At present only little information is available concerning the acquisition of skilled movements in musicians. Although optimally a longitudinal study of changing movement patterns during the process of increasing expertise is required, long-term follow up over several years is difficult to manage. Therefore, in the present cross-sectional study a comparative kinematic analysis of skilled movements in drummers with different levels of expertise was carried out.The aim of the investigation was (1) to analyze the kinematic differences between beginners, students and expert drummers, and (2) to deduce from the results general rules related to the acquisition of drumming expertise and (3) to discuss the implications for drum teaching.Two highly skilled experts, eight professional drumming students and five beginners participated in the experiment. Fast repetitive drumming movements were assessed using an active infrared measurement setup (SELSPOT-System). Recording was obtained from LEDs positioned over the shoulder-, elbow-, wrist- and MCP-joints and close to the tip of the stick at a sampling rate of 300 Hz. Kinematic analysis included calculation of angles, velocities and accelerations and assessment of the relation between velocity and acceleration as phase diagrams.Temporal accuracy of the drumming movements was related to expertise. In contrast to beginners, experts and students revealed a high degree of self-similarity of movements and a predominant use of low-mass distal joints, resulting in a whiplash-like movement when hitting the pad.Intense training in students and experts results in economic utilization of forces. Percussion teachers can take advantage of the kinematic analysis and improve their instructions according to the student’s observed motor pattern. The precise execution of very fast and in many instances extremely complex movement patterns characterizes the motor skills of professional musicians. To gain such a high level of expertise prolonged and intense training over many years is a prerequisite. A classical pianist for example has practiced his instrument more than 10,000 h before entering the “professional” level and performing in public . Basis oAlthough the acquisition of professional skills in musicians represents an excellent paradigm to study the neurobiological and biomechanical foundations of sensory-motor learning in general, only in the last 25 years high quality studies using Motion Capture were devoted explicitly to these special abilities. Focusing on changes in motor patterns with increasing expertise, Although pianists were preferred subjects in MoCap studies, mostly due to the visibility of finger- and hand movements with camera systems and to the ease of recording the playing using MIDI-technology MoCap has been used in the last years also in other instrumentalists, for examples in string players  and woodSummarizing the reported studies on movement analysis in musicians in a more global way, three basic principles emerge:(1)Precision of timing and dynamics of movements depends primarily on auditory feedback: “What musicians do not hear, they do not program.”(2)Movement patterns are executed in a serial and parallel manner. Parallel execution of movements comprising multiple joints and fingers is a prerequisite for anticipatory movements. Anticipatory movements in turn  are a characteristic feature of expert musicianship.(3)Movement strategies in expert musicians vary inter-individually, depending on biomechanical properties of the movement apparatus, on the physical properties of the musical instrument and on the individual internal representation of the intended sound quality, the “Sound-Ideal” .Up to now, only limited information is available concerning the acquisition of skilled movements in drummers. Although optimally a longitudinal study of changing movement patterns during the process of increasing expertise is required, long-term follow up over several years is difficult to manage. Therefore, in the present cross-sectional study a comparative kinematic analysis of skilled movements in drummers with different levels of expertise was carried out. The first aim of the investigation was to analyze the kinematic differences between beginners, students and expert drummers. The second aim was to clarify, whether we could deduce from the results general rules related to the acquisition of drumming expertise and draw conclusion with respect to teaching percussion.The specific aim of the study was to delineate parameters characterizing the movements of drummers as a function of their levels of professional expertise. Therefore, we compared healthy male drummers with different levels of expertise, two internationally renowned percussionists, eight students of percussion of the Hanover University of Music, Drama and Media and five non-percussionists. All subjects gave informed consent according to the declaration of Helsinki. The local ethics committee of the Leibniz University Hannover approved the study protocol (LUH EK2309). Subjects were right-handed according to the Edinburgh Handedness Inventory . Age andR). This specific drum pad was chosen, since it has excellent rebound qualities, indistinguishable from a real snare drum. The exercises were to play (a) repetitive quarter notes in forte and (b) repetitive sixteenth notes in forte at a metronome-paced tempo of 76 beats per minute (bpm) for a quarter note. Subjects were instructed to play as regular as possible and stay with the metronome and keep an even loudness. Each exercise had to be performed for 20 s. Drumming movements were recorded with an active three-dimensional movement analysis system  using five infrared-light emitting diodes (LEDs) attached close to the tip of the drumstick (i), and to four bony marks. Subjects had to perform two different drumming exercises with their right hand on a drum practice pad  and the standard deviations were calculated. perfect the performance, musicians have to spend many years of practice in order to achieve outstanding temporal accuracy . The 180-degree angles reflect the relative extension of the wrist following the previous dorsal flexion. The elbow joint remains at a fairly constant angle of 90 degrees during the complete cycle.In the left side of 1 and ω2. The contribution of the elbow joint is minimal. In consequence, a flexible, whip-lash-like motion pattern can be observed, allowing high accelerations at the tip of the stick. It should be noted that in the angle-diagram ω1 no or only very small reversed peaks can be detected. The accurate control of the muscular interplay in this expert results in an anticipatory lifting of the wrist immediately prior to the impact, avoiding the reaction impulse of the impact which is reflected in reversed peaks (see As can be seen in 1) are reduced and reversed peaks can be observed during every impact, demonstrating a certain lack of muscular coordination.In the professional student , the emp3). This is due to the fact, that the subject is unable to control the movement appropriately with the wrist and between the hand and the stick. As a consequence, a stiffening as well as irregular movements of the wrist and at the MCP joint occur, which in turn leads to the necessity of predominant utilization of the elbow joint to produce the stroke movements. It should be noted that in 1. Although it is difficult to see in the angle diagrams, the particular traces of ω1 and ω2 are due to the predominant reaction of the stick and the wrist joint subsequently to the impact on the pad. Since control of the stick is poor, every impact leads to repulsion toward the palm of the hand. The reaction on the impact is also documented in the knotting of the traces of angle ω2 in synchrony with the angle ω1. In summary, the subject has not learned to adjust his muscular coordination to the physical properties of the integrated body-instrument system since the movement is disturbed by every pad stroke.Compared to the expert and the student, the beginner DS14  demonstrz-axis. An animated point would go clockwise on the line through quadrants I, II, III, and IV. About 15 movement cycles are superimposed. Important for the understanding of the movement pattern are quadrant I, representing the movement away from the pad and quadrant II, representing the movement toward the pad. Quadrants III and IV (gray area) represent the very short phase of the impact on the pad. Velocity can attain positive or negative values. Positive values denominate movements toward the pad, negative values movements away from the pad. The acceleration, too, can attain positive or negative values. Negative values represent acceleration toward the pad; positive values the deceleration after the sudden impact on the pad.In a further step of analysis, velocity and acceleration were calculated from the motion data. A better understanding of the data and additional insights are provided by graphs depicting velocity versus the acceleration. In The low degree of scattering of the traces shows the accuracy and the self-similarity of motion cycles in this expert. Furthermore, a constant acceleration in quadrant I (during the upward movement) can be observed, which is due to gravitational forces and intrinsic damping of the biomechanical properties of the muscles. This implies that kinetic energy is transformed into potential – anti-gravitational – energy, and only a very small amount of energy has to be applied actively by muscular contraction. In other words, a highly economical use of force – and therefore of energy – can be deduced from these traces. In quadrant II, during the downward movement toward the pad, the potential energy is efficiently transformed into kinetic energy. But furthermore, muscular force is applied, which