The goal of this paper is to enhance a practical nominal characteristic trajectory following(NCTF) controller that is specifically designed for two-mass point-to-point positioning systems. A nominal characteristics tr...The goal of this paper is to enhance a practical nominal characteristic trajectory following(NCTF) controller that is specifically designed for two-mass point-to-point positioning systems. A nominal characteristics trajectory contained in the NCTF controller acts as movement/motion reference and a compensator is utilized to force the object to detect and follow the reference/desired trajectory. The object must follow and track closely and should be as fast as possible. The NCTF controller is designed with two different intelligent based compensator approaches which are fuzzy logic and extended minimal resource allocation network. The proposed controller which is NCTF are compared with the conventional proportional integral compensator. Then the results of simulation are discussed for the positioning performances. The inertia variations due to the effect of the design parameters are also assessed to see the robustness of controllers. The results show that the NCTF control method designed from an intelligent based compensator has a better positioning performance in terms of percentage of overshoot, settling time, and steady state error than the classical based compensator.展开更多
Objective: Influenza is a highly infectious viral disease, which occurs epidemically almost every winter in Japan. Rapid screening of patients with suspected influenza in places of mass gathering is important to delay...Objective: Influenza is a highly infectious viral disease, which occurs epidemically almost every winter in Japan. Rapid screening of patients with suspected influenza in places of mass gathering is important to delay or prevent transmission of the infection. The aim of this study was to assess the effectiveness of our newly developed infection screening system that employed vital signs and percutaneous oxygen saturation (SpO2) as parameters in a clinical setting. Methods: Since SpO2 accurately reflects respiratory status during influenza virus infection, we upgraded our previous system by adding SpO2 as a new parameter to improve the screening accuracy. This system instantly measures SpO2 and vital signs (i.e., heart rate, respiration rate, and facial temperature), which automatically detects infected individuals via a neural network-based nonlinear discriminant function using these derived parameters. We tested the system on 45 patients with seasonal influenza (35.8℃ < body temperature < 40.0℃, 18-35 years) and 64 normal control subjects (35.0℃ < body temperature < 37.5℃, 18-30 years) at Japan Self-Defense Central Hospital in 2012. Results: The system identified 40/45 patients with influenza and 60/64 normal control subjects, and provided sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of 88.8%, 93.8%, 90.9%, and 92.3%, respectively. By including SpO2 as a screening parameter, we achieved superior sensitivity and NPV compared to that reported in our previous paper (sensitivity = 88%;NPV = 82%). Conclusions: Our results suggest that SpO2 is a good screening parameter that improves the accuracy of infection screening. The proposed system has the potential to efficiently identify infected individuals, thereby delaying or preventing the spread of infection during epidemic seasons.展开更多
This paper deals with the application of data mining techniques to the conceptual design knowledge for a LV （launch vehicle） with a HRE （hybrid rocket engine）. This LV is a concept of the space transportation, whi...This paper deals with the application of data mining techniques to the conceptual design knowledge for a LV （launch vehicle） with a HRE （hybrid rocket engine）. This LV is a concept of the space transportation, which can deliver micro-satellite to the SSO （sun-synchronous orbit）. To design the higher performance LV with HRE, the optimum size of each component, such as an oxidizer tank containing liquid oxidizer, a combustion chamber containing solid fuel, a pressurizing tank and a nozzle, should be acquired. The Kriging based ANOVA （analysis of variance） and SOM （self-organizing map） are employed as data mining techniques for knowledge discovery. In this study, the paraffin （FT-0070） is used as a propellant of HRE. Then, the relationship among LV performances and design variables are investigated through the analysis and the visualization. To calculate the engine performance, the regression rate is computed based on an empirical expression. The design knowledge is extracted for the design knowledge of the multi-stage LV with HRE by analysis using ANOVA and SOM. As a result, the useful design knowledge on the present design problem is obtained to design HRE for space transportation.展开更多
Multimodal ultrasonic vibration(UV)assisted micro-forming has been widely investigated for its advantages of further reducing forming loads and improving forming quality.However,the influence mechanism of different UV...Multimodal ultrasonic vibration(UV)assisted micro-forming has been widely investigated for its advantages of further reducing forming loads and improving forming quality.However,the influence mechanism of different UV modes on microstructure evolution and mechanical properties was still unclear.Mul-timodal UV assisted micro-compression tests on T2 copper with different grains and sample sizes were conducted in this study.The microstructure evolution for different UV modes was observed by EBSD.The results showed that the true stress reduction caused by UV was increased sequentially with tool ultrasonic vibration(TV),mold ultrasonic vibration(MV)and compound ultrasonic vibration(CV).The region of grain deformation was shifted along the direction of UV,and the MV promoted the uniform distribution of deformation stress.The grain refinement,fiber streamline density,grain deformation and rotation degree were further enhanced under CV,due to the synergistic effect of TV and MV.Additionally,a coupled theoretical model considering both acoustic softening effect and size effect was proposed for describing the mechanical properties.And a physical model of dislocation motion in different UV modes was developed for describing the microstructure evolution.The maximum error between the theoretical and experimental results was only 2.39%.This study provides a theoretical basis for the optimization of UV assisted micro-forming process.展开更多
