weakly developed lateral and medial ginglymi separated by a shallow groove. The lateral ginglymus is half the size of the medial ginglymus. In medial view metatarsal 2 is dumbbell-shaped and the medial surface is gently concave. In ventral view the articular surface has straight medial, anterior and lateral margins. The posterior margin is notched. The medial part of the posterior articular surface extends further posteriorly than the lateral part. The articular surface for the phalanges is strongly convex anteroposteriorly and a shallow groove extends from the posterior groove anteriorly for a short distance.In proximal view metatarsal 3 has a sub-triangular outline that is longest anteroposteriorly. The medial and lateral surfaces meet to form the rounded apex of this triangle posteriorly. The articular surface is very gently concave and the margins are slightly rugose, especially anteriorly and laterally. The straight medial margin articulated with metatarsal 2 and the slightly rugose lateral margin with metatarsal 4. In anterior view metatarsal 3 is hourglass-shaped with sub-equal proximal and distal expansions joined by a waisted shaft. The articular surface for the phalanges wraps around the ventral-most part of the anterior surface. In lateral view the expansion of the proximal end is asymmetrical so that the posterior part overhangs the posterior margin of the bone. The anterior margin is slightly sinuous, the dorsal margin is straight, and the posterior margin is strongly concave in its proximal part but becomes convex ventrally to merge with the convex ventral margin of the bone. Most of the lateral surface is strongly concave dorsoventrally. A deep ligament pit is present at the distal end on the lateral surface, defined by a stout curved ridge that surrounds it posteriorly and ventrally. The dorsal margin of the distal articular surface forms a raised lip that is situated on the posterior surface just dorsal to the ligament pit. In posterior view the element is hourglass-shaped. In medial view the element is similar to that in lateral view but there is no ligament pit or ridge. The ventral surface is strongly convex anteroposteriorly and shallowly convex transversely. In contrast to metatarsal 2, it is not divided into ginglymi. The articular surface extends further up the shaft posteriorly than anteriorly.Metatarsal 4 consists of proximal and distal expansions linked by a short, stout shaft. The proximal expansion is transversely wider than the ventral one. In anterior view, the dorsomedial corner is angled slightly dorsomedially in anterior view but this may be the result of distortion. The medial and lateral surfaces of the shaft are mildly concave whereas the dorsal and ventral margins are straight. The articular surface wraps onto the ventral-most part of the anterior surface of the shaft only and does not extend as far dorsally as in metatarsals 2 and 3. In lateral view both the proximal and lateral ends are expanded relative to the shaft; the proximal expansion is greater. An indistinct ligament pit is present on the distal surface of the shaft defined anteriorly by a shallow ridge and posteriorly by a small sharp process . The anterior shaft margin is straight to very slightly concave and the posterior margin is strongly concave, particularly in its ventral part, whereas the dorsal margin is straight. The posterior surface is similar to the anterior surface, and the medial surface is similar to the lateral surface except that there is no ligament pit. Instead there is a groove on the mediodistal part of the shaft in that position and it lacks the sharp process, although a posterior ridge is present in its place. In dorsal view the proximal surface has an oval outline that is broadest medially and tapers laterally. The ventral articular facet is transversely wider than it is long anteroposteriorly and convex.Kentrosaurus  osaurus (: fig 34)The proximal articular surface has a straight posterior margin and continuously curved lateral, anterior and medial margins giving it a D-shaped outline in dorsal view. This surface is shallowly concave. In anterior view, the phalanx has a sub-rectangular outline with a strongly concave ventral surface that divides it into two equal-sized portions. The anterior surface is gently concave dorsoventrally and gently convex transversely and merges into the lateral and medial surfaces with no distinct break of slope. The posterior surface is divided from the others by a slight break in slope and is gently concave dorsoventrally. The distal articular surface is saddle-shaped with a deep midline groove dividing it into distinct ginglymi. There are no distinct co-lateral ligament pits. In distal view the articular surface has a trapezoidal outline with a long posterior margin and lateral and medial margins that converge anteriorly to meet the shorter anterior margin.Two unguals are preserved. One is well preserved, but the other is a rugose, pitted lump of bone that appears to be pathological. The following description is consequently based on the former. In lateral and medial views, the ungual is wedge-shaped, with a straight articular margin and dorsal and ventral margins that converge anteriorly to meet at a blunt point. The dorsal margin is convex, whereas the ventral margin is flat. The articular surface is oval in outline with the long axis trending transversely and is gently concave dorsoventrally. The margins of this facet are rugose. In dorsal view, the ungual is hoof-shaped and blunt-ended, with gently convex lateral margins that are offset from the articular region by shallow notches both medially and laterally. The area posterior to the notches is smooth, whereas the rest of the dorsal surface is strongly rugose. In ventral view, the surface is strongly convex transversely and smooth. Small pits are situated either side of this central convexity.Stegosaurus was 19, with four spines at the end of the tail. [Stegosaurus. Since the armor was found largely in situ, the order of the plates preserved in NHMUK PV R36730 is likely to be correct, as are their anteroposterior orientations; however, it is not possible to determine whether the plates angled to the left or right side of the body. Herein, the plates are described as they are mounted. [Eighteen plates and four spines were recovered in place along the spine. When the specimen was discovered, there was a space above the proximal portion of the tail suggesting that another plate was originally present but became disarticulated post-mortem and was not preserved, so it is likely that the full complement of plates for he tail.  did not mounted.  