WorldWideScience

Sample records for model racing car

  1. Aerodynamics of Race Cars

    Science.gov (United States)

    Katz, Joseph

    2006-01-01

    Race car performance depends on elements such as the engine, tires, suspension, road, aerodynamics, and of course the driver. In recent years, however, vehicle aerodynamics gained increased attention, mainly due to the utilization of the negative lift (downforce) principle, yielding several important performance improvements. This review briefly explains the significance of the aerodynamic downforce and how it improves race car performance. After this short introduction various methods to generate downforce such as inverted wings, diffusers, and vortex generators are discussed. Due to the complex geometry of these vehicles, the aerodynamic interaction between the various body components is significant, resulting in vortex flows and lifting surface shapes unlike traditional airplane wings. Typical design tools such as wind tunnel testing, computational fluid dynamics, and track testing, and their relevance to race car development, are discussed as well. In spite of the tremendous progress of these design tools (due to better instrumentation, communication, and computational power), the fluid dynamic phenomenon is still highly nonlinear, and predicting the effect of a particular modification is not always trouble free. Several examples covering a wide range of vehicle shapes (e.g., from stock cars to open-wheel race cars) are presented to demonstrate this nonlinear nature of the flow field.

  2. Simulation Study of FSC Racing Car Modeling and Handling Stability Based on CarSim%基于CarSim的FSC赛车建模与操纵稳定性仿真研究

    Institute of Scientific and Technical Information of China (English)

    贾丽娟; 韩忠浩; 李刚; 冯莉原; 张杨; 王运辉

    2015-01-01

    针对FSC赛车开发过程中的操纵稳定性分析,论文基于车辆系统动力学仿真软件CarSim进行建模与仿真研究。应用CarSim建立了包含车体、轮胎、转向系统、悬架系统、制动系统及传动系统的FSC赛车整车动力学模型,并应用3D软件绘制三维车身、尾翼和发动机模型导入到CarSim中实现整车动画仿真。在CarSim中按照比赛要求设置方向盘角阶跃输入转向瞬态响应试验工况和蛇形试验工况进行 FSC 赛车操纵稳定性仿真分析。仿真结果表明:开发的FSC赛车具有良好的操纵稳定性。%For the analysis of handling stability, modeling and simulation of FSC racing car based on dynamics simulation software CarSim were studied. FSC racing vehicle dynamics model was established by CarSim, which includes body, tires, steering systems, suspension systems, brake systems and driveline. The three-dimensional body, tail and engine models were built by 3D software and import to CarSim for animated simulation. The steering step input transient response test and snake test were set in the CarSim according to the racing requirements. The simulation results show that the developed FSC racing car has good handling stability.

  3. The 2009 Simulated Car Racing Championship

    DEFF Research Database (Denmark)

    Loiacono, Daniele; Lanzi, Pier Luca; Togelius, Julian

    2011-01-01

    In this paper, we overview the 2009 Simulated Car Racing Championship-an event comprising three competitions held in association with the 2009 IEEE Congress on Evolutionary Computation (CEC), the 2009 ACM Genetic and Evolutionary Computation Conference (GECCO), and the 2009 IEEE Symposium....... The organizers provide short summaries of the other competitors. Finally, we summarize the championship results, followed by a discussion about what the organizers learned about 1) the development of high-performing car racing controllers and 2) the organization of scientific competitions....

  4. Modeling and handling stability simulation of a FSAE racing car based on ADAMS%基于ADAMS的FSAE赛车建模与操纵稳定性仿真

    Institute of Scientific and Technical Information of China (English)

    倪俊; 徐彬

    2011-01-01

    为建立某FSAE赛车的虚拟样机模型及评价其操纵稳定性,采用机械系统动力学分析软件ADAMS中的ADAMS/CAR模块,建立了某中国大学生方程式(FSAE)赛车模型,并介绍了建模的过程及要点.建立了比赛赛道的模型,利用ADAMS/CHASSIS得到赛车在此赛道上的最佳行驶路径.利用Smart driver模块仿真得到赛车模型在此赛道的极限行驶性能.通过与比赛实际成绩的比较,验证了虚拟样机模型的准确性,为方程式赛车的设计及优化提供了有力依据.在此基础上进行了操纵稳定性的仿真试验,结果表明,赛车具有明显的不足转向趋势,符合设计要求.%In order to establish the virtual prototyping model of a certain FSAE racing car and to assess its handling stability, the model of a certain Formula SAE racing car was established by applying the ADAMS/CAR module of mechanical system simulation software ADAMS. The main points and process of the modeling were introduced. The model of the race track was built and the best path of racing car in the track was obtained by ADAMS/CHASSIS. The extreme driving performance of the racing car in the track was calculated through Smart driver module simulation. By comparison to the actual results of competition, the correctness of the virtual prototyping model is verified, which provides a strong basis for the design and optimization of Formula SAE racing car. Based on the above results, the handling stability test of virtual prototype was performed. The research results show that the understeer tendency of the racing car is obvious, which achieves the design goal.

  5. 赛车前悬架和转向系统ADAMS/CAR建模及仿真%Modeling and Simulation of a FSAE Racing Car's Front Suspension and Steering Based on ADAMS/CAR

    Institute of Scientific and Technical Information of China (English)

    向铁明; 沈理真

    2012-01-01

    A FSAE racing car's model of double wishbone independent front suspension and steering system was built in ADAMS/CAR.The kinematics simulation was done by using parallel wheel travel analysis.The simulations was done again after the ball hinge of the lower control arm moved up and down respectively.The influences of front wheels alignment parameters were obvious when the position of the ball hinge of the lower control arm charged.%借助ADAMS/CAR,对某FSAE赛车双横臂独立前悬架和转向系统建立多体动力学模型,并对其进行前轮同向跳动仿真,对下控制臂球头铰上移和下移后再次仿真.仿真结果表明,下控制臂球头铰位置的变化对前轮定位参数影响显著.

  6. Forze hydrogen racing team Delft; TU Delft students develop hydrogen race-car

    NARCIS (Netherlands)

    Hartvelt, M.

    2014-01-01

    ‘Working towards a sustainable, yet exciting future’ is one of the big challenges in engineering nowadays. A group of students from the TU Delft accepted this challenge and designed a zero-emission hydrogen powered race-car. Combining green technology with racing, Forze wants to show the potential

  7. Business Class in a race car

    NARCIS (Netherlands)

    Wassink, J.

    2008-01-01

    It's not a car, it's not a bus, it's not a truck, and it's not even a super stretch limousine. What is being built in Delft is the much-discussed Superbus, which is to travel from door to door, reaching speeds of 250 kilometres per hour. This summer this new form of public transport is to enter serv

  8. Application of CAD/CAE class systems to aerodynamic analysis of electric race cars

    Science.gov (United States)

    Grabowski, L.; Baier, A.; Buchacz, A.; Majzner, M.; Sobek, M.

    2015-11-01

    Aerodynamics is one of the most important factors which influence on every aspect of a design of a car and car driving parameters. The biggest influence aerodynamics has on design of a shape of a race car body, especially when the main objective of the race is the longest distance driven in period of time, which can not be achieved without low energy consumption and low drag of a car. Designing shape of the vehicle body that must generate the lowest possible drag force, without compromising the other parameters of the drive. In the article entitled „Application of CAD/CAE class systems to aerodynamic analysis of electric race cars” are being presented problems solved by computer analysis of cars aerodynamics and free form modelling. Analysis have been subjected to existing race car of a Silesian Greenpower Race Team. On a basis of results of analysis of existence of Kammback aerodynamic effect innovative car body were modeled. Afterwards aerodynamic analysis were performed to verify existence of aerodynamic effect for innovative shape and to recognize aerodynamics parameters of the shape. Analysis results in the values of coefficients and aerodynamic drag forces. The resulting drag forces Fx, drag coefficients Cx(Cd) and aerodynamic factors Cx*A allowed to compare all of the shapes to each other. Pressure distribution, air velocities and streams courses were useful in determining aerodynamic features of analyzed shape. For aerodynamic tests was used Ansys Fluent CFD software. In a paper the ways of surface modeling with usage of Realize Shape module and classic surface modeling were presented. For shapes modeling Siemens NX 9.0 software was used. Obtained results were used to estimation of existing shapes and to make appropriate conclusions.

  9. Forze hydrogen racing team Delft; TU Delft students develop hydrogen race-car

    OpenAIRE

    Hartvelt, M.

    2014-01-01

    ‘Working towards a sustainable, yet exciting future’ is one of the big challenges in engineering nowadays. A group of students from the TU Delft accepted this challenge and designed a zero-emission hydrogen powered race-car. Combining green technology with racing, Forze wants to show the potential of hydrogen as an alternative fuel. Find out how Forze has been developing hydrogen powered racecars since 2007.

  10. Running performance of racing solar car; Kyogiyo solar car no soko seino

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H. [Osaka Sangyo Univ., Osaka (Japan); Ando, Y.

    1997-11-25

    The paper reported on `96 World Solar Challenge which is a solar car race traveling a total of 3010km from Darwin to Adelaide of the Australian continent. We accomplished running with general cars on general roads at mean speed of 60.3km/h for 6 days. To reduce vehicle weight, the monocock structure honeycombed with carbon fiber and aramid was adopted to the whole vehicle, and a light alloy to driving system parts. To reduce air resistance, adopted were reduction in the front projection area and the smooth body form. The required power is 44.8 kWh, and the power consumption ratio during travel is very high, approximately 67 km/kWh. In the travel of solar car in the unstable weather, dependence upon battery becomes higher, and therefore the battery capacity of 3.5 kWh with which the car was loaded is small, which resulted in affecting the race totally. To predict the travel in the race and determine the travel method, needed are collection and management of realtime and accurate travel data. The measuring management system developed this time together with the vehicle was applicable to the actual race and high in practicality. 2 refs., 7 figs., 1 tab.

  11. Design and Implementation of Navigation Algorithm for Intelligent Racing Car

    Directory of Open Access Journals (Sweden)

    Praween Sinha

    2011-02-01

    Full Text Available Design and implementation of navigation algorithm for intelligent racing car. The paper describes the implementation of intelligent racing car that can recognize the track automatically to run onthe specifically designed complex racing track. The objective is to recognize and and modify the actual performance of the movements of the car during its pathway by getting information in real time from IRsensors in the system. The travel trajectory consists of continuous black line of about 25 millimeters in width, on a white background in order to have acceptable functioning. Analyzing of the sensor readingswas done during the travel, capturing data at the fixed sampling rate and this data was used as inputs to the newly developed algorithm to achieve corrections on the decision speed and control movements. Amicrocontroller assigns the required movement turn and speeds to optimize the performance in order to get a closer behavior as humans could do it without a vision system to catch its environment. The task of this work was to develop an efficient navigation algorithm and it has been successfully implemented in a Motorola S12X 16-bit microcontroller.

  12. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    Science.gov (United States)

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  13. Stand for testing the electrical race car engine

    Science.gov (United States)

    Baier, M.; Franiasz, J.; Mierzwa, P.; Wylenzek, D.

    2015-11-01

    An engine test stand created especially for research of electrical race car is described in the paper. The car is an aim of Silesian Greenpower project whose participants build and test electrical vehicles to take part in international races in Great Britain. The engine test stand is used to test and measure the characteristics of vehicles and their engines. It has been designed particularly to test the electric cars engineered by students of Silesian Greenpower project. The article contains a description how the test stand works and shows its versatility in many areas. The paper presents both construction of the test stand, control system and sample results of conducted research. The engine test stand was designed and modified using PLM Siemens NX 8.5. The construction of the test stand is highly modular, which means it can be used both for testing the vehicle itself or for tests without the vehicle. The test stand has its own wheel, motor, powertrain and braking system with second engine. Such solution enables verifying various concepts without changing the construction of the vehicle. The control system and measurement system are realized by enabling National Instruments product myRIO (RIO - Reconfigurable Input/Output). This controller in combination with powerful LabVIEW environment performs as an advanced tool to control torque and speed simultaneously. It is crucial as far as the test stand is equipped in two motors - the one being tested and the braking one. The feedback loop is realized by an optical encoder cooperating with the rotor mounted on the wheel. The results of tests are shown live on the screen both as a chart and as single values. After performing several tests there is a report generated. The engine test stand is widely used during process of the Silesian Greenpower vehicle design. Its versatility enables powertrain testing, wheels and tires tests, thermal analysis and more.

  14. Aoyama Gakuin University team winning the second prize in junior class in a solar car race; Aogaku team wa junior nii (solar car race ni sankashite)

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y. [Aoyama Gakuin University, Tokyo (Japan)

    1994-09-20

    This paper introduces how the Aoyama Gakuin University team competed in the World Solar Car Rally race held at Ogata Village in Akita Prefecture, Japan, in the summer of 1994. The race was formed with solar cars mounting a solar panel with the maximum area of 8 m{sup 2} and batteries with a total output of 3 kWh to compete how many rounds the cars can run around a course of 31 km during three days (25 hours in total). The solar car used by the University team had consumed power of about 600 W at a speed of 40 km/h, with the solar panel generating power of 800 Wp. The first day morning was sunny making possible to set the average speed to 45 km/h (power generation of 500 W or more), but the weather worsened in the afternoon compelling the car to change the speed to 30 km/h (power generation of 200 W). The power generated on the second day, which was cloudy all day, stayed at 250 W at the maximum, hence the speed was kept at 30 km/h to suppress the power consumption. On the sunny third day, the team drove the car worrying about the remaining battery capacity, and succeeded the drive of 23 rounds in total, winning the second prize among 30 cars participated in the junior class race.

  15. Dynamics control of autonomous vehicle at driving limits and experiment on an autonomous formula racing car

    Science.gov (United States)

    Ni, Jun; Hu, Jibin

    2017-06-01

    In this paper, a novel dynamics controller for autonomous vehicle to simultaneously control it to the driving limits and follow the desired path is proposed. The dynamics controller consists of longitudinal and lateral controllers. In longitudinal controller, the G-G diagram is utilized to describe the driving and handling limits of the vehicle. The accurate G-G diagram is obtained based on phase plane approach and a nonlinear vehicle dynamic model with accurate tyre model. In lateral controller, the tyre cornering stiffness is estimated to improve the robustness of the controller. The stability analysis of the closed-looped error dynamics shows that the controller remains stable against parameters uncertainties in extreme condition such as tyre saturation. Finally, an electric autonomous Formula race car developed by the authors is used to validate the proposed controller. The autonomous driving experiment on an oval race track shows the efficiency and robustness of the proposed controller.

  16. Modeling the Mousetrap Car

    Science.gov (United States)

    Jumper, William D.

    2012-01-01

    Many high school and introductory college physics courses make use of mousetrap car projects and competitions as a way of providing an engaging hands-on learning experience incorporating Newton's laws, conversion of potential to kinetic energy, dissipative forces, and rotational mechanics. Presented here is a simple analytical and finite element…

  17. Development of a Car Racing Simulator Game Using Artificial Intelligence Techniques

    Directory of Open Access Journals (Sweden)

    Marvin T. Chan

    2015-01-01

    Full Text Available This paper presents a car racing simulator game called Racer, in which the human player races a car against three game-controlled cars in a three-dimensional environment. The objective of the game is not to defeat the human player, but to provide the player with a challenging and enjoyable experience. To ensure that this objective can be accomplished, the game incorporates artificial intelligence (AI techniques, which enable the cars to be controlled in a manner that mimics natural driving. The paper provides a brief history of AI techniques in games, presents the use of AI techniques in contemporary video games, and discusses the AI techniques that were implemented in the development of Racer. A comparison of the AI techniques implemented in the Unity platform with traditional AI search techniques is also included in the discussion.

  18. Design of Mechanically Actuated Aerodynamic Braking System on a Formula Student Race Car

    Science.gov (United States)

    Muralidharan, Vivek; Balakrishnan, Abhijith; Vardhan, Vinit Ketan; Meena, Nikita; Kumar, Y. Suresh

    2017-05-01

    Every second in a racing competition counts the performance of a team against the other. Many innovative and sophisticated techniques are being employed to overcome loses in time and add to the performance of the vehicle. Especially in a car racing challenge there is more freedom to install these innovative systems to empower the car to maximum efficiency due to availability of more space. At the global spectrum there are few events which encourage such innovations. Formula Student Racing competitions are one of the global events organized by the Society of Automotive Engineers of different countries which gives opportunity to university students to build and race formula style cars. Like any other racing competitions in this high octane event having an inch over their opponents is always an advantage. Not just better acceleration and high velocities but also good deceleration is required to excel in the competition. Aerodynamic braking system is utilizing the aerodynamic drag force to create high deceleration. This mechanism can be installed on any car with spoilers with minimum modification. Being a student event great amount of care needs to be given to the safety concerns of the driver.

  19. AERODYNAMIC IMPROVEMENT OF KhADI 33 RACING CAR RADIATOR COMPARTMENT

    Directory of Open Access Journals (Sweden)

    A. Avershyn

    2011-01-01

    Full Text Available Aerodynamic characteristics of radiator compartment of KhADI 33 racing car on the basis of the decision of the interfaced problem of internal and external aerodynamics are numerically investigated. The rational variant of radiator compartment which is characterized by high throughput and low level of non-uniformity of speed field at the input is offered.

  20. Implementation of object-oriented programming in study of electrical race car

    Science.gov (United States)

    Nowak, M.; Baier, M.

    2016-08-01

    The paper covers issue of conducting advanced research of electrical race car participating in international competition called Sileverline Corporate Challenge. Process of designing race cars in Silesian Greenpower team is aided by a professional engine test stand built particularly in purpose of this research. Phase of testing and simulation is an important part of the implementation of new technologies. Properly developed solutions and test procedures are able to significantly shorten development time and reduce design costs. Testing process must be controlled by a modular and flexible application, easy to modify and ensuring safety. This paper describes the concept of object-oriented programming in LabVIEW and exemplary architecture of object-oriented control application designed to control engine test stand of the electrical race car. Eventually, the task of application will be to steer the electromagnetic brake and the engine load torque to perform according to data from the actual race track. During the designing process of the car, minimizing energy losses and maximizing powertrain efficiency are the main aspects taken into consideration. One of the crucial issues to accomplish these goals is to maintain optimal performance of the motor by applying effective cooling. The paper covers the research verifying the effectiveness of the cooling system.

  1. MICRO ENGINE START PERFORMANCE RESEARCH FOR RACING CAR

    Directory of Open Access Journals (Sweden)

    O. Vrublevskiy

    2015-07-01

    Full Text Available A methodology of modernization of the single-cylinder engine start by replacing the standard system by an electric starter is presented. Based on the calculated and experimental studies there have been provided the start-up characteristics of a single-cylinder engine. The measures to reduce the start-up time of the engine during the race in the Shell – EcoMarathon are offered.

  2. Collision Detection and Overtaking Using Artificial Potential Fields in Car Racing game TORCS using Multi-Agent based Architecture

    OpenAIRE

    Salman, Muhammad

    2013-01-01

    The Car Racing competition platform is used for evaluating different car control solutions under competitive conditions [1]. These competitions are organized as part of the IEEE Congress on Evolutionary Computation (CEC) and Computational Intelligence and Games Sym-posium (CIG). The goal is to learn and develop a controller for a car in the TORCS open source racing game [2]. Oussama Khatib [3] (1986) introduced Artificial potential fields (APFs) for the first time while looking for new ways t...

  3. The science of vehicle dynamics handling, braking, and ride of road and race cars

    CERN Document Server

    Guiggiani, Massimo

    2014-01-01

    Vehicle dynamics is often perceived as a quite intuitive subject. As a matter of fact, lots of people are able to drive a car. Nevertheless, without a rigorous mathematical formulation it is very difficult to truly understand the physical phenomena involved in the motion of a road vehicle. In this book, mathematical models of vehicles are developed, always paying attention to state the relevant assumptions and to provide explanations for each step. This approach allows for a deep, yet simple, analysis of the dynamics of vehicles, without having to resort to foggy concepts. The reader will soon achieve a clear understanding of the subject, which will be of great help both in dealing with the challenges of designing and testing new vehicles and in tackling new research topics. The book covers handling and performance of both road and race cars. A new approach, called MAP (Map of Achievable Performance), is presented and thoroughly discussed. It provides a global and intuitive picture of the handling features of...

  4. Bayesian calibration of car-following models

    NARCIS (Netherlands)

    Van Hinsbergen, C.P.IJ.; Van Lint, H.W.C.; Hoogendoorn, S.P.; Van Zuylen, H.J.

    2010-01-01

    Recent research has revealed that there exist large inter-driver differences in car-following behavior such that different car-following models may apply to different drivers. This study applies Bayesian techniques to the calibration of car-following models, where prior distributions on each model p

  5. Monte-Carlo Tree Search for Simulated Car Racing

    DEFF Research Database (Denmark)

    Fischer, Jacob; Falsted, Nikolaj; Vielwerth, Mathias

    2015-01-01

    Monte Carlo Tree Search (MCTS) has recently seen considerable success in playing certain types of games, most of which are discrete, fully observable zero-sum games. Consequently there is currently considerable interest within the research community in investigating what other games this algorithm...... of the action space. This combination allows the controller to effectively search the tree of potential future states. Results show that it is indeed possible to implement a competent MCTS-based racing controller. The controller generalizes to most road tracks as long as a warm-up period is provided....

  6. Monte-Carlo Tree Search for Simulated Car Racing

    DEFF Research Database (Denmark)

    Fischer, Jacob; Falsted, Nikolaj; Vielwerth, Mathias

    2015-01-01

    Monte Carlo Tree Search (MCTS) has recently seen considerable success in playing certain types of games, most of which are discrete, fully observable zero-sum games. Consequently there is currently considerable interest within the research community in investigating what other games this algorithm...... of the action space. This combination allows the controller to effectively search the tree of potential future states. Results show that it is indeed possible to implement a competent MCTS-based racing controller. The controller generalizes to most road tracks as long as a warm-up period is provided....

  7. Training for the 1st international nano-car race: the Dresden molecule-vehicle

    Science.gov (United States)

    Eisenhut, Frank; Durand, Corentin; Moresco, Francesca; Launay, Jean-Pierre; Joachim, Christian

    2016-10-01

    The first international nano-car race will be held in Toulouse, France in spring 2017, with the participation of six international teams. The training session of the Dresden Team is reported using the Toulouse LT-UHV 4-STM reconfigured with four independent controllers in preparation for the race. During the training, the total Au(1 1 1) surface was prepared over the full gold substrate and a 90 nm long race track with two turns was defined according to the new nano-car race rules. The Dresden windmill molecule-vehicle was deposited in ultrahigh vacuum conditions, imaged, and manipulated by any one of the four tips on race tracks to reach a 5 nm per hour driving speed including the STM image time after a given driving bias voltage pulse. During the manipulation with one of the tips, it was possible to image with another tip in parallel. Strategies for a safe and fast driving was established by the Dresden team along the fcc rafter of the Au(1 1 1) surface together with the possibility to repair on the spot the destroyed molecule for example during the negotiation of a turn. Other teams will beneficiate from this experience to also improve their driving strategy.

  8. Project based, Collaborative, Algorithmic Robotics for High School Students: Programming Self Driving Race Cars at MIT

    Science.gov (United States)

    2017-02-19

    program is an excellent example of the utilization of state-of-the-art robotics equipment. It has also emphasized collaboration and teamwork since...Project-based, Collaborative , Algorithmic Robotics for High School Students: Programming Self-driving Race Cars at MIT Sertac Karaman...implemented in a collaborative fashion: the students learn the basics of collaboration and technical communication in lectures, and they work in teams to

  9. Design and fabrication of intake manifold for formula SAE (Society of Automotive Engineers) race car

    Science.gov (United States)

    Dore, Sylvie; Lavallee, Patrice

    1997-01-01

    Every year, a group of students from Ecole de technologie superieure (ETS) in Montreal design and build a formula-type race car and compete in the Formula SAE competition. In this paper, we examine the design and fabrication of the ir intake system, A number of constraints challenge the designers. For example, to ensure the security of amateur drivers, motors are restrained to 600 cc and a circular restriction of 20 mm in diameter is placed at the entry of the system. Under these conditions, it is important to optimize the quality of the air/fuel mixture which depends mostly on the air intake system. A theoretical analysis reduced the field of possible runner length. However, the influence of runner configuration, plenum shape and size can only be determined experimentally. Polyacrylic functional prototypes were produced and tested on a dynamometric bench. A stereolithography model representing the inner passageways of the optimal intake manifold was built and used as a positive for a polyurethane mold. A composite lamination process was used to laminate the pre-production prototype over a molded wax plug. The major advantage of this approach over craftsmanship or even machining is the time saved to make the mold and the unlimited complexity of the shape permitted by the rapid prototyping systems.