The effect of fluidity on open cell AZ31 metal foam samples fabricated using a solid state space holder method was investigated.Granule was fabricated by plaster powder and perlite powder.Granules were sieved which co...The effect of fluidity on open cell AZ31 metal foam samples fabricated using a solid state space holder method was investigated.Granule was fabricated by plaster powder and perlite powder.Granules were sieved which compacted layer by layer in casting mold.Preforms which made by granules were then heated to 200℃,300℃,400℃,500℃ under a rough(mechanical)vacuum before pressure infiltration with AZ31 Mg alloy.Samples were infiltrated using vacuum pressure values range of 8-14 KPa.The conditions of pressure and temperature were performed in order to get different fluidity on manufacturer of open cell AZ31 metal foam specimen quantity.It is found that the fluidity plays significant role to determine the open cell AZ31 alloy foam.The fluidity is affected by preheat temperature and infiltration vacuum pressure.The macrostructure,the distribution of the pores,microstructure,infiltration length,and porosity were investigated.展开更多
The accuracy of a flight simulation is highly dependent on the quality of the aerodynamic database and prediction accuracies of the aerodynamic coefficients and derivatives. A surrogate model is an approximation metho...The accuracy of a flight simulation is highly dependent on the quality of the aerodynamic database and prediction accuracies of the aerodynamic coefficients and derivatives. A surrogate model is an approximation method that is used to predict unknown functions based on the sampling data obtained by the design of experiments. This model can also be used to predict aerodynamic coefficients/derivatives using several measured points. The objective of this paper is to develop an efficient digital flight simulation by solving the equation of motion to predict the aerodynamics data using a surrogate model. Accordingly, there is a need to construct and investigate aerodynamic databases and compare the accuracy of the surrogate model with the exact solution, and hence solve the equation of motion for the flight simulation analysis. In this study, sample datas for models are acquired from the USAF Stability and Control DATCOM, and a database is constructed for two input variables （the angle of attack and Mach number）, along with two derivatives of the X-force axis and three derivatives for the Z-force axis and pitching moment. Furthermore, a comparison of the value predicted by the Kriging model and the exact solution shows that its flight analysis prediction ability makes it possible to use the surrogate model in future analyses.展开更多
Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simp...Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.展开更多
In the consistently evolving artificial intelligence(AI)and large language models(LLMs),many organizations adopt these technologies’capabilities to solve and assist core operations in many industries.In disaster area...In the consistently evolving artificial intelligence(AI)and large language models(LLMs),many organizations adopt these technologies’capabilities to solve and assist core operations in many industries.In disaster areas,well-known organizations in disaster management try to shift their focus to apply the potential capabilities of AI and LLM to support disaster management.As AI and LLM continue to develop,this research aims to perform a structured summarization process to identify their current trend that can assist the disaster management process using a systematic review approach.The study follows the guidelines of PRISMA to ensure transparency in the review results.The findings highlighted the outstanding benefits of AI and LLM and the introduction of integrated technologies to facilitate disaster management,which can eventually mitigate disaster impacts and casualties.The refined results also proposed the technologies’benefits in assisting the decision support process,creating a business continuity plan,and detecting early warnings.However,ethics and transparency remain the main concerns in fully implementing AI and LLM in disaster management operations.Moreover,the SWOT analysis,represented by the TOWS matrix,was also performed to identify core strategies based on internal and external factors for assisting the disaster management operations.展开更多
Previous findings,such as split-line of the articular cartilage surface and curving of sliced cartilage specimen,would suggest that residual stress is contained in articular cartilage.This study was performed to deter...Previous findings,such as split-line of the articular cartilage surface and curving of sliced cartilage specimen,would suggest that residual stress is contained in articular cartilage.This study was performed to determine the effect of collagen fibre-induced residual stress on the biphasic lubrication property of articular cartilage.A fibre-reinforced poroelastic model of articular cartilage was developed in Abaqus.In the model,residual stress was contained in the collagen fibre in the surface layer by applying 1-5%of tensile strain.Reciprocating friction analysis was performed between the model and a sphere at a friction speed of 1.0-10.0 mm/s.Results revealed that the coefficients of start-up and dynamic friction at second friction cycle were lower in residual stress model than in no-residual stress model,with the largest decreases observed at a friction speed of 1 mm/s.It was obse rved that re hydration was promoted in the bearing area in residual stress model.These results suggest that collagen-induced residual stress plays an important role in enhancing the biphasic lubrication property of articular cartilage.展开更多