presentemounted. : fig S21mounted.  suggesteThe four anterior-most plates (Pl) are almost identical in morphology, differing only in size. All are complete, with the exception of Pl2, which is missing its dorsal-most third, and this is reconstructed with plaster. The plates are elliptical in outline with the long axis of the ellipse directed dorsoventrally. They are transversely thickest along their ventral margins, which are strongly rugose and have sub-elliptical outlines in ventral view. Dorsally, the plates narrow in width to form thin vertically extending sheets that are reduced to a transverse thickness of only 3 mm around their dorsal margins. The anterior margins of the plates are slightly thickened with respect to the rest of the dorsal part of the plates. In lateral view, the margins of the plates are smooth and merge into each other with no distinct breaks of the slope and the plate apices are broadly rounded. The lateral and medial surfaces are coarsely textured, but there are no distinct vascular grooves. The maximum anteroposterior width of these plates lies at a point approximately level with their mid-height, and they contract in anteroposterior width both dorsal and ventral to this point. The bases of these plates are symmetrical in anterior and posterior view.Pl5 is parallelogram-shaped in lateral view, and the plate apex overhangs the posterior margin of the base. It is longer than tall. The anterior margin is straight and slopes posterodorsally, the dorsal margin is convex, the posterior margin is parallel to the anterior margin, but shorter, and the basal margin is very gently convex. The margins of the plate are smooth. The basal region is transversely expanded with respect to the rest of the plate, which tapers in thickness dorsally to form an isosceles triangle-shaped cross-section. The ventral margin of the basal region is strongly rugose and has a narrow, elongate elliptical outline. Numerous fine, shallow vascular grooves extend posterodorsally across both plate surfaces. The base of the plate is symmetrical in anterior and posterior view.Pl6 differs from Pl1–5 in that its base is asymmetrical: when the base is held vertically, the plate is angled dorsolaterally in anterior view, and in the mount the plate is angled to the left. The plate has a sub-oval outline, with a convex, dorsally orientated anterior margin that merges smoothly with the straight and only slightly dorsally extending dorsal margin. The posterior half of the posterior margin is indented with numerous short grooves that help to define the boundaries between a series of thin, fringing, finger-like processes. The dorsal margin of the plate is also the longest. Posteriorly, a distinct break in slope separates the dorsal and posterior margins; the latter is straight and extends ventrally and slightly anteriorly. The ventral margin is convex and rugose. The lateral surface bears some evidence of vascular grooves, but these are neither as numerous nor as well defined as on Pl5. In ventral view, the attachment surface is rugose and sub-crescentic in outline. A distinct break in slope separates the ventral surface from the medial surface, forming a low ridge that divides the surface that was presumably embedded in the dermis from that which was free. The plate is thickest basally and tapers dorsally. The anterior and posterior margins are equally thin.Pl7 is not well preserved and little surface detail is visible. The basal region of the plate is crushed and the margins are damaged and incomplete. However, the plate appears to have been taller than long and oval in outline, being broader basally and tapering apically, and having its maximum anteroposterior dimension at a point about halfway between the base and apex. The apex of the plate is located in line with the centre of the plate base in lateral view. There is some evidence for the presence of finger-like processes around the dorsal margin. The plate is uniformly thin transversely.Pl8 is deformed, with the dorsal and anterior margins being warped relative to the central part of the plate. The anteroventral and posteroventral margins of the plate are damaged and small sections of both are missing. The original outline of the plate is difficult to determine due to broken margins but as preserved it has a sub-pentagonal outline. The plate is taller than long and the maximum anteroposterior dimension is positioned at a point about halfway up the plate. The tallest point of the plate is situated just posterior to the anteroposterior midpoint of the element. The base is poorly preserved but is transversely expanded relative to the rest of the plate. Surface preservation is poor but there are some indications of narrow vascular grooves extending dorsoventrally across the plate surface.Pl9 is sub-rhomboidal in outline but is reconstructed along its anterodorsal margin and the surface is covered in plaster. It has been slightly deformed so that the right lateral surface is gently concave whereas the left lateral surface is convex. The anterior margin is anteriorly convex, sloping anterodorsally