  10. Using the centre of percussion to design a steering controller for an autonomous race car

    Science.gov (United States)

    Kritayakirana, Krisada; Gerdes, J. Christian

    2012-01-01

    Understanding how a race car driver controls a vehicle at its friction limits can provide insights into the development of vehicle safety systems. In this paper, a race car driver's behaviour inspires the design of an autonomous racing controller. The resulting controller uses the vehicle's centre of percussion (COP) to design feedforward and feedback steering. At the COP, the effects of rotation and translation from the rear tire force cancel each other out; consequently, the feedforward steering command is robust to the disturbances from the rear tire force. Using the COP also simplifies the equations of motion, as the vehicle's lateral motion is decoupled from the vehicle's yaw motion and highlights the challenge of controlling a vehicle when the rear tires are highly saturated. The resulting dynamics can be controlled with a linear state feedback based on a lane-keeping system with additional yaw damping. Utilising Lyapunov theory, the closed-loop system is shown to remain stable even when the rear tires are highly saturated. The experimental results demonstrate that an autonomous vehicle can operate at its limits while maintaining a minimal lateral error.

  11. Electromobility concept for racing cars based on lithium-ion batteries and supercapacitors

    Science.gov (United States)

    Frenzel, B.; Kurzweil, P.; Rönnebeck, H.

    For the construction of an all-electric race car, all aspects from engineering design over cost estimation up to the road capability are illuminated. From the most promising batteries for electric vehicle propulsion, the state-of-the art and commercial availability of lithium-ion secondary batteries is critically discussed with respect to cycle-life and unfavorable charge-discharge conditions. A market-overview is given with respect to a small electric car. Different combinations of electric motors and a recuperation system have been investigated. Weight aspects of central drive systems were considered and compared with decentralized wheel-hub drives. As a result, a centralized high-speed drive train based on a permanent-magnet synchronous engine with high-energy magnets seems to be superior due to limited space for assembly.

  12. Car-following models of vehicular traffic

    Institute of Scientific and Technical Information of China (English)

    翁彦琳; 吴铁军

    2002-01-01

    The Car-following model is a kind of microscopic simulation model for vehicular traffic, which describe the one-by-one following behaviors of vehides in the same traffic lane. As a common traffic phenomenon, following behavior is of great importance in the micro-study of intelligent traffic control.Compared with other traffic-flow models, car-following model embodies the human factors and feflects the real traffic sit-uation in a better way. This paper gives a systematic review of the development and actuality of car-following models by introducing and analyzing in detail the advantages and disavantages of GHR model, OV model,CA model and fuzzy-logic model. In addition, local stability and asymptotic stability of car-following models are discussed in this paper.

  13. Car-following models of vehicular traffic

    Institute of Scientific and Technical Information of China (English)

    翁彦琳; 吴铁军

    2002-01-01

    The Car-following models is a kind of microscopic simulation model f or vehicular traffic, which describe the one-by-one following behaviors of v ehicles in the same traffic lane. As a common traffic phenomenon, following behavior is of great importance in the micro-study of intelligent traffic control. Compared with other traffic-flow models, car-following model embodies the human factors a nd reflects the real traffic situation in a better way. This paper gives a syste matic review of the development and actuality of car-following models by introd u cing and analyzing in detail the advantages and disadvantages of GHR model, OV m odel, CA model and fuzzy-logic model. In addition, local stability and asymptot ic stability of car-following models are discussed in this paper.

  14. Suspension Structure Optimization Oriented to Crosswind Stability of FSAE Racing Car%面向FSAE赛车侧风稳定性的悬架结构优化

    Institute of Scientific and Technical Information of China (English)

    徐彬; 倪俊; 朱丽君

    2012-01-01

    为研究FSAE赛车侧风稳定性,依据多刚体动力学理论,利用ADAMS软件建立了某FSAE赛车模型及比赛赛道模型.通过与2010年中国方程式汽车大赛(FSAE)中车载信息系统所采集数据的对比,验证了虚拟样机模型的准确性.在此基础上,对典型侧风进行了模拟,利用虚拟试验分析了赛车的侧风稳定性.通过对侧风作用下的三自由度赛车模型的分析,利用ADAMS/Insight模块得到了悬架主要结构参数对侧风稳定性影响的灵敏度,并进行优化.优化结果表明,赛车的侧风稳定性得到了提高.%In order to improve the crosswind stability of formula-SAE racing car, based on multi-body dynamics theory, models of a certain FSAE racing car and race track were established with the aid of software ADAMS. By comparing the model's structure and parameters with the data collected by vehicle data logger in 2010 China FSAE competition, the correctness of the virtual prototyping model was verified. Then, the typical crosswind was simulated and the crosswind stability of racing car was analyzed through virtual test. The sensitivity of suspension main structure parameters oriented to crosswind stability was obtained and optimized by ADAMS/ Insight module. The optimization results show that the crosswind stability of the racing car could be improved to some extent.

  15. Optimization of a FSAE Racing Car's Front Suspension Based on ADAMS%基于ADAMS的FSAE赛车前悬架优化设计

    Institute of Scientific and Technical Information of China (English)

    王行; 阳林; 彭仁杰; 冯勇

    2013-01-01

    In order to study the handling and stability of Formula SAE racing car better , based on the College Students'Formula SAE racing competition ( Formula SAE racing car ) of a university , it estab-lished the simulation model for the front double wishbone independent suspension system by using the me -chanical system simulation software ADAMS , obtained the variation curve of kingpin inclination angle , caster, camber and toe-in four parameters by simulating and analyzing the wheels'jumping, analyzed the influence of each parameter changes on the handling and stability of Formula SAE racing car , and used In-sight module in ADAMS for the multi-objective optimization of the suspension system'hard point position . The results show that the motion characteristics of front double wishbone independent suspension system are effectively improved , which meets the expected design requirements of the Formula SAE racing car .This study has a certain guiding significance for the designing of the racing car 'suspension system .%为更好地研究方程式赛车的操纵稳定性,基于机械系统动力学仿真软件ADAMS对某大学的大学生方程式赛车( Formula SAE racing car )的前悬架系统建立仿真模型,并进行运动学仿真分析,得到车轮在跳动时主销内倾角、主销后倾角、车轮外倾角和前轮前束4项参数的变化曲线,分析各参数变化对赛车操纵稳定性的影响,利用ADAMS/Insight模块对悬架的硬点位置进行多目标优化。结果表明,前悬架系统的运动特性得到有效提升,满足设计要求,该研究对于赛车的悬架设计具有一定的指导意义。

  16. Structure Design of FSAE Racing Car Suspension System%FSAE赛车悬架系统的结构设计

    Institute of Scientific and Technical Information of China (English)

    牛礼民; 张杰坤; 刘超

    2012-01-01

    Abstract:In order to establish virtual prototype car model for FSAE and based on competition rules of FSAE. the paper introduces the suspension system structure design of racing car. Selection and design of rim, wheel track as well as front and rear suspension strut have been conducted. When unequal-length wishbone suspension is selected, the paper calculates the major dimensions of flexible components, absorber and guide mechanism, establishes 3D model with the help of the software of Pro/E as well as conducts strength check for major supporting parts by software of SolidWorks. The results show that the maximum displacement of the supporting parts is4.260×10-3,2.838×10-2mm respectively, a pretty small deformation. Therefore,tile suspension design can meet tile requirements of FSAE racing car, which also provide reference for car research and production.%为配合建立中国大学生方程式汽车大赛(FSAE)赛车的虚拟样机模型,根据FSAE赛事规则要求,时赛车悬架系统进行了结构设计根据设计思路对轮辋、轮距及前后悬架立柱等相关部件进行了选择与设计,在确定采用不等长双横臂式悬架类型的基础上对弹性元件、减振器和导向机构的主要结构尺寸进行了设计计算,并应用软件Pro/E进行了三维建模设计,同时在SolidWorks环境下对前后摇块进行了强度校核.结果表明,前后摇块的最大合位移分别为4.260×10-3,2.838×10-2mm,最大变形均很小,设计的FSAE誊车悬架系统能够满足参赛要求,为进一步的实车研制提供了参考依据。

  17. An improved car-following model considering the immediately ahead car's velocity difference

    Science.gov (United States)

    Yu, Shaowei; Zhao, Xiangmo; Xu, Zhigang; Shi, Zhongke

    2016-11-01

    The field car-following data at a signalized intersection of Jinan in China are collected for data mining. An improved car-following model considering the immediately ahead car's velocity difference on a single-lane road was proposed, calibrated and verified based on full velocity difference model. The results of some numerical simulations indicate that the immediately ahead car's velocity difference has significant effects on the following car's motion, that the improved car-following model fits the measured data well and can qualitatively describe the impacts of the immediately ahead car's velocity difference on traffic flow, and that modeling the car-following behavior considering the immediately ahead car's velocity difference can improve the stability of the simulated traffic flow.

  18. High-risk driving attitudes and everyday driving violations of car and racing enthusiasts in Ontario, Canada.

    Science.gov (United States)

    Yildirim-Yenier, Zümrüt; Vingilis, Evelyn; Wiesenthal, David L; Mann, Robert E; Seeley, Jane

    2015-01-01

    Attitudes and individual difference variables of car and racing enthusiasts regarding high-risk behaviors of street racing and stunt driving have recently been investigated. Positive attitudes toward high-risk driving, personality variables such as driver thrill seeking, and other self-reported risky driving acts were associated with these behaviors. However, probable relationships among high-risk driving tendencies, everyday driving behaviors, and negative road safety outcomes have remained largely unexamined. This study aimed to investigate the associations among car and racing enthusiasts' high-risk driving attitudes, self-reported everyday driving violations (i.e., ordinary and aggressive violations), and self-reported negative outcomes (i.e., collisions and driving offense citations). A web-based survey was conducted with members and visitors of car club and racing websites in Ontario, Canada. Data were obtained from 366 participants. The questionnaire included 4 attitude measures-(1) attitudes toward new penalties for Ontario's Street Racers, Stunt and Aggressive Drivers Legislation; (2) attitudes toward new offenses of stunt driving under the same legislation; (3) general attitudes toward street racing and stunt driving; (4) comparison of street racing with other risky driving behaviors-self-reported driving violations (i.e., ordinary and aggressive violations); self-reported collisions and offense citations; and background and driving questions (e.g., age, driving frequency). Results revealed that attitudes toward stunt driving offenses negatively and general attitudes toward street racing and stunt driving positively predicted ordinary violations, which, in turn, predicted offense citations. Moreover, general attitudes toward street racing and stunt driving positively predicted aggressive violations, which, in turn, predicted offense citations. The findings indicate that positive high-risk driving attitudes may be transferring to driving violations in

  19. Study on Performances of Car-following Models Induced by Motions of a Leading Car

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper investigated the performances of a well-known car-following model with numerical simulations in describing the deceleration process induced by the motion of a leading car. A leading car with a pre-specified speed profile was used to test the above model. The results show that this model is to some extent deficient in performing the process aforementioned. Modifications of the model to overcome these deficiencies were demonstrated and a modified car-following model was proposed accordingly. Furthermore, the delay time of car motion of the new model were studied.

  20. Dynamics Simulation and Experimental Verification for a Racing Car Orientating FSAE Competition%面向FSAE竞赛的某赛车动力学仿真及试验验证

    Institute of Scientific and Technical Information of China (English)

    杨林; 吴志成; 倪俊

    2012-01-01

    建立了考虑空气动力学因素的北京理工大学2010FSAE赛车多体动力学虚拟样机及2010中国大学生方程式汽车大赛耐久赛的赛道模型.在多体动力学仿真软件ADAMS/Car环境中,仿真了北京理工大学2010 FSAE赛车的直线加速比赛和耐久赛首圈比赛过程.仿真结果表明,得到的赛车车速、车身纵向加速度和车身侧向加速度等数据与实测数据具有较强的一致性.验证了2010 FSAE赛车多体动力学虚拟样机的准确性.%A multi-body dynamics virtual prototype for BIT's 2010 FSAE racing car was completed with the consideration of aerodynamic factors. A race course model of the endurance race for 2010 China FSAE competition was built. The race processes of straight-line acceleration and the first circle of endurance race of BIT's 2010 FSAE racing car were simulated under ADAMS/Car software environment. Comparing the simulation data with measured data of race car velocity, body longitudinal acceleration and body lateral acceleration, the consistence of two sets of data was shown. The accuracy of the multi-body dynamics virtual prototype for BIT's 2010 FSAE racing car has been verified.

  1. An improved car-following model with two preceding cars' average speed

    Science.gov (United States)

    Yu, Shao-Wei; Shi, Zhong-Ke

    2015-01-01

    To better describe cooperative car-following behaviors under intelligent transportation circumstances and increase roadway traffic mobility, the data of three successive following cars at a signalized intersection of Jinan in China were obtained and employed to explore the linkage between two preceding cars' average speed and car-following behaviors. The results indicate that two preceding cars' average velocity has significant effects on the following car's motion. Then an improved car-following model considering two preceding cars' average velocity was proposed and calibrated based on full velocity difference model and some numerical simulations were carried out to study how two preceding cars' average speed affected the starting process and the traffic flow evolution process with an initial small disturbance, the results indicate that the improved car-following model can qualitatively describe the impacts of two preceding cars' average velocity on traffic flow and that taking two preceding cars' average velocity into account in designing the control strategy for the cooperative adaptive cruise control system can improve the stability of traffic flow, suppress the appearance of traffic jams and increase the capacity of signalized intersections.

  2. Modeling Strategic Interactions to Car and Fuel Taxation

    NARCIS (Netherlands)

    Heijnen, P.; Kooreman, P.

    2006-01-01

    We develop a model to analyse the interactions between actors involved in car and fuel taxation: consumers, car producers, fuel producers and the government. Heterogeneous consumers choose between two versions of a car that differ in engine type (diesel or gasoline). Car manufacturers and fuel produ

  3. Modelling strategic responses to car and fuel taxation

    NARCIS (Netherlands)

    Heijnen, P.; Kooreman, P.

    2006-01-01

    We develop a model to analyse the interactions between actors involved in car and fuel taxation: consumers, car producers, fuel producers and the government. Heterogeneous consumers choose between two versions of a car that differ in engine type (diesel or gasoline). Car manufacturers and fuel produ

  4. Modelling strategic responses to car and fuel taxation

    NARCIS (Netherlands)

    Heijnen, P.; Kooreman, P.

    We develop a model to analyse the interactions between actors involved in car and fuel taxation: consumers, car producers, fuel producers and the government. Heterogeneous consumers choose between two versions of a car that differ in engine type (diesel or gasoline). Car manufacturers and fuel

  5. Modeling Strategic Interactions to Car and Fuel Taxation

    NARCIS (Netherlands)

    Heijnen, P.; Kooreman, P.

    2006-01-01

    We develop a model to analyse the interactions between actors involved in car and fuel taxation: consumers, car producers, fuel producers and the government. Heterogeneous consumers choose between two versions of a car that differ in engine type (diesel or gasoline). Car manufacturers and fuel

  6. Optimization and Virtual Test of Steering Trapezoid of Formula Racing Car based on Particular Race Track%基于特定赛道的方程式赛车转向梯形优化与虚拟试验

    Institute of Scientific and Technical Information of China (English)

    陈思忠; 倪俊; 吴志成

    2012-01-01

    In order to optimize the steering trapezoid of formula racing car, based on the kinematics characteristics of the steering trapezoid, as well the data of steering angle collected by data logger in the race, the mathematics model as the goal of ideal Ackerman geometrical relationship is built by the introduction of weight factors, then the optimization is performed by using nonlinear least square method. By applying mechanical system simulation software ADAMS, the whole model of racing car is built, and its accuracy is verified by the experiment, then the comparison of the handling characteristics is performed. The virtual test shows that, after optimization, the tendency to understeer of the racing car is aggravated, the rangeability of wheel track decreases and the outer tire can provide more lateral force because the increase of verticality to the ground, and the rangeability of toe angle decreases when tires jump. It provides reference for the design of steering trapezoid of racing car.%以对某方程式赛车的转向梯形传动机构进行优化为目的,基于转向梯形的运动学特性,及对赛车在特定赛道上比赛时传感器所采集的方向盘转角数据的分析,通过引入加权因子建立了以理想Ackerman几何关系为目标函数的优化模型,利用非线性最小二乘法进行了优化.并通过机械系统仿真软件ADAMS建立了赛车的虚拟样机整车模型,在通过试验验证其准确度的基础上,对优化前后的赛车的操纵特性进行了对比.虚拟试验结果表明,优化后的赛车不足转向特性略有加大,同时转向时前轮距变化幅度变小,转向时外侧车轮更加垂直于地面从而可以提供更大的侧向力,并且轮胎跳动时的前束角变化幅度变小.为同类赛车的转向梯形设计提供了借鉴.

  7. Modelling and optimization of car-to-car compatibility - Modellierung und optimierung von pkw-pkw-kompatibilität

    NARCIS (Netherlands)

    Mooi, H.G.; Nastic, T.; Huibers, J.H.A.M.

    1999-01-01

    In this paper simple and more detailed MADYMO multibody models were used to simulate the car structure for improving the car-to-car compatibility of the whole car fleet. As a first step, survey studies were performed to develop a method for the optimization of car design with respect to frontal and

  8. Modelling and optimization of car-to-car compatibility - Modellierung und optimierung von pkw-pkw-kompatibilität

    NARCIS (Netherlands)

    Mooi, H.G.; Nastic, T.; Huibers, J.H.A.M.

    1999-01-01

    In this paper simple and more detailed MADYMO multibody models were used to simulate the car structure for improving the car-to-car compatibility of the whole car fleet. As a first step, survey studies were performed to develop a method for the optimization of car design with respect to frontal and

  9. Cars

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The first car In 1885,German mechanical engineer,Karl Benz designed and built the world’s first practical automobile to be powered by an internal-combustion engine(内燃机).On January 29,1886,Benz received the first patent(专利)for a gas-fueled car.It was a three- wheeler;Benz built his first four-wheeled car in 1891.Benz & Company,the company started by the inventor,became the world’s largest manufacturer of automobiles by 1900.

  10. Exact results for car accidents in a traffic model

    Science.gov (United States)

    Huang, Ding-wei

    1998-07-01

    Within the framework of a recent model for car accidents on single-lane highway traffic, we study analytically the probability of the occurrence of car accidents. Exact results are obtained. Various scaling behaviours are observed. The linear dependence of the occurrence of car accidents on density is understood as the dominance of a single velocity in the distribution.

  11. Showing that the race model inequality is not violated

    DEFF Research Database (Denmark)

    Gondan, Matthias; Riehl, Verena; Blurton, Steven Paul

    2012-01-01

    important being race models and coactivation models. Redundancy gains consistent with the race model have an upper limit, however, which is given by the well-known race model inequality (Miller, 1982). A number of statistical tests have been proposed for testing the race model inequality in single...... participants and groups of participants. All of these tests use the race model as the null hypothesis, and rejection of the null hypothesis is considered evidence in favor of coactivation. We introduce a statistical test in which the race model prediction is the alternative hypothesis. This test controls...

  12. An improved car-following model with multiple preceding cars' velocity fluctuation feedback

    Science.gov (United States)

    Guo, Lantian; Zhao, Xiangmo; Yu, Shaowei; Li, Xiuhai; Shi, Zhongke

    2017-04-01

    In order to explore and evaluate the effects of velocity variation trend of multiple preceding cars used in the Cooperative Adaptive Cruise Control (CACC) strategy on the dynamic characteristic, fuel economy and emission of the corresponding traffic flow, we conduct a study as follows: firstly, with the real-time car-following (CF) data, the close relationship between multiple preceding cars' velocity fluctuation feedback and the host car's behaviors is explored, the evaluation results clearly show that multiple preceding cars' velocity fluctuation with different time window-width are highly correlated to the host car's acceleration/deceleration. Then, a microscopic traffic flow model is proposed to evaluate the effects of multiple preceding cars' velocity fluctuation feedback in the CACC strategy on the traffic flow evolution process. Finally, numerical simulations on fuel economy and exhaust emission of the traffic flow are also implemented by utilizing VT-micro model. Simulation results prove that considering multiple preceding cars' velocity fluctuation feedback in the control strategy of the CACC system can improve roadway traffic mobility, fuel economy and exhaust emission performance.

  13. FSAE赛车车架刚度特性分析%Stiffness Properties of the FSAE Racing Car Frame

    Institute of Scientific and Technical Information of China (English)

    彭倩; 韩锋钢; 洪汉池; 郭福森

    2014-01-01

    Frame stiffness and dynamic stiffness of the engine mounting points are important factors that account for the vibration function of the FSAE racing car. In this study, an FE model of the frame was established, and torsional stiffness and dynamic stiffness of the frame model were analyzed to identify the characteristics of the frame stiffness. The results indicate that the torsional stiffness is enhanced as the cabin section increases, and the dynamic stiffness of engine mounting point along the longitudinal direction is the maximum among those of the three directions, whereas the value along the lateral direction is the minimum. The vibration characteristics of the engine compartment can be represented with the mode vibration and acceleration response curves.%车架刚度及发动机悬置安装点动刚度是影响FSAE赛车振动性能的重要因素,通过建立某FSAE赛车车架有限元模型,进行车架扭转刚度及悬置安装点动刚度分析,研究车架静态与动态刚度性能。结果表明:增大车架驾驶舱段截面可有效提高扭转刚度;悬置安装点各向动刚度值以纵向最大,横向最小。结合模态振型及加速度响应曲线能够较好地反映发动机舱的振动特性。

  14. The car following model considering traffic jerk

    Science.gov (United States)

    Ge, Hong-Xia; Zheng, Peng-jun; Wang, Wei; Cheng, Rong-Jun

    2015-09-01

    Based on optimal velocity car following model, a new model considering traffic jerk is proposed to describe the jamming transition in traffic flow on a highway. Traffic jerk means the sudden braking and acceleration of vehicles, which has a significant impact on traffic movement. The nature of the model is researched by using linear and nonlinear analysis method. A thermodynamic theory is formulated to describe the phase transition and critical phenomenon in traffic flow. The time-dependent Ginzburg-Landau (TDGL) equation and the modified Korteweg-de Vries (mKdV) equation are derived to describe the traffic flow near the critical point and the traffic jam. In addition, the connection between the TDGL and the mKdV equations are also given.

  15. Context-aware smart car: from model to prototype

    Institute of Scientific and Technical Information of China (English)

    Jie SUN; Zhao-hui WU; Gang PAN

    2009-01-01

    Smart cars are promising application domain for ubiquitous computing. Context-awareness is the key feature of a smart car for safer and easier driving. Despite many industrial innovations and academic progresses have been made, we find a lack of fully context-aware smart cars. This study presents a general architecture of smart cars from the viewpoint of contextawareness. A hierarchical context model is proposed for description of the complex driving environment. A smart car prototype including software platform and hardware infrastructures is built to provide the running environment for the context model and applications. Two performance metrics were evaluated: accuracy of the context situation recognition and efficiency of the smart car. The whole response time of context situation recognition is nearly 1.4 s for one person, which is acceptable for non-time critical applications in a smart car.

  16. Comparative analysis of used car price evaluation models

    Science.gov (United States)

    Chen, Chuancan; Hao, Lulu; Xu, Cong

    2017-05-01

    An accurate used car price evaluation is a catalyst for the healthy development of used car market. Data mining has been applied to predict used car price in several articles. However, little is studied on the comparison of using different algorithms in used car price estimation. This paper collects more than 100,000 used car dealing records throughout China to do empirical analysis on a thorough comparison of two algorithms: linear regression and random forest. These two algorithms are used to predict used car price in three different models: model for a certain car make, model for a certain car series and universal model. Results show that random forest has a stable but not ideal effect in price evaluation model for a certain car make, but it shows great advantage in the universal model compared with linear regression. This indicates that random forest is an optimal algorithm when handling complex models with a large number of variables and samples, yet it shows no obvious advantage when coping with simple models with less variables.

  17. Modelling of fire spread in car parks

    NARCIS (Netherlands)

    Noordijk, L.M.; Lemaire, A.D.

    2005-01-01

    Currently, design codes assume that in a car park fire at most 3-4 vehicles are on fire at the same time. Recent incidents in car parks have drawn international attention to such assumptions and have raised questions as to the fire spreading mechanism and the resulting fire load on the structure.

  18. NEW CAR DEMAND MODELING AND FORECASTING USING BASS DIFFUSION MODEL

    Directory of Open Access Journals (Sweden)

    Zuhaimy Ismail

    2013-01-01

    Full Text Available Forecasting model of new product demand has been developed and applied to forecast new vehicle demand in Malaysia. Since the publication of the Bass model in 1969, innovation of new diffusion theory has sparked considerable research among marketing science scholars, operational researchers and mathematicians. The building of Bass diffusion model for forecasting new product within the Malaysian society is presented in this study. The proposed model represents the spread level of new Proton car among a given set of the society in terms of a simple mathematical function that elapsed since the introduction of the new car. With the limited amount of data available for the new car, a robust Bass model was developed to forecast the sales volume. A procedure of the proposed diffusion model was designed and the parameters were estimated. Results obtained by applying the proposed model and numerical calculation shows that the proposed diffusion model is robust and effective for forecasting demand of new Proton car. The proposed diffusion model is shown to forecast more effectively and accurately even with insufficient previous data on the new product.