is reflected in the increasing acceleration resulting in high velocity of the stick.The velocity-acceleration diagram of the student  resembleThe non-drummer’s diagram  finally The results of the present study can be summarized as follows:Instrumental expertise is reflected in(a)accuracy of both, timing and amplitude of movements,(b)predominant use of distal “low mass” parts of the body and the body-instrument system, probably as an optimization strategy for economy of forces,(c)recurrent characteristic movement patterns, determined by both, skill and biomechanical factors.Professional musicians are trained to execute complex and prolonged movement patterns at high speed and full volume. But the most demanding features of these movements, surpassing the level of more or less pure athleticism, emerge from the requirements concerning their quality. Making music is the only complex sensory-motor action of the upper extremities, which relies on the auditory pathway as a feedback system. The musician’s – and in many instances the listener’s ear is a highly skilled pattern analyzer, revealing inaccuracies in timing in a range of a few milliseconds and inaccuracies in meeting a given target in a range of less than millimeters. A professional musician, at least in the typical frame of a classical western orchestra, is expected to reproduce movements almost perfectly with high reliability. Additionally, the execution of movements is subject to many more or less implicitly mediated traditional rules of interpretation, especially the requirements of high regularity in timing and loudness of cyclic movements such as trills or drum rolls. It is trivial to state that these specialized sensory-motor skills require extensive training periods over many years, starting in early childhood and passing through stages of increasing physical and strategic complexities.With respect to temporal accuracy, the data presented here reflect long-term training processes. The two internationally renowned experts attained higher degrees of temporal accuracy compared to the students and the non-drummers. The control of amplitude of drumming movements was similar to those of the students. Compared to non-drummers, both other groups executed much more regular stick movements. Besides the above-mentioned temporal accuracy, another – more subtle – training effect could be observed, namely the anticipation of the wrist movement prior to the impact on the pad. According to legato style was investigated with special focus on hand and finger coordination in the thumb-under movements in the ulnar playing direction as well as finger cross-over maneuvers in the radial playing direction. Over all scales of all pianists, the mean standard deviation of inter-onset intervals was 8.1 ms in the ulnar playing direction and 8.9 ms in the radial playing-direction indicating a high level of evenness in playing. Expertise-related temporal precision as seen in our results has been reported recently in amateur and expert drummers: a high number of life practice hours predicted an increased temporal precision in a variety of drumming tasks (Few studies have investigated temporal accuracy in professional musicians. ng tasks . Of courBesides the temporal and spatial precision of movements, musicians are confronted with a second critical demand: the ability to perform complex movements over a long time period. This is especially true for percussionists, since orchestral pieces can require fast high-rate drumming at forte over more than 20 s. It is therefore mandatory to use muscles with the greatest possible economy of force. The present data demonstrate this skill in both, experts and students. Not only the predominant use of low mass distal joints but also the benefit from gravity could be observed in all trained subjects and therefore must be regarded as a general rule. The training induced “distalization” of movements has been observed according to a personal communication of our subject DS01 by many drumming pedagogues and is communicated to their students as a training goal. With respect to more general rules of motor learning, other investigators have described this phenomenon previously. It should be emphasized that, albeit there are some general rules, which are in common in the group of students and experts, individual characteristics are reflected in the present analysis as well. The details of the individual phase diagrams are highly reproducible but inter-individually variable, corresponding to individual biomechanical properties of the arm. As one weakness of the study, biomechanical analyses of the upper arm, EMG-, or ultrasound measurements were not taken. Furthermore sound analysis was not possible due to the restrictions to utilize a practice drum-pad. These shortcomings will be remediated in future studies, implementing the methods for acoustical analysis and EMG analysis developed in our labs e.g., .In summary, highly trained drummers are able to control their instrument in a subtle but precise and efficient way. Extensive training results in excellent temporal and spatial accuracy, the benefit from gravity and the distalization of movements. The tuned phases of kinetic chains from the shoulder to the stick produces a “whip-lash-like” movement, with maximal energy brought “to the point” of the pad.What can a drumming teacher learn from such a study? To prevent overuse injury maximal economy of force is mandatory. The data presented in this paper enables the pedagogue to observe a student in a more specific way and to control his technique with respect to use of joints and gravity, either by means of conventional video-technique or even by direct visual observation. Teachers will preferably obtain such an optimized movement pattern by encouraging kinesthetic perception and awareness of unnecessary co-contractions. Here, training in slow tempo with variable movements-patterns and stepwise refinement of motor control through kinesthetic awareness and auditory control will be helpful. Furthermore, according to the OPTIMAL theory of The datasets generated for this study are available on request to the corresponding author.The studies involving human participants were reviewed and approved by the Ethics Committee of the Leibniz University Hannover, LUH EK2309. The patients/participants provided their written informed consent to participate in this study.EA designed the experiment, performed the measurements, discussed the data, and wrote the manuscript. WT designed the experiment, performed the measurements and analyzed the data, and contributed to the discussion of the manuscript. H-CJ discussed the data and contributed to writing of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


This paper investigates the payment scheme and forecast information sharing issues in the express delivery logistics with the high-speed railway. The HSR carriers need to coordinate the transportation capacity between passenger and freight. It is widely recognized that the advance payment scheme (APS) using as deposit is a beneficial way for the HSR carriers to make decisions on the transportation capacity preserved for express delivery. However, the express service providers, who possess private forecast information of express delivery demand, may share inaccurate information with the HSR carriers to acquire sufficient preserved transportation capacity. This paper discusses what payment scheme is preferred by the HSR carrier, the express service provider through discussing the deposit decisions with or without forecast information sharing. We show that sharing demand forecast information can reduce the prereserved capacity and increase the profits of the HSR carrier. With the delayed payment scheme (DPS), the express service provider has no motivation to share the information; while with the APS, the HSR carrier can reasonably choose the deposit to encourage the express service provider to share the demand information. Our analysis also shows that the HSR carrier’s profits with the APS is restricted by the investment returns and the express service provider’s information sharing decisions. We also analyze the value range of the deposit, which is a proportion of the overall payment, that allows both the HSR carrier and the express service provider to prefer the APS, as well as to encourage the express service provider to share the demand information. Over the past decade, the quantity of express delivery parcels in China has climbed up from 1.9 billion pieces to 64 billion pieces. With the rapid development of e-commerce and online grocery, the market demand of express delivery continues surging. Even during the massive quarantines in case of the outbreak of COVID-19 pandemic, the express delivery business has surprisingly risen by 11.5% over the same period of the last year. In contrast, the shortage of express transportation capacity is always the bottleneck in response to the cost and time efficiency required by express industry . For insTo take full advantage of the transportation capacity, the HSR carriers need to coordinate the space between passenger and freight. There are four mainstream carrying modes adopted for HSReD, i.e., using the dynamic inspecting train, sharing the spare space of passenger carriages, transforming passenger carriages into freight carriages and operating specialized high-speed freight trains. All these carrying modes require HSR carriers to evaluate the transportation capacity prereserved for express delivery services. In the face of uncertain express market demand and potential competition with other transportation modes , the HSR carriers prefer to contract with the express service providers before the selling season to pre-determine the transportation volume. In practice, the