Dome display is expected to be used as effective visualization environment for modeling and simulation due to the features of frameless and high immersive sensation.However,since the users in the dome display can see ...Dome display is expected to be used as effective visualization environment for modeling and simulation due to the features of frameless and high immersive sensation.However,since the users in the dome display can see the projected image in arbitrary direction freely,it is difficult to share information among the viewers.In this research,in order to solve such a problem,the effect of visual attention guidance in the dome environment due to the effect of camera work was examined.As a visualization system,DomePlayer that can express the effect of camera work based on the camera work description language was developed.From the result of evaluation experiments using this system,the constraint condition of the camera work in the dome environment was derived and the effect of visual attention guidance by the camera work was evaluated.展开更多
This study focuses on carbon emissions of the building sector in relation to local climate zone(LCZ)classification,concentrating on two major parts.First,we estimated carbon emissions in the building sector,which were...This study focuses on carbon emissions of the building sector in relation to local climate zone(LCZ)classification,concentrating on two major parts.First,we estimated carbon emissions in the building sector,which were cal-culated for weekdays and weekends real-time daily energy consumption patterns.The estimations were divided into direct(from petroleum products consumption)and indirect emissions(from electricity consumption).Sec-ond,we examined urban carbon emissions mapping in relation to LCZ.Bangkok Metropolitan Administration(BMA)was used as the case study and 2016 as the base year for examination.The results illustrate that indirect emissions in Bangkok can be up to ten times higher than direct emissions.The analysis indicates that LCZ,such as compact high-rise,large low-rise,light industry,and warehouse zones had a relatively higher carbon emission intensity than others.Additionally,we identified that the compact high-rise zone has the highest indirect emission intensity,while the light industry and warehouse zone have the greatest direct emission intensity.These results provide insights into the dynamics of carbon emission characteristics in the building sector and the methodology purported here can be used to support low carbon city planning and policymaking in Bangkok.展开更多
文摘The goal of this paper is to enhance a practical nominal characteristic trajectory following(NCTF) controller that is specifically designed for two-mass point-to-point positioning systems. A nominal characteristics trajectory contained in the NCTF controller acts as movement/motion reference and a compensator is utilized to force the object to detect and follow the reference/desired trajectory. The object must follow and track closely and should be as fast as possible. The NCTF controller is designed with two different intelligent based compensator approaches which are fuzzy logic and extended minimal resource allocation network. The proposed controller which is NCTF are compared with the conventional proportional integral compensator. Then the results of simulation are discussed for the positioning performances. The inertia variations due to the effect of the design parameters are also assessed to see the robustness of controllers. The results show that the NCTF control method designed from an intelligent based compensator has a better positioning performance in terms of percentage of overshoot, settling time, and steady state error than the classical based compensator.
文摘Objective: Influenza is a highly infectious viral disease, which occurs epidemically almost every winter in Japan. Rapid screening of patients with suspected influenza in places of mass gathering is important to delay or prevent transmission of the infection. The aim of this study was to assess the effectiveness of our newly developed infection screening system that employed vital signs and percutaneous oxygen saturation (SpO2) as parameters in a clinical setting. Methods: Since SpO2 accurately reflects respiratory status during influenza virus infection, we upgraded our previous system by adding SpO2 as a new parameter to improve the screening accuracy. This system instantly measures SpO2 and vital signs (i.e., heart rate, respiration rate, and facial temperature), which automatically detects infected individuals via a neural network-based nonlinear discriminant function using these derived parameters. We tested the system on 45 patients with seasonal influenza (35.8℃ < body temperature < 40.0℃, 18-35 years) and 64 normal control subjects (35.0℃ < body temperature < 37.5℃, 18-30 years) at Japan Self-Defense Central Hospital in 2012. Results: The system identified 40/45 patients with influenza and 60/64 normal control subjects, and provided sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of 88.8%, 93.8%, 90.9%, and 92.3%, respectively. By including SpO2 as a screening parameter, we achieved superior sensitivity and NPV compared to that reported in our previous paper (sensitivity = 88%;NPV = 82%). Conclusions: Our results suggest that SpO2 is a good screening parameter that improves the accuracy of infection screening. The proposed system has the potential to efficiently identify infected individuals, thereby delaying or preventing the spread of infection during epidemic seasons.