  19. An extended car-following model at signalized intersections

    Science.gov (United States)

    Yu, Shaowei; Shi, Zhongke

    2014-08-01

    To simulate car-following behaviors better when the traffic light is red, three successive car-following data at a signalized intersection of Jinan in China were collected by using a new proposed data acquisition method and then analyzed to select input variables of the extended car-following model. An extended car-following model considering two leading cars' accelerations was proposed, calibrated and verified with field data obtained on the basis of the full velocity difference model and then a comparative model used for comparative research was also proposed and calibrated in the light of the GM model. The results indicate that the extended car-following model could fit measured data well, and that the fitting precision of the extended model is prior to the comparative model, whose mean absolute error is reduced by 22.83%. Finally a theoretical car-following model considering multiple leading cars' accelerations was put forward which has potential applicable to vehicle automation system and vehicle safety early warning system, and then the linear stability analysis and numerical simulations were conducted to analyze some observed physical features existing in the realistic traffic.

  20. Showing that the race model inequality is not violated

    DEFF Research Database (Denmark)

    Gondan, Matthias; Riehl, Verena; Blurton, Steven Paul

    2012-01-01

    important being race models and coactivation models. Redundancy gains consistent with the race model have an upper limit, however, which is given by the well-known race model inequality (Miller, 1982). A number of statistical tests have been proposed for testing the race model inequality in single...... participants and groups of participants. All of these tests use the race model as the null hypothesis, and rejection of the null hypothesis is considered evidence in favor of coactivation. We introduce a statistical test in which the race model prediction is the alternative hypothesis. This test controls...... the Type I error if a theory predicts that the race model prediction holds in a given experimental condition. © 2011 Psychonomic Society, Inc....

  1. Showing that the race model inequality is not violated

    DEFF Research Database (Denmark)

    Gondan, Matthias; Riehl, Verena; Blurton, Steven Paul

    2012-01-01

    important being race models and coactivation models. Redundancy gains consistent with the race model have an upper limit, however, which is given by the well-known race model inequality (Miller, 1982). A number of statistical tests have been proposed for testing the race model inequality in single...... participants and groups of participants. All of these tests use the race model as the null hypothesis, and rejection of the null hypothesis is considered evidence in favor of coactivation. We introduce a statistical test in which the race model prediction is the alternative hypothesis. This test controls...... the Type I error if a theory predicts that the race model prediction holds in a given experimental condition. © 2011 Psychonomic Society, Inc....

  2. Model-based vision for car following

    Science.gov (United States)

    Schneiderman, Henry; Nashman, Marilyn; Lumia, Ronald

    1993-08-01

    This paper describes a vision processing algorithm that supports autonomous car following. The algorithm visually tracks the position of a `lead vehicle' from the vantage of a pursuing `chase vehicle.' The algorithm requires a 2-D model of the back of the lead vehicle. This model is composed of line segments corresponding to features that give rise to strong edges. There are seven sequential stages of computation: (1) Extracting edge points; (2) Associating extracted edge points with the model features; (3) Determining the position of each model feature; (4) Determining the model position; (5) Updating the motion model of the object; (6) Predicting the position of the object in next image; (7) Predicting the location of all object features from prediction of object position. All processing is confined to the 2-D image plane. The 2-D model location computed in this processing is used to determine the position of the lead vehicle with respect to a 3-D coordinate frame affixed to the chase vehicle. This algorithm has been used as part of a complete system to drive an autonomous vehicle, a High Mobility Multipurpose Wheeled Vehicle (HMMWV) such that it follows a lead vehicle at speeds up to 35 km/hr. The algorithm runs at an update rate of 15 Hertz and has a worst case computational delay of 128 ms. The algorithm is implemented under the NASA/NBS Standard Reference Model for Telerobotic Control System Architecture (NASREM) and runs on a dedicated vision processing engine and a VME-based multiprocessor system.

  3. Thermal modelling of a torpedo-car

    Directory of Open Access Journals (Sweden)

    Verdeja-González, L. F.

    2005-12-01

    Full Text Available A two-dimensional finite element model for computing the temperature distribution in a torpedo-car holding pig iron is described in this work. The model determines the temperature gradients in steady and transient conditions within the different parts that constitute the system, which are considered to be the steel casing, refractory lining, liquid iron, slag and air. Heat transfer within the main fluid phases (iron and air is computed assuming an apparent thermal conductivity term incorporating the contribution from convection and radiation, and it is affected by the dimensions of the vessel. Thermal gradients within the constituents of the torpedo-car are used to calculate heat losses during operation. It was found that the model required the incorporation of a region within the iron-refractory interface to reproduce thermographic data recorded during operation; the heat transfer coefficient of this interface was found to be equal to 30 Wm-2K-1.

    En este trabajo se describe un modelo bidimensional basado en el método del elemento finito para calcular la distribución de temperaturas en un carro torpedo lleno de arrabio. El modelo determina los gradientes térmicos en condiciones estacionarias y transitorias dentro de las partes que constituyen el sistema considerado, como son cubierta de acero, recubrimientos refractarios, arrabio líquido, escoria y aire. La transferencia de calor en las fases fluidas (arrabio y aire se calcula suponiendo un coeficiente de conductividad térmica aparente que incorpora las contribuciones por convección y radiación y está afectado por las dimensiones del recipiente. El conocimiento de los gradientes térmicos permite calcular las pérdidas de calor durante la operación del carro. Se encontró que el modelo requiere de la incorporación de una región en la intercara hierro-refractario para reproducir la información termográfica recopilada durante pruebas en planta. El

  4. FSC赛车轻量化系统研究%Study on Lightweight System of FSC Race Car

    Institute of Scientific and Technical Information of China (English)

    彭仁杰; 阳林; 周永光; 冯勇; 贺绍华; 曾繁武

    2014-01-01

    提出针对FSC赛车轻量化研究的四种方法:材料轻量化、结构轻量化、制造轻量化和功能轻量化;介绍轻量化设计原则、功能轻量化方法、材料的强度属性和刚度属性、结构优化的方法、零部件的加工工艺和连接技术,并将这些方法应用于赛车设计的工程实际。实践结果表明,多种轻量化方法联合应用的减重效果比单个轻量化方法应用减重效果好。%The four ways research for FSC race lightweight are put forward in this paper, including materials lightweight, structural lightweight, manufacturing lightweight and functional lightweight. The authors introduce the principles of lightweight design, methods of functional lightweight, strength properties and stiffness properties of materials, methods of structural optimization, processing technology and connectivity technologies of parts, apply these methods to engineering practice of race car design. The practice shows that it is better to use the combination of a variety of lightweight methods than to use a single lightweight method.

  5. Non-lane-based full velocity difference car following model

    Science.gov (United States)

    Jin, Sheng; Wang, Dianhai; Tao, Pengfei; Li, Pingfan

    2010-11-01

    In order to describe car following behavior in real world, this paper presents a non-lane-based car following model by incorporating the effects of the lane width in traffic. The stability condition of the model is obtained by using the linear stability theory. And numerical simulation is carried out to validate the analytic results. The property of the model is investigated, and it is found that the proposed model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion. The results implied that incorporating the lane width effects in car following model not only stabilize traffic flow and suppress the traffic jam, but also lower critical headway and increase capacity. Thus, the lateral separation effects greatly enhance the realism of car following models.

  6. MODAL ANALYSIS OF QUARTER CAR MODEL SUSPENSION SYSTEM

    OpenAIRE

    Viswanath. K. Allamraju *

    2016-01-01

    Suspension system is very important for comfort driving and travelling of the passengers. Therefore, this study provides a numerical tool for modeling and analyzing of a two degree of freedom quarter car model suspension system. Modal analysis places a vital role in designing the suspension system. In this paper presented the modal analysis of quarter car model suspension system by considering the undamped and damped factors.  The modal and vertical equations of motions describing the su...

  7. Modeling the number of car theft using Poisson regression

    Science.gov (United States)

    Zulkifli, Malina; Ling, Agnes Beh Yen; Kasim, Maznah Mat; Ismail, Noriszura

    2016-10-01

    Regression analysis is the most popular statistical methods used to express the relationship between the variables of response with the covariates. The aim of this paper is to evaluate the factors that influence the number of car theft using Poisson regression model. This paper will focus on the number of car thefts that occurred in districts in Peninsular Malaysia. There are two groups of factor that have been considered, namely district descriptive factors and socio and demographic factors. The result of the study showed that Bumiputera composition, Chinese composition, Other ethnic composition, foreign migration, number of residence with the age between 25 to 64, number of employed person and number of unemployed person are the most influence factors that affect the car theft cases. These information are very useful for the law enforcement department, insurance company and car owners in order to reduce and limiting the car theft cases in Peninsular Malaysia.

  8. Jam-absorption driving with a car-following model

    Science.gov (United States)

    Taniguchi, Yohei; Nishi, Ryosuke; Ezaki, Takahiro; Nishinari, Katsuhiro

    2015-09-01

    Jam-absorption driving (JAD) refers to the action performed by a single car to dynamically change its headway to remove a traffic jam. Because of its irregular motion, a car performing JAD perturbs other cars following it, and these perturbations may grow to become the so-called secondary traffic jams. A basic theory for JAD (Nishi et al. 2013) does not consider accelerations of cars or the stability of traffic flow. In this paper, by introducing car-following behaviors, we implement these elements in JAD. Numerous previous studies on the instability of traffic flow showed that even in a region whose density is below a critical density, perturbation may grow if its initial magnitude is large. According to these previous studies, we expect that the perturbations caused by JAD, if they are sufficiently small, do not grow to become secondary traffic jams. Using a microscopic car-following model, we numerically confirmed that the stability of a flow obeying the model depends on the magnitude of JAD perturbations. On the basis of this knowledge, numerical results indicate that parameter regions exist where JAD allows traffic jams to be removed without causing secondary traffic jams. Moreover, JAD is robust against a parameter of acceleration in the model, as well as the choice of car-following models.

  9. Mathematical model of convection diathermanous coefficient of refrigerator car

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    It is analyzed that the influence factors on temperature field of refrigerator car. The mathematical model of convection diathermanous coefficient has been put forward. It is considered in the model that the parameters of wind speed, ear speed, temperature of car surface, temperature of surroundings, etc. If the boundary conditions and parameters used in calculation model of convection transmits heat coefficient are confirmed as following: the cold plank car velocity V is 120 km/h, and air temperature is 25℃, and the atmosphere press is 1013250 Pa, and wind velocity V f is 10 m/s, and the length of car bodywork L is 5 m, and body work surface temperature is 25℃. The results were obtained by the model: when the wind velocity direction is the same as car velocity, the coefficient K of convection transmits heat is 51.4 ( W·m-2·K-1) , and when the wind velocity direction is against the car velocity. K is 90.58 ( W·m-2·K-1) .

  10. Car Delay Model near Bus Stops with Mixed Traffic Flow

    OpenAIRE

    Yang Xiaobao; Huan Mei; Gao Ziyou

    2013-01-01

    This paper proposes a model for estimating car delays at bus stops under mixed traffic using probability theory and queuing theory. The roadway is divided to serve motorized and nonmotorized traffic streams. Bus stops are located on the nonmotorized lanes. When buses dwell at the stop, they block the bicycles. Thus, two conflict points between car stream and other traffic stream are identified. The first conflict point occurs as bicycles merge to the motorized lane to avoid waiting behind the...

  11. Simple and effective lumped mass models for determining kinetics and dynamics of car-to-car crashes

    NARCIS (Netherlands)

    Mooi, H.G.; Huibers, J.H.A.M.

    1998-01-01

    A simple two-mass-spring model was developed to describe the dynamics of car-to-car collisions. The characteristics of the spring in this model can be chosen as a piecewise linear function. The model was applied to determine the dynamics of a range of crashes and to compare the dynamics of a

  12. Cars, Cars, Cars

    Science.gov (United States)

    McIntosh, Phyllis

    2013-01-01

    Cars are the focus of this feature article, which explores such topics as the history of cars in the United States, the national highway system, safety and pollution concerns, mobility and freedom for women, classic car shows, and the road trip in American literature and film. Also included are links to the websites of Automobile in American Life…

  13. Car Delay Model near Bus Stops with Mixed Traffic Flow

    Directory of Open Access Journals (Sweden)

    Yang Xiaobao

    2013-01-01

    Full Text Available This paper proposes a model for estimating car delays at bus stops under mixed traffic using probability theory and queuing theory. The roadway is divided to serve motorized and nonmotorized traffic streams. Bus stops are located on the nonmotorized lanes. When buses dwell at the stop, they block the bicycles. Thus, two conflict points between car stream and other traffic stream are identified. The first conflict point occurs as bicycles merge to the motorized lane to avoid waiting behind the stopping buses. The second occurs as buses merge back to the motorized lane. The average car delay is estimated as the sum of the average delay at these two conflict points and the delay resulting from following the slower bicycles that merged into the motorized lane. Data are collected to calibrate and validate the developed model from one site in Beijing. The sensitivity of car delay to various operation conditions is examined. The results show that both bus stream and bicycle stream have significant effects on car delay. At bus volumes above 200 vehicles per hour, the curbside stop design is not appropriate because of the long car delays. It can be replaced by the bus bay design.

  14. A New Car Following Model: Comprehensive Optimal Velocity Model

    Institute of Scientific and Technical Information of China (English)

    TIAN Jun-Fang; JIA Bin; LI Xing-Gang

    2011-01-01

    In this paper, we present a new car-following model, i.e.comprehensive optimal velocity model (COVM),whose optimal velocity function not only depends on the following distance of the preceding vehicle, but also depends on the velocity difference with preceding vehicle.Simulation results show that COVM is an improvement over the previous ones theoretically.Then, the stability condition of the model is obtained by the linear stability analysis, which has shorwn that the model could obtain a bigger stable region than previous models in the phase diagram.Through the nonlinear analysis, the Burgers, Korteweg-de Vries (KdV) and modified KdV (mKdV) equations are derived for the triangular shock wave, the soliton wave, and the kink-antikink soliton wave.At the same time, numerical simulations are edso carried out to show that the model could simulate these density waves.

  15. A tutorial on testing the race model inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias; Minakata, Katsumi

    2016-01-01

    effect. Several models have been proposed to explain this effect, including race models and coactivation models of information processing. In race models, the two stimulus components are processed in separate channels and the faster channel determines the processing time. This mechanism leads, on average......, to faster responses to redundant signals. In contrast, coactivation models assume integrated processing of the combined stimuli. To distinguish between these two accounts, Miller (1982) derived the well-known race model inequality, which has become a routine test for behavioral data in experiments...... model inequality, such as inappropriate control of Type I error, insufficient statistical power, wrong treatment of omitted responses or anticipations and the interpretation of violations of the race model inequality. We make detailed recommendations on the design of redundant signals experiments...

  16. An improved car-following model considering relative velocity fluctuation

    Science.gov (United States)

    Yu, Shaowei; Shi, Zhongke

    2016-07-01

    To explore and evaluate the impacts of relative velocity fluctuation on the dynamic characteristics and fuel consumptions of traffic flow, we present an improved car-following model considering relative velocity fluctuation based on the full velocity difference model, then we carry out several numerical simulations to determine the optimal time window length and to explore how relative velocity fluctuation affects cars' velocity and its fluctuation as well as fuel consumptions. It can be found that the improved car-following model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion, and that taking relative velocity fluctuation into account in designing the advanced adaptive cruise control strategy can improve the traffic flow stability and reduce fuel consumptions.

  17. A tutorial on testing the race model inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias; Minakata, Katsumi

    2016-01-01

    , to faster responses to redundant signals. In contrast, coactivation models assume integrated processing of the combined stimuli. To distinguish between these two accounts, Miller (1982) derived the well-known race model inequality, which has become a routine test for behavioral data in experiments...... with redundant signals. In this tutorial, we review the basic properties of redundant signals experiments and current statistical procedures used to test the race model inequality during the period between 2011 and 2014. We highlight and discuss several issues concerning study design and the test of the race...

  18. A tutorial on testing the race model inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias; Minakata, Katsumi

    2016-01-01

    , to faster responses to redundant signals. In contrast, coactivation models assume integrated processing of the combined stimuli. To distinguish between these two accounts, Miller (1982) derived the well-known race model inequality, which has become a routine test for behavioral data in experiments...... with redundant signals. In this tutorial, we review the basic properties of redundant signals experiments and current statistical procedures used to test the race model inequality during the period between 2011 and 2014. We highlight and discuss several issues concerning study design and the test of the race...... model inequality, such as inappropriate control of Type I error, insufficient statistical power, wrong treatment of omitted responses or anticipations and the interpretation of violations of the race model inequality. We make detailed recommendations on the design of redundant signals experiments...

  19. Calibrating Car-Following Model Considering Measurement Errors

    Directory of Open Access Journals (Sweden)

    Chang-qiao Shao

    2013-01-01

    Full Text Available Car-following model has important applications in traffic and safety engineering. To enhance the accuracy of model in predicting behavior of individual driver, considerable studies strive to improve the model calibration technologies. However, microscopic car-following models are generally calibrated by using macroscopic traffic data ignoring measurement errors-in-variables that leads to unreliable and erroneous conclusions. This paper aims to develop a technology to calibrate the well-known Van Aerde model. Particularly, the effect of measurement errors-in-variables on the accuracy of estimate is considered. In order to complete calibration of the model using microscopic data, a new parameter estimate method named two-step approach is proposed. The result shows that the modified Van Aerde model to a certain extent is more reliable than the generic model.

  20. Cloud-Aerosol-Radiation (CAR ensemble modeling system

    Directory of Open Access Journals (Sweden)

    X.-Z. Liang

    2013-04-01

    Full Text Available A Cloud-Aerosol-Radiation (CAR ensemble modeling system has been developed to incorporate the largest choices of alternative parameterizations for cloud properties (cover, water, radius, optics, geometry, aerosol properties (type, profile, optics, radiation transfers (solar, infrared, and their interactions. These schemes form the most comprehensive collection currently available in the literature, including those used by the world leading general circulation models (GCMs. The CAR provides a unique framework to determine (via intercomparison across all schemes, reduce (via optimized ensemble simulations, and attribute specific key factors for (via physical process sensitivity analyses the model discrepancies and uncertainties in representing greenhouse gas, aerosol and cloud radiative forcing effects. This study presents a general description of the CAR system and illustrates its capabilities for climate modeling applications, especially in the context of estimating climate sensitivity and uncertainty range caused by cloud-aerosol-radiation interactions. For demonstration purpose, the evaluation is based on several CAR standalone and coupled climate model experiments, each comparing a limited subset of the full system ensemble with up to 896 members. It is shown that the quantification of radiative forcings and climate impacts strongly depends on the choices of the cloud, aerosol and radiation schemes. The prevailing schemes used in current GCMs are likely insufficient in variety and physically biased in a significant way. There exists large room for improvement by optimally combining radiation transfer with cloud property schemes.

  1. A compound compensation method for car-following model

    Science.gov (United States)

    Zhu, Wen-Xing; Jun, Du; Zhang, Li-Dong

    2016-10-01

    A compound compensation mechanism was introduced into the car-following system. Two basic compensation methods were combined to generate a compound control strategy to improve the performance of the traffic flow system. The compensation effect was analyzed with unit step response in time domain and bode diagram in frequency domain, respectively. Two lemmas and one theorem were proved with the use of Routh criteria and small gain theorem. Numerical simulations were conducted in two situations under three types of condition. The simulation results verify the truth that with the increasing compensation parameters the stability of the car-following system is strengthened. It is shown that numerical results are in accordance with analytical results. In general, the performance of car-following model can be improved with an exterior control method.

  2. Swales' Cars Model and the Metaphor of Research Space: An ...

    African Journals Online (AJOL)

    ANDCORPgh changing the world

    following academics for reading through drafts of the paper and offering valuable ... The CARS (Create a Research Space) model for writing academic introductions ..... metaphysical and sometimes mystical or psychological experience of the poet, .... 'COVERT' STEP 3: [A lot has been written about the traditional music of.

  3. Modelling of Security Principles Within Car-to-Car Communications in Modern Cooperative Intelligent Transportation Systems

    Directory of Open Access Journals (Sweden)

    Jan Durech

    2016-01-01

    Full Text Available Intelligent transportation systems (ITS bring advanced applications that provide innovative services for various transportation modes in the area of traffic control, and enable better awareness for different users. Communication connections between intelligent vehicles with the use of wireless communication standards, so called Vehicular Ad Hoc Networks (VANETs, require ensuring verification of validity of provided services as well as services related to transmission confidentiality and integrity. The goal of this paper is to analyze secure mechanisms utilised in VANET communication within Cooperative Intelligent Transportation Systems (C-ITS with a focus on safety critical applications. The practical part of the contribution is dedicated to modelling of security properties of VANET networks via OPNET Modeler tool extended by the implementation of the OpenSSL library for authentication protocol realisation based on digital signature schemes. The designed models simulate a transmission of authorised alert messages in Car-to-Car communication for several traffic scenarios with recommended Elliptic Curve Integrated Encryption Scheme (ECIES. The obtained results of the throughput and delay in the simulated network are compared for secured and no-secured communications in dependence on the selected digital signature schemes and the number of mobile nodes. The OpenSSL library has also been utilised for the comparison of time demandingness of digital signature schemes based on RSA (Rivest Shamir Adleman, DSA (Digital Signature Algorithm and ECDSA (Elliptic Curve Digital Signature Algorithm for different key-lengths suitable for real time VANET communications for safety-critical applications of C-ITS.

  4. 基于 FSAE 赛车的空气动力学套件设计及 CFD 分析%Design of an Aerodynamic Package for FSAE Racing Car and CFD Analysis

    Institute of Scientific and Technical Information of China (English)

    韩小强; 王洪宇; 侯文彬

    2016-01-01

    在赛车领域,空气动力学研究已经成为各项赛事以及车队之间竞争的焦点。文中通过对 G03C 赛车进行整车空气动力学分析,找出整车造型对空气动力学的影响因素,并根据空气动力学原理设计了一套相匹配的空气动力学套件,包括鼻翼、尾翼及扩散器。对比改装前后赛车的空气力学性能,结果表明,安装空气动力学套件后,产生一定的下压力使得赛车的高速稳定性能得到提升。%In the field of racing cars,air dynamics research has become the focus of competition between the events and teams. For Formula SAE,aerodynamic research is very important.This paper through aerodynamic simulation analysis of G03C racing car, finds out influence aerodynamic factors of the vehicle model,and designs an aerodynamics package for it according to the principle of aerodynamics,including the front wing,rear wing and diffuser.Compared the aerodynamic performance of the car before and after modification,the results show that the increase of pressure makes the car high -speed stability improve under suite aerodynamic pack-age.

  5. Two velocity difference model for a car following theory

    Science.gov (United States)

    Ge, H. X.; Cheng, R. J.; Li, Z. P.

    2008-09-01

    In the light of the optimal velocity model, a two velocity difference model for a car-following theory is put forward considering navigation in modern traffic. To our knowledge, the model is an improvement over the previous ones theoretically, because it considers more aspects in the car-following process than others. Then we investigate the property of the model using linear and nonlinear analyses. The Korteweg-de Vries equation (for short, the KdV equation) near the neutral stability line and the modified Korteweg-de Vries equation (for short, the mKdV equation) around the critical point are derived by applying the reductive perturbation method. The traffic jam could be thus described by the KdV soliton and the kink-anti-kink soliton for the KdV equation and mKdV equation, respectively. Numerical simulations are made to verify the model, and good results are obtained with the new model.

  6. Stochastic Car-Following Model for Explaining Nonlinear Traffic Phenomena

    Science.gov (United States)

    Meng, Jianping; Song, Tao; Dong, Liyun; Dai, Shiqiang

    There is a common time parameter for representing the sensitivity or the lag (response) time of drivers in many car-following models. In the viewpoint of traffic psychology, this parameter could be considered as the perception-response time (PRT). Generally, this parameter is set to be a constant in previous models. However, PRT is actually not a constant but a random variable described by the lognormal distribution. Thus the probability can be naturally introduced into car-following models by recovering the probability of PRT. For demonstrating this idea, a specific stochastic model is constructed based on the optimal velocity model. By conducting simulations under periodic boundary conditions, it is found that some important traffic phenomena, such as the hysteresis and phantom traffic jams phenomena, can be reproduced more realistically. Especially, an interesting experimental feature of traffic jams, i.e., two moving jams propagating in parallel with constant speed stably and sustainably, is successfully captured by the present model.

  7. A Model of Car-Following with Adaptive Headway

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-peng; LIU Yun-cai

    2006-01-01

    The performances of a well-known GHR car-following model was investigated by using numerical simulations in describing the acceleration and deceleration process induced by the motion of a leading car. It is shown that in GHR model vehicle is allowed to run arbitrarily close together if their speed are identical ,and it waves aside even though the separation is larger than its desired distance. Based on these investigations, a modified GHR model which features a new nonlinear term which attempts to adjust the inter-vehicle spacing to a certain desired value was proposed accordingly to overcome these deficiencies. In addition, the analysis of the additive nonlinear term and steady-state flow of the new model were studied to prove its rationality.