Chinese HSR carriers, such as the China Railway Express, ask the express service providers to pay a deposit, which is a proportion of the overall freightage, for the transportation capacity preservation. By pulling the demand risk with express service providers, it is a beneficial way for the HSR carriers to better organize the shipping operations for express freight in coordination with passenger carrying services. However, while the HSR carriers expect to increase the deposit to shift the demand risk, a high deposit may force the express service providers to quit the cooperation and use other transportation modes for express delivery. How much should the express service providers pay as a deposit for transportation capacity preservation? How does the deposit decision relate to the preserved transportation capacity decision? We are interested in these questions.On the other hand, information structure plays a vital role in the trade-off problems. When the express service providers are equipped with private information about the demand, forecast information sharing will help the HSR carriers make more accurate decisions on the preservation of transportation capacity for express freight. However, the express service providers, who share the demand risk with the HSR carriers, are possibly reluctant to share the demand information in contracting, depending on the deposit they paid. If the overall freightage is paid afterwards, it is difficult to guarantee that the express service providers would share real-demand information . What deIn this paper, we will investigate what payment scheme is preferred by the HSR carrier, the express service provider through discussing the deposit decisions with or without forecast information sharing. Our model is based on the classic newsvendor model and we assume that the HSR carrier and the express service provider play a Stackelberg game. By giving the thresholds of the deposit, we first analyze the impact of advance payment scheme (APS) on the preservation decision of transportation capacity and discuss the conditions that encourage the express service providers to voluntarily accept the APS. Then, we analyze the value of information sharing to HSR carriers, express service providers with APS and show the conditions under which the express service providers would voluntarily share the demand forecast information.This paper contributes to the state of the art research in three ways. First, as the HSReD has become competitive in the express delivery market, the revenue management of express delivery logistics from the perspective of payment scheme has not been emphasized by the literature. Second, the APS is considered as a beneficial way for the HSR carriers to better organize the shipping operations for express freight in coordination with passenger carrying services. However, a high deposit may force the express service provider to turn to air transportation carriers. We determine the optimal deposit decisions that encourage the express service provider to voluntarily accept the APS. Third, we investigate the role of demand forecast information sharing in the decision-making of the transportation capacity preservation and the deposit, which is a critical issue but has not yet been well explored in the relevant literature.The rest of the paper is organized as follows. We review the relevant literature in the next section. We introduce the model framework and build the basic model with delayed payment scheme (DPS) in the third section and discuss the equilibrium results with APS in the fourth section. Based on our equilibrium results with two payment schemes, we discuss the respective conditions for the HSR carrier and the express service providers to adopt APS, and the express service providers to share the demand information. The sixth section is the numerical study and in the last section, we summarize our conclusions and provide additional managerial insights for additional discussions.The present study is correlated to the previous work on revenue management in HSReD logistics. At present, some scholars have begun to carry out theoretical research on China’s HSReD logistics: Liu et al.  put forwInventory management with the Advance Payment Scheme is also a popular research topic in recent years. Taleizadeh  investigResearch on supply chain information sharing has been very rich. Previous studies have concentrated on the incentive to share information and the value of information. The bulk of the extant literature on this topic has investigated how information sharing affects pricing decisions within a supply chain –27. AnotThe present study is more closely related to the literature focus on the capacity reservation decision in a supply chain where asymmetric demand information exists. Özalp Özer  has concAll these above-mentioned literatures realized information sharing through the relevant design of supply chain contracts. The present focus the optimal deposit decision, which makes express service providers voluntarily share the real-demand forecast information. If the feasibility can be demonstrated in theory, this would provide an economical and easy way for both sides to realize information sharing.w to an express service provider, who sells the express product to consumers at the fixed market price p. HSR carrier is responsible for acquiring the necessary capacity before receiving an order from the express service provider who possesses private forecast information for end express product. HSR carrier reserves high-speed rail transport capacity Q with the unit capacity reservation cost CQ, and provides high-speed rail express service with unit volume service cost c.Considering a HSReD supply chain that comprises of a HSR carrier selling transport service at a agreed freight rate It was assumed that w and the proportion of the overall freightage paid in advance (1-t), express service provider forecasts market demand and determines whether to share information with HSR carrier; (2) in the HSReD planning period, HSR carrier determines the reserve capacity Q, express service provider need to pay part of the freight in advance according to (1-t); (3) in the sales period of HSReD, the market demand D is clear, express service provider orders the actual needed high-speed rail express service according to the market demand D, HSR carrier provides service which is not greater than the reserve capacity Q. After the completion of the service, express service provider needs to pay the remaining freight.The sequence of events is as follows: (1) when the two sides establish a cooperative relationship, HSR carrier determines the agreed freight rate The demand function was set as terature , 40, it To compare this with the APS, the present study initially constructs the basic game model and analyze the equilibrium with DPS. DPS refers to the payment of the express service provider for the freight, according to the actual transportation volume after the express transportation task was completed by HSR carrier. In fact, DPS is a special form of the APS. That is, when the deposit is 0, it is easier to implement, since there is no need to consider the setting of the deposit. Hence, this has been widely used in aviation and maritime transportation.D), express service provider often only pays the cost of the actual transportation volume after the completion of the express service. The loss caused by part of the reserve capacity, which is greater than the actual market demand, is borne by HSR carrier.With DPS (D), the function of expected profit of the HSR carrier (R) isWith DPS  isBased on the above profit function, it is easy to get Lemma D), the optimal reserve capacity of HSR carrier and the expected profit of both parties are as follows:With DPS ((i) Under the condition that express service provider does not share information (DN), the optimal reserve capacity of HSR carrier isthe profits of HSR carrier and express service provider are, respectively,(ii) Under the condition that express service provider shares information (DY), the optimal reserve capacity of HSR carrier isthe profits of HSR carrier and express service provider are, respectively,in which With APS, HSR carrier needs to set a reasonable deposit, and determine the reserve capacity, to maximize its own profits, on the premise of ensuring that the express service provider participates in the cooperation. It is noteworthy that the HSR carrier uses the deposit in the investment, and obtains the corresponding investment returns. In the case of HSR carrier collects deposit in advance, and uses these for investment, the expected profit function of HSR carrier (R) isi, and for convenience, set I = 1 + i, then Hence, The expected profit function of express service provider (E) isHence, with APS, the express service provider needs to pay the deposit Based on the above-mentioned profit function, the game equilibrium analysis was carried out for the HSReD supply chain with APS under the conditions of sharing information and not sharing information.D into the profit function of HSR carrier, the following can be obtained:Since the express service provider does not share information, HSR carrier can only determine the reserve capacity By solving the above formula, we can get Lemma N), the optimal reserve capacity is as follows:When express service provider does not share demand forecast information , the optimal reserve capacity is as follows:the profits of HSR carrier and express service provider are as follows:where t that indicates the proportion of the overall freightage paid after the service is completed is preliminarily analyzed. According to the value range of the probability distribution function in formula  indicates the proportion of the overall freightage paid in advance, and it should not exceed t) is determined by the capacity reservation cost i. When Furthermore,  When the profit obtained by HSR carrier with APS is greater than that with DPS, that is, HSR carrier adopts APS.t meets the following condition:(ii) When the profit obtained by express service provider with APS is greater than that with DPS, that is, express service provider accepts APS.t meets the following condition:(iii) When the profits of whole supply chain with APS are both greater than those with DPS.