from the base, then posterodorsally towards the apex of the plate. The plate apex is positioned posterior to the anteroposterior midpoint of the plate base. The plate is taller than it is long. The posterior margin of the plate descends more steeply than the anterior margin and is constricted in its ventral-most part as it merges into the basal surface. The maximum anteroposterior dimension is in the lower half of the plate just below mid-length, in contrast to the condition in preceding plates, where the maximum anteroposterior dimension is at mid-length. The dorsal margin of the plate is divided into a number of slender finger-like processes. The plate is transversely compressed and thickest ventrally at its base. The basal region bears a number of low rugosities, is irregular, and is indistinctly defined. There are a number of fine elongate vascular grooves on the surface that are poorly preserved.Pl10 is rhomboidal in outline, with straight anteroventral, anterodorsal, posterodorsal and posteroventral margins that are separated from each other by a distinct break in slope. The area just dorsal to the junction between the anterodorsal and anteroventral margins is reconstructed, as the entire posterodorsal margin. Deformation has resulted in the left lateral surface being anteroposteriorly convex, while the right lateral surface is correspondingly concave. The dorsal part of the right lateral surface has been restored extensively with plaster. The maximum anteroposterior dimension of the plate is situated in its ventral half below mid-height, as in Pl9. The apex of the plate is situated above the anteroposterior midpoint of the plate basal margin, and the plate is sub-equally expanded anteriorly and posteriorly either side of this axis. The basal region is substantially transversely thicker than in any of the preceding plates and is rugose and irregular. It is transversely thickest in the centre of the plate and tapers anteriorly and posteriorly, merging with the plate margins. There are abundant dorsoventrally extending vascular grooves and the dorsal margin bears numerous finger-like processes both anterior and posterior to the plate apex.Pl11 is sub-rhomboidal in outline. It is missing a small portion of its anteroventral surface and part of the posterodorsal region is reconstructed. The body of the plate is slightly deformed and warped, particularly posteroventrally. The anterior margin of the plate is smoothly convex in its ventral-most quarter but the slope changes abruptly to extend posterodorsally toward the apex of the plate. This anterodorsal margin is subdivided into a large number of finger-like processes of varying size, giving it a feathered appearance. The apex of the plate lies dorsal to the posterior margin of the basal region so that it is strongly asymmetrical in lateral view. The posterior margin of the plate is gently convex along its entire length, although the dorsal-most part immediately adjacent to the apex is also subdivided into delicate finger-like processes. The basal margin is straight, rugose, clearly defined, and is the transversely widest part of the plate. The plate surface is well preserved and there are numerous sub-parallel, dorsoventrally-extending vascular grooves on its surface. The anteroposteriorly longest dimension is situated at a point within the basal third of the plate in lateral view. The maximum anteroposterior and dorsoventral lengths of the plate are sub-equal.Pl12 is very similar in overall shape to Pl10. The anterior margin is partially reconstructed, as are sections of the dorsal part of the plate, and much of the posterior margin is damaged. The central region of the plate has been damaged and warped. The apex of the plate lies posterior to the posterior margin of the basal region. The maximum anteroposterior dimension is in the lower third of the plate. The anterodorsal and dorsal-most part of the posterodorsal margins are subdivided into numerous finger-like processes. The plate is taller than long as preserved.Pl13 is the largest in the series but its anterior margin is missing and a considerable part is reconstructed in plaster. As a result it has an elongate elliptical outline, although originally it was probably more similar in shape to Pl11 or 12. Deformation has resulted in the right lateral surface of the plate being convex anteroposteriorly, while the left lateral surface is concave. The posterior margin is complete and well preserved and from a point approximately one-third along this surface to the dorsal apex the plate is divided into numerous finger-like elongate processes giving it a strongly feathered appearance. These continue onto the anterodorsal surface but as this region is incomplete it is unclear how far they extended anteriorly. There are some grooves that are continuous with with the indentations below the finger-like processes but otherwise the surface of the plate is poorly preserved. The posterior margin is straight. The basal region, which comprises the basal one-fifth of the plate in lateral videw, is irregular and rugose. It may have been entirely embedded in the skin, so that the anteroposteriorly widest part of the plate would have projected immediately above the level of the skin in life.This plate was not recovered with the specimen (see above) and a reconstruction has been positioned in its place within the mount.Pl15 is missing its posteroventral corner. As with many of the other plates, it is slightly deformed so that the right lateral surface is dorsoventrally and anteroposteriorly concave and the left lateral surface is correspondingly convex. It is very similar in overall outline and size to Pl12, with a steeply convex posterior margin and shallowly convex anterior margin, resulting in an asymmetrical outline with more expansion anteriorly than posteriorly. The anteroposteriorly longest