  8. Emission factors for passenger cars: application of instantaneous emission modeling

    Science.gov (United States)

    de Haan, Peter; Keller, Mario

    This paper discusses the use of 'instantaneous' high-resolution (1 Hz) emission data for the estimation of passenger car emissions during real-world driving. Extensive measurements of 20 EURO-I gasoline passenger cars have been used to predict emission factors for standard (i.e. legislative) as well as non-standard (i.e. real-world) driving patterns. It is shown that emission level predictions based upon chassis dynamometer tests over standard driving cycles significantly underestimate emission levels during real-world driving. The emission characteristics of modern passenger cars equipped with a three-way catalytic converter are a low, basic emission level on the one hand, and frequent emission 'peaks' on the other. For real-world driving, up to one-half of the entire emission can be emitted during these short-lasting peaks. Their frequency depends on various factors, including the level of 'dynamics' (speed variation) of the driving pattern. Because of this, the use of average speed as the only parameter to characterize emissions over a specific driving pattern is not sufficient. The instantaneous emissions approach uses an additional parameter representing engine load in order to resolve the differences between driving patterns with comparable average speeds but different levels of 'dynamics'. The paper includes an investigation of different statistical indicators and discusses methods to further improve the prediction capability of the instantaneous emission approach. The fundamental differences in emission-reduction strategies between different car manufacturers make the task of constructing a model valid for all catalyst passenger cars seemingly impossible, if the model is required to predict both fleet-averaged emission levels and emission factors for driving patterns of short duration for individual vehicles simultaneously.

  9. Design and modeling of a prototype fiber scanning CARS endoscope

    Science.gov (United States)

    Veilleux, Isra"l.; Doucet, Michel; Coté, Patrice; Verreault, Sonia; Fortin, Michel; Paradis, Patrick; Leclair, Sébastien; Da Costa, Ralph S.; Wilson, Brian C.; Seibel, Eric; Mermut, Ozzy; Cormier, Jean-François

    2010-02-01

    An endoscope capable of Coherent Anti-Stokes Raman scattering (CARS) imaging would be of significant clinical value for improving early detection of endoluminal cancers. However, developing this technology is challenging for many reasons. First, nonlinear imaging techniques such as CARS are single point measurements thus requiring fast scanning in a small footprint if video rate is to be achieved. Moreover, the intrinsic nonlinearity of this modality imposes several technical constraints and limitations, mainly related to pulse and beam distortions that occur within the optical fiber and the focusing objective. Here, we describe the design and report modeling results of a new CARS endoscope. The miniature microscope objective design and its anticipated performance are presented, along with its compatibility with a new spiral scanningfiber imaging technology developed at the University of Washington. This technology has ideal attributes for clinical use, with its small footprint, adjustable field-of-view and high spatial-resolution. This compact hybrid fiber-based endoscopic CARS imaging design is anticipated to have a wide clinical applicability.

  10. An improved car-following model considering headway changes with memory

    Science.gov (United States)

    Yu, Shaowei; Shi, Zhongke

    2015-03-01

    To describe car-following behaviors in complex situations better, increase roadway traffic mobility and minimize cars' fuel consumptions, the linkage between headway changes with memory and car-following behaviors was explored with the field car-following data by using the gray correlation analysis method, and then an improved car-following model considering headway changes with memory on a single lane was proposed based on the full velocity difference model. Some numerical simulations were carried out by employing the improved car-following model to explore how headway changes with memory affected each car's velocity, acceleration, headway and fuel consumptions. The research results show that headway changes with memory have significant effects on car-following behaviors and fuel consumptions and that considering headway changes with memory in designing the adaptive cruise control strategy can improve the traffic flow stability and minimize cars' fuel consumptions.

  11. Boundary effects on car accidents in a cellular automaton model

    Science.gov (United States)

    Yang, Xian-Qing; Ma, Yu-Qiang; Zhao, Yue-Min

    2004-04-01

    In this paper we numerically study the probability Pac of occurrence of car accidents in the Nagel-Schreckenberg (NS) model with open boundary condition. In the deterministic NS model, numerical results show that there exists a critical value of extinction rate bgr above which no car accidents occur, and below which the probability Pac is independent of the speed limit vmax and the injection rate agr, but only determined by the extinction rate bgr. In the non-deterministic NS model, the probability Pac is a non-monotonic function of bgr in the region of low bgr value, while it is independent of bgr in the region of high bgr value. The stochastic braking not only reduces the occurrence of car accidents, but splits degenerate effects of vmax on the probability Pac. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the non-deterministic NS model with vmax = 1 in the case of low bgr value region. Qualitative differences between open and periodic systems in the relations of Pac to the bulk density rgr imply that various correlations may exist between the two systems.

  12. Boundary effects on car accidents in a cellular automaton model

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xianqing [National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Ma Yuqiang [National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Zhao Yuemin [School of Chemical Engineering and Technology, China University of Ming and Technology, Xuzhou 221008 (China)

    2004-04-30

    In this paper we numerically study the probability P{sub ac} of occurrence of car accidents in the Nagel-Schreckenberg (NS) model with open boundary condition. In the deterministic NS model, numerical results show that there exists a critical value of extinction rate {beta} above which no car accidents occur, and below which the probability P{sub ac} is independent of the speed limit v{sub max} and the injection rate {alpha}, but only determined by the extinction rate {beta}. In the non-deterministic NS model, the probability P{sub ac} is a non-monotonic function of {beta} in the region of low {beta} value, while it is independent of {beta} in the region of high {beta} value. The stochastic braking not only reduces the occurrence of car accidents, but splits degenerate effects of v{sub max} on the probability P{sub ac}. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the non-deterministic NS model with v{sub max} = 1 in the case of low {beta} value region. Qualitative differences between open and periodic systems in the relations of P{sub ac} to the bulk density {rho} imply that various correlations may exist between the two systems.

  13. 基于有限元的新型赛车车架的强度及刚度计算与分析%Calculation and Analysis of Racing Car's Frame Strength and Stiffness Based on Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    兰新武

    2011-01-01

    During the new style racing car's design, it is an important task to analyze the reasonableness of the racing car's frame structure and calculate its static strength and stiffness. This paper takes the second generation racing car designed by XMUT for example and obtains the maximum car's frame strength and stiffness by static analysis of the frame. This can ensure the structural strength of car's frame and improve the whole performance of racing car.%在新型赛车的开发设计中,计算与分析车架结构合理性及其结构静态强度和刚度,是一项重要工作.以赛车车架为例,对其进行静力学分析,计算赛车车架的强度和刚度的极限位置,保证赛车车架结构强度等要求,对提高整车性能具有一定的参考价值.

  14. Modelling and arrangement of composite panels in modernized freight cars

    Directory of Open Access Journals (Sweden)

    Płaczek Marek

    2017-01-01

    Full Text Available A process of modelling in a CAD system and designing of arrangement of composite panels used for freight cars’ body shell protection against corrosion and for easier unloading of transported cargo in winter conditions is presented in this work. Arrangement of used composite panels was designing in order to fulfil assumed criteria and thus to improve the process of freight cars modernization during periodic repairs.

  15. How skill expertise shapes the brain functional architecture: an fMRI study of visuo-spatial and motor processing in professional racing-car and naive drivers.

    Directory of Open Access Journals (Sweden)

    Giulio Bernardi

    Full Text Available The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI, we measured brain activity while eleven Formula racing-car drivers and eleven 'naïve' volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both 'quantitative' and 'qualitative' modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased 'neural efficiency' in the brain of highly skilled individuals.

  16. Dynamic Modelling of Axle Tramp in a Sport Type Car

    Directory of Open Access Journals (Sweden)

    Ali Zargartalebi

    2013-01-01

    Full Text Available One of the most significant dynamic aspects of coupled vibration of transmission system and dependent type suspension systems is axle tramp. The tramp is defined as undesirable oscillation of rigid live axle around roll axis. In spite of utilizing powerful engines in some type of sport cars, tramp occurrence causes loss of longitudinal performance. The aim of this paper is to derive a mathematical model for predicting and classifying of the tramp. A parameter study reveals that, some parameters such as engine torque, moving parts moment of inertia, car and wheels weight and the material used in suspension system play important role in controlling the tramp. It is shown that large difference between sprung and unsprung mass moment of inertia around the roll-axis, low vehicle mass, short rear track and medium damping values have significant effects on the severity of tramp.

  17. Car Accidents in the Deterministic and Nondeterministic Nagel-Schreckenberg Models

    Science.gov (United States)

    Yang, Xian-Qing; Ma, Yu-Qiang

    In this paper, we study further the probability for the occurrence of car accidents in the Nagel-Schreckenberg model. By considering the braking probability, the conditions for car accidents to occur are modified to obtain accurate results. A universal phenomenological theory will also be presented to describe the probability for car accidents to occur in the deterministic and nondeterministic models, respectively.

  18. A permutation test for the race model inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias

    2010-01-01

    signals. Several statistical procedures have been used for testing the race model inequality. However, the commonly employed procedure does not control the Type I error. In this article a permutation test is described that keeps the Type I error at the desired level. Simulations show that the power...... of such experiments is whether the observed redundancy gains can be explained by parallel processing of the two stimuli in a race-like fashion. To test the parallel processing model, Miller derived the well-known race model inequality which has become a routine test for behavioral data in experiments with redundant...... of the test is reasonable even for small samples. The scripts discussed in this article may be downloaded as supplemental materials from http://brm.psychonomic-journals.org/content/supplemental....

  19. A permutation test for the race model inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias

    2010-01-01

    When participants are asked to respond in the same way to several stimulus identities, responses are often observed to be faster if two stimuli are presented simultaneously as opposed to when a single stimulus is presented (redundant signals effect; Miller, 1982). An important issue...... of such experiments is whether the observed redundancy gains can be explained by parallel processing of the two stimuli in a race-like fashion. To test the parallel processing model, Miller derived the well-known race model inequality which has become a routine test for behavioral data in experiments with redundant...... signals. Several statistical procedures have been used for testing the race model inequality. However, the commonly employed procedure does not control the Type I error. In this article a permutation test is described that keeps the Type I error at the desired level. Simulations show that the power...

  20. Full velocity difference and acceleration model for a car-following theory

    Science.gov (United States)

    Yu, Shaowei; Liu, Qingling; Li, Xiuhai

    2013-05-01

    In order to describe the car-following behavior more actually in real traffic, a full velocity difference and acceleration model (for short, FVDAM) is proposed by synthetically taking into account headway, velocity difference and acceleration of the leading car on the basis of full velocity difference model. The analytical method and numerical simulation results show that the proposed model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion, that incorporating the acceleration of the leading car into car-following model can stabilize traffic flow, suppress the traffic jam and increase capacity, and that the following car in FVDAM can accelerate more quickly than in FVDM.

  1. Design of Wideband MIMO Car-to-Car Channel Models Based on the Geometrical Street Scattering Model

    Directory of Open Access Journals (Sweden)

    Nurilla Avazov

    2012-01-01

    Full Text Available We propose a wideband multiple-input multiple-output (MIMO car-to-car (C2C channel model based on the geometrical street scattering model. Starting from the geometrical model, a MIMO reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS and non-LOS (NLOS propagation environments. The proposed channel model assumes an infinite number of scatterers, which are uniformly distributed in two rectangular areas located on both sides of the street. Analytical solutions are presented for the space-time-frequency cross-correlation function (STF-CCF, the two-dimensional (2D space CCF, the time-frequency CCF (TF-CCF, the temporal autocorrelation function (ACF, and the frequency correlation function (FCF. An efficient sum-of-cisoids (SOCs channel simulator is derived from the reference model. It is shown that the temporal ACF and the FCF of the SOC channel simulator fit very well to the corresponding correlation functions of the reference model. To validate the proposed channel model, the mean Doppler shift and the Doppler spread of the reference model have been matched to real-world measurement data. The comparison results demonstrate an excellent agreement between theory and measurements, which confirms the validity of the derived reference model. The proposed geometry-based channel simulator allows us to study the effect of nearby street scatterers on the performance of C2C communication systems.

  2. A new car-following model considering velocity anticipation

    Science.gov (United States)

    Tian, Jun-Fang; Jia, Bin; Li, Xin-Gang; Gao, Zi-You

    2010-01-01

    The full velocity difference model proposed by Jiang et al. [2001 Phys. Rev. E 64 017101] has been improved by introducing velocity anticipation. Velocity anticipation means the follower estimates the future velocity of the leader. The stability condition of the new model is obtained by using the linear stability theory. Theoretical results show that the stability region increases when we increase the anticipation time interval. The mKdV equation is derived to describe the kink-antikink soliton wave and obtain the coexisting stability line. The delay time of car motion and kinematic wave speed at jam density are obtained in this model. Numerical simulations exhibit that when we increase the anticipation time interval enough, the new model could avoid accidents under urgent braking cases. Also, the traffic jam could be suppressed by considering the anticipation velocity. All results demonstrate that this model is an improvement on the full velocity difference model.

  3. A permutation test for the race model inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias

    2010-01-01

    signals. Several statistical procedures have been used for testing the race model inequality. However, the commonly employed procedure does not control the Type I error. In this article a permutation test is described that keeps the Type I error at the desired level. Simulations show that the power...

  4. A new car-following model with two delays

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Lei, E-mail: yuleijk@126.com [College of Automation, Northwestern Polytechnical University, Xi' an, ShaanXi (China); Shi, Zhong-ke [College of Automation, Northwestern Polytechnical University, Xi' an, ShaanXi (China); Li, Tong [Department of Mathematics, University of Iowa, Iowa City, IA (United States)

    2014-01-17

    A new car-following model is proposed by taking into account two different time delays in sensing headway and velocity. The effect of time delays on the stability analysis is studied. The theoretical and numerical results show that traffic jams are suppressed efficiently when the difference between two time delays decreases and those can be described by the solution of the modified Korteweg–de Vries (mKdV) equation. Traffic flow is more stable with two delays in headway and velocity than in the case with only one delay in headway. The impact of local small disturbance to the system is also studied.

  5. A new car-following model with two delays

    Science.gov (United States)

    Yu, Lei; Shi, Zhong-ke; Li, Tong

    2014-01-01

    A new car-following model is proposed by taking into account two different time delays in sensing headway and velocity. The effect of time delays on the stability analysis is studied. The theoretical and numerical results show that traffic jams are suppressed efficiently when the difference between two time delays decreases and those can be described by the solution of the modified Korteweg-de Vries (mKdV) equation. Traffic flow is more stable with two delays in headway and velocity than in the case with only one delay in headway. The impact of local small disturbance to the system is also studied.

  6. Car accidents in cellular automata models for one-lane traffic flow

    Science.gov (United States)

    Moussa, Najem

    2003-09-01

    Conditions for the occurrence of car accidents are introduced in the Nagel-Schreckenberg model. These conditions are based on the thought that a real accident depends on several parameters: an unexpected action of the car ahead (sudden stop or abrupt deceleration), the gap between the two cars, the velocity of the successor car and its delayed reaction time. We discuss then the effect of this delayed reaction time on the probability of traffic accidents. We find that these conditions for the occurrence of car accidents are necessary for modeling realistic accidents.

  7. Optimization of Double-wishbone Independent Suspension for FSAE Racing Car by ADAMS%基于ADAMS的FSAE赛车双横臂悬架的仿真优化

    Institute of Scientific and Technical Information of China (English)

    柳威; 师忠秀; 于渊; 王甜甜

    2013-01-01

    A model of double-wishbone suspension for FSAE racing car was established by ADAMS/Car . Then the dynamic simulation of the model was done ,the kinematic performance parameters of the suspension were analyzed to determine optimization objective .Multi-objective optimization was carried out by ADAMS/Insight through setting design variables ,target function and constraint condition .Afterwards the kinematic model was modified according to optimization result ,and the simulation was analyzed again to compare the total suspension performance before and after optimization .The simulation results show that the kinematic characteristics of the optimized suspension were improved .%在ADAMS/Car模块中建立FSAE赛车双横臂悬架模型,对模型进行运动学仿真,分析仿真结果,确定优化目标;在ADAMS/Insight模块中设定设计变量、目标函数和约束条件进行多目标优化;根据优化结果修改模型,再次进行仿真分析,并比较优化前和优化后悬架的综合性能。仿真结果表明,优化后悬架系统的运动学性能得到改善。

  8. Design and optimazation of braking system on FSAE racing car%FSAE赛车制动系统的设计及其优化

    Institute of Scientific and Technical Information of China (English)

    李栋新; 黄光绪; 包耳

    2014-01-01

    按照FSAE规定,赛车制动系统要求简单控制,必须有两条液压回路而且每条液压回路必须有独立的储液罐,不允许采用带有助力的制动装置。将制动系统全部采用液压动力制动系统。这种方式作用滞后时间较短、工作压力高,因而主缸尺寸小,使制动器结构简单、质量小、机械效率高。假定附地面附着系数为0.8的情况下,赛车以20km/h制动的情况下计算了赛车的最大减速度和制动距离。对于制动系统的设计和优化具有指导性的意义。%According to the FSAE competition rules, the braking system of racing cars should be easily controlled, two hydraulic circuits and two independent resevoirs for each circuit are required, and no power assisting device is allowed. We put hydraulic power braking system into practice, by this mean we have short delay time and high working pressure so that the size of the master cylinder could be small. In this case the brake is constructed easily, having less mass and much more efficient. Assume adhension coefficient was 0.8 and initial speed of braking was 20 km/h, maximum deceleration and braking distance was calculated. This study is helpful for the braking system design of racing car.

  9. Solitons and kinks in a general car-following model

    Science.gov (United States)

    Kurtze, Douglas A.

    2013-09-01

    We study a general car-following model of traffic flow on an infinitely long single-lane road, which assumes that a car's acceleration depends on time-delayed values of its own speed, the headway between it and the car ahead, and the rate of change of headway, but makes minimal assumptions about the functional form of that dependence. We present a detailed characterization of the onset of linear instability; in particular we find a specific limit on the delay time below which the marginal wave number at the onset of instability is zero, and another specific limit on the delay time above which steady flow is always unstable. Crucially, the threshold of absolute stability generally does not coincide with an inflection point of the steady-state velocity function. When the marginal perturbation at onset has wave number 0, we show that Burgers and Korteweg-de Vries (KdV) equations can be derived under the usual assumptions, and that corrections to the KdV equation “select” a single member of the one-parameter set of its one-soliton solutions by driving a slow evolution of the soliton parameter. While in previous models this selected soliton has always marked the threshold of a finite-amplitude instability of linearly stable steady flow, we find that it can alternatively be a stable, small-amplitude jam that occurs when steady flow is linearly unstable. The model reduces to the usual modified Korteweg-de Vries (mKdV) equation only in the special situation that the threshold of absolute stability coincides with an inflection point of the steady-state velocity function; in general, near the threshold of absolute stability the model reduces instead to a KdV equation in the regime of small solitons, while near an inflection point it reduces to a Hayakawa-Nakanishi equation. Like the mKdV equation, the Hayakawa-Nakanishi equation admits a continuous family of kink solutions, and the selection criterion arising from the corrections to this equation can be written down

  10. Virtual simulation and experimental study of handling and stability of FSAE racing car%FSAE赛车操纵稳定性虚拟仿真与实车试验研究

    Institute of Scientific and Technical Information of China (English)

    邓召文; 徐成强; 王保华

    2015-01-01

    Based on ADAMS/Car module ,the vehicle simulation model of FSAE racing car was built . The result of constant radius corner virtual simulation showed that the model had high accuracy and that the car had a very slight understeer characteristic .The good performance of steering ,anti-roll and anti-skid was verified through Fish Hook virtual simulation .With the suspension data acquisition system ,the real Fish Hook experiment was done ,the data obtained through the test was compared with the virtual simulation results ,and some useful suggestions through comparative research were proposed for the vehicle handling tuning and optimization design .%文章基于ADAMS/Car模块建立FSAE赛车整车模型 ,通过虚拟稳态回转仿真试验 ,表明该赛车具有极轻微的不足转向特性 ,验证了模型的准确性 ;通过虚拟蛇形穿越仿真试验 ,验证赛车在过弯、抗侧倾和抗侧滑等方面均具有良好的操纵稳定性 ;借助悬架数据采集系统 ,进行实车蛇形穿越试验数据采集分析 ,通过与虚拟蛇形穿越仿真曲线对比分析研究 ,为赛车操控性调校及优化设计提供有效建议.

  11. The race to break the standard model

    CERN Multimedia

    Brumfiel, Geoff

    2008-01-01

    The Large Hadron Collider is the latest attempt to move fundamental physics past the frustratingly successful "standard model". But it is not the only way to do it... The author surveys the contenders attempting to capture the prize before the collider gets up to speed.(4 pages)

  12. BODY WORK MODELING AND GENERAL DESIGN FOR A RADIO CONTROLLED CAR

    Directory of Open Access Journals (Sweden)

    DOROBANŢU Bogdan

    2012-11-01

    Full Text Available This paper presents the general design of a small radio controlled car with its main systems and also the process and phases of modeling the body work for this kind of car. The modeling started from the sketch of a real car, a Porsche 997, shaping the clay to its final form looking like a mixture of Nissan GTR and Porsche Cayenne but keeping the proportions of the 997 to a scale of 1:14.

  13. A Car-Following Model Based on Quantified Homeostatic Risk Perception

    Directory of Open Access Journals (Sweden)

    Guangquan Lu

    2013-01-01

    Full Text Available This study attempts to elucidate individual car-following behavior using risk homeostasis theory (RHT. On the basis of this theory and the stimulus-response concept, we develop a desired safety margin (DSM model. Safety margin, defined as the level of perceived risk in car-following processes, is proposed and considered to be a stimulus parameter. Acceleration is assessed in accordance with the difference between the perceived safety margin (perceived level of risk and desired safety margin (acceptable level of risk of a driver in a car-following situation. Sixty-three cases selected from Next Generation Simulation (NGSIM are used to calibrate the parameters of the proposed model for general car-following behavior. Other eight cases with two following cars taken from NGSIM are used to validate the model. A car-following case with stop-and-go processes is also used to demonstrate the performance of the proposed model. The simulation results are then compared with the calculations derived using the Gazis-Herman-Rothery (GHR model. As a result, the DSM and GHR models yield similar results and the proposed model is effective for simulation of car following. By adjusting model parameters, the proposed model can simulate different driving behaviors. The proposed model gives a new way to explain car-following process by RHT.

  14. Effects of quenched randomness induced by car accidents on traffic flow in a cellular automata model

    Science.gov (United States)

    Yang, Xian-Qing; Ma, Yu-Qiang; Zhao, Yue-Min

    2004-10-01

    In this paper we numerically study the impact of quenched disorder induced by car accidents on traffic flow in the Nagel-Schreckenberg (NS) model. Car accidents occur when the necessary conditions proposed by [Boccara J. Phys. A 30, 3329 (1997)] are satisfied. Two realistic situations of cars involved in car accidents have been considered. Model A is presented to consider that the accident cars become temporarily stuck. Our studies exhibit the “inverse- λ form” or the metastable state for traffic flow in the fundamental diagram and wide-moving waves of jams in the space-time pattern. Model B is proposed to take into account that the “wrecked” cars stay there forever and the cars behind will pass through the sites occupied by the “wrecked” cars with a transmission rate. Four-stage transitions from a maximum flow through a sharp decrease phase and a density-independent phase to a high-density jamming phase for traffic flow have been observed. The density profiles and the effects of transmission rate and probability of the occurrence of car accidents in model B are also discussed.

  15. Racing Academy

    Science.gov (United States)

    Turner, Jim; Gavin, Carl; Owen, Martin

    2004-09-01

    This paper outlines an innovative education project that, by using a cutting-edge racing car physics simulation, will help create the next generation of engineers. The article gives an overview of this genre of games to give a background to the non-games expert. It also identifies key educational methodologies that have helped to form the goals of the project.

  16. Modeling of Car-Following Required Safe Distance Based on Molecular Dynamics

    OpenAIRE

    Dayi Qu; Xiufeng Chen; Wansan Yang; Xiaohua Bian

    2014-01-01

    In car-following procedure, some distances are reserved between the vehicles, through which drivers can avoid collisions with vehicles before and after them in the same lane and keep a reasonable clearance with lateral vehicles. This paper investigates characters of vehicle operating safety in car following state based on required safe distance. To tackle this problem, we probe into required safe distance and car-following model using molecular dynamics, covering longitudinal and lateral safe...