文摘This paper deals with the application of data mining techniques to the conceptual design knowledge for a LV （launch vehicle） with a HRE （hybrid rocket engine）. This LV is a concept of the space transportation, which can deliver micro-satellite to the SSO （sun-synchronous orbit）. To design the higher performance LV with HRE, the optimum size of each component, such as an oxidizer tank containing liquid oxidizer, a combustion chamber containing solid fuel, a pressurizing tank and a nozzle, should be acquired. The Kriging based ANOVA （analysis of variance） and SOM （self-organizing map） are employed as data mining techniques for knowledge discovery. In this study, the paraffin （FT-0070） is used as a propellant of HRE. Then, the relationship among LV performances and design variables are investigated through the analysis and the visualization. To calculate the engine performance, the regression rate is computed based on an empirical expression. The design knowledge is extracted for the design knowledge of the multi-stage LV with HRE by analysis using ANOVA and SOM. As a result, the useful design knowledge on the present design problem is obtained to design HRE for space transportation.
基金supported by the National Key Research and Development Program(No.2022YFB4602502)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515011991)+2 种基金the Key Research and Development Program Fund of Hubei Province(No.2022BAA057)the state Key Lab-oratory of Solidification Processing in NPU(No.SKLSP202325)the China Scholarship Council Visiting PhD Program(No.202306410136).
文摘Multimodal ultrasonic vibration(UV)assisted micro-forming has been widely investigated for its advantages of further reducing forming loads and improving forming quality.However,the influence mechanism of different UV modes on microstructure evolution and mechanical properties was still unclear.Mul-timodal UV assisted micro-compression tests on T2 copper with different grains and sample sizes were conducted in this study.The microstructure evolution for different UV modes was observed by EBSD.The results showed that the true stress reduction caused by UV was increased sequentially with tool ultrasonic vibration(TV),mold ultrasonic vibration(MV)and compound ultrasonic vibration(CV).The region of grain deformation was shifted along the direction of UV,and the MV promoted the uniform distribution of deformation stress.The grain refinement,fiber streamline density,grain deformation and rotation degree were further enhanced under CV,due to the synergistic effect of TV and MV.Additionally,a coupled theoretical model considering both acoustic softening effect and size effect was proposed for describing the mechanical properties.And a physical model of dislocation motion in different UV modes was developed for describing the microstructure evolution.The maximum error between the theoretical and experimental results was only 2.39%.This study provides a theoretical basis for the optimization of UV assisted micro-forming process.
文摘The effect of fluidity on open cell AZ31 metal foam samples fabricated using a solid state space holder method was investigated.Granule was fabricated by plaster powder and perlite powder.Granules were sieved which compacted layer by layer in casting mold.Preforms which made by granules were then heated to 200℃,300℃,400℃,500℃ under a rough(mechanical)vacuum before pressure infiltration with AZ31 Mg alloy.Samples were infiltrated using vacuum pressure values range of 8-14 KPa.The conditions of pressure and temperature were performed in order to get different fluidity on manufacturer of open cell AZ31 metal foam specimen quantity.It is found that the fluidity plays significant role to determine the open cell AZ31 alloy foam.The fluidity is affected by preheat temperature and infiltration vacuum pressure.The macrostructure,the distribution of the pores,microstructure,infiltration length,and porosity were investigated.