dimension of the plate is situated in its ventral half. Fine, elongate, finger-like processes are present both anterior and posterior to the plate apex. The basal region is strongly rugose and expanded transversely. A few vascular grooves are present on the plate surface.Pl16 is reconstructed along its anterior and basal margins, and some reconstruction is also present posteriorly. As in the preceding plates, there is some deformation so that the plate is convex on the left lateral surface and concave on the right lateral surface. As reconstructed, the plate has a sub-triangular outline in lateral view with the apex directed posterodorsally. One or two deep vascular channels are present on the surface of the plate, and finger-like processes are present around the plate apex. The plate apex is situated in line with the posterior margin of the basal region but due to reconstruction of the anterior margin it is not clear where the level of the maximum anteroposterior length would have been situated.Pl17 is reconstructed posteroventrally, including its posterior margin, the ventral half of the posterior part of the plate and the entire basal region. As a result its dimensions cannot be accurately estimated. However, it is clearly smaller than the preceding plates, and part of a decreasing size trend along the remainder of the tail. The anterior margin of the plate is almost straight, while the dorsal margin is steeply convex. Six stout, finger-like processes are present around the plate apex, and these are more robust than any of those in the preceding plates. There is faint evidence for shallow grooves on the dorsal part of the plate. The plate is asymmetrical so that its apex lies in line with the posterior margin of the basal region, as reconstructed.Pl18 is sub-elliptical in outline, although its ventral margin has been reconstructed. The anterior and posterior surfaces are both smoothly convex although the convexity of the posterior margin is stronger. This results in the posterior margin of the plate strongly overhanging the posterior margin of the basal region. The plate is longer than tall. The maximum anteroposterior dimension of the plate is situated at approximately mid-height. The left lateral surface is convex anteroposteriorly while its right lateral surface is concave, and this appears to be the natural condition. The tip of the plate has several short grooves incipiently dividing the apical region into finger-like processes, although these are not well developed.Pl19 is incomplete and poorly preserved. It appears to be a small plate but it lacks its original margins. It has been extensively crushed and offers no useful anatomical details.All four spines are present. They are well-preserved, although heavily consolidated, with surfaces lightly skimmed with plaster. They are undeformed and appear to be missing only their distal-most tips.In lateral, anterior and posterior views, the margins of the spine are straight and converge dorsally to form a narrow pointed tip. In lateral view, the basal margin is asymmetrical so that it extends further anteriorly than posteriorly. With the flat basal region held horizontally, the spine extends posterodorsolaterally at an angle of 70 degrees to the horizontal. The anterior margin bears a distinct ridge that extends dorsally from the basal region to a point approximately one-half of the length of the spine. This acts as a break in slope to divide the spine into lateral and medial surfaces. The lateral surface is convex in its lower half, whereas the medial surface is straight, giving it a D-shaped transverse cross-section at this point. The transverse cross-section in the dorsal half of the spine becomes more symmetrical and is elliptical. In ventral view, the basal region is elliptical in outline with its long axis trending anteroposteriorly. The surface of the basal region is rugose and gently convex in its posterior part.The posterior spines are slightly shorter than their anterior counterparts. In anterior, posterior and lateral views, the margins of the spine are essentially straight and converge dorsally to meet in a sharp pointed tip. In contrast to the anterior pair of spines, the basal region is not expanded anteriorly, but is of the same dimensions as the ventral part of the spine. Assuming the basal region is held horizontally, the spine angles at approximately 80 degrees from the horizontal to extend posterodorsolaterally. Both spines are slightly crushed, but probably maintained an ovate cross-section throughout their entire lengths. In ventral view, the basal region of the plate has an ovate outline, with its apex pointing anteriorly. The basal surface is rugose and generally flat anteriorly, but merges seamlessly with a convex posterior region, which grades into the posterior surface of the spine without a distinct break in slope.Stegosaurus homheni (IVPP V4006) has been illustrated as a series of long, low plates. However, the single plate associated with the specimen is broken dorsally, so that the shape of the plate is unknown. It is, however, elongate, being 58 cm anteroposteriorly at its base, and transversely compressed, similar to the plates of NHMUK PV R36730 and other individuals of Stegosaurus (e.g. USNM 4934). The holotype of S. stenops . In conDacentrurus armatus  001; [Gigantspinosaurus [Stegosaurus.Several partial plates are preserved in the holotype of V R3167; : fig 18GBR) 001; : fig 2G–nosaurus , 47; thuKentrosaurus rib cage .Stegosaurus individuals [Stegosaurus development [Several postcranial features of NHMUK PV R36730 indicate that this individual was not fully skeletally mature at time of death. The presence of visible neurocentral sutures on many of the cervical vertebrae indicates that sutural fusion may have just occurred or was occurring at the time of death, but had not advanced to the stage