  17. The effects of motivational factors on car use : a multidisciplinary modelling approach

    NARCIS (Netherlands)

    Steg, L; Geurs, K; Ras, M

    2001-01-01

    Current transport models usually do not take motivational factors into account, and if they do, it is only implicitly. This paper presents a modelling approach aimed at explicitly examining the effects of motivational factors on present and future car use in the Netherlands. A car-use forecasting mo

  18. The effects of motivational factors on car use: a multidisciplinary modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Steg, L.; Ras, M. [University of Groningen (Netherlands). Centre for Environmental and Traffic Psychology; Geurs, K. [National Institute of Public Health and Environment, Bilthoven (Netherlands)

    2001-11-01

    Current transport models usually do not take motivational factors into account, and if they do, it is only implicitly. This paper presents a modelling approach aimed at explicitly examining the effects of motivational factors on present and future car use in the Netherlands. A car-use forecasting model for the years 2010 and 2020 was constructed on the basis of (i) a multinominal regression analysis, which revealed the importance of a motivational variable (viz., problem awareness) in explaining current car-use behavior separate from socio-demographic and socio-economic variables, and (ii) a population model constructed to forecast the size and composition of the Dutch population. The results show that car use could be better explained by taking motivational factors explicitly into account, and that the level of car use forecast might change significantly if changes in motivations are assumed. The question on how motivational factors could be incorporated into current (Dutch) national transport models was also addressed. (author)

  19. How tires influence the performance of the racing-car%轮胎对赛车性能的影响

    Institute of Scientific and Technical Information of China (English)

    李祥; 徐文冰; 张运花; 曹华

    2013-01-01

    本文以多体系统动力学的理论方法为基础,利用机械系统仿真软件ADAMS/Car,建立了某校2011年FSAE整车虚拟样机,参照中国2011年FSAE大赛规则,进行了整车动力性及操纵稳定性等动力学仿真和评价.本文主要仿真分析了直线加速、常半径转弯等两个试验.分别研究了轮胎气压和直径在直线加速过程中对整车动力性能的影响及在常半径转弯试验中对整车操纵稳定性的影响.通过仿真分析找到了相关规律,为车队购买轮胎和参加实际的比赛提供了理论指导.

  20. A dynamic random effects multinomial logit model of household car ownership

    DEFF Research Database (Denmark)

    Bue Bjørner, Thomas; Leth-Petersen, Søren

    2007-01-01

    Using a large household panel we estimate demand for car ownership by means of a dynamic multinomial model with correlated random effects. Results suggest that the persistence in car ownership observed in the data should be attributed to both true state dependence and to unobserved heterogeneity ...

  1. A PANEL-DATA SWITCHING REGRESSION-MODEL OF MOBILITY AND CAR OWNERSHIP

    NARCIS (Netherlands)

    MEURS, H

    1993-01-01

    The objective of this paper is to present a panel data model of car ownership and mobility. Unobserved heterogeneity is controlled for by including correlated random effects in the equations describing car ownership and mobility. A mass-points approach is adopted to control for unobserved heterogene

  2. INTELLIGENT CAR STYLING TECHNIQUE AND SYSTEM BASED ON A NEW AERODYNAMIC-THEORETICAL MODEL

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Car styling technique based on a new theoretical model of automotive aerodynamics is introduced, which is proved to be feasible and effective by wind tunnel tests. Development of a multi-module software system from this technique, including modules of knowledge processing, referential styling and ANN aesthetic evaluation etc, capable of assisting car styling works in an intelligent way, is also presented and discussed.

  3. A PANEL-DATA SWITCHING REGRESSION-MODEL OF MOBILITY AND CAR OWNERSHIP

    NARCIS (Netherlands)

    MEURS, H

    1993-01-01

    The objective of this paper is to present a panel data model of car ownership and mobility. Unobserved heterogeneity is controlled for by including correlated random effects in the equations describing car ownership and mobility. A mass-points approach is adopted to control for unobserved

  4. Modelling and Optimization of the Half Model of a Passenger Car with Magnetorheological Suspension System

    Science.gov (United States)

    Segla, S.

    The paper deals with modelling and optimization of the half model of a passenger car with an ideal semi-active suspension, semi-active suspension equipped with magnetorheological dampers, passive suspension equipped with hydraulic dampers without control and compares their dynamic characteristics. The conventional skyhook control is used to control semi-active dampers taking into account the time delay. Selected parameters of the suspension systems are optimized for given road profiles using genetic algorithms. The results show that implementation of the magnetorheological dampers can lead to a significant improvement of the ride comfort and handling properties of passenger cars provided that the time delay is low enough.

  5. Formula SAE赛车转向节的拓扑优化%Topological Optimization of the Steering Knuckle in a Formula SAE Racing Car

    Institute of Scientific and Technical Information of China (English)

    曾忠敏; 张英朝

    2012-01-01

    运用OptiStruct求解器对某一Formula SAE赛车的后转向节进行多工况加权拓扑优化,并将结果和以往的设计方案进行对比.结果表明,优化后在强度和刚度满足要求的条件下,后转向节的质量减轻45.1%,说明了该方法的可行性和有效性.%A multi-load case weighted topology optimization is conducted on the steering knuckle of a Formula SAE racing car by using OptiStruct solver and the results are compared with early design schemes. The results show that after optimization the mass of the rear steering knuckle is reduced by 45. 1% , while its strength and stiffness meet requirements, demonstrating the feasibility and effectiveness of the method used.

  6. FSAE方程式赛车附着系数分析%Analysis on the Adhesion Coefficient of FSAE Formula Racing Car

    Institute of Scientific and Technical Information of China (English)

    李佳佳; 闫文青; 廖卫杰; 李仲锋

    2015-01-01

    本文介绍了两种计算最大制动器制动力的方法,并分析附着系数的选取方法和在计算中使用的顺序对计算结果造成的影响。通过MATLAB计算,用ORIGIN软件绘制曲线分析比较,找出其中的不同计算原理和计算方法的优缺点。FSAE方程式赛车的设计数据的检验结果表明,制动器制动力满足制动系统的要求。%This article described two methods of calculating the maximum braking force,and the effects of adhesion coefficients selecting method and sequence used in the calculation on the calculation results were analyzed.Through MATLAB computing,and analysis and comparison by drawing curves with ORIGIN software,the advantages and dis⁃advantages of different principles and calculation methods were obtained.Results of inspection for FSAE Racing Car design data showed that braking force met the requirements of the braking system.

  7. OPERATION STUDY OF DIFFERENT STRUCTURAL OPTIONS OF FLEXIBLE FLOWS FOR CAR REPAIR USING SIMULATION MODELING

    Directory of Open Access Journals (Sweden)

    V. V. Myamlin

    2014-04-01

    Full Text Available Purpose. The article is aimed to improve the methods of car repair organization using the search of rational structures of flexible flows. Methodology. For operation analyses of the car repair flows the simulation modeling was used. The initial data for random value generation of cars repair duration are the statistical data. They were collected at the existing car repair enterprises. Findings. Obtained results show that at the same amount of modules the flexible repair flow is more efficient. Flexible flow increases the working capacity, improves the removal of cars from one module and reduces car detention time in repair. Originality. There were identified the mechanisms, which allow establishing links between the different structural variants of flexible flow and their operational performance. Concrete data that give a fresh look to the organization of car repair production were obtained. Practical value. These results can be used in designing the new perspective enterprises for car repair and also under reconstruction or expansion of existing enterprises in order to transfer them to the flexible flow. It is recommended to incorporate the obtained results and try to put them into production during designing and construction of new car enterprises.

  8. MODEL CAR TRAFFIC ON SECTIONS OF ROADS WITH LIMITED VISIBILITY

    Directory of Open Access Journals (Sweden)

    A. V. Skrypnikov

    2014-01-01

    Full Text Available Summary. Existing theoretical calculations speeds in areas of horizontal and vertical curves designed for the needs of construction and calculation of cars and can not be used for valuation. When calculating the value of the coefficient of friction velocity determined at full wheel lock that does not correspond to the actual conditions of braking stability conditions of the car within its lane. The article proposes to calculate the permissible vehicle speed for the sites of horizontal and vertical curves on forest roads from the requirement car stop within the zone of visibility without buckling considering assumptions: during braking movement remains manageable, the driver keeps the car in the outside lane; magnitude of the angular velocity of the steering wheel is small; fully utilized inhibitory properties least loaded wheel; cornering power coefficient of resistance of tires depends little on the change of loads on the bus; low rolling resistance. Studied are normal reactions to the vehicle wheels when braking, namely found that if the friction coefficient on the road for less than the calculated optimal braking, the restriction on the braking occurs danger of losing control of the car skidding due to the front wheels. If the coefficient of friction on the road more than the calculated optimal braking, the braking force limitation occurs for blocking the rear axle. When comparing full stopping distance with the existing area of visibility is determined permissible speed.

  9. Effects of a type of quenched randomness on car accidents in a cellular automaton model

    Science.gov (United States)

    Yang, Xian-Qing; Zhang, Wei; Qiu, Kang; Zhao, Yue-Min

    2006-01-01

    In this paper we numerically study the probability Pac of the occurrence of car accidents in the Nagel-Schreckenberg (NS) model with a defect. In the deterministic NS model, numerical results show that there exists a critical value of car density below which no car accident happens. The critical density ρc1 is not related only to the maximum speed of cars, but also to the braking probability at the defect. The braking probability at a defect can enhance, not suppress, the occurrence of car accidents when its value is small. Only the braking probability at the defect is very large, car accidents can be reduced by the bottleneck. In the nondeterministic NS model, the probability Pac exhibits the same behaviors with that in the deterministic model except the case of vmax=1 under which the probability Pac is only reduced by the defect. The defect also induces the inhomogeneous distribution of car accidents over the whole road. Theoretical analyses give an agreement with numerical results in the deterministic NS model and in the nondeterministic NS model with vmax=1 in the case of large defect braking probability.

  10. Dynamic performance of freight cars on bogies model 18-1711

    Directory of Open Access Journals (Sweden)

    N.B. Mankevych

    2013-08-01

    Full Text Available Purpose. To analyze the results of study of dynamic parameters of the tank-car model 15-1900 and gondola car model 12-1905, equipped with the bogies model 18-1711 with axle loading of 25 ton and unified according to major parts and joints with the cars of previous generation. According to results of the study to conclude about the possibility of using bogies model 18-1711 as the running parts of the freight rolling stock of the new generation of 1520 mm track with increased axle loading. Methodology. The dynamic performance of the rolling stock running parts directly affects the safety of railway traffic. Experimental studies of the car dynamic qualities are an important step in the modernization of existing bogie constructions and in the creation of the new ones. These tests allow one to confirm the results of theoretical studies and to check the correctness of the constructive solutions. Findings. Basic results of dynamic studies are presented as the graphs of dynamic performance dependencies on the motion speed of the experimental train. Results show that the freight cars on the bogies model 18-1711 have satisfactory dynamic properties meeting current regulatory requirements. Originality. The dynamic characteristics of freight cars on bogies model 18-1711, which give a complete view of the car loading allow us to estimate the dependency of the car dynamic performance on the bogie design parameters. Practical value. The bogie model 18-1711 with axle loading 25 ton can be used as a freight car undercarriages of the new generation of 1520 mm track.

  11. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars. Part 1. Model structure, simulation of bounded rationality, and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Michel G.; Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland)

    2009-03-15

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated. (author)

  12. Automobilismo: no calor da competição Automovilismo: en el calor de la competición Car racing: in the heat of competition

    Directory of Open Access Journals (Sweden)

    Luiz Oswaldo Carneiro Rodrigues

    2004-06-01

    la producción del calor metabólico capaz de aumentar excesivamente la temperatura interna del piloto en las condiciones ambientales del autódromo el día de su muerte.The present study discusses the role of heat as an additional risk factor for the accident that killed the pilot Ayrton Senna. The competition car racing is a biological challenge, a stressing situation from the physical and mental point of view. The maintenance of performance depends on the oxygen and carbohydrates availability, adequate hydration and constant internal temperature, between 37 and 38ºC. The dissipation of heat produced by the metabolism occurs through the increase on the cutaneous blood flow and sweat and maintaining brain temperature constant becomes a permanent problem. It was experimentally verified that the energy required to the racecar driving is comparable to a sport such as volleyball. During a car race, the individual is exposed to a hot microenvironment in the cockpit, sometimes reaching 50ºC, generated by mechanical and environmental sources of heat. The obstruction of the sweat evaporation by the racesuit results in humidity and personal discomfort, what leads to higher mental effort to drive the car. The anti-heat measures are adopted before the race, considering the nutritional state, hydration and specially the physical conditioning through adequate and regular aerobic exercises that enable increasing the work capacity and the heat tolerance, resulting in lower fatigue during the car racing. Another important procedure should be the previous acclimation of pilots to hot and humid environments. All efforts should be done to reduce the vehicle heating and to respect the warning flag system for the risks of hyperthermia. Finally, although Ayrton Senna was an individual with higher risk of developing hyperthermia, regardless other causes, it seems not to have elapsed sufficient time of race in order to produce metabolic heat capable to increase excessively the pilot

  13. An improved car-following model considering influence of other factors on traffic jam

    Science.gov (United States)

    Ge, Hong-xia; Meng, Xiang-pei; Ma, Jian; Lo, Siu-ming

    2012-12-01

    In the Letter, a modified car-following model is presented, in which, the effects of vehicles (or non-motor vehicles) on other lanes without isolation belts are taken into account. The stability condition of the model is obtained by using the control theory method. To check the validity of the present theoretical scheme, the numerical simulation is carried out for the new car-following model, and the simulation result is consistent with the theoretical analysis.

  14. Cellular Automation Model of Traffic Flow Based on the Car-Following Model

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You

    2004-01-01

    @@ We propose a new cellular automation (CA) traffic model that is based on the car-following model. A class of driving strategies is used in the car-following model instead of the acceleration in the NaSch traffic model. In our model, some realistic driver behaviour and detailed vehicle characteristics have been taken into account, such as distance-headway and safe distance, etc. The simulation results show that our model can exhibit some traffic flow states that have been observed in the real traffic, and both of the maximum flux and the critical density are very close to the real measurement. Moreover, it is easy to extend our method to multi-lane traffic.

  15. A generalized quarter car modelling approach with frame flexibility and other nonlocal effects

    Indian Academy of Sciences (India)

    HUSAIN KANCHWALA; ANINDYA CHATTERJEE

    2017-07-01

    Quarter-car models are popular, simple, unidirectional in kinematics and enable quicker computation than full-car models. However, they do not account for three other wheels and their suspensions, nor for the frame’s flexibility, mass distribution and damping. Here we propose a generalized quarter-car modelling approach, incorporating both the frame as well as other-wheel ground contacts. Our approach is linear, uses Laplace transforms, involves vertical motions of key points of interest and has intermediate complexity with improved realism. Our model uses baseline suspension parameters and responses to step force inputs at suspensionattachment locations on the frame. Subsequently, new suspension parameters and unsprung mass compliance parameters can be incorporated, for which relevant formulas are given. The final expression for the transfer function, between ground displacement and body point response, is approximated using model orderreduction. A simple Matlab code is provided that enables quick parametric studies. Finally, a parametric study and wheel hop analysis are performed for a realistic numerical example. Frequency and time domain responses obtained show clearly the effects of other wheels, which are outside the scope of usual quarter-car models. The displacements obtained from our model are compared against those of the usual quarter-car model and show ways in which predictions of the quarter-car model include errors that can be reduced in our approach. In summary, our approach has intermediate complexity between that of a full-car model and a quarter-car model, and offers corresponding intermediate detail and realism.

  16. Relay race

    CERN Multimedia

    Staff Association

    2011-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 19th May starting at 12·15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on the course, and how to register your team for the relay race, can be found at: https://espace.cern.ch/Running-Club/CERN-Relay Some advice for all runners from the medical service can also be found here: https://espace.cern.ch/Running-Club/CERN-Relay/RelayPagePictures/MedicalServiceAnnoncement.pdf

  17. Relay race

    CERN Multimedia

    Staff Association

    2011-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 19th May starting at 12:15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on the course, and how to register your team for the relay race, can be found at: https://espace.cern.ch/Running-Club/CERN-Relay Some advice for all runners from the medical service can also be found here: https://espace.cern.ch/Running-Club/CERN-Relay/RelayPagePictures/MedicalServiceAnnoncement.pdf

  18. One-Quarter-Car Active SuspensionModel Verification

    Directory of Open Access Journals (Sweden)

    Hyniova Katerina

    2017-01-01

    Full Text Available Suspension system influences both the comfort and safety of the passengers. In the paper, energy recuperation and management in automotive suspension systems with linear electric motors that are controlled by a designed H∞ controller to generate a variable mechanical force for a car damper is presented. Vehicle shock absorbers in which forces are generated in response to feedback signals by active elements obviously offer increased design flexibility compared to the conventional suspensions with passive elements (springs and dampers. The main advantage of the proposed solution that uses a linear AC motor is the possibility to generate desired forces acting between the unsprung (wheel and sprung (one-quarter of the car body mass masses of the car, providing good insulation of the car sprung mass from the road surface roughness and load disturbances. As shown in the paper, under certain circumstances linear motors as actuators enable to transform mechanical energy of the vertical car vibrations to electrical energy, accumulate it, and use it when needed. Energy flow control enables to reduce or even eliminate the demands on the external power source. In particular, the paper is focused on experiments with active shock absorber that has been taken on the designed test bed and the way we developed an appropriate input signal for the test bed that as real road disturbance acts upon the vibration absorber and the obtained results are evaluated at the end. Another important point the active suspension design should satisfy is energy supply control that is made via standard controller modification, and which allows changing amount of energy required by the system. Functionality of the designed controller modification was verified taking various experiments on the experiment stand as mentioned in the paper.

  19. A Self-identity Based Model of Electric Car Adoption Intention

    DEFF Research Database (Denmark)

    Barbarossa, Camilla; Beckmann, Suzanne C.; de Pelsmacker, Patrick

    2015-01-01

    This study proposes a self-identity based eco-friendly intention formation model to assess the effects of green self-identity, care for the environmental consequences of consumption, and green moral obligation, on the attitude toward and the intention to adopt electric cars. The model is empirica......This study proposes a self-identity based eco-friendly intention formation model to assess the effects of green self-identity, care for the environmental consequences of consumption, and green moral obligation, on the attitude toward and the intention to adopt electric cars. The model...... between the countries. Results show that the independent variables influence consumer attitude toward the adoption of electric cars, which, in turn, determines the intention to adopt them. Significant differences emerge concerning the influence of the antecedents of consumer attitude toward electric car...

  20. A Control Method for Congested Traffic in the Car-Following Model

    Science.gov (United States)

    Ge, Hong-Xia; Yu, Jian; Lo, Siu-Ming

    2012-05-01

    A simple control method to suppress traffic congestion is proposed for the car-following model. The stability conditions are derived by using the control method, and the feedback signals, which act on our traffic system, are extended to the car-following model. The control signals will play an effect only if the traffic is congested. The corresponding numerical simulation results agree well with our theoretical analysis, and our control method can successfully suppress traffic jams.

  1. A new car-following model with the consideration of incorporating timid and aggressive driving behaviors

    Science.gov (United States)

    Peng, Guanghan; He, Hongdi; Lu, Wei-Zhen

    2016-01-01

    In this paper, a new car-following model is proposed with the consideration of the incorporating timid and aggressive behaviors on single lane. The linear stability condition with the incorporating timid and aggressive behaviors term is obtained. Numerical simulation indicates that the new car-following model can estimate proper delay time of car motion and kinematic wave speed at jam density by considering the incorporating the timid and aggressive behaviors. The results also show that the aggressive behavior can improve traffic flow while the timid behavior deteriorates traffic stability, which means that the aggressive behavior is better than timid behavior since the aggressive driver makes rapid response to the variation of the velocity of the leading car. Snapshot of the velocities also shows that the new model can approach approximation to a wide moving jam.

  2. MODELING OF OCCUPANT DYNAMIC RESPONSE TO CAR-BARRIERS CRASH ON HIGHWAY

    Institute of Scientific and Technical Information of China (English)

    Huang Hongwu; Yang Jikuang; Liu Zhengheng; Zhong Zhihua

    2004-01-01

    The dynamic response involved in car-roadside barrier impacts is studied.The risk of occupant injures in such accidents is investigated.An approach based on accident analysis and mathematical modeling is developed and described in three steps.Firstly a study of car-roadside barrier impact accidents is carried out with available data to define a system including car,road,roadside barrier,and occupant.Secondly a mathematical model to simulate car-to-barrier impact is developed by using multi-body program MADYMO.Finally,dynamic responses of the occupant during impact are simulated using a car compartment model with a HYBRID III occupant model and an input load pulse calculated in the second step.The dynamic responses of the car are analyzed by changing impact conditions such as impact angle and impact velocity.The injury risks of the occupants are discussed in terms of the occupant kinematics and calculated parameters:accelerations of the head,chest,and pelvis,as well as HIC value.Verification of model with experimental data is performed.Possible countermeasures for highway vehicle traffic safety and improvement of roadside barrier design are presented.Research prospects in this field are also proposed.

  3. Modeling of Car-Following Required Safe Distance Based on Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Dayi Qu

    2014-01-01

    Full Text Available In car-following procedure, some distances are reserved between the vehicles, through which drivers can avoid collisions with vehicles before and after them in the same lane and keep a reasonable clearance with lateral vehicles. This paper investigates characters of vehicle operating safety in car following state based on required safe distance. To tackle this problem, we probe into required safe distance and car-following model using molecular dynamics, covering longitudinal and lateral safe distance. The model was developed and implemented to describe the relationship between longitudinal safe distance and lateral safe distance under the condition where the leader keeps uniform deceleration. The results obtained herein are deemed valuable for car-following theory and microscopic traffic simulation.

  4. Tire Changes, Fresh Air, and Yellow Flags: Challenges in Predictive Analytics for Professional Racing.

    Science.gov (United States)

    Tulabandhula, Theja; Rudin, Cynthia

    2014-06-01

    Our goal is to design a prediction and decision system for real-time use during a professional car race. In designing a knowledge discovery process for racing, we faced several challenges that were overcome only when domain knowledge of racing was carefully infused within statistical modeling techniques. In this article, we describe how we leveraged expert knowledge of the domain to produce a real-time decision system for tire changes within a race. Our forecasts have the potential to impact how racing teams can optimize strategy by making tire-change decisions to benefit their rank position. Our work significantly expands previous research on sports analytics, as it is the only work on analytical methods for within-race prediction and decision making for professional car racing.

  5. Behavioural Comparison of Driverswhen Driving a Motorcycle or a Car: A Structural Equation Modelling Study

    OpenAIRE

    Darja Topolšek; Dejan Dragan

    2015-01-01

    The goal of the study was to investigate if the drivers behave in the same way when they are driving a motorcycle or a car. For this purpose, the Motorcycle Rider Behaviour Questionnaire and Driver Behaviour Questionnaire were conducted among the same drivers population. Items of questionnaires were used to develop a structural equation model with two factors, one for the motorcyclist’s behaviour, and the other for the car driver’s behaviour. Exploratory and confirmatory factor analyses were ...

  6. Safe distance car-following model including backward-looking and its stability analysis

    Science.gov (United States)

    Yang, Da; Jin, Peter Jing; Pu, Yun; Ran, Bin

    2013-03-01

    The focus of this paper is the car-following behavior including backward-looking, simply called the bi-directional looking car-following behavior. This study is motivated by the potential changes of the physical properties of traffic flow caused by the fast developing intelligent transportation system (ITS), especially the new connected vehicle technology. Existing studies on this topic focused on general motors (GM) models and optimal velocity (OV) models. The safe distance car-following model, Gipps' model, which is more widely used in practice have not drawn too much attention in the bi-directional looking context. This paper explores the property of the bi-directional looking extension of Gipps' safe distance model. The stability condition of the proposed model is derived using the linear stability theory and is verified using numerical simulations. The impacts of the driver and vehicle characteristics appeared in the proposed model on the traffic flow stability are also investigated. It is found that taking into account the backward-looking effect in car-following has three types of effect on traffic flow: stabilizing, destabilizing and producing non-physical phenomenon. This conclusion is more sophisticated than the study results based on the OV bi-directional looking car-following models. Moreover, the drivers who have the smaller reaction time or the larger additional delay and think the other vehicles have larger maximum decelerations can stabilize traffic flow.

  7. A Novel Approach in Designing PID Controller for Semi-active Quarter Car Model

    Directory of Open Access Journals (Sweden)

    Mehta Vedant

    2016-01-01

    Full Text Available This paper implements Teaching-Learning based optimization (TLBO to obtain optimized value of spring stiffness for better ride comfort. Further, this optimized value is then used in a semi-active quarter car setup to remove any discrepancies due to non-optimized spring. This paper also introduces a novel approach to control the Semi-active suspension parameter (damping coefficient for a better performance. For controlling semi-active parameters, PID controller has been used. PID controller output is fed to the quarter car setup as a damping coefficient. Thus changing the damping coefficient dynamically as the disturbance occurs, and thus improving the ride comfort. The sprung mass acceleration and rattle space of semi-active quarter car has been compared with sprung mass acceleration and rattle space of passive quarter car model to show the difference in results and thereby, results and conclusions are drawn.

  8. An Improved General Motor Car-Following Model considering the Lateral Impact

    Directory of Open Access Journals (Sweden)

    Pengfei Tao

    2015-02-01

    Full Text Available We improve the typical GM car-following model. In order to describe the impacts of the lateral offset between the vehicles in car-following state, this paper proposes time distance to measure the drivers' attention of driving environment and uses generalized expectation headway to describe the ideal driving state of the driver. Take the difference between the actual and expected headway as the important standard for driver to decide whether to speed up or slow down. Then take the drivers' attentions and the expected headway as the decision-making factors, and consider them while revising the GM car-following model. The numerical simulation shows the improved GM model conforms to the general driving behavior, enhances the function of the typical model, and strengthens the model stability.