(iv) When the conditions in (i) and (ii) are met at the same time, the profits of HSR carrier and express service provider with APS are both greater than those with DPS, that is, APS is superior to DPS, where Result 3. When express service provider does not share information, if t meets the following conditions, this can make HSR carrier and express service provider obtain more profits with APS:t meets the following condition:(i) When the profit obtained by HSR carrier with APS is greater than that with DPS, that is, HSR carrier adopts APS.t meets the following condition:(ii) When the profit obtained by express service provider with APS is greater than that with DPS, that is, express service provider accepts APS.t meets the following condition:(iii) When the profits of whole supply chain with APS are both greater than those with DPS.(iv) When the conditions in (i) and (ii) are met at the same time, the profits of HSR carrier and express service provider with APS are both greater than those with DPS, that is, APS is superior to DPS.Where Initially, the present study analyzed the incentive of information sharing of express service provider with DPS. According to Lemma Result 4. With DPS, in the cases of information sharing (Y) and no information sharing (N), the relationship between the reserve capacity and the profits of both parties is as follows: It can be observed that when express service provider shares information, this can improve the accuracy of the demand forecast of HSR carrier, reduce capacity reservation, and increase the profits of HSR carrier. However, HSR carrier reduce the reserved capacity, the risk that reserved capacity cannot meet the market demand increase, thereby reducing the profits of express service provider. Therefore, with DPS, express service provider will not voluntarily share the information. In existing research, information sharing was based on contract implementation.Next, this analyzed the incentive of information sharing of express service provider with APS. According to Lemmas Result 5. With APS, and in the case of information sharing (Y) and no information sharing (N), the relationship between the reserve capacity and profits of both parties is as follows: t. Therefore, with APS, HSR carrier can realize information sharing by adjusting the proportion of advance payment. The following presents the specific analysis of the value range of t, which can encourage the express service provider to voluntarily share information.It can be observed that with APS, sharing information can reduce the reserve capacity of HSR carrier, and increase its profits. However, the profits of the express service provider under information sharing and non-sharing, which are According to Lemmas where For further analysis of conditions that make Lemma 4. (i) When t meets the following conditions, t meets the following condition, (ii) When t meets the following condition, (iii) When t and the information sharing decision of express service provider is detailed in Result 6.According to Lemma 4, the relationship between the value range of Result 6. When t meets the following conditions, demand forecast information sharing can increase the profits of HSR carrier, the express service provider, and the supply chain.t meets the basic conditions for the optimal reserve capacity, the value of information sharing to HSR carrier (i) When (ii)When (iii) When (iv) When t that can make HSR carrier and express service provider accept APS and encourage the express service provider to share information can be further determined. According to the actual operation data of the high-speed rail express [t concluded in the present study, set The reserve capacity and expected profits of both parties with different payment schemes and information sharing strategies can be calculated, the influence of payment scheme and information sharing can be analyzed, and the range of  express , 27, 42,The expected profit of HSR carrier was calculated with DPS (D) and the APS (A), respectively, and the influence of the payment scheme on the profit of HSR carrier was analyzed. In the case of information that was not shared (N), the values of mentclass2pt{minimIt can be observed that when express service provider does not share information Fig. , HSR carThe expected profit of the express service provider with DPS (D) and APS (A) can be calculated. In the case of no information sharing (N), the values of It can be observed that when information is not shared Fig. , the expThe reserve capacity with DPS (D) and APS (A) was calculated, respectively, and the influence of the payment scheme on reserve capacity was analyzed. In the case of no information sharing (N), the values of As shown in Figs. N) and sharing information (Y), respectively. The expected profit of HSR carrier The expected profit of HSR carrier and express service provider were calculated in the case of no sharing information (t = 1) or The APS (t < 1), HSR carrier can obtain more profits, which is consistent with the conclusions of Results 4 and 5. For express service provider , the profit when sharing information is smaller. That is, sharing information would lead to profit loss, while with The APS (t < 1), by setting the deposit within the appropriate scope, express service provider can obtain more profits when sharing information. That is, express service provider can be encouraged to voluntarily share information by reasonably setting the proportion of advance payment.As shown in Fig. der Fig. , with DPThe optimal reserve capacity Regardless of whether it was with DPS or APS, as shown in Fig. N), the profit of HSR carrier with DPS, the profit of HSR carrier with DPS when HSR carrier does not invest (I = 1) and the return on investment is 0.1 (I = 1.1), are shown in Fig. If HSR carrier does not invest after collecting the fees in advance, the rate of return on investment is 0, that is, As shown in Fig. t for both parties to accept APS is As shown in Figs. t, which can encourage express service provider to share information, is As shown in Fig. t for express service provider to voluntarily share information, and for both parties accept APS is In summary, the value range of In terms of information sharing, with both payment schemes, the sharing of demand forecast information by express service provider can reduce the reserve capacity, and increase its profits of HSR carrier. For express service provider, there is no motivation to share information with DPS, but while with APS, a reasonable prepayment proportion can be set according to Results 6, in order to make it voluntarily share information.In terms of the payment scheme, HSR carrier reserves more capacity with APS. However, whether these two parties accept APS depends on the setting of the deposit. It is noteworthy that HSR carrier may not be able to obtain more profits with APS, especially when express service provider does not share information and charge a higher proportion of prepayment. This is because HSR carrier will reserve more capacity with APS, and the decision-making error of reserve capacity caused by the inaccurate market forecast information may be greater, and the profit loss may also be greater. Therefore, when HSR carrier adopts APS, it should pay more attention to encourage information sharing from express service provider.The key advantage of HSR carrier to adopt APS is that the deposit collected in advance can be used to investment. If HSR carrier does not invest, or the return on investment is too low, the APS may be unfavorable.In the present study, a game model of the high-speed rail express supply chain was constructed with DPS and APS, when express service provider shares and does not share demand forecasting information. Then, the influence of the payment scheme and information sharing strategy on the reserve capacity and profits of both sides were analyzed by comparing the game equilibrium results. The following conclusions were drawn:In summary, the present study shows that HSR carrier can reasonably set the deposit, allowing both sides to accept APS, and encouraging the express service provider to share information. The present also worked out the value range of the proportion of the overall freightage paid in advance under these above two circumstances, providing a theoretical basis for HSR carrier to promote the APS, and an economical and easy approach to realize the information sharing of both sides in express delivery logistics with the high-speed railway.The present study investigates and analyzes the possibility of encouraging express service providers to share demand forecasting information by adjusting the deposit. However, express service providers also have private information, such as operating cost, margin, and reservation profit. Hence, information sharing decision-making and incentive problems can be further considered when express service providers have a variety of private information. In addition, the present study only considered the cooperation between one HSR carrier and one express service provider. Hence, the follow-up research should consider the information sharing and incentive problems under the situation of different types of express service providers participating in the cooperation.