where the sutures were completely obliterated . Scapulaividuals  and may ividuals . In NHMUelopment . In NHMUelopment . These felopment .Stegosaurus, their results should be treated with caution because the majority of specimens included in their growth series are referable to a different species of Stegosaurus, S. mjosi (SCRM pers. obs. 2009), and at least some individuals of that species are much smaller than those of S. stenops when fully skeletally mature (SCRM pers. obs. 2005–2009), a problem not considered by those authors. Growth stages of Stegosaurus stenops have been determined histologically elsewhere [Stegosaurus  show histological and morphological features consist with skeletal maturity .Stegosaurus. Histological work on the specimen did not reveal the presence of medullary bone [Kentrosaurus might represent a sexual difference, but it is also possible that this observation captures a population-level difference rather than sexual dimorphism [The sex of the individual is unknown, although the nicknames associated with the specimen during its collection and preparation (‘Sarah’ ) and acqary bone , so NHMUary bone  proposedmorphism .Stegosaurus, presumably because the total sample of individuals is small. Nevertheless, several cases of broken armor elements have been reported [Pathologies are rarely reported in reported ,54 as wereported ,55. The S1 Fig(PDF)Click here for additional data file.


As a framework to combine existing experimental data, we propose a mathematical model of the SC, consisting of multiple compartments, to explicitly address and investigate the depth-dependency of the SC permeability barrier. Using this mathematical model, we derive a measure of the water permeability barrier, i.e. resistance to water diffusion in the SC, from the measurement data on transepidermal water loss and water concentration profiles measured non-invasively by Raman spectroscopy. The derived resistance profiles effectively characterize the depth-dependency of the permeability barrier, with three distinct regions corresponding to formation, maintenance, and degradation of the barrier. Quantitative characterization of the obtained resistance profiles allows us to compare and evaluate the permeability barrier of skin with different morphology and physiology  and elucidates differences in underlying mechanisms of processing barriers. The resistance profiles were further used to predict the spatial-temporal effects of skin treatments by in silico experiments, in terms of spatial-temporal dynamics of percutaneous water penetration.The stratum corneum (SC) provides a permeability barrier that limits the inflow and outflow of water. The permeability barrier is continuously and dynamically formed, maintained, and degraded along the depth, from the bottom to the top, of the SC. Naturally, its functioning and structure also change dynamically in a depth-dependent manner. While transepidermal water loss is typically used to assess the function of the SC barrier, it fails to provide any information about the dynamic mechanisms that are responsible for the depth-dependent characteristics of the permeability barrier. This paper aims to quantitatively characterize the depth-dependency of the permeability barrier using  The main function of the stratum corneum (SC) is to provide a permeability barrier that limits the inflow of external potential irritants, while at the same time controlling the outflow of water from the body to prevent dehydration and retain water . ApproprExtensive research has revealed the contribution of many SC components to the permeability barrier. Corneocytes, the main components of the SC, are held together by corneodesmosomes to form tight cellular junctions to provide structural integrity to the SC . They arin vivo measurement data. Accordingly, this paper aims to propose a novel method to combine these non-invasive in vivo measurement data and derive the depth-dependent resistance of the SC to water diffusion, using a mathematical model.The permeability barrier is typically assessed through measuring transepidermal water loss (TEWL) , 8, whicWhile previous pharmacokinetic models of the SC for studying transepidermal drug delivery and absorption mostly assume that the SC is a single compartment with a fixed diffusion coefficient , 14, thiin silico experiments to predict the spatial-temporal dynamics of water diffusion in the SC, which is difficult to obtain through conventional experiments. Combining the available TEWL and water concentration data using a mathematical model complements experiments in gaining quantitative understanding of intricate biological mechanisms.To demonstrate that the proposed mathematical model can effectively evaluate the depth-dependency of the water permeability barrier, we apply the model to previously published experimental data on TEWL and water concentration measured non-invasively at different depths in the SC by confocal Raman spectroscopy. The original studies for these data sets compared the skin of infants and adults , differeSC compartment model in this paper. The model incorporates Fick’s first law of diffusion  is a relative unit (% mg water/mg protein). Second, the resistance profile for each individual is obtained by plotting the resistances against the normalized depth (depth divided by the SC thickness) and interpolating them. The SC thickness is calculated from the water concentration profiles by the method described in [The resistance profiles describing the depth-dependent resistance to water diffusion Figs.  and 3 ardividual –19 . The Matlab code can be found in The eriments  were pereriments ). The reent data , 19. Topfminunc in Matlab. We confirmed that the results are robust against the choice of initial values for minimization.Direct comparison between the experimental and model simulation results was carried out as follows. We first ran the simulation using the SC compartment dynamic model  to obtaiThe statistical significance of the difference between the means of indices was determined using a two-tailed Student’s t-test for comparing the means of infants and adults and using one-way ANOVA for comparing the means of the three skin sites . The variance in the mean resistance profiles is not displayed  for visuS1 DatasetThis dataset contains the experimental data used in this paper. It includes water concentration profile and TEWL data on infants and adults , differe(XLSX)Click here for additional data file.S1 Information(PDF)Click here for additional data file.S1 Code(M)Click here for additional data file.