  9. Numerical and experimental investigations of drag force on scaled car model

    Directory of Open Access Journals (Sweden)

    Ponnusamy Nallusamy Selvaraju

    2016-01-01

    Full Text Available The numerical simulation and wind tunnel experiment were involved to observe the aerodynamic characteristics of car model. The investigation of aerodynamic characteristics on car model were difficult by using wind tunnel. It provides more comprehensive experimental data as a reference to validate the numerical simulation. In the wind tunnel experiments, the pressures on various ports over the car model were measured by using pressure scanner (64 bit channels. The drag force was calculated based on experimental and computational results. The realizable k-e model was employed to compute the aerodynamic drag and surface pressure distribution over a car model simulated at various wind velocity. The tetrahedron mesh approach was used to discretize the computational domain for accuracy. The computational results showed a good agreement with the experimental data and the results revealed that the induced aerodynamic drag determines the best car shape. In order to reveal the internal connection between the aerodynamic drag and wake vortices, the turbulent kinetic, re-circulation length, position of vortex core, and velocity profile in the wake were investigated by numerical analysis.

  10. Vehicles' Sample Generation and Realization in Car-Following Mathematical Models

    Directory of Open Access Journals (Sweden)

    Algimantas Danilevičius

    2016-02-01

    Full Text Available The object of the article is the adjustment of car-following mathematical models according to collected traffic data. Here the problem of ineffectively burdened road section is solved by adjusting the speed of vehicles in order to reduce the distance between the cars to a safe distance. The paper analyzes the car-following models to measure the interaction between vehicles in the same lane. Experimental data processed in Matlab and traffic distribution histograms are created using the most appropriate distribution curve. Distribution curve is used to compile congestion scenario of road section. Applicable model uses fundamental diagrams, which are created from the kind of traffic flow measurements. The mathematical model allows to choose the optimal vehicle speed while maintaining safe distance between vehicles, and to make recommendations to improve the traffic as the process.

  11. Integration of Theory of Planned Behavior and Norm Activation Model on Student Behavior Model Using Cars for Traveling to Campus

    Directory of Open Access Journals (Sweden)

    Setiawan, R.

    2014-01-01

    Full Text Available Although there are clear environmental, economic, and social drawbacks in using private vehicles, students still choose cars to get to campus. This study reports an investigation of psychological factors influencing this behavior from the perspective of the Theory of Planned Behavior and Norm Activation Model. Students from three different university campuses in Surabaya, Indonesia, (n = 312 completed a survey on their car commuting behavior. Results indicated that perceived behavioral control and personal norm were the strongest factors that influence behavioral intention. Attitude, subjective norm, perceived behavioral control, and personal norm explain 62.7% variance of the behavioral intention. In turn, behavioral intention explains 42.5% of the variance of the actual car use. Implications of these findings are that in order to alter the use of car, university should implement both structural and psychological interventions. Effective interventions should be designed to raise the awareness of negative aspects of car use.

  12. Phase transitions in a new car-following traffic flow model

    Institute of Scientific and Technical Information of China (English)

    Li Li; Shi Peng-Fei

    2005-01-01

    In this paper, we investigate the performance of the well-known optimal velocity car-following model(the OVM) with numerical simulation in describing the acceleration process that is induced by the motion of a ldading car with a pre-specifide speed profile. Results show that this model is to some extent deficient in performing this process. Modification of the OVM to overcome the deficiency is demonstrated. The linear stability for the modified model is analysed. If the linear stability condition can not be satisfied, phase transitions occur on varying the initial homogeneous headway of the traffic flow.

  13. Numerical analysis on car-following traffic flow models with delay time

    Institute of Scientific and Technical Information of China (English)

    LI Li; SHI Peng-fei

    2006-01-01

    Effects of the speed relaxation time on the optimal velocity car-following model (OVM) with delay time due to driver reaction time proposed by Bando et al.(1995) were studied by numerical methods. Results showed that the OVM including the delay is not physically sensitive to the speed relaxation times. A modified car-following model is proposed to overcome the deficiency. Analyses of the linear stability of the modified model were conducted. It is shown that coexisting flows appear ifthe initial homogeneous headway of the traffic flow is between critical values. In addition, phase transitions occur on varying the initially homogeneous headway.

  14. Traffic chaos and its prediction based on a nonlinear car-following model

    Institute of Scientific and Technical Information of China (English)

    Hui FU; Jianmin XU; Lunhui XU

    2005-01-01

    This paper discusses the dynamic behavior and its predictions for a simulated traffic flow based on the nonlinear response of a vehicle to the leading car's movement in a single lane.Traffic chaos is a promising field,and chaos theory has been applied to identify and predict its chaotic movement.A simulated traffic flow is generated using a car-following model(GM model),and the distance between two cars is investigated for its dynamic properties.A positive Lyapunov exponent confirms the existence of chaotic behavior in the GM model.A new algorithm using a RBF NN (radial basis function neural network) is proposed to predict this traffic chaos.The experiment shows that the chaotic degree and predictable degree are determined by the first Lyapunov exponent.The algorithm proposed in this paper can be generalized to recognize and predict the chaos of short-time traffic flow series.

  15. A new car-following model with consideration of the traffic interruption probability

    Institute of Scientific and Technical Information of China (English)

    Tang Tie-Qiao; Huang Hai-Jun; Wong S. C.; Jiang Rui

    2009-01-01

    In this paper, we present a new car-following model by taking into account the effects of the traffic interruption probability on the car-following behaviour of the following vehicle. The stability condition of the model is obtained by using the linear stability theory. The modified Korteweg-de Vries (KdV) equation is constructed and solved, and three types of traffic flows in the headway sensitivity space-stable, metastable, and unstable-are classified. Both the analytical and simulation results show that the traffic interruption probability indeed has an influence on driving behaviour, and the consideration of traffic interruption probability in the car-following model could stabilize traffic flow.

  16. An Improved Car-Following Model in Vehicle Networking Based on Network Control

    Directory of Open Access Journals (Sweden)

    D. Y. Kong

    2014-01-01

    Full Text Available Vehicle networking is a system to realize information interoperability between vehicles and people, vehicles and roads, vehicles and vehicles, and cars and transport facilities, through the network information exchange, in order to achieve the effective monitoring of the vehicle and traffic flow. Realizing information interoperability between vehicles and vehicles, which can affect the traffic flow, is an important application of network control system (NCS. In this paper, a car-following model using vehicle networking theory is established, based on network control principle. The car-following model, which is an improvement of the traditional traffic model, describes the traffic in vehicle networking condition. The impact that vehicle networking has on the traffic flow is quantitatively assessed in a particular scene of one-way, no lane changing highway. The examples show that the capacity of the road is effectively enhanced by using vehicle networking.

  17. Modeling Car-Following Dynamics During the Starting and Stopping Process Based on a Spring System Model

    Institute of Scientific and Technical Information of China (English)

    王殿海; 杨少辉; 初连禹

    2004-01-01

    Car-following models describe how one vehicle follows the preceding vehicles. In order to better model and explain car-following dynamics, this paper categorizes the state of a traveling vehicle into three sub-processes: the starting (acceleration) process, the car-following process, and the stopping (deceleration) process. The starting process primarily involves vehicle acceleration behavior. The stopping process involves not only car-following behavior but also deceleration behavior. This paper regards both the stopping process and the starting process as spring systems. The car-following dynamics during the starting process and the stopping process is modeled in this paper. The parameters of the proposed models, which are represented in the form of trigonometric functions, possess explicit physical meaning and definitive ranges. We have calibrated the model of the starting process using data from the Traffic Engineering Handbook, and obtained reasonable results. Compared with traditional stimulus-response car-following models, this model can better explain traffic flow phenomena and driver behavior theory.

  18. Modelling the evolution of common cuckoo host-races: speciation or genetic swamping?

    Science.gov (United States)

    Krüger, O; Kolss, M

    2013-11-01

    Co-evolutionary arms races have provided clear evidence for evolutionary change, especially in host-parasite systems. The evolution of host-specific races in the common cuckoo (Cuculus canorus), however, is also an example where sexual conflict influences the outcome. Cuckoo females benefit from better adaptation to overcome host defences, whereas cuckoo males face a trade-off between the benefits of better adaptation to a host and the benefits of multiple mating with females from other host-races. The outcome of this trade-off might be genetic differentiation or prevention of it by genetic swamping. We use a simulation model to test which outcome is more likely with three sympatric cuckoo host-races. We assume a cost for cuckoo chicks that express a host adaptation allele not suited to their foster host species and that cuckoo males that switch to another host-race experience either a fitness benefit or cost. Over most of the parameter space, cuckoo male host-race fidelity increases significantly with time, and gene flow between host-races ceases within a few thousand to a hundred thousand generations. Our results hence support the idea that common cuckoo host-races might be in the incipient stages of speciation.

  19. A Stochastic Route Choice Model for Car Travellers in the Copenhagen Region

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker; Frederiksen, Rasmus Dyhr; Daly, A.

    2002-01-01

    The paper presents a large-scale stochastic road traffic assignment model for the Copenhagen Region. The model considers several classes of passenger cars (different trip purposes), vans and trucks, each with its own utility function on which route choices are based. The utility functions include...

  20. An improved car-following model considering variable safety headway distance

    Science.gov (United States)

    Jia, Yu-han; Du, Yi-man; Wu, Jian-ping

    2014-12-01

    Considering high speed following on expressway or highway, an improved car-following model is developed in this paper by introducing variable safety headway distance. Stability analysis of the new model is carried out using the control theory method. Finally, numerical simulations are implemented and the results show good consistency with theoretical study.

  1. An improved car-following model considering variable safety headway distance

    OpenAIRE

    Jia, Yuhan; Wu, Jianping; Du, Yiman

    2014-01-01

    Considering high speed following on expressway or highway, an improved car-following model is developed in this paper by introducing variable safety headway distance. Stability analysis of the new model is carried out using the control theory method. Finally, numerical simulations are implemented and the results show good consistency with theoretical study.

  2. MACRO MODEL OF SEAT BELT USE BY CAR DRIVERS AND PASSENGERS

    Directory of Open Access Journals (Sweden)

    Kazimierz JAMROZ

    2013-12-01

    Full Text Available The article presents some problems of seat belt use by car drivers and passengers. It looks in particular at seat belt use and effectiveness in selected countries. Next, factors of seat belt use are presented and methodology of model development. A macro model of seat belt use is presented based on data from around fifty countries from different continents.

  3. The tariff for fire and theft car insurance: analysis with a Cox model

    Directory of Open Access Journals (Sweden)

    Bruno Scarpa

    2013-05-01

    Full Text Available In this paper we analyze the problem of identification of a tariff for a Fire & Theft Car policy for Insurance Companies. Usually companies obtain this tariff by empirical estimate of the pure rate by evaluating the impact of some personalization variables. In this paper we propose the usage of a semi-parametric Cox model, where the response variable is not the waiting time until an event, but the degree of damage because of theft or fire of a car. The proposed model allows to easily tackle typical problems in data available to the companies, like the presence of franchises, which are treated as censored data.

  4. The Stability Analysis for an Extended Car Following Model Based on Control Theory

    Science.gov (United States)

    Ge, Hong-Xia; Meng, Xiang-Pei; Zhu, Ke-Qiang; Cheng, Rong-Jun

    2014-08-01

    A new method is proposed to study the stability of the car-following model considering traffic interruption probability. The stability condition for the extended car-following model is obtained by using the Lyapunov function and the condition for no traffic jam is also given based on the control theory. Numerical simulations are conducted to demonstrate and verify the analytical results. Moreover, numerical simulations show that the traffic interruption probability has an influence on driving behavior and confirm the effectiveness of the method on the stability of traffic flow.

  5. Microscopic Calibration and Validation of Car-Following Models -- A Systematic Approach

    CERN Document Server

    Treiber, Martin

    2014-01-01

    Calibration and validation techniques are crucial in assessing the descriptive and predictive power of car-following models and their suitability for analyzing traffic flow. Using real and generated floating-car and trajectory data, we systematically investigate following aspects: Data requirements and preparation, conceptional approach including local maximum-likelihood and global LSE calibration with several objective functions, influence of the data sampling rate and measuring errors, the effect of data smoothing on the calibration result, and model performance in terms of fitting quality, robustness, parameter orthogonality, completeness and plausible parameter values.

  6. Outlier-Tolerance RML Identification of Parameters in CAR Model

    Directory of Open Access Journals (Sweden)

    Hong Teng-teng

    2016-10-01

    Full Text Available The measured data inevitably contain abnormal data under the normal operating conditions. Most of the existing algorithms, such as least squares identification and maximum likelihood estimation, are easily affected by abnormal data and appear large indentation deviation. It is a difficult task needed to be addressed that how to improve the sensitivity of the existing algorithm or build a new parameter identifying algorithm with outlier-tolerance ability to abnormal data in system identification technology application. In this paper, the sensitivity of the RML to the sampled abnormal data was analyzed and a new improvement algorithm of CAR process is established to improve outlier-tolerance ability of the RML identification when there are outliers in the sampling series. The improved algorithm not only effectively inhibits the negative impact of the abnormal data but also effectively improve the quality of the parameter identification results. Some simulation given in this paper shows that the improved RML algorithm has strong outlier-tolerance. This paper’s research results play an important role in engineering control, signal processing, industrial automation and aerospace or other fields.

  7. ACEEE's green book: The environmental guide to cars and trucks, Model year 2000

    Energy Technology Data Exchange (ETDEWEB)

    DeCicco, J.; Kliesch, J.; Thomas, M.

    2000-07-01

    This pathbreaking guide ranks cars and trucks according to environmental friendliness. Buyers can compare cars, vans, pickups, and sport utility vehicles by their environmental impacts, including air pollution, global warming, and fuel efficiency. Inside the guide: how to buy the cleanest and most efficient vehicle that meets your needs; Green Scores for all 2000 makes and models, listed by class--compact, mid-size, and large cars, vans, pickups, and sport utilities; Best of 2000 section featuring the greenest models in each class; Green by Design chapter highlighting advanced technologies and what makes some vehicles greener than others; listings for electric and other alternative fuel vehicles in addition to gasoline and diesel vehicles; tips on keeping your vehicle running cleanly and efficiently; and the environmental impacts of vehicles, including global warming and the health effects of vehicle pollution.

  8. Modeling the Turning Speed and Car Following Behaviors of Autonomous Vehicles in a Virtual World

    Directory of Open Access Journals (Sweden)

    Carrillo-González José Gerardo

    2015-07-01

    Full Text Available This article deals with mathematical models for controlling vehicles behavior in a virtual world, where two behaviors are considered: 1 curve turning and 2 car following situations, in this last is essential to provide a safety distance between the leader and the follower and at the same time keep the follower not delayed with respect to the leader, and in a curve turning the complexity is to provide a safety speed inside the curve and keep the car inside the lane. Using basic information as vehicles position, mathematical models can be developed for explaining the heading angle and the autonomous vehicles speed on curves, i.e. the controlled by the models. A model that predicts the autonomous vehicle speed on curves is developed considering previous data in other curves. Two models that control the acceleration/deceleration behavior of autonomous vehicles in a car following situation are proposed. In the first model, the parameters are calibrated with a proposed algorithm which enables accuracy in order to imitate the human behavior for accelerating and braking, and the second model provides a safety distance between the follower and the leader at sudden stops of the latter and employs the acceleration/deceleration top capabilities to follow the leader car similar to the human behavior.

  9. How skill expertise shapes the brain functional architecture: an fMRI study of visuo-spatial and motor processing in professional racing-car and naïve drivers.

    Science.gov (United States)

    Bernardi, Giulio; Ricciardi, Emiliano; Sani, Lorenzo; Gaglianese, Anna; Papasogli, Alessandra; Ceccarelli, Riccardo; Franzoni, Ferdinando; Galetta, Fabio; Santoro, Gino; Goebel, Rainer; Pietrini, Pietro

    2013-01-01

    The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI), we measured brain activity while eleven Formula racing-car drivers and eleven 'naïve' volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD) signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both 'quantitative' and 'qualitative' modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased 'neural efficiency' in the brain of highly skilled individuals.

  10. Cloud-Aerosol-Radiation (CAR) Ensemble Modeling System:Overall Accuracy and Efficiency

    Institute of Scientific and Technical Information of China (English)

    Feng ZHANG; Xin-Zhong LIANG; ZENG Qingcun; Yu GU; Shenjian SU

    2013-01-01

    The Cloud-Aerosol-Radiation (CAR) ensemble modeling system has recently been built to better understand cloud/aerosol/radiation processes and determine the uncertainties caused by different treatments of cloud/aerosol/radiation in climate models.The CAR system comprises a large scheme collection of cloud,aerosol,and radiation processes available in the literature,including those commonly used by the world's leading GCMs.In this study,detailed analyses of the overall accuracy and efficiency of the CAR system were performed.Despite the different observations used,the overall accuracies of the CAR ensemble means were found to be very good for both shortwave (SW) and longwave (LW) radiation calculations.Taking the percentage errors for July 2004 compared to ISCCP (International Satellite Cloud Climatology Project)data over (60°N,60°S) as an example,even among the 448 CAR members selected here,those errors of the CAR ensemble means were only about-0.67% (-0.6 W m-2) and-0.82% (-2.0 W m-2) for SW and LW upward fluxes at the top of atmosphere,and 0.06% (0.1 W m-2) and-2.12% (-7.8 W m-2) for SW and LW downward fluxes at the surface,respectively.Furthermore,model SW frequency distributions in July 2004 covered the observational ranges entirely,with ensemble means located in the middle of the ranges.Moreover,it was found that the accuracy of radiative transfer calculations can be significantly enhanced by using certain combinations of cloud schemes for the cloud cover fraction,particle effective size,water path,and optical properties,along with better explicit treatments for unresolved cloud structures.

  11. GENERAL: Considering Backward Effect in Coupled Map Car-Following Model

    Science.gov (United States)

    Yu, Han-Mei; Cheng, Rong-Jun; Ge, Hong-Xia

    2010-07-01

    Based on the pioneer work of Konishi et al., a new control method is proposed to suppress the traffic congestion in the coupled map (CM) car-following model under open boundary condition. The influence of the following car to the system has been considered. Our method and that presented by Konishi et al. [Phys. Rev. E 60 (1999) 4000] are compared. Although both the methods could suppress the traffic jam, the simulation results show that the temporal behavior obtained by ours is better than that proposed by the Konishi's et al. The simulation results are consistent with the theoretical analysis.

  12. Development of dynamical model of wheel machinery allocated on a flat–car

    Directory of Open Access Journals (Sweden)

    Khabibulla TURANOV

    2010-01-01

    Full Text Available The paper gives the results of dynamical modeling of the mechanical system “flat car – elastic elements – wheel machinery body”, allocated on a railway flat car. There have been obtained the formulas of equivalent rigidity of fastening spatial flexible elements relative to a vertical line, which are equal to rigidity of bus and spring flexible elements being plugged in series and which are then equal to rigidity of all elastic elements of wheeled machinery as springs being plugged in parallel.

  13. Measurement and modeling of race and health in Brazil: continuing the discussion.

    Science.gov (United States)

    Hicken, Margaret T

    2017-05-25

    Recent reviews have discussed the conceptualization of race in health studies in Brazil. This review further documents and discusses specific measurement and modeling issues with regard to race and how this can impact result interpretation. Three scientific databases were used to search the literature on race and three health outcomes. The search yielded 38 empirical studies on birth outcomes, self-rated health, and weight. Results suggest that, while there are racial patterns in the overall literature, conceptual and methodological challenges can be addressed to clarify the ways in which racial group membership is linked to health.

  14. The Research of Car-Following Model Based on Real-Time Maximum Deceleration

    Directory of Open Access Journals (Sweden)

    Longhai Yang

    2015-01-01

    Full Text Available This paper is concerned with the effect of real-time maximum deceleration in car-following. The real-time maximum acceleration is estimated with vehicle dynamics. It is known that an intelligent driver model (IDM can control adaptive cruise control (ACC well. The disadvantages of IDM at high and constant speed are analyzed. A new car-following model which is applied to ACC is established accordingly to modify the desired minimum gap and structure of the IDM. We simulated the new car-following model and IDM under two different kinds of road conditions. In the first, the vehicles drive on a single road, taking dry asphalt road as the example in this paper. In the second, vehicles drive onto a different road, and this paper analyzed the situation in which vehicles drive from a dry asphalt road onto an icy road. From the simulation, we found that the new car-following model can not only ensure driving security and comfort but also control the steady driving of the vehicle with a smaller time headway than IDM.

  15. Comparative Genre Analysis on RA Introductions of Computer Science Using CARS Model

    Institute of Scientific and Technical Information of China (English)

    杨文静

    2013-01-01

    Using Swales’CARS model, the present study combines the methods of quantitative analysis and qualitative analysis and makes a comparative analysis on the moves and steps of RA introductions between Chinese English journals and international English journals, which will benefit researchers in RA writing and publishing in core English journals.

  16. Task-Difficulty Homeostasis in Car Following Models: Experimental Validation Using Self-Paced Visual Occlusion.

    Science.gov (United States)

    Pekkanen, Jami; Lappi, Otto; Itkonen, Teemu H; Summala, Heikki

    2017-01-01

    Car following (CF) models used in traffic engineering are often criticized for not incorporating "human factors" well known to affect driving. Some recent work has addressed this by augmenting the CF models with the Task-Capability Interface (TCI) model, by dynamically changing driving parameters as function of driver capability. We examined assumptions of these models experimentally using a self-paced visual occlusion paradigm in a simulated car following task. The results show strong, approximately one-to-one, correspondence between occlusion duration and increase in time headway. The correspondence was found between subjects and within subjects, on aggregate and individual sample level. The long time scale aggregate results support TCI-CF models that assume a linear increase in time headway in response to increased distraction. The short time scale individual sample level results suggest that drivers also adapt their visual sampling in response to transient changes in time headway, a mechanism which isn't incorporated in the current models.

  17. A new multi-anticipative car-following model with consideration of the desired following distance

    OpenAIRE

    Chen, J.; Liu, R.; Ngoduy, D; Shi, Z.

    2016-01-01

    We propose in this paper an extension of the multi-anticipative optimal velocity car-following model to consider explicitly the desired following distance. The model on the following vehicle’s acceleration is formulated as a linear function of the optimal velocity and the desired distance, with reaction-time delay in elements. The linear stability condition of the model is derived. The results demonstrate that the stability of traffic flow is improved by introducing the desired following dist...

  18. Modelling the effect on injuries and fatalities when changing mode of transport from car to bicycle.

    Science.gov (United States)

    Nilsson, Philip; Stigson, Helena; Ohlin, Maria; Strandroth, Johan

    2017-03-01

    Several studies have estimated the health effects of active commuting, where a transport mode shift from car to bicycle reduces risk of mortality and morbidity. Previous studies mainly assess the negative aspects of bicycling by referring to fatalities or police reported injuries. However, most bicycle crashes are not reported by the police and therefore hospital reported data would cover a much higher rate of injuries from bicycle crashes. The aim of the present study was to estimate the effect on injuries and fatalities from traffic crashes when shifting mode of transport from car to bicycle by using hospital reported data. This present study models the change in number of injuries and fatalities due to a transport mode change using a given flow change from car to bicycle and current injury and fatality risk per distance for bicyclists and car occupants. show that bicyclists have a much higher injury risk (29 times) and fatality risk (10 times) than car occupants. In a scenario where car occupants in Stockholm living close to their work place shifts transport mode to bicycling, injuries, fatalities and health loss expressed in Disability-Adjusted Life Years (DALY) were estimated to increase. The vast majority of the estimated DALY increase was caused by severe injuries and fatalities and it tends to fluctuate so that the number of severe crashes may exceed the estimation with a large margin. Although the estimated increase of traffic crashes and DALY, a transport mode shift is seen as a way towards a more sustainable society. Thus, this present study highlights the need of strategic preventive measures in order to minimize the negative impacts from increased bicycling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Enhancing and Calibrating the Rakha-Pasumarthy-Adjerid Car-Following Model using Naturalistic Driving Data

    Directory of Open Access Journals (Sweden)

    John D. Sangster, PE

    2014-09-01

    Full Text Available The research presented in this paper analyzes the simplified behavioral vehicle longitudinal motion model, currently implemented in the INTEGRATION software, known as the Rakha-Pasumarthy-Adjerid (RPA model. The model utilizes a steady-state formulation along with two constraints, namely: acceleration and collision avoidance. An analysis of the model using the naturalistic driving data identified a deficiency in the model formulation, in that it predicts more conservative driving behavior compared to naturalistic driving. Much of the error in simulated car-following behavior occurs when a car-following event is initiated at a spacing that is often much shorter than is desired. The observed behavior is that, rather than the following vehicle decelerating aggressively, the following vehicle coasts until the desired headway/spacing is achieved. Consequently, the model is enhanced to reflect this empirically observed behavior. Finally, a quantitative and qualitative evaluation of the original and proposed model formulations demonstrates that the proposed modification significantly decreases the modeling error and produces car-following behavior that is consistent with empirically observed driver behavior.