The RoScan is a novel, high-accuracy multispectral surface scanning system producing colored 3D models that include a thermal layer. (1) Background: at present, medicine still exhibits a lack of objective diagnostic methods. As many diseases involve thermal changes, thermography may appear to be a convenient technique for the given purpose; however, there are three limiting problems: exact localization, resolution vs. range, and impossibility of quantification. (2) Methods: the basic principles and benefits of the system are described. The procedures rely on a robotic manipulator with multiple sensors to create a multispectral 3D model. Importantly, the structure is robust, scene-independent, and features quantifiable measurement uncertainty; thus, all of the above problems of medical thermography are resolved. (3) Results: the benefits were demonstrated by several pilot case studies: medicament efficacy assessment in dermatology, objective recovery progress assessment in traumatology, applied force quantification in forensic sciences, exact localization of the cause of pain in physiotherapy, objective assessment of atopic dermatitis, and soft tissue volumetric measurements. (4) Conclusion: the RoScan addresses medical quantification, which embodies a frequent problem in several medical sectors, and can deliver new, objective information to improve the quality of healthcare and to eliminate false diagnoses. In general terms, the effectiveness of treatment, and thus also the recovery time and the amount of resources spent, stands on two prominent pillars: correct diagnosis and appropriate therapy . At presThe pace of progress in the former pillar, however, is markedly different. Although the correct diagnosis is at least as important as proper therapy, many of the current, commonly used diagnostic procedures still rely on healthcare professionals’ experience, intuition, and memory. The correctness of the decision then depends on the specific abilities of the medical specialist . The diaTo prevent mistakes in determining the correct diagnosis, to decrease the required time, and to reduce the dependence of successful disease classification on the doctor’s expertise and experience, supporting diagnostic medical devices are introduced increasingly more often. Most hospitals are presently equipped with general-purpose imaging methods, such as X-ray, MRI, and CT; these tools, however, may be very expensive and thus less accessible to smaller medical centres. In such cases, smaller, cheaper, and more specialized instruments are employed.Almost all types of injuries, multiple diseases, and pathological changes share a significant symptom: the local temperature change. This thermal abnormality is caused by increased blood flow and stronger cellular metabolism in the affected area; the two aspects then induce a local temperature difference generated by the given negative health-related effect . Such loExact localization problem—due to the lack of easily recognizable and clearly bounded landmarks in the thermal image (which contains mostly smooth gradients instead of sharp edges), it is not possible to determine the exact position of a thermal deviation on the skin. This issue is illustrated in Resolution vs. range problem—the low resolution of thermal imagers forces the user to search for a compromise between two options: (a) a wide-range view, where the entire part of the body is represented, but the resolution is too low to show enough details a; and bb. As theQualitative only, no quantification—although 2D thermography basically constitutes a quantification tool (since it accurately measures the temperature in each pixel), in terms of the medical quantification of disease or injury it is a qualitative method only ,17. By uMedical thermography is generally referred to as Digital Medical Thermal Imaging (DMTI); the technique currently finds use in several relevant applications  and a non-physiological  change. Moreover, it is also difficult to assess the impact of the treatment procedures because the existing treatment evaluation exploits subjective health surveys or low-resolution scoring systems with poor inter-observer correlation.These problems (and many others) are tackled by the RoScan multispectral 3D scanning system. In this study, the basic principles and benefits of the approach are characterized and demonstrated on several medical applications where pilot case studies were performed with positive results.This paper discusses novel approaches to and applications within 3D thermal scanning. The presented scanning system, developed completely at Brno University of Technology, combines a high operational flexibility with high absolute accuracy of the resulting 3D model. Such a fusion of capabilities is still uncommon in current commercial 3D scanners, as these usually embody a compromise between the scanning accuracy and flexibility ; in mediThe RoScan multispectral 3D system consists of a robotic manipulator and several sensors, grouped together at the endpoint into a sensing head a. To allThe manipulator moves the sensors along the body being scanned d, and thIn addition to the laser scanner necessary for acquiring the 3D model itself, the robot’s endpoint is equipped with a color camera c, which To this point, the RoScan’s output may have seemed to be almost the same as that of commercially available 3D scanners; such an impression, however, will change quickly if we emphasize the fact that the output model can be large and complex without any influence on the accuracy. Compared to other current 3D scanning instruments, the robotic manipulator ensures very accurate and independent localization of the sensors; the accuracy of the resulting model then does not affect the object’s appearance or shape. The method is robust, and the accuracy constraints are identical regardless of the scanned scene. Smooth homogeneous structures or repeated patterns are processed flawlessly , and thAn additional information layer, unavailable in current 3D scanners, is generated by the thermal imager. The advantageously composed structure utilizes the robotic manipulator to capture the temperature images and 3D spatial data at different positions: The images are taken at a significantly greater proximity to compensate for the low resolution of thermal cameras and to achieve the same resolution in the thermogram, the other layers, and the entire 3D model. Consequently, a true, non-interpolated temperature value is assignable to each model point, even in extensive and highly detailed models. This capability then resolves and eliminates one of the problems that accompany the use of DMTI  markedly more thermal images from a significantly shorter distance. Thus, we finally obtain the same resolution in the color and the thermal layers .All of the collected distance profiles are aligned to the same system of coordinates by using homogeneous transformations; subsequently, the 3D shaded mesh is generated .In the next step, the 2D images from the cameras are mapped to the surface of the 3D model . At thisThe output model is delivered in a particular file format, which can be opened in the RoScan Analyzer software tool, described in the next section.Multispectral 3D surface models created with the RoScan can be displayed via the RoScan Analyzer. In addition to the common features, such as rotating, scaling, and adjusting the modes of view, the software instrument also facilitates measuring many spatial parameters of the selected region of interest (ROI) and allows exporting the 3D data in several standard file formats ; the data are then processable with any third-party 3D modeling program.Color—the basic view of the clinician. In the model, this layer is used mainly for localization, either by natural landmarks of the skin (such as pigmented spots), via pen-marked markers, or through the use of region boundaries; such landmarks can be highlighted to be visible also in other layers . AlternaTemperature—the layer with false colors that correspond to the temperature of the skin; here, the exact value of a particular point can be examined by clicking. To reach the appropriate contrast between the physiological and the non-physiological areas, we can adjust the coloring palette by moving a slider.Roughness—this layer shows false colors that correspond to the roughness of the scanned surface. This output utilizes the measuring principle of the applied laser scanner, which exploits triangulation . As a siSurface only—in certain cases, the coloring and shading of the model may hide some details or produce an optical illusion. Representing the surface in a single color allows us to see even the tiny details that normally often remain uncovered. When spatial details are to be examined, it is often convenient to show the 3D surface only, with the coloring eliminated.Each model can be viewed in the following modes :Color—thDistance [mm]—separates several selected points. The distances are measured either in the direct mode or via the shortest path along the surface .Angle [degree]—the angle between every three subsequent POIs, including, for example, those that allow an analysis of vertebrae positions.2]—relating to the whole model or the ROI only, for example, the area of burn, or extent of lesion.Surface area [mm3]—concerning the entire model or a part thereof. Such a portion can be defined by the cutting plane or deflected cutting surface. Useful for, e.g., measurements of the limb volume.Volume —of a highlighted point or the average temperature of the ROI. This parameter has the highest information value, since it correlates with inflammation in the area.On each layer, the user can select points of interest (POIs), facilitating spatial measurements with the model. In the selected points or regions of interest (ROIs) defined thereby, the following parameters can be assessed:Such a multimodal 3D computer model finds use in, for example, inflammation monitoring. The process then comprises the following stages: first, the thermal layer is studied, and possible thermal abnormalities are highlighted in the 3D model. Second, we switch to the color mode, which facilitates exact localization of the inflammation foci and allows us to set up the region of interest (ROI). Afterwards, we can quantify the inflammation activity . At the last stage, the swelling-induced volume variation is measured accurately.The inflammation monitoring and quantification constitute only one of the RoScan’s potential target applications. To illustrate the claim, we can note in this context that while inflammation leads to a positive thermal data gradient, ischemia results in a local decrease; thus, the RoScan may be employed in the monitoring of diabetic necrotic tissues.The central advantage of the discussed concept rests in the applied combination of spatial, color, and thermal data within a single 3D model; such an approach delivers new research opportunities, which would otherwise remain virtually impossible to implement. More concretely, the RoScan has a major potential in the objective evaluation of spatial changes of the body; this medical task includes, above all, the monitoring of oedemas, muscle growth and