Cognitive impairment frequently co-occurs with type 2 diabetes but is often undiagnosed. Cognitive impairment affects self-management leading to treatment-related complications.The aim of this study is to develop a stepped diagnostic procedure, consisting of a screening test complemented by an evaluation by a general practitioner (GP), to detect undiagnosed cognitive impairment in older people with type 2 diabetes.The accuracy of two self-administered cognitive tests, the “Test Your Memory” (TYM) and “Self-Administered Gerocognitive Examination” (SAGE) alone, and in combination with an evaluation by a GP will be assessed. A diagnosis of mild cognitive impairment (MCI) or dementia at a memory clinic will serve as reference standard. This cognitive impairment in diabetes (Cog-ID) study will include 513 people from primary care facilities aged ≥70 with type 2 diabetes. The participants will first fill out the TYM and SAGE tests, followed by a standardized GP evaluation for cognitive impairment, including a mini mental state examination (MMSE). Subsequently, participants suspected of cognitive impairment (on either test or the GP assessment) and a random sample of 15% (65/435) of participants without suspected cognitive impairment will be referred to the memory clinic. At the memory clinic, a medical examination, neuropsychological examination, and magnetic resonance imaging (MRI) of the brain will be performed. Participants will also fill out questionnaires assessing health status and depressive symptoms at baseline and after 6 and 24 months.This research obtained funding and ethical approval. Enrolment started in August, 2012, and all study-related activities will be completed in September, 2016.With the results from this study, physicians will be able to detect cognitive impairment affecting type 2 diabetes patients through case-finding, and can use tailored care to reduce associated complications. Additionally, the results may stimulate discussions about cognitive impairment and whether early recognition is desirable. Patients with type 2 diabetes have an increased risk of cognitive impairment and a doubled risk of dementia compared to people without diabetes ,2. CogniRoutine screening for cognitive impairment in elderly patients with type 2 diabetes has been advocated . The AmeThese issues may be resolved by the recent introduction of self-administered cognitive tests, such as the Test Your Memory (TYM)  and the The ultimate goal of a diagnostic procedure for cognitive impairment is to improve clinical outcomes and patients' quality of life. However, before the effect of a diagnostic procedure can be evaluated, which specific tests to include must be determined. The latter is examined in this cognitive impairment in diabetes (Cog-ID) study. Here, we aim to establish a reliable, valid, and efficient stepped diagnostic procedure to detect cognitive impairment in patients ≥70 years of age with type 2 diabetes, starting with the TYM and the SAGE tests. It is unknown which of these two tests is best suited for application in a primary care setting; therefore we will assess the accuracy and feasibility of both. In addition, we will describe how early detection of cognitive impairment affects treatment and quality of life in an observational study that is part of the main study. Together, the results will help shape future studies with the goal of answering the unresolved, but increasingly relevant and heavily debated question , whetherOur overall aim is to establish a reliable, valid, and efficient stepped diagnostic procedure to detect undiagnosed cognitive impairment in patients ≥70 years of age with type 2 diabetes. The procedure will consist of a self-administered cognitive test and an evaluation by a GP. Additionally, we will describe how early detection of cognitive impairment affects treatment and quality of life in participating patients in a parallel observational study. The specific objectives of the study are (1) to assess the validity of two self-administered cognitive tests (TYM and SAGE) in detecting undiagnosed cognitive impairment in elderly patients with type 2 diabetes in a primary care setting and to select the best instrument, (2) to assess the diagnostic accuracy of a standardized evaluation by a GP in detecting undiagnosed cognitive impairment in patients with type 2 diabetes, (3) to estimate the accuracy and efficiency of the best cognitive test(s) combined with the evaluation by the GP, and (4) to describe the effect of the diagnostic procedure on several aspects of diabetes care  and patients’ quality of life.General practitioners (GPs) in the surroundings of Utrecht, the Netherlands, will be asked to select patients with type 2 diabetes mellitus ≥70 years of age. Exclusion criteria include a diagnosis of dementia, previous investigation at a memory clinic, and the inability to write or read in Dutch. Patients with a disorder that might influence cognitive functioning, like substance abuse or a psychiatric or neurological disorder, but without a diagnosis of cognitive impairment are not excluded as we are interested in the presence of unknown cognitive impairment regardless