  20. DYNAMICS OF FREIGHT CARS ON BOGIES MODEL 18-1711 WITH DIFFERENT WEDGE DE-SIGNS OF SPRING SUSPENSION

    Directory of Open Access Journals (Sweden)

    N. B. Mankevych

    2014-01-01

    Full Text Available Purpose. To analyze the results of the study of dynamic parameters of a gondola car, model 12-1704-04 with axle load 23.5 ton in bogies, models 18-1750 and two gondola cars, model 12-1905 with axial load of 25 ton, one of which is equipped with bogies, model 18-1711 with friction wedges of spring suspension with spatial form with increased angle to the horizontal line of intersection of the contact surfaces between the wedge and bolster, the other gondola car, model 12-1905 is equipped with bogies of the same model on which the friction wedges fitted with a flat form of contact surface. It has an angle of inclination like a wedge of bogie, model 18-100. On the basis of the obtained results to draw conclusions about the feasibility of unification design bogie bolster, model 18-1711 with bogie, model 18-100 by contact surfaces with elements of spring suspension. Methodology. Research on dynamic performance of cars was performed during running dynamic tests of specimens of freight cars in experimental train consisting of two locomotives, a laboratory, and three gondola cars of the above mentioned models. Findings. Main results of dynamic studies are presented as graphs of indicators on the speed of the train and the experimental evidence that the freight gondola cars on bogies, model 18-1711 with flat-shaped wedges, in most cases are better than the others. Originality. Research results of cars on bogies, model 18-1711 were obtained. They let assess the dependence of the dynamic performance of the car from the design of the friction wedges of spring suspension. Practical value. Cast parts of bogie, model 18-1711 with 25 ton axle load can be used as a replacement of defective parts of bogie, model 18-100 and its analogs.

  1. Exact Shock Solution of a Coupled System of Delay Differential Equations: A Car-Following Model

    Science.gov (United States)

    Tutiya, Yohei; Kanai, Masahiro

    2007-08-01

    In this letter, we present exact shock solutions of a coupled system of delay differential equations, which was introduced as a traffic-flow model called car-following model. We use the Hirota method, originally developed in order to solve soliton equations. The relevant delay differential equations have been known to allow exact solutions expressed by elliptic functions with periodic boundary conditions. In the present work, however, shock solutions are obtained with open boundaries, representing the stationary propagation of a traffic jam.

  2. A Bi-modal Model for Chinese Cities: City Size, Car Use and Land Rent

    Institute of Scientific and Technical Information of China (English)

    DAI Teqi; WANG Liang; ZHOU Binxue

    2016-01-01

    China is experiencing rapid urbanization and motorization.Urban transport congestion poses a challenge to the cities of China.Policies have been made trying to control the car use and the land use in Chinese cities without sound modelling researches.The existing literature on monocentric city modelling has shown that the parameters are critical for the outcome of the modelling.Following the Alonso-type monocentric model,this paper introduces a bi-modal model to simulate the city size,the distribution of land rent and the modal substitution in Chinese cities.We set the key parameters according to the recent available data of China's cities,and re-explain the hypothesis of the model.Then we make a sensitivity analysis to reveal the impacts of key parameters on the Chinese cities.According to the results,we find that the wage,the price of car use and the agriculture rent have significant impacts on city size.The land supply for the private transport or the public transport has the strongest impacts on car use and the level of transport congestion.The total population of the city and the wage level have strong impacts on land rent.Some results are counter-intuitive,but explainable.We also discuss implication of these results for policy making.

  3. An Improved Approach for Detecting Car in Video using Neural Network Model

    Directory of Open Access Journals (Sweden)

    S. N. Sivanandam

    2012-01-01

    Full Text Available The study represents a novel approach taken towards car detection, feature extraction and classification in a video. Though many methods have been proposed to deal with individual features of a vehicle, like edge, license plate, corners, no system has been implemented to combine features. Combination of four unique features, namely, color, shape, number plate and logo gives the application a stronghold on various applications like surveillance recording to detect accident percentage(for every make of a company, authentication of a car in the Parliament(for high security, learning system(readily available knowledge for automobile tyro enthusiasts with increased accuracy of matching. Video surveillance is a security solution for government buildings, facilities and operations. Installing this system can enhance existing security systems or help start a comprehensive security solution that can keep the building, employees and records safe. The system uses a Haar cascaded classifier to detect a car in a video and implements an efficient algorithm to extract the color of it along with the confidence rating. An gadabouts trained classifier is used to detect the logo (Suzuki/Toyota/Hyunadai of the car whose accuracy is enhanced by implementing SURF matching. A combination of blobs and contour tracing is applied for shape detection and model classification while number plate detection is performed in a smart and efficient algorithm which uses morphological operations and contour tracing. Finally, a trained, single perceptron neural network model is integrated with the system for identifying the make of the car. A thorough work on the system has proved it to be efficient and accurate, under different illumination conditions, when tested with a huge dataset which has been collected over a period of six months.

  4. Bifurcations and multiple traffic jams in a car-following model with reaction-time delay

    Science.gov (United States)

    Orosz, Gábor; Krauskopf, Bernd; Wilson, R. Eddie

    2005-11-01

    We investigate an optimal velocity car-following model for n cars on a circular single-lane road, where reaction-time delay of drivers is taken into account. The stability of the uniform flow equilibrium is studied analytically, while bifurcating periodic solutions for different wave numbers are investigated with numerical continuation techniques. This reveals that the periodic solution with the smallest wave number may be stable, and all other periodic solutions are unstable. As n is increased, periodic solutions develop stop- and go-fronts that correspond to rapid deceleration and acceleration between regions of uniformly flowing and stagnant traffic. In terms of the positions of all cars on the ring these fronts are associated with traffic jams. All traffic jams form a traffic pattern that evolves under time, due to slow motion of the fronts. The traffic pattern corresponding to the stable periodic motion of cars is the only stable one. However, we find that other periodic orbits may be unstable only so weakly that they give rise to transient traffic jams that may persist for long times. Eventually, such traffic jams either merge with one another or disperse, until the stable traffic pattern is reached.

  5. Cellular automata model simulating traffic car accidents in the on-ramp system

    Science.gov (United States)

    Echab, H.; Lakouari, N.; Ez-Zahraouy, H.; Benyoussef, A.

    2015-01-01

    In this paper, using Nagel-Schreckenberg model we study the on-ramp system under the expanded open boundary condition. The phase diagram of the two-lane on-ramp system is computed. It is found that the expanded left boundary insertion strategy enhances the flow in the on-ramp lane. Furthermore, we have studied the probability of the occurrence of car accidents. We distinguish two types of car accidents: the accident at the on-ramp site (Prc) and the rear-end accident in the main road (Pac). It is shown that car accidents at the on-ramp site are more likely to occur when traffic is free on road A. However, the rear-end accidents begin to occur above a critical injecting rate αc1. The influence of the on-ramp length (LB) and position (xC0) on the car accidents probabilities is studied. We found that large LB or xC0 causes an important decrease of the probability Prc. However, only large xC0 provokes an increase of the probability Pac. The effect of the stochastic randomization is also computed.

  6. Comparing Numerical Integration Schemes for Time-Continuous Car-Following Models

    CERN Document Server

    Treiber, Martin

    2014-01-01

    When simulating trajectories by integrating time-continuous car-following models, standard integration schemes such as the forth-order Runge-Kutta method (RK4) are rarely used while the simple Euler's method is popular among researchers. We compare four explicit methods: Euler's method, ballistic update, Heun's method (trapezoidal rule), and the standard forth-order RK4. As performance metrics, we plot the global discretization error as a function of the numerical complexity. We tested the methods on several time-continuous car-following models in several multi-vehicle simulation scenarios with and without discontinuities such as stops or a discontinuous behavior of an external leader. We find that the theoretical advantage of RK4 (consistency order~4) only plays a role if both the acceleration function of the model and the external data of the simulation scenario are sufficiently often differentiable. Otherwise, we obtain lower (and often fractional) consistency orders. Although, to our knowledge, Heun's met...

  7. Modelling Research on Consumer Attitude Toward Car Brands

    OpenAIRE

    Vlad (Uta) Daniela Steluta

    2014-01-01

    A quantitative research of consumer behaviour usually takes under consideration the following processes: perception, information/ learning, motivation, attitude and actual behaviour. From all this dynamic processes that define consumer behaviour, attitude is the one process relatively stable in time, with a very strong affective and cognitive component. In attempt to model attitude research one need to take under consideration external factors that influence attitude formation as well as this...

  8. A two-dimensional CA model for traffic flow with car origin and destination

    Science.gov (United States)

    In-nami, Junji; Toyoki, Hiroyasu

    2007-05-01

    Dynamic phase transitions in a two-dimensional traffic flow model defined on a decorated square-lattice are studied numerically. The square-lattice point and the decorated site denote intersections and roads, respectively. In the present model, a car has a finite deterministic path between the origin and the destination, which is assigned to the car from the beginning. In this new model, we found a new phase between the free-flow phase and the frozen-jam phase that is absent from previous models. The new model is characterized by the persistence of a macroscopic cluster. Furthermore, the behavior in this macroscopic cluster phase is classified into three regions characterized by the shape of the cluster. The boundary of the three regions is phenomenologically estimated. When the trip length is short and the car density is high, both ends of the belt-like cluster connect to each other through the periodic boundary with some probability. This type of cluster is classified topologically as a string on a two-dimensional torus.

  9. Simulating train movement in railway traffic using a car-following model

    Institute of Scientific and Technical Information of China (English)

    Li Ke-Ping; Guan Li-Jia

    2009-01-01

    Based on a car-following model, in this paper, we propose a new traffic model for simulating train movement in railway traffic. In the proposed model, some realistic characteristics of train movement are considered, such as the distance headway and the safety stopping distance. Using the proposed traffic model, we analyse the space-time diagram of traffic flow, the trajectory of train movement, etc. Simulation results demonstrate that the proposed model can be successfully used for simulating the train movement. Some complex phenomena can be reproduced, such as the complex acceleration and deceleration of trains and the propagation of train delay.

  10. Modelling Accuracy of a Car Steering Mechanism with Rack and Pinion and McPherson Suspension

    Science.gov (United States)

    Knapczyk, J.; Kucybała, P.

    2016-08-01

    Modelling accuracy of a car steering mechanism with a rack and pinion and McPherson suspension is analyzed. Geometrical parameters of the model are described by using the coordinates of centers of spherical joints, directional unit vectors and axis points of revolute, cylindrical and prismatic joints. Modelling accuracy is assumed as the differences between the values of the wheel knuckle position and orientation coordinates obtained using a simulation model and the corresponding measured values. The sensitivity analysis of the parameters on the model accuracy is illustrated by two numerical examples.

  11. CERN Relay Race

    CERN Multimedia

    CERN Running Club

    2010-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 20 May, starting at 12.15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on the route, and how to register your team for the relay race, can be found at: https://espace.cern.ch/Running-Club/CERN-Relay

  12. CERN Relay Race 2009

    CERN Multimedia

    2009-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 14th May starting at 12:15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. More details on how to register your team for the relay race

  13. Model Application of Accounting Information Systems of Spare Parts Sales and Purchase on Car Service Company

    Directory of Open Access Journals (Sweden)

    Lianawati Christian

    2015-12-01

    Full Text Available The purpose of this research is to analyze accounting information systems of sales and purchases of spare parts in general car service companies and to identify the problems encountered and the needs of necessary information. This research used literature study to collect data, field study with observation, and design using UML (Unified Modeling Language with activity diagrams, class diagrams, use case diagrams, database design, form design, display design, draft reports. The result achieved is an application model of accounting information systems of sales and purchases of spare parts in general car service companies. As a conclusion, the accounting information systems of sales and purchases provides ease for management to obtain information quickly and easily as well as the presentation of reports quickly and accurately.

  14. LEAD ACID BATTERY MODELING FOR ELECTRIC CAR POWER SOURCES

    Directory of Open Access Journals (Sweden)

    Bambang Sri Kaloko

    2010-06-01

    Full Text Available Successful commercialization of electric vehicles will require a confluence of technology, market, economic, and political factors that transform EVs into an attractive choice for consumers. The characteristics of the traction battery will play a critical role in this transformation. The relationship between battery characteristics such as power, capacity and efficiency, and EV customer satisfaction are discussed based on real world experience. A general problem, however, is that electrical energy can hardly be stored. In general, the storage of electrical energy requires its conversion into another form of energy. Electrical energy is typically obtained through conversion of chemical energy stored in devices such as batteries. In batteries the energy of chemical compounds acts as storage medium, and during discharge, a chemical process occurs that generates energy which can be drawn from the battery in form of an electric current at a certain voltage. A computer simulation is developed to examine overall battery design with the MATLAB/Simulink. Battery modelling with this program have error level less than 5%.   Keywords: Electrochemistry, lead acid battery, stored energy

  15. Pneumatic active suspension system for a one-wheel car model using fuzzy reasoning and a disturbance observer.

    Science.gov (United States)

    Yoshimura, Toshio; Takagi, Atsushi

    2004-09-01

    This paper presents the construction of a pneumatic active suspension system for a one-wheel car model using fuzzy reasoning and a disturbance observer. The one-wheel car model can be approximately described as a nonlinear two degrees of freedom system subject to excitation from a road profile. The active control is composed of fuzzy and disturbance controls, and functions by actuating a pneumatic actuator. A phase lead-lag compensator is inserted to counter the performance degradation due to the delay of the pneumatic actuator. The experimental result indicates that the proposed active suspension improves much the vibration suppression of the car model.

  16. Pneumatic active suspension system for a one-wheel car model using fuzzy reasoning and a disturbance observer

    Institute of Scientific and Technical Information of China (English)

    YOSHIMURAToshio; TAKAGIAtsushi

    2004-01-01

    This paper presents the construction of a pneumatic active suspension system for a one-wheel car model using fuzzy reasoning and a disturbance observer. The one-wheel car model can be approximately described as a nonlinear two degrees of freedom system subject to excitation from a road profile. The active control is composed of fuzzy and disturbance controls, and the active control force is constructed by actuating a pneumatic actuator. A phase lead-lag compensator is inserted to counter the performance degradation due to the delay of the pneumatic actuator. The experimental result indicates that the proposed active suspension improves much the vibration suppression of the car model.

  17. An extended car-following model with consideration of the electric vehicle's driving range

    Science.gov (United States)

    Tang, Tie-Qiao; Chen, Liang; Yang, Shi-Chun; Shang, Hua-Yan

    2015-07-01

    In this paper, we propose a car-following model to explore the influences of the electric vehicle's driving range on the driving behavior under four traffic situations. The numerical results illustrate that the electric vehicle's behavior of exchanging battery at the charge station can destroy the stability of traffic flow and produce some prominent jams, and that the influences are related to the electric vehicle's driving range, i.e., the shorter the driving range is, the greater the effects are.

  18. Pulsive feedback control of a quarter car model forced by a road profile

    Energy Technology Data Exchange (ETDEWEB)

    Litak, G. [Department of Applied Mechanics, Technical University of Lublin, Nadbystrzycka 36, PL-20-618 Lublin (Poland)]. E-mail: g.litak@pollub.pl; Borowiec, M. [Department of Applied Mechanics, Technical University of Lublin, Nadbystrzycka 36, PL-20-618 Lublin (Poland); Ali, M. [Department of Mathematics, Faculty of Mathematical Science, University of Delhi, Delhi 110007 (India); Saha, L.M. [Zakhir Husain College, University of Delhi, Delhi 110002 (India); Friswell, M.I. [Department of Aerospace Engineering, University of Bristol, Queens Building, Bristol BS8 1TR (United Kingdom)

    2007-08-15

    We examine the strange chaotic attractor and its unstable periodic orbits for a one degree of freedom nonlinear oscillator with a non-symmetric potential that models a quarter car forced by the road profile. We propose an efficient method of chaos control that stabilizes these orbits using a pulsive feedback technique. A discrete set of pulses is able to transfer the system from one periodic state to another.

  19. Frontal Crash Analysis of a Fully Detailed Car Model Based on Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    Han Shan-Ling; Zhu Ping; Lin Zhong-Qin; Shi Yu-Liang

    2004-01-01

    This paper sets up a highly detailed finite element model of a car for frontal crashworthiness applications, and then explains the characteristics of it. The geometry model is preprocessed by Hypermesh software. The finite element method solver program selected for the simulation is LS-DYNA. After the crash simulation is carefully analyzed, the frontal crash experiment is aimed to validate the finite element model. The simulation results are basically in agreement with the experimental results. The validation of the finite element model is crucial for the further research in optimization of the automotive structure or lightweighting of the vehicle.

  20. Validation of a regression model for standardizing lifetime racing performances of thoroughbreds.

    Science.gov (United States)

    Martin, G S; Strand, E; Kearney, M T

    1997-06-01

    To determine the relationship between prediction errors of a regression model of racing finish times and earnings or finish position; the relationship between standardized finish times, determined by use of this model, and earnings or finish position; and whether this model was valid when applied to data for horses that underwent surgical treatment. Survey. Records of 6,700 healthy Thoroughbreds racing in Louisiana and of 31 Thoroughbreds with idiopathic left laryngeal hemiplegia that underwent surgical treatment. Predicted and standardized finish times were calculated by use of the regression model for healthy horses, and the relationships between prediction error (actual--predicted finish time) and standardized finish times, and earnings and finish position, were examined. Then, the regression model was applied to data for horses with hemiplegia to determine whether the model was valid when used to calculate predicted and standardized finish times for lifetime performance data. Prediction error and standardized finish times were negatively correlated with earnings and positively correlated with finish position and, thus, appeared to be reliable measures of racing performance. The regression model was found to be valid when applied to lifetime performance records of horses with laryngeal hemiplegia. Prediction error and standardized finish times are measures of racing performance that can be used to compare performances among Thoroughbred racehorses across a variety of circumstances that would otherwise confound comparison.

  1. Testing the race model inequality in redundant stimuli with variable onset asynchrony

    DEFF Research Database (Denmark)

    Gondan, Matthias

    2009-01-01

    to the high number of statistical tests, Type I and II errors are increased. Here a straightforward method is demonstrated to collapse these multiple tests into one test by summing the inequalities for the different SOAs. The power of the procedure is substantially increased by assigning specific weights......In speeded response tasks with redundant signals, parallel processing of the signals is tested by the race model inequality. This inequality states that given a race of two signals, the cumulative distribution of response times for redundant stimuli never exceeds the sum of the cumulative...... distributions of response times for the single-modality stimuli. It has been derived for synchronous stimuli and for stimuli with stimulus onset asynchrony (SOA). In most experiments with asynchronous stimuli, discrete SOA values are chosen and the race model inequality is separately tested for each SOA. Due...

  2. THE MODEL OF WORK IN PROCESS INVENTORY MANAGEMENT OF RAIL CARS BUILDING COMPANY

    Directory of Open Access Journals (Sweden)

    Julia BULGAKOVA

    2013-12-01

    Full Text Available The necessity of work-in-process management of rail-cars production by intelligent decision support software, which is based on JIT and Kanban principles, is identified. The scheme of one type cargo-flow movement between two workshops with control by electronic and traditional kanban-card is offered. For simulation of rail-cars production cargo flows Markov chain of M/M/1/1 type was applied. Simulation shows the dependence of the work-in-process on the in-flow and out-flow intensity. To determine the high level of the optimal work-in-process the stochastic inventory management model is applied.

  3. Behavioural Comparison of Driverswhen Driving a Motorcycle or a Car: A Structural Equation Modelling Study

    Directory of Open Access Journals (Sweden)

    Darja Topolšek

    2015-12-01

    Full Text Available The goal of the study was to investigate if the drivers behave in the same way when they are driving a motorcycle or a car. For this purpose, the Motorcycle Rider Behaviour Questionnaire and Driver Behaviour Questionnaire were conducted among the same drivers population. Items of questionnaires were used to develop a structural equation model with two factors, one for the motorcyclist’s behaviour, and the other for the car driver’s behaviour. Exploratory and confirmatory factor analyses were also applied in this study. Results revealed a certain difference in driving behaviour. The principal reason lies probably in mental consciousness that the risk-taking driving of a motorbike can result in much more catastrophic consequences than when driving a car. The drivers also pointed out this kind of thinking and the developed model has statistically confirmed the behavioural differences. The implications of these findings are also argued in relation to the validation of the appropriateness of the existing traffic regulations.

  4. Car accidents determined by stopped cars and traffic flow

    Science.gov (United States)

    Yang, Xian-qing; Ma, Yu-qiang

    2002-12-01

    The product of traffic flow and the fraction of stopped cars is proposed to determine the probability Pac for car accidents in the Fukui-Ishibashi model by analysing the necessary conditions of the occurrence of car accidents. Qualitative and quantitative characteristics of the probability Pac can well be explained. A strategy for avoiding car accidents is suggested.

  5. Modeling the vertical dynamics of a car on an mechatronic basis

    Directory of Open Access Journals (Sweden)

    Przemysław CHRÓST

    2015-09-01

    Full Text Available This paper presents the results obtained on the basis of the mechatronic model of a passenger car. In order to minimize the induced mechanical vibrations during drive event on a coarse road surface, a modification of the structure of the vehicle suspension has been applied. The proposed modification introduces additional active damping element, which task is to reduce the vertical displacement of the vehicle body. In the real world such a target can be achieved by use of appropriate control units, which drive the electronic and hydraulic components of the suspension. Additionally, the phenomenological models of the passengers have been included into the computer simulation model.

  6. Coupling Mechanism and Decoupled Suspension Control Model of a Half Car

    OpenAIRE

    Hailong Zhang; Ning Zhang; Fuhong Min; Subhash Rakheja; Chunyi Su; Enrong Wang

    2016-01-01

    A structure decoupling control strategy of half-car suspension is proposed to fully decouple the system into independent front and rear quarter-car suspensions in this paper. The coupling mechanism of half-car suspension is firstly revealed and formulated with coupled damping force (CDF) in a linear function. Moreover, a novel dual dampers-based controllable quarter-car suspension structure is proposed to realize the independent control of pitch and vertical motions of the half car, in which ...

  7. Computational analysis of flow field around Ahmed car model passing underneath a flyover

    Science.gov (United States)

    Musa, Md Nor; Osman, Kahar; Hamat, Ab Malik A.

    2012-06-01

    A flow structure around a ground vehicle has been studied by many researchers using numerous methods, either computational or experimental. However, no analysis of flow field generated by a car passing under a flyover has been carried out. One of the famous simplified models of a car is the Ahmed body that has been established to investigate the influence of the flow structure on the drag. In this paper, we investigate a flow field around Ahmed body of a single cruising condition as the vehicle passes under a flyover, using a computational method with RANS equation. The main objective of this paper is to evaluate the turbulence kinetic energy and velocity magnitude developed within the wall boundary created by the flyover, to the air flow field that is generated by the Ahmed reference car. It was observed that the simulated airflow passes the vehicle was bounded by the wall of the flyover and consequently changes the pattern of the flow field. Understanding the characteristic of this flow field under a flyover is essential if one wants to maximize the recovery of the dissipated energy which, for example, can be used to power a small vertical-axis wind turbine to produce and store electrical energy for lighting under the flyover.

  8. Modelling human behaviour in a bumper car ride using molecular dynamics tools: a student project

    Science.gov (United States)

    Buendía, Jorge J.; Lopez, Hector; Sanchis, Guillem; Pardo, Luis Carlos

    2017-05-01

    Amusement parks are excellent laboratories of physics, not only to check physical laws, but also to investigate if those physical laws might also be applied to human behaviour. A group of Physics Engineering students from Universitat Politècnica de Catalunya has investigated if human behaviour, when driving bumper cars, can be modelled using tools borrowed from the analysis of molecular dynamics simulations, such as the radial and angular distribution functions. After acquiring several clips and obtaining the coordinates of the cars, those magnitudes are computed and analysed. Additionally, an analogous hard disks system is simulated to compare its distribution functions to those obtained from the cars’ coordinates. Despite the clear difference between bumper cars and a hard disk-like particle system, the obtained distribution functions are very similar. This suggests that there is no important effect of the individuals in the collective behaviour of the system in terms of structure. The research, performed by the students, has been undertaken in the frame of a motivational project designed to approach the scientific method for university students named FISIDABO. This project offers both the logistical and technical support to undertake the experiments designed by students at the amusement park of Barcelona TIBIDABO and accompanies them all along the scientific process.

  9. Robustly Aligning a Shape Model and Its Application to Car Alignment of Unknown Pose.

    Science.gov (United States)

    Li, Yan; Gu, Leon; Kanade, Takeo

    2011-09-01

    Precisely localizing in an image a set of feature points that form a shape of an object, such as car or face, is called alignment. Previous shape alignment methods attempted to fit a whole shape model to the observed data, based on the assumption of Gaussian observation noise and the associated regularization process. However, such an approach, though able to deal with Gaussian noise in feature detection, turns out not to be robust or precise because it is vulnerable to gross feature detection errors or outliers resulting from partial occlusions or spurious features from the background or neighboring objects. We address this problem by adopting a randomized hypothesis-and-test approach. First, a Bayesian inference algorithm is developed to generate a shape-and-pose hypothesis of the object from a partial shape or a subset of feature points. For alignment, a large number of hypotheses are generated by randomly sampling subsets of feature points, and then evaluated to find the one that minimizes the shape prediction error. This method of randomized subset-based matching can effectively handle outliers and recover the correct object shape. We apply this approach on a challenging data set of over 5,000 different-posed car images, spanning a wide variety of car types, lighting, background scenes, and partial occlusions. Experimental results demonstrate favorable improvements over previous methods on both accuracy and robustness.