atrophy, inflammation, and necrosis.The color layer guarantees the precise selection of a ROI . The thermal layer helps to find inflamed areas or determine if a spatial change is caused by physiological or non-physiological processes. Finally, 3D scanning yields an undistorted view, thus offering an effective alternative to standard 2D imaging technologies, where the distortion prevents objective measurements from being performed. The essential capabilities and properties of the RoScan system are summarized in The price of the device indicated in the table above relates to the research setup characterized herein; that is, a configuration which utilizes a robotic manipulator. Advantageously, this component delivers superior flexibility and versatility, allowing the entire device to find use in many different applications, even outside of medicine. If deployed in practice, however, the system is usually not required to perform an overly wide range of activities, and thus its six-degrees-of-freedom flexibility can become overkill. The manipulator can then be replaced by a cheaper (but still very accurate) positioning system with fewer degrees of freedom , maintaining the key parameters. As the price of the manipulator amounts to 19,000 EUR out of the total of 30,000 EUR, the acquisition costs could then drop markedly.Although the purchase costs are significantly lower than those in the current imaging methods, the most extensive savings are achieved in regular operation, where the RoScan generates almost zero additional costs, regardless of the frequency of use. This is a major benefit compared to, for example, MRI, in which each scan is worth 200–400 EUR ,33.As described in the Introduction, thermography is considered a useful method, even though its benefits are limited by three fundamental drawbacks ,14,15,16exact localization problem arises from a lack of clear point objects in a thermogram. Despite being able to detect areas with non-physiological behavior in a thermogram, we cannot determine exactly where they are ((1) The they are a and thethey are b, which resolution vs. range problem is generated by the low resolution of thermal imagers. Since the thermal changes inside the human body are usually small and can hide in the physiological temperature gradients [(2) The radients , it is nradients . This ob(3) The most prominent drawback lies in that classic DMTI is a mere qualitative tool, enabling us to distinguish between the physiological and non-physiological states of the body but lacking the ability to quantify them ,17. ThisResolving these limitations opens the door to suitable thermal imaging applications within the medical domain. Later in the text, a set of pilot case studies is presented, showing the potential of quantification carried out via 3D thermal imaging.Assessing medicament efficacy in dermatology .Assessing the objective progress of recovery in traumatology .Quantifying applied force in forensic sciences .Localizing exactly the cause of pain in physiotherapy .Volumetric measurements of soft tissues .Objective assessment of atopic dermatitis .Several pilot experiments were performed within multiple medical specialties to validate the benefits of the RoScan. As this is the first application of 3D thermography utilizing the RoScan in the discussed field , we preferred case studies to broader analyses with wider populations of subjects. The outcomes of these experiments pointed to considerable usability of the device in medical diagnostics and demonstrated its advantages as related to the state of the art in a particular subdomain. We focused on the following activities and fields:The results obtained from the experiments, complemented with the methodologies used, are summarized in the relevant subchapters of this section. In order to provide a comprehensive overview of possible applications, we also included the studies already published; these studies already cite our original findings partially released through other articles, which contain more details about the experiment.The case study was performed on a subject suffering from allergy to hazelnut substances. The experiment started when red, itchy lesions appeared on one of the subject’s feet. The lesion-containing regions were highlighted with markers directly on the skin and then divided into two areas: K, where the Protopic 0.1% ointment was applied, and V, where a shea butter and coconut oil lotion was utilized. The patient was repeatedly scanned with the RoScan, and the average temperature gradient in both areas was evaluated by selecting the boundaries visible on the color layer of the 3D model. The results are shown in The growth of the temperature gradient in the sector treated with Protopic 0.1% culminated earlier than in the shea butter and coconut oil zone, showing Protopic 0.1% to be the more effective medicament in this particular case.It is important to stress that the series of experiments would not have been executable with a regular state-of-the-art method. At present, the clinical tests are usually performed on two groups of subjects, of which one is treated with the tested medicament, while the other is not; the overall progress of each subject’s symptoms  is evaluated by a coarse scoring system . Such an approach then may lead to wrong conclusions if the selected group does not constitute a representative sample of the population , and its sensitivity is rather low.The RoScan allows comparing the effects exerted by two different drugs on the same subject and even the same lesion, thus greatly increasing the reliability of the study because an identical spontaneous development is markedly more likely to be found in two parts of one lesion than in the lesions of two different patients.This task is virtually impossible to implement via the current methods; moreover, the system’s sensitivity and selectivity enables the user to evaluate the progress of the treatment in great detail, as shown in Another major advantage of the RoScan consists in that more quantitative parameters are available at the same time, while the current methods usually focus on a single item only; thus, in addition to the lesion temperature, the data relating to the color, reflectance, and roughness of the lesion surface and area are accessible.As the thermal distribution of a patient’s surface temperature is affected by many environmental factors and also the subject’s pre-measurement activities, the measured index was established as a difference between the area’s average temperature and reference temperature, normalized by the value at the time when the dermatological medicaments were applied. Assessing the thermal difference between the reference point and the ROI eliminates environmental influences . Normalization had been chosen due to the unequal distance of both areas from the edge of the body, i.e., a problem that causes differences in the absolute values of a temperature. This approach normalizes both values to the same scaled index and makes the areas comparable between each other. Further details concerning this experiment are provided in source .The experiment was performed with a subject having a bruised toe following a hit by a heavy object. In order to eliminate temperature fluctuations generated by external factors, which are non-negligible especially in the lower limbs, we choose the difference between the average temperatures of both toes as an objective index, since we assume that the impact of external influences will be comparable in both toes, and their thermal difference will then be almost zero in the physiological state.Importantly, the subject’s feelings of pain subsided already 74 h after the injury b; howeveThis scenario shows that the RoScan facilitates early detection of inflamed regions before they start to give pain or develop significantly; the system is thus capable of reducing the treatment and recovery time and cost. Unlike the current visual evaluation-based approach, the novel technique yields more accurate and objective data.The relevant experiment was performed with five subjects suffering from the same problem at various degrees of intensity. In all of the cases, the thermal difference progressed similarly, with the maximum value corresponding to the bruise severity.Another use for 3D thermography is in the evaluation of the force applied in violent crimes. Although the RoScan will probably be unable to determine the specific value of the force or the exact time of the actual act, it may beneficially allow comparison of two forces by examining their consequences.In the simulation, the subject was punched with an imaginary attacker’s fist in the biceps, once and then twice, at two pre-marked places; the first was modeled by using a heavy pack of sand having a small, hard rubber ball attached to the bottom. The pack was invariably released from the same height, thus hitting the biceps with an identical force in each cycle. During the 6 h following the experiment, both areas were repeatedly scanned, and the temperature differences between the pre-marked locations and the pre-marked reference point on the shoulder were evaluated .The temperature in both of the affected areas increased sharply at the exact time of the punch and then continued to grow during the first 50 min after the act. Interestingly, the measured temperature correlated with the number of the first hits, and the traces of the assault remained visible on the thermogram for more than 3 h following the punching. In this context, it should be noted that the “experimental punches” were very soft, and the subject had already stopped feeling pain 10 min later; such a progress stresses the high sensitivity of the method, even though in a real attack the signs would likely have been noticeable for markedly longer.Conversely, we need to admit that the hits were aimed at a temperature-homogeneous area of the body, in which a uniform change caused by external influences can be expected. This type of results may not be generally achievable throughout the whole body; however, given that violent cases are often accompanied by a lack of evidence, such a record, too, has a useful potential.An important premise for selecting the right treatment in physiotherapy consists in ensuring the correct diagnosis of the cause of the pain ; howeverIn practice, DMTI is used where suitable, helping the examiners to reveal the source of inflammation and to determine the character of the problem . The technique is nevertheless incapable of accurately localizing the center of pain and preserving an objective record similar to that produced by the RoScan.Such records can be employed as follows: First, the ability to capture the current state of the patient objectively facilitates further comparison during his or her next clinical consultation; otherwise, if the changes are not large enough to be observable, the patient’s condition may be wrongly considered inalterable. The records also enable us to reliably assess the severity of the disease because the method is not as subjective as the others. Second, the thermal quantification (if possible) leads towards an assessment of the treatment suitability or medication