of the cause. Eligible patients will receive a letter from their GP with information regarding the study. Patients will be asked to return the response form on which they can mark whether or not they are willing to participate. In the case of non-response, one reminder will be sent.th task (5 points); because of our study design all patients will receive these 5 points. The maximum score is 50 points. A score of ≤39 is suggestive of dementia [The TYM is developed to test a range of cognitive functions and consists of 10 tasks . It is adementia . The TYMThe SAGE measures cognitive functioning in the domains of orientation (4 points), language (4 points), memory (2 points), executive function (4 points), calculations (2 points), abstraction (2 points), and visuospatial abilities (4 points) . FurtherParticipants will be visited at home by a research physician (a trainee GP). The home visit will take about 1 hour. The participant will be asked to fill out the TYM, SAGE, and a questionnaire assessing health status and depressive symptoms, including the Short Form Health Survey (SF-36), EuroQolBased on the history taken, the research physician will decide whether the participant should be classified as "suspected of cognitive impairment" or "no cognitive impairment" according to the criteria for MCI and dementia ,20. If tAfter the home visit, an independent physician, not involved in the home visit or in the memory clinic, will determine whether the participant will be selected for a visit to the memory clinic of the University Medical Centre Utrecht. To minimize the influence of the increasing experience of the research physician because of the growing number of home visits during the study period, the research physician who visited the participant at home will not be informed about the results of the memory clinic. The following 3 criteria will be used to decide whether a participant will be invited to the memory clinic (1) a classification of “suspected of cognitive impairment” by the research physician, (2) a score of ≤39 on the TYM, and (3) a score of ≤14 on the SAGE. When a participant scores positive on one of these criteria, the participant will be invited to the memory clinic. In addition, a random sample of 15% (65/435) of participants with negative scores on all 3 criteria will be invited to the memory clinic  neurologist who will perform a diagnostic interview and a neurological examination, administer the Cambridge Cognitive Examination (CAMCOG) , and meaVisual Object and Space Perception Battery(VOSP). Furthermore, the premorbid level of intelligence (intelligence quotient (IQ)) will be estimated by the Dutch version of the National Adult Reading Test (NART). Educational level will be recorded in seven categories and subsequently translated into years of education. Frailty will be examined with the Short Physical Performance Battery (SPPB).A neuropsychologist will administer a 90-minute standardized neuropsychological assessment examining memory, information processing speed, attention and executive functioning, and visuoconstruction. The division in cognitive domains will be made a priori, according to standard neuropsychological practice and cognitive theory . The dom3), a 3D T1 scan , a fluid attenuated inversion recovery (FLAIR) scan , and diffusion-weighted MRI data using a single-shot spin echo planar imaging sequence .MRI data will be acquired on a Philips 3.0 Tesla scanner using a standardized protocol and consisting of a T2-weighted scan , thyroid function, liver functions, and kidney function.Within two weeks of the visit to the memory clinic, a multidisciplinary team meeting will be planned with a neurologist, the neurology resident, and the neuropsychologist to establish the diagnosis. Cognitive impairment  is our primary outcome. For the diagnosis of dementia, the DSM-IV criteria will be used . In shorGuided by the diagnosis, tailored treatment advice will be given to the participants’ GP regarding management of the diabetes treatment and cognitive impairment. Advice for the diabetes treatment will consist of re-evaluation of the proper glycemic target and the risk of insulin treatment. As well, advice evaluating the need for extra support for participants unable to meet treatment goals or in need of tools, for example a memory aid for appointments or medication, will be provided.The results of the visit to the memory clinic and the treatment advice will be sent to the GPs who will discuss the results with the participant. Subsequently, the GP and the participant will decide together what actions will be taken. Further support by the memory clinic will be available if considered desirable by the GP and the participant.Following the home visit (6 months), participants will receive a follow-up questionnaire, including the SF-36, EQ-5D, EQ-VAS, and the CES-D to evaluate the course of their health status, quality of life, and depressive symptoms. A questionnaire asking whether and how many hypoglycemic events, visits to emergency services, and hospital admissions they experienced will also be included. In addition, participants will be asked whether they regret their participation in the study and whether they would again participate in the study. A second follow-up questionnaire with the same questions will be sent after 24 months.After the home visit (6 months), the medical records of the participants will be examined to obtain information on the medical history, values of recent diabetes controls , complications (hypo- or hyperglycemic events), and visits to emergency services and hospital admissions in the year before and six months after participation in the study.To further assess the impact of the study on participants’ treatment, GPs of participants that attended the memory clinic will receive a questionnaire 6 months after the evaluation at the memory clinic to