  10. Prediction of the result in race walking using regularized regression models

    Directory of Open Access Journals (Sweden)

    Krzysztof Przednowek

    2013-04-01

    Full Text Available The following paper presents the use of regularized linear models as tools to optimize training process. The models were calculated by using data collected from race-walkers' training events. The models used predict the outcomes over a 3 km race and following a prescribed training plan. The material included a total of 122 training patterns made by 21 players. The methods of analysis include: classical model of OLS regression, ridge regression, LASSO regression and elastic net regression. In order to compare and choose the best method a cross-validation of the extit{leave-one-out} was used. All models were calculated using R language with additional packages. The best model was determined by the LASSO method which generates an error of about 26 seconds. The method has simplified the structure of the model by eliminating 5 out of 18 predictors.

  11. Car sick.

    Science.gov (United States)

    Renner, M G

    1988-01-01

    The automobile is currently seen as the most desirable mode of transportation. However, this view needs to be changed since the proliferation of the automobile worldwide is leading to the poisoning of the environment and people. In the US the number of passenger cars grew 51% between 1971-86 and in the noncommunist industrialized community that figure is 71%. The gasoline and diesel fuel used to power the overwhelming majority of cars creates a variety of problems. The pollution is estimated to have a hidden cost of US $.80/gallon. Others estimate that the pollution causes 30,000 premature deaths annually just in the US. 75% of the carbon monoxide (CO), 48% of nitrogen oxides (NO2), 13% of particulates (P), and 3% of sulfur (S) emissions come from cars in the countries of the Organization for Economic Cooperation and Development (OECD), which includes the US, Canada, Western Europe, Japan, Australia, and New Zealand. 17% of all worldwide carbon dioxide (CO2) emission comes from the production and use of fossil fuels for cars. The single biggest problem associated with cars is the photochemical smog they create in urban areas. In 1986 75 million Americans lived in areas that failed to meet national air quality standards for CO, P, and ozone (03). The only area of major improvement has been the removal of lead from gasoline. It was known to cause problems from the beginning of its use in the 1920s, but remained for 50 years because of auto and oil company pressure. Ground 03 is estimated by the US government to cost US $4 billion in annual losses, just for corn, wheat, soybeans, and peanuts. Acid rain is the other major problem associated with cars, and its damage is estimated at US $5 billion annually. Both these problems are shortterm, their effects occur immediately; the longterm disadvantage is the build up of CO2 and its contribution to the greenhouse effect. While the US is at the forefront of regulation and many other countries are modeling their emission

  12. The feedback control research on straight and curved road with car-following model

    Science.gov (United States)

    Zheng, Yi-Ming; Cheng, Rong-Jun; Ge, Hong-Xia

    2017-07-01

    Taking account of the road consisting of curved part and straight part, an extended car-following model is proposed in this paper. A control signal including the velocity difference between the considered vehicle and the vehicle in front is taken into account. The control theory method is applied into analysis of the stability condition for the model. Numerical simulations are implemented to prove that the stability of the traffic flow strengthens effectively with an increase of the radius of curved road, and the control signal can suppress the traffic congestion. The results are in good agree with the theoretical analysis.

  13. Effect of looking backward on traffic flow in a cooperative driving car following model

    Science.gov (United States)

    Ge, H. X.; Zhu, H. B.; Dai, S. Q.

    2006-12-01

    An extended car following model is proposed by incorporating intelligent transportation system and the backward looking effect under certain condition in traffic flow. The neutral stability condition of this model is obtained by using the linear stability theory. The results show that anticipating the behavior of vehicles preceding and following one vehicle could lead to appreciable stabilization of traffic system. From the simulation of space-time evolution of the vehicle headways, it is shown that the traffic jam could be suppressed efficiently via taking into account the information about the motion of two preceding vehicles and one following vehicle, and the analytical result is consistent with the simulation one.

  14. Enhanced stability of car-following model upon incorporation of short-term driving memory

    Science.gov (United States)

    Liu, Da-Wei; Shi, Zhong-Ke; Ai, Wen-Huan

    2017-06-01

    Based on the full velocity difference model, a new car-following model is developed to investigate the effect of short-term driving memory on traffic flow in this paper. Short-term driving memory is introduced as the influence factor of driver's anticipation behavior. The stability condition of the newly developed model is derived and the modified Korteweg-de Vries (mKdV) equation is constructed to describe the traffic behavior near the critical point. Via numerical method, evolution of a small perturbation is investigated firstly. The results show that the improvement of this new car-following model over the previous ones lies in the fact that the new model can improve the traffic stability. Starting and breaking processes of vehicles in the signalized intersection are also investigated. The numerical simulations illustrate that the new model can successfully describe the driver's anticipation behavior, and that the efficiency and safety of the vehicles passing through the signalized intersection are improved by considering short-term driving memory.

  15. Modeling mechanical restriction differences between car and heavy truck in two-lane cellular automata traffic flow model

    Science.gov (United States)

    Li, Xin; Li, Xingang; Xiao, Yao; Jia, Bin

    2016-06-01

    Real traffic is heterogeneous with car and truck. Due to mechanical restrictions, the car and the truck have different limited deceleration capabilities, which are important factors in safety driving. This paper extends the single lane safety driving (SD) model with limited deceleration capability to two-lane SD model, in which car-truck heterogeneous traffic is considered. A car has a larger limited deceleration capability while a heavy truck has a smaller limited deceleration capability as a result of loaded goods. Then the safety driving conditions are different as the types of the following and the leading vehicles vary. In order to eliminate the well-known plug in heterogeneous two-lane traffic, it is assumed that heavy truck has active deceleration behavior when the heavy truck perceives the forming plug. The lane-changing decisions are also determined by the safety driving conditions. The fundamental diagram, spatiotemporal diagram, and lane-changing frequency were investigated to show the effect of mechanical restriction on heterogeneous traffic flow. It was shown that there would be still three traffic phases in heterogeneous traffic condition; the active deceleration of the heavy truck could well eliminate the plug; the lane-changing frequency was low in synchronized flow; the flow and velocity would decrease as the proportion of heavy truck grows or the limited deceleration capability of heavy truck drops; and the flow could be improved with lane control measures.

  16. Modified coupled map car-following model and its delayed feedback control scheme

    Institute of Scientific and Technical Information of China (English)

    Ge Hong-Xia

    2011-01-01

    A modified coupled map car-following model is proposed,in which two successive vehicle headways in front of the considering vehicle is incorporated into the optimal velocity function. The steady state under certain conditions is obtained. An error system around the steady state is studied further. Moreover,the condition for the state having no traffic jam is derived. A new control scheme is presented to suppress the traffic jam in the modified coupled map car-following model under the open boundary. A control signal including the velocity differences between the following and the considering vehicles,and between the preceding and the considering vehicles is used. The condition under which the traffic jam can be well suppressed is analysed. The results are compared with that presented by Konishi et al. (the KKH model). The simulation results show that the temporal behaviour obtained in our model is better than that in the KKH model. The simulation results are in good agreement with the theoretical analysis.

  17. Modified coupled map car-following model and its delayed feedback control scheme

    Science.gov (United States)

    Ge, Hong-Xia

    2011-09-01

    A modified coupled map car-following model is proposed, in which two successive vehicle headways in front of the considering vehicle is incorporated into the optimal velocity function. The steady state under certain conditions is obtained. An error system around the steady state is studied further. Moreover, the condition for the state having no traffic jam is derived. A new control scheme is presented to suppress the traffic jam in the modified coupled map car-following model under the open boundary. A control signal including the velocity differences between the following and the considering vehicles, and between the preceding and the considering vehicles is used. The condition under which the traffic jam can be well suppressed is analysed. The results are compared with that presented by Konishi et al. (the KKH model). The simulation results show that the temporal behaviour obtained in our model is better than that in the KKH model. The simulation results are in good agreement with the theoretical analysis.

  18. An Improved Car-Following Model for Multiphase Vehicular Traffic Flow and Numerical Tests

    Science.gov (United States)

    Li, Zhi-Peng; Gong, Xiao-Bo; Liu, Yun-Cai

    2006-08-01

    This paper attempts to introduce an improved difference model that modifies a car-following model, which takes the next-nearest-neighbor interaction into account. The improvement of this model over the previous one lies in that it performs more realistically in the dynamical motion for small delay time. The traffic behavior of the improved model is investigated with analytic and numerical methods with the finding that the new consideration could further stabilize traffic flow. And some simulation tests verify that the proposed model can demonstrate some complex physical features observed recently in real traffic such as the existence of three phases: free flow, coexisting flow, and jam flow; spontaneous formation of density waves; sudden flow drop in flow-density plane; traffic hysteresis in transition between the free and the coexisting flow. Furthermore, the improved model also predicts that the stable state to relative density in the coexisting flow is insusceptible to noise.

  19. Children forgotten in hot cars: a mental models approach for improving public health messaging.

    Science.gov (United States)

    Williams, Castle A; Grundstein, Andrew J

    2017-08-09

    On average, in the USA, 37 young children die every year due to vehicular heatstroke. Additionally, over half of these incidents occur when a parent/caregiver forgets a child in a vehicle. While various governmental and child safety advocacy groups have worked to raise awareness about these tragedies, rigorous studies have yet to be conducted that examine the current understanding and effectiveness of this public health messaging. This study will employ a mental models approach in order to identify differences that exist between experts' and parents'/caregivers' knowledge and beliefs surrounding the topic of children forgotten in hot cars. We interviewed a diverse set of 25 parents/caregivers and seven experts in order to construct and explore these mental models. A comparative analysis was conducted, and three key differences were observed between these mental models. Unlike the experts, the parents/caregivers in the study emphasised perceived lifestyle factors (eg, low-income parent) as important elements in increasing an individual's likelihood of forgetting a child in a car. Importantly, the parents/caregivers primarily obtained information from news reports, while experts believed public health campaigns would reach more parents/caregivers. Lastly, while experts stressed that this tragedy could happen to anyone, most parents/caregivers failed to acknowledge that they could forget their own child in a car. To confront this denial, future public health messaging must strive to engage and reach all parents/caregivers. This can be accomplished using a multifaceted messaging strategy that includes personalising core messaging, providing additional resources to media outlets and building rapport between key partners. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. A novel car following model considering average speed of preceding vehicles group

    Science.gov (United States)

    Sun, Dihua; Kang, Yirong; Yang, Shuhong

    2015-10-01

    In this paper, a new car following model is presented by considering the average speed effect of preceding vehicles group in cyber-physical systems (CPS) environment. The effect of this new consideration upon the stability of traffic flow is examined through linear stability analysis. A modified Korteweg-de Vries (mKdV) equation was derived via nonlinear analysis to describe the propagating behavior of traffic density wave near the critical point. Good agreement between the simulation and the analytical results shows that average speed of preceding vehicles group leads to the stabilization of traffic systems, and thus can efficiently suppress the emergence of traffic jamming.

  1. Effects of signal light on the fuel consumption and emissions under car-following model

    Science.gov (United States)

    Tang, Tie-Qiao; Yi, Zhi-Yan; Lin, Qing-Feng

    2017-03-01

    In this paper, a car-following model is utilized to study the effects of signal light on each vehicle's fuel consumption, CO, HC and NOX. The numerical results show that each vehicle's fuel consumption and emissions are influenced by the signal light and that the effects are related to the green split of the signal light and the vehicle's time headway at the origin, which can help drivers adjust their micro driving behavior on the road with a signal light to reduce their fuel consumption and emissions.

  2. A new coupled-map car-following model based on a transportation supernetwork framework

    Science.gov (United States)

    Yao, Jing; Huang, Jing-Yi; Chen, Guan-Rong; Xu, Wei-Sheng

    2013-06-01

    A new car-following model is proposed by considering information from a number of preceding vehicles with inter-vehicle communication. A supernetwork architecture is first described, which has two layers: a traffic network and a communication network. The two networks interact with and depend on each other. The error dynamic system around the steady state of the model is theoretically analyzed and some nonjam criteria are derived. A simple control signal is added to the model to analyze the criteria of suppressing traffic jams. The corresponding numerical simulations confirm the correctness of the theoretical analysis. Compared with previous studies concerning coupled map models, the controlled model proposed in this paper is more reasonable and also more effective in the sense that it takes into account the formation of traffic congestion.

  3. Car-following model with relative-velocity effect and its experimental verification

    Science.gov (United States)

    Shamoto, Daisuke; Tomoeda, Akiyasu; Nishi, Ryosuke; Nishinari, Katsuhiro

    2011-04-01

    In driving a vehicle, drivers respond to the changes of both the headway and the relative velocity to the vehicle in front. In this paper a new car-following model including these maneuvers is proposed. The acceleration of the model becomes infinite (has a singularity) when the distance between two vehicles is zero, and the asymmetry between the acceleration and the deceleration is incorporated in a nonlinear way. The model is simple but contains enough features of driving for reproducing real vehicle traffic. From the linear stability analysis, we confirm that the model shows the metastable homogeneous flow around the critical density, beyond which a traffic jam emerges. Moreover, we perform experiments to verify this model. From the data it is shown that the acceleration of a vehicle has a positive correlation with the relative velocity.

  4. An Improved Car-Following Model for Multiphase Vehicular Traffic Flow and Numerical Tests

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Peng; GONG Xiao-Bo; LIU Yun-Cai

    2006-01-01

    This paper attempts to introduce an improved difference model that modifies a car-following model, which takes the next-nearest-neighbor interaction into account. The improvement of this modelover the previous one lies in that it performs more realistically in the dynamical motion for small delay time. The traffic behavior of the improved model is investigated with analytic and numerical methods with the finding that the new consideration could further stabilize traffic flow. And some simulation tests verify that the proposed model can demonstrate some complex physical features observed recently in real traffic such as the existence of three phases: free flow, coexisting flow, and jam flow;spontaneous formation of density waves; sudden flow drop in flow-density plane; traffic hysteresis in transition between the free and the coexisting flow. Furthermore, the improved model also predicts that the stable state to relative density in the coexisting flow is insusceptible to noise.

  5. Modelling and Simulation for Train Movement Control Using Car-Following Strategy

    Institute of Scientific and Technical Information of China (English)

    LI Ke-Ping; GAO Zi-You; TANG Tao

    2011-01-01

    Based on optimal velocity car-following model, in this paper, we propose a new railway traffc model for describing the process of train movement control.In the proposed model, we give an improved form of the optimal velocity function Vopt, which is considered as the desired velocity function for train movement control under different control conditions.In order to test the proposed model, we simulate and anaiyze the trajectories of train movements,moreover, discuss the relationship curves between the train allowable velocity and the site of objective point in detail Analysis results indicate that the proposed model can well capture some realistic futures of train movement control.PACS numbers: 02.70.-c, 89.40.-a

  6. Coupling Mechanism and Decoupled Suspension Control Model of a Half Car

    Directory of Open Access Journals (Sweden)

    Hailong Zhang

    2016-01-01

    Full Text Available A structure decoupling control strategy of half-car suspension is proposed to fully decouple the system into independent front and rear quarter-car suspensions in this paper. The coupling mechanism of half-car suspension is firstly revealed and formulated with coupled damping force (CDF in a linear function. Moreover, a novel dual dampers-based controllable quarter-car suspension structure is proposed to realize the independent control of pitch and vertical motions of the half car, in which a newly added controllable damper is suggested to be installed between the lower control arm and connection rod in conventional quarter-car suspension structure. The suggested damper constantly regulates the half-car pitch motion posture in a smooth and steady operation condition meantime achieving the expected completely structure decoupled control of the half-car suspension, by compensating the evolved CDF.

  7. Testing a Theoretical Model of the Stress Process in Alzheimer's Caregivers With Race as a Moderator

    OpenAIRE

    Hilgeman, Michelle M.; Durkin, Daniel W.; Sun, Fei; DeCoster, Jamie; Allen, Rebecca S.; Gallagher-Thompson, Dolores; Burgio, Louis D.

    2009-01-01

    Purpose: The primary aim of this study was to test the stress process model (SPM; Pearlin, Mullan, Semple, & Skaff, 1990) in a racially diverse sample of Alzheimer's caregivers (CGs) using structural equation modeling (SEM) and regression techniques. A secondary aim was to examine race or ethnicity as a moderator of the relation between latent constructs (e.g., subjective stressors and role strain) in the SPM. Sample: Participants included White or Caucasian (n = 212), Black or African Americ...

  8. Response of a quarter car model with optimal magnetorheological damper parameters

    Science.gov (United States)

    Prabakar, R. S.; Sujatha, C.; Narayanan, S.

    2013-04-01

    In this paper, the control of the stationary response of a quarter car model to random road excitation with a Magnetorheological (MR) damper as a semi-active suspension device is considered. The MR damper is a hypothetical analytical damper whose parameters are determined optimally using a multi-objective optimization technique Non-dominated Sorting Genetic Algorithm II (NSGA II). The hysteretic behaviour of the MR damper is characterized using Bingham and modified Bouc-Wen models. The multi-objective optimization problem is solved by minimizing the difference between the root mean square (rms) sprung mass acceleration, suspension stroke and the road holding responses of the quarter car model with the MR damper and those of the active suspension system based on linear quadratic regulator (LQR) control with the constraint that the MR damper control force lies between ±5 percent of the LQR control force. It is observed that the MR damper suspension systems with optimal parameters perform an order of magnitude better than the passive suspension and perform as well as active suspensions with limited state feedback and closer to the performance of fully active suspensions.

  9. Floating Car Data Based Nonparametric Regression Model for Short-Term Travel Speed Prediction

    Institute of Scientific and Technical Information of China (English)

    WENG Jian-cheng; HU Zhong-wei; YU Quan; REN Fu-tian

    2007-01-01

    A K-nearest neighbor (K-NN) based nonparametric regression model was proposed to predict travel speed for Beijing expressway. By using the historical traffic data collected from the detectors in Beijing expressways, a specically designed database was developed via the processes including data filtering, wavelet analysis and clustering. The relativity based weighted Euclidean distance was used as the distance metric to identify the K groups of nearest data series. Then, a K-NN nonparametric regression model was built to predict the average travel speeds up to 6 min into the future. Several randomly selected travel speed data series,collected from the floating car data (FCD) system, were used to validate the model. The results indicate that using the FCD, the model can predict average travel speeds with an accuracy of above 90%, and hence is feasible and effective.

  10. Over consumption. A horse race of Bayesian DSGE models

    OpenAIRE

    Argentiero, Amedeo; Bovi, Maurizio; Cerqueti, Roy

    2015-01-01

    Standard dynamic stochastic general equilibrium (DSGE) models are populated by fully-informed-optimising Muth-rational agents. This kind of agent is at odds with well-known psychological biases, not to mention real life people. In particular, there are strong theoretical and empirical reasons to believe that consumers are overly optimistic. Also, the size of over optimism is likely to show cyclical features. In this paper we simulate two DSGE models, one standard with Muth-rational consumers,...

  11. Race, urban governance, and crime control: creating model cities.

    Science.gov (United States)

    Brown, Elizabeth

    2010-01-01

    In the late 1960s and early 1970s, the city of Seattle received federal Department of Housing and Urban Development “Model cities” funds to address issues of racial disenfranchisement in the city. Premised under the “Great Society” ethos, Model cities sought to remedy the strained relationship between local governments and disenfranchised urban communities. Though police-community relations were not initially slated as an area of concern in the city's grant application, residents of the designated “model neighborhood” pressed for the formation of a law and justice task force to address the issue. This article examines the process and outcome of the two law-and-justice projects proposed by residents of the designated “model neighborhood”: the Consumer Protection program and the Community Service Officer project. Drawing on the work of legal geographies scholars, I argue that the failure of each of these efforts to achieve residents' intentions stems from the geographical imagination of urban problems. Like law-and-order projects today, the geographical imagination of the model neighborhood produced a discourse of exceptionality that subjected residents to extraordinary state interventions. The Model cities project thus provides an example of a “history of the present” of mass incarceration in which the geographical imagination of crime helps facilitate the re-creation of a racialized power structure.

  12. SEMI-ACTIVE SUSPENSION SYSTEM DESIGN FOR QUARTER CAR MODEL AND ITS ANALYSIS WITH PASSIVE SUSPENSION MODEL

    OpenAIRE

    Vinayak S. Dixit*, Sachin C. Borse

    2017-01-01

    The three main objectives that a suspension system of an automobile must satisfy are ride comfort, vehicle handling and suspension working space. Ride comfort is directly related to the vehicle acceleration experienced by the driver and the passengers. Lesser vertical acceleration, higher is the level of comfort. The aim of the Project was to design and analyze the semi active suspension system models using skyhook, ground hook and hybrid control for quarter car. The project work includes mod...

  13. Racing to define pharmaceutical R&D external innovation models.

    Science.gov (United States)

    Wang, Liangsu; Plump, Andrew; Ringel, Michael

    2015-03-01

    The pharmaceutical industry continues to face fundamental challenges because of issues with research and development (R&D) productivity and rising customer expectations. To lower R&D costs, move beyond me-too therapies, and create more transformative portfolios, pharmaceutical companies are actively capitalizing on external innovation through precompetitive collaboration with academia, cultivation of biotech start-ups, and proactive licensing and acquisitions. Here, we review the varying innovation strategies used by pharmaceutical companies, compare and contrast these models, and identify the trends in external innovation. We also discuss factors that influence these external innovation models and propose a preliminary set of metrics that could be used as leading indicators of success.

  14. Coupled map car-following model and its delayed-feedback control.

    Science.gov (United States)

    Konishi, K; Kokame, H; Hirata, K

    1999-10-01

    This paper proposes a coupled map car-following traffic model, which describes a dynamical behavior of a group of road vehicles running in a single lane without overtaking. This model consists of a lead vehicle and following vehicles, which have a piecewise linear optimal velocity function. When the lead-vehicle speed is varied, we can observe a traffic jam in the group of the vehicles. We derive a condition under which the traffic jam never occurs in our model. Furthermore, in order to suppress the traffic jam, for each vehicle we use a dynamic version of decentralized delayed-feedback control proposed in [Konishi, Hirai, and Kokame, Phys. Rev. E 58, 3055 (1998)], and provide a systematic procedure for designing the controller.

  15. 基于STM32的FSAE赛车底盘数据采集系统设计%Design of data acquisition system of FSAE racing car chassis based on STM32

    Institute of Scientific and Technical Information of China (English)

    李淼林; 戴海燕; 徐杰龙; 欧阳奕涛; 陈晓楷

    2016-01-01

    本文基于STM32设计了一套高精度、大容量、多通道、廉价的数据采集系统,包括硬件设计和软件设计,使其应用于校内FSAE赛车的底盘调校,实现准确的数据分析与调试。该系统选用STM32F103ZET6作为微处理器,以SD卡作为存储器,实现了多通道信号的同步、连续采集和存储,具有性能稳定、实时性强、扩展灵活等特点。%In this paper, a high precision, large capacity, multi channel, cheap data acquisition system based on the STM32 is designed, including hardware design and software design, which is applied to the FSAE racing car chassis calibration. It can realize accurate data analysis and debugging. The system uses STM32F103ZET6 as the microprocessor, uses SD as memory card, realizes multi channel signals synchronization, continuous acquisition and storage, has the characteristics of stable performance, strong real-time, flexible expansion, etc.

  16. FSAE 纯电动方程式赛车制动盘发热研究%Study of Thermal about Braking Discs of FSAE Electric Racing Car

    Institute of Scientific and Technical Information of China (English)

    韩小强; 高天涵; 蒋迪; 郭炯珉

    2016-01-01

    基于大学生方程式赛车比赛的特点,该文根据制动原理与传热理论,使用理论分析法分别研究了赛车在紧急制动和持续制动两种工况中制动盘的温度情况,判定是否会因为温度过高而发生热衰退等失效。通过 COMSOL Multiphysics 的固体传热模块对赛车的紧急制动与持续制动进行仿真分析,得出在紧急制动以及持久制动后制动盘的温度,从而对理论计算进行验证,为制动盘的优化设计提供了理论依据。%It is important to study the thermal of the braking disc when having the FSAE competition.In this paper,the heat of the braking discs is studied during the process of emergency braking and continuous braking by the theory of heat transfer and the theory of braking in order to estimate whether the temperature of disc is extremely hot and have failure or not.After that,heat transfer in solid’s modular of Comsol Multiphysics is used to have thermal analysis about the racing car’s emergency braking condition and continuous bra-king condition,then have the temperature of the disc after emergency condition and duration condition.Finally,we validate theoretical calculation and provide theoretical basis for optimal design of disks.

  17. Analysis of the equilibrium trip cost without late arrival and the corresponding traffic properties using a car-following model

    Science.gov (United States)

    Tang, Tie-Qiao; Chen, Liang; Huang, Hai-Jun; Song, Ziqi

    2016-10-01