effectiveness .In our study, several patients were repeatedly scanned with the RoScan during the recovery process following an injury or surgery. A comparison of the inter-visit 3D scans provided a proof of positive progress and facilitated the initial choice and definition of further treatment. In this context, for example, we can refer to the evidence of inflammation in a subject suffering from entezopathy of the deltoid muscle, revealed during the first examination a. The inThe benefit of the RoScan in physiotherapy rests mainly in the exact localization capability; however, the device can also function as a quantification tool in cases where it is possible to suppress the external fluctuations that affect body temperature. Such a situation is presented in Within this experiment, the current volumetric techniques were compared with the RoScan via measuring the volumes of reference objects (phantoms). When performing against the current gold standard, i.e., water displacement volumetry, the RoScan delivered volumetric measurements at higher accuracy and repeatability, as shown in In terms of its parameters and capabilities, the RoScan embodies a faster, safer, and more accurate approach with very low operational costs; the system is especially valuable in specific cases where advanced ROI examination and high accuracy are needed. Such special volumetric cycles normally require the standard MRI or CT; however, the RoScan, if employed, reaches more accurate results at significantly lower costs .As the RoScan is generally the most accurate method, it will allow measuring of even very small changes in the volume, which can enable us to discover pathological changes in a timely manner, well before they have developed significantly.Additional details on the experiment can be found in source , and theThere are many diagnostic methods for assessing atopic dermatitis (AD), varying from scoring systems  to sophisticated and expensive options .In this context, DMTI is considered a relatively objective  method, as it measures increased blood flow, which manifests itself almost identically in all patients . The tecAs mentioned above, the RoScan’s structure eliminates this difficulty, and thus it finds use in AD lesion assessment. The capability was demonstrated in the experiment, whereby an AD patient was examined via DMTI; nevertheless, the thermal data could not be causally linked to the real lesions. The relationship was then established only by using the RoScan and its ability to select the nonphysiological locations and to navigate in the color layer . The theThe RoScan project, completely developed at Brno University of Technology, embodies a novel concept of using a robotic manipulator combined with several sensors producing data in different spectra. For medical applications, it appears to be advantageous to combine a laser scanner, a color camera (wavelength range between 390 and 750 nm), and a thermal imager (wavelength range from 8 to 14 µm); such a configuration is beneficial because the thermal changes commonly accompany the non-physiological states. This innovative method for multispectral 3D scanning brings several advantages compared to the state-of-the-art approaches.Thanks to the projection of the spectral data onto the surface of the 3D model via an independent localization system, the process of registering the 2D images is robust and independent of the scanned object. The procedure is applicable to any smooth and homogeneous surface or texture, thus being especially valuable in merging several thermal images into a large one if there is a lack of reliably detectable registration landmarks.Another major benefit of independent localization lies in cross-spectral image registration . With this method, one can reach the same resolution in both the thermal and the color layers, even if the native resolutions of the sensor differ significantly. Moreover, both layers are properly aligned to the 3D model and to each other; importantly, the uncertainty is exactly specified and equal in the entire dataset.Advancement beyond the possibilities of the state-of-the-art is recognizable also within 3D scanning; unlike many of the current, commercially available 3D methods, the RoScan allows each point of the captured model to exhibit an equal, absolute spatial accuracy independent of the scanned scene and lacking cumulative deviations. Additionally, the accuracy is precisely quantifiable from the parameters of the manipulator and sensor, bringing a major advantage in precise measurements, where the uncertainty must be specified in an exact manner. Most of the current 3D scanners are not capable of such operations ,44.The RoScan offers a considerable potential in those medical applications where objective quantification plays the key role. The system quantifies inflammatory processes inside the human body; several pilot case studies described in this paper showed that using the RoScan to quantify inflammation is feasible when the inflamed region remains close to the skin, has sufficient “strength” to influence the skin temperature, and ideally appears in an area where the temperature distribution is as homogeneous as possible, enabling us to find an index with the potential to eliminate the environmental factors.The RoScan-based assessment of medicament efficacy in dermatology showed the possibility of comparing the impacts of two different drugs on the same subject and even the same lesion, an objective virtually unachievable via the current methods. Standard clinical tests are usually carried out on two groups of subjects, of which one is treated with the tested medicament, while the other is not; such an approach then may lead to wrong conclusions if the selected group does not constitute a representative sample of the population, and its sensitivity is rather low (meaning that only major progress is distinguishable).A traumatology-related study discussing the assessment of objective progress in recovery pointed out that the RoScan enables early detection of inflamed regions before they start to give pain or develop significantly, stressing also the facts that the system is thus capable of reducing the treatment and recovery time and cost.Moreover, the technique embodies a valuable tool to yield an objective record of the current state of a disease; producing such records is a common problem of present medicine, which intensively relies on the personal memory of the clinician.Another research subdomain where the RoScan reaches beyond the state of the art lies in investigating the quantification of applied force: the system proved to be highly sensitive, with the traces of a physical assault remaining visible on the thermogram for more than 3 h after the violent act, even though the actual pain caused by the punching disappeared in only 10 min. The measured temperature correlated with the number of punches received.In physiotherapy, the RoScan delivered objective evaluation of the treatment effects, documenting objectively blood circulation improvement after an invasive surgery.Finally, the tool has been verified as suitable for soft tissue volumetry, bringing superior accuracy and repeatability. An additional benefit is the possibility to select the edema only, stemming from the ability of the thermal layer to distinguish the edema from a healthy tissue. Neither of the achievements is obtainable via the current volumetric methods.At this point, however, it is necessary to emphasize that 3D thermography remains a mere tool requiring expert assessment by a doctor. The RoScan does not aim to offer automatic detection and localization of inflammation; rather, the device is designed to embody a source of objective data that will allow clinicians to decide and quantify better and more correctly than if such data are lacking. Areas with higher temperatures are not always inflamed; often the effect expresses an anatomical constitution . A significant impact is generated also by external influences, including the ambient temperature, the patient’s previous activity, and current footwear or clothing. Although the effect of these elements can be limited in many cases by choosing a suitable relative index, this approach is not applicable generally, meaning that the 3D thermogram will still have to be interpreted and evaluated by a medical doctor, who nevertheless may not be as experienced as a physician diagnosing without the thermogram.Generally, precise 3D thermography tools, such as the RoScan, can yield major benefits in various healthcare domains. The relevant instruments facilitate early detection of inflamed areas, the reason being that their sensitivities surpass those of the commonly used methods, which are mostly based on visual observations ,46,47. TThe RoScan system eliminates all of these issues, thus opening new possibilities for thermal imaging in medicine. Several pilot case studies confirmed the benefits introduced by the RoScan into diverse subdomains of healthcare, where the advanced concept overcomes the limits inherent in the other state of-the-art methods. This scanning approach appears to be particularly beneficial within medical efficacy assessment, dermatology, traumatology, and physiotherapy, where it facilitates objective monitoring of the recovery progress. In all of these areas, the novel multispectral 3D method can be advantageously adopted as an objective quantification tool to fill the void in the set of options available for the given purpose.More concretely, the RoScan is especially useful when the common symptoms have not yet fully developed; however, multispectral 3D scanning in general finds application also when the symptoms are already visible. Importantly, the capability of preserving the exact state of the patient’s body  leads to objective evaluation of the progress of the disease.The positive results of the initial case studies presented herein pointed out the areas where the opportunity to enhance the state of the art is potentially high. In future projects, we will focus predominantly on these domains, and we will attempt to transfer the proposed technology into everyday medical practice. Although it will probably be necessary to modify the system for the given applications, this task will not be problematic, especially due to the fact that the entire system was fully developed at our department and is thus completely controlled by the authors of the paper. Major portions of the research will be dedicated to the maximum simplification and automation of the scanning process because if the system is to be practically usable, it must offer easy operability without expert knowledge and significant time intensity.The system is convenient for not only medicine but also technology and science: thermal 3D scanning procedures are usable in, for example, electrical engineering to ensure thermal analyses centered on the efficiency of electrical components ; civil eMoreover, if we also take into account the fact all algorithms are universal and thus make it possible to easily replace the color and thermal camera with another sensor of a different spectral range, the usability of the RoScan system will expand even more significantly.