assess whether the study led to new insights and whether it changed their treatment plan .Did the result come as a surprise to you or did you expect it? And why?Do you agree with the result of the memory clinic? And why?Did you adjust your diabetes treatment or management because of the results? And why?Did the results have consequences for your overall medical treatment of the patient? And why?The diagnosis of cognitive impairment (MCI or dementia) at the memory clinic will be used as the reference standard. To address the first two objectives, participants will be classified as true positive, false positive, false negative, or true negative separately for the evaluation by the GP, TYM, and SAGE.Not all of the patients in our study will receive the reference standard, which could lead to partial verification bias . HoweverThe extent to which the cognitive tests and the evaluation by the GP discriminate between participants with and without cognitive impairment will be determined by the area under the receiver operating characteristic (ROC) curve. Next, the optimal cutoff values of the tests for this population will be determined according to the best combination of corresponding sensitivity and specificity assessed with the Youden index. The Youden index measures the effectiveness of a diagnostic marker and enables the selection of an optimal cutoff point . By meanFor assessing the accuracy and efficiency of the diagnostic procedure  the results of the best cognitive test and the evaluation by the GP will be combined. This should reflect the future implementation of the stepped diagnostic procedure, in which a GP will only evaluate those patients with a positive test result. Participants will be categorized in the “test positive” group when both the best cognitive test and the evaluation by the GP are positive. This combination will likely have a higher PPV than the cognitive test or the evaluation by the GP alone, leading to a more efficient diagnostic procedure. The added value of the GP’s evaluation will be assessed by calculating the adjusted ROC curve and the net reclassification index .The fourth objective of this study will be addressed by comparing the difference in health status and depressive symptoms between those with and without a diagnosis of cognitive impairment, both at baseline and at the 6- and 24-month follow-up, taking into account potential baseline differences of relevant parameters. In addition, we will describe the changes that were made in diabetes care by comparing the diabetes management before and after study participation .For our sample size calculations, we assumed a prevalence of undiagnosed cognitive impairment of 8%. Since little quantitative information is available on the prevalence of undiagnosed cognitive impairment, we based this assumption on four considerations. The first assumption is the prevalence of dementia in the Dutch population >65 years of age is around 16% .The prevIn previous research in adults aged ≥59 years recruited from geriatric and memory clinics and facilities for seniors, the SAGE had a PPV of 64%, a NPV of 95%, a sensitivity of 79%, and a specificity of 95% with regard to diagnosing cognitive impairment . In a meBecause of uncertainty on the actual prevalence of undiagnosed cognitive impairment in our cohort, an interim analysis is planned after the inclusion of 80 participants. During this interim analysis, only the proportion of participants classified as "suspected of cognitive impairment" will be checked without unblinding the test scores or the findings at the memory clinic. If the proportion deviates significantly from our assumptions we will adjust the sample size of the study population accordingly.This study will be conducted according to the principles of the declaration of Helsinki and in accordance with the Dutch law on Medical Research Involving Human Subjects Act (WMO).The cognitive impairment in diabetes (Cog-ID) study was approved by the medical ethics committee of the University Medical Centre Utrecht, the Netherlands. Written informed consent will be obtained from all participants.Funding was obtained through the EFSD/Lilly Mental Health and Diabetes Program in 2012. Participant enrolment started in August, 2012. All study-related activities will be completed in September, 2016. The first results are expected to be published in 2015.This cognitive impairment in diabetes (Cog-ID) study will provide a stepped diagnostic procedure to identify patients with type 2 diabetes and undiagnosed cognitive impairment, which can be readily implemented in daily practice. This is essential to improve the care for this vulnerable patient group. We will have information on the diagnostic accuracy of two new cognitive tests, the TYM and the SAGE, and whether these tests can be used in a diagnostic procedure  to detect cognitive impairment in primary care. In addition, we will collect observational data on the impact of such diagnostic procedures on several aspects of patients’ lives  after 6 and 24 months. Physicians often assume that informing the patient about a diagnosis of cognitive impairment will negatively influence their health status, quality of life, and depressive symptoms . HoweverA potential bias in diagnostic studies in which not all patients receive the reference standard is partial verification bias . HoweverWith the information from this study, we can advise GPs on how to assess cognitive functioning in their patients so they can adjust diabetes treatment to the preserved capacities of their patients, as advocated by the American Diabetes Association, and consequently might prevent treatment-related complications. In addition, the results will form a base for future discussions on whether the early recognition of cognitive impairment in patients with type 2 diabetes with a case-finding strategy is desirable.