文摘The accuracy of a flight simulation is highly dependent on the quality of the aerodynamic database and prediction accuracies of the aerodynamic coefficients and derivatives. A surrogate model is an approximation method that is used to predict unknown functions based on the sampling data obtained by the design of experiments. This model can also be used to predict aerodynamic coefficients/derivatives using several measured points. The objective of this paper is to develop an efficient digital flight simulation by solving the equation of motion to predict the aerodynamics data using a surrogate model. Accordingly, there is a need to construct and investigate aerodynamic databases and compare the accuracy of the surrogate model with the exact solution, and hence solve the equation of motion for the flight simulation analysis. In this study, sample datas for models are acquired from the USAF Stability and Control DATCOM, and a database is constructed for two input variables （the angle of attack and Mach number）, along with two derivatives of the X-force axis and three derivatives for the Z-force axis and pitching moment. Furthermore, a comparison of the value predicted by the Kriging model and the exact solution shows that its flight analysis prediction ability makes it possible to use the surrogate model in future analyses.
文摘Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.
基金funded by Thailand Science Research and Innovation Fund Chulalongkorn University[DIS_FF_68_256_2100_034]and supported by the Second Century Fund(C2F),Chulalongkorn University.
文摘In the consistently evolving artificial intelligence(AI)and large language models(LLMs),many organizations adopt these technologies’capabilities to solve and assist core operations in many industries.In disaster areas,well-known organizations in disaster management try to shift their focus to apply the potential capabilities of AI and LLM to support disaster management.As AI and LLM continue to develop,this research aims to perform a structured summarization process to identify their current trend that can assist the disaster management process using a systematic review approach.The study follows the guidelines of PRISMA to ensure transparency in the review results.The findings highlighted the outstanding benefits of AI and LLM and the introduction of integrated technologies to facilitate disaster management,which can eventually mitigate disaster impacts and casualties.The refined results also proposed the technologies’benefits in assisting the decision support process,creating a business continuity plan,and detecting early warnings.However,ethics and transparency remain the main concerns in fully implementing AI and LLM in disaster management operations.Moreover,the SWOT analysis,represented by the TOWS matrix,was also performed to identify core strategies based on internal and external factors for assisting the disaster management operations.
基金JSPS KAK ENHI grant numbers JP16H03172 and JP16K18002.
文摘Previous findings,such as split-line of the articular cartilage surface and curving of sliced cartilage specimen,would suggest that residual stress is contained in articular cartilage.This study was performed to determine the effect of collagen fibre-induced residual stress on the biphasic lubrication property of articular cartilage.A fibre-reinforced poroelastic model of articular cartilage was developed in Abaqus.In the model,residual stress was contained in the collagen fibre in the surface layer by applying 1-5%of tensile strain.Reciprocating friction analysis was performed between the model and a sphere at a friction speed of 1.0-10.0 mm/s.Results revealed that the coefficients of start-up and dynamic friction at second friction cycle were lower in residual stress model than in no-residual stress model,with the largest decreases observed at a friction speed of 1 mm/s.It was obse rved that re hydration was promoted in the bearing area in residual stress model.These results suggest that collagen-induced residual stress plays an important role in enhancing the biphasic lubrication property of articular cartilage.
基金Grant No.25540171 Grant-in-Aid for Scientific Research.
文摘Dome display is expected to be used as effective visualization environment for modeling and simulation due to the features of frameless and high immersive sensation.However,since the users in the dome display can see the projected image in arbitrary direction freely,it is difficult to share information among the viewers.In this research,in order to solve such a problem,the effect of visual attention guidance in the dome environment due to the effect of camera work was examined.As a visualization system,DomePlayer that can express the effect of camera work based on the camera work description language was developed.From the result of evaluation experiments using this system,the constraint condition of the camera work in the dome environment was derived and the effect of visual attention guidance by the camera work was evaluated.
基金supported by the faculty of architecture,Khon Kaen University.
文摘This study focuses on carbon emissions of the building sector in relation to local climate zone(LCZ)classification,concentrating on two major parts.First,we estimated carbon emissions in the building sector,which were cal-culated for weekdays and weekends real-time daily energy consumption patterns.The estimations were divided into direct(from petroleum products consumption)and indirect emissions(from electricity consumption).Sec-ond,we examined urban carbon emissions mapping in relation to LCZ.Bangkok Metropolitan Administration(BMA)was used as the case study and 2016 as the base year for examination.The results illustrate that indirect emissions in Bangkok can be up to ten times higher than direct emissions.The analysis indicates that LCZ,such as compact high-rise,large low-rise,light industry,and warehouse zones had a relatively higher carbon emission intensity than others.Additionally,we identified that the compact high-rise zone has the highest indirect emission intensity,while the light industry and warehouse zone have the greatest direct emission intensity.These results provide insights into the dynamics of carbon emission characteristics in the building sector and the methodology purported here can be used to support low carbon city planning and policymaking in Bangkok.