In this paper, a novel hybrid damage detection system is proposed, which utilizes piezoelectric actuators for guided wave excitation and a new fibre optic (FO) sensor based on Fabry-Perot (FP) and Fiber Bragg Grating (FBG). By replacing the FBG sensors with FBG-based FP sensors in the hybrid damage detection system, a higher strain resolution is achieved, which results in higher damage sensitivity and higher reliability in diagnosis. To develop the novel sensor, optimum parameters such as reflectivity, a wavelength spectrum, and a sensor length were chosen carefully through an analytical model of the sensor, which has been validated with experiments. The sensitivity of the new FBG-based FP sensors was compared to FBG sensors to emphasize the superiority of the new sensors in measuring micro-strains. Lastly, the new FBG-based FP sensor was utilized for recording guided waves in a hybrid setup and compared to the conventional FBG hybrid sensor network to demonstrate their improved performance for a structural health monitoring (SHM) application. The increasing environmental concerns such as energy conservation and reducing life-cycle costs of engineering structures has led to the increasing use of composite materials in aeronautics and wind energy industries. Composite materials have a high strength-weight ratio and fatigue resistance and, therefore, their usage can reduce the fuel consumption and extend the aircraft’s service life. The application of composites in wind turbines can reduce the weight of the blade and, therefore, lead to an increase of the wind energy conversion rate and service time. However, composites’ anisotropic properties render them vulnerable to impact damage. Even a low-energy impact can cause various internal damage such as matrix cracking or delamination. These types of damage can lead to a catastrophic consequence if not detected.Non-destructive inspection (NDI) methods such as radiography, ultrasound, magnetic testing, or visual inspections are involved and are widely used in the maintenance of engineering structures to ensure the integrity of composites. However, these technologies cannot perform a real-time monitoring of the structure in-service and require long down-times . In windOne solution that addresses the challenge of unknown load distribution for damage detection is to use the FO sensors in an active sensing system where the structure is loaded with a known waveform, e.g., generated by a PZT actuator where the recorded response has an expected waveform as well. The frequency of the excited waves is much higher than the external loading. Therefore, it is easily distinguished by filtering the low-frequency signals out. By combining the FO sensors with PZT actuators, the advantages of both technologies are enhanced, and the number of PZT transducers significantly decreased, which leads to a reduction in the additional weight, wiring, connectors, and electromagnetic interference.In 2004, Ogisu et al.  developeSome researchers have focused on maximizing the wave transfer to the optical fiber by enlarging the strain transfer rate (STR) of the optical fiber. Sakai et al. (2016) demonstrated the enhancement of the FBG output response by using an acoustic lens . The priThis paper aims to develop a new hybrid PZT-FO solution that has higher sensitivity to strain signals and, therefore, is more reliable for damage detection in composite structures. To achieve this hybrid system, a novel FBG-based Fabry–Pérot (FP) sensor has been developed, which has higher strain sensitivity and, hence, higher SNR. This paper first starts with the principle of the hybrid system architecture, which is followed by the developments of the novel sensor by designing the sensor and validating its spectrum experimentally against the simulated results. Afterwards, the novel sensor is tested with the hybrid setup to detect guided waves and compare its strain sensitivity to the conventional FBG-based hybrid response. Lastly, the application of the new hybrid system to detect artificial damage on a composite plate is demonstrated experimentally.Currently, there are two system architectures used in hybrid FBG measurement each with its own demodulation algorithm: power detection and edge filter detection demodulation . In the In the edge filter detection method, a TLS is used. The wavelength of the TLS is adjusted to the middle of the FBG peak where the maximum slope is located. When the strain signal shifts the FBG sensors’ wavelength (due to propagation of an ultrasonic wave), the reflected light intensity changes as well, as depicted in The hybrid system developed in this paper is based on the edge filter detection method to have a higher SNR.Interferometric sensors - There are four types of interferometric sensors  Once the focused point was determined, Lamb wave signals of different frequencies were actuated by the PZTs. In order to assess their strain sensitivity, i.e., amplitude of the recorded waves by the new FBG-based FP sensor, its response was compared with the similar signal recorded by FBG sensors, placed at the same distance as shown in The results in different frequency excitations showed that the amplitude of the FBG-based FP sensors in recording lower frequency waves, i.e., anti-symmetric modes was noticeably higher than the FBG recorded guided waves. This means that the SNR for anti-symmetric modes was higher, which results in higher sensitivity and reliability in damage detection. To analyse the reliability of the FBG-based FP sensors, their responses under varying environmental effects have been investigated in the next sub-section. This was followed by simulating artificial damage on the plate, by adding mass on the plate, and by examining the residual signal (damage effect).When the structure was monitored under varying environmental conditions, the noise  were different every time, which led to a difference in each measured waveform due to shifts in the optical intensity. According to the measurements, the environmental noise were within The solid line within To study the sensitivity of the FBG-based FP sensors in detecting damage, their response under artificial damage were recorded and compared to the FBG sensor signals . In this paper, for proof of concept, an artificial damage in the form of an additional mass was introduced onto the specimen. The added mass would change the propagation properties of the guided wave, which causes alterations to the signal in the form of refraction and reflection. Therefore, it could be used in the development stage as representative of damage in the composite plate. From the study on the pristine signals presented in It can be seen that the effect of damage was much more pronounced on the FBG-based FP recorded sensor signals due to higher SNR and amplitude. Some of the selected frequency responses are shown in In addition, to analyze the effect of a varying load on the reliability of the damage detection based on the recorded signals, the experiment was repeated by adding vibration (noise) as well as a random load to the structure. As the results in In this section, the results of the FBG-based FP hybrid system are further analyzed to detect damage in composite plates. In the previous sections, it was shown that the residual signal from the proposed hybrid SHM system has high sensitivity to small changes in strain, and can be used to identify the presence of damage in the structure reliably. In this section, a damage detection algorithm based on the residual signal is proposed to quantify the reliability of the proposed methodology.To detect damage based on the guided wave signals three different damage indices are examined in this paper.1. Normalized squared error between the signal and the baseline proposed by Michaels .(5)DI1=2. The correlation coefficient between the signal and the baseline , which c3. The maximum amplitude of the residual envelope .(7)DI3=All three damage indices have been applied to the FBG-based FP recorded signals for the range of measured frequencies and compared to the conventional hybrid setup with the FBG sensor.From the results presented in In this research, a novel FBG-based FP sensor was developed for an SHM system to monitor the integrity of composite structures and detect damage with high reliability under varying operational conditions. It was demonstrated that, by simulating the spectrum of the FBG-based FP sensors, a novel sensor with high sensitivity to small variations in strain can be designed and manufactured. The simulated FO spectrum was validated experimentally before the FBG-based FP sensor was integrated onto a composite panel for recording guided waves simulated by the PZT actuator. The FBG-based FP sensors demonstrated to have higher sensitivity to strain waves, i.e., higher intensity shift compared to traditional FBG sensors. In addition, under varying environmental conditions, such as varying noise level (vibration) and load in the structure, the pristine sensor signals recorded had high repeatability, which minimized the false alarm. This results in changes in the operational environment. When artificial damage was introduced in the structure, the FBG-based FP sensors residual showed to have higher amplitude was compared to the traditional FBG sensors for detecting guided waves. The lower frequency range such as 50 and 100 kHz were more reliable for detecting the added mass. This first experiment was a proof of concept, which showed the advantages of the novel FPG-FP sensor for SHM application in composite structures. The next step will be to test this new SHM system for detecting a barely visible impact damage (BVID) in a composite structure. Furthermore, the multiplexing capability of the sensor will be evaluated by developing more sensors on a single optic fiber with different central wavelengths. In addition, in the current set-up, only the FP cavity part in an FBG-based FP sensor is used for Lamb wave signal detection while the two FBG parts are not used for recording any response. The possibility of using them to measure the local temperature near the sensor to compensate the temperature effect on Lamb wave’s signal will be explored. Compared to FBG sensors, the spectrum shifting of each FBG-based FP sensor is within its own wavelength range. The multiplexing capability of the FBG-based FP sensors will also be evaluated in load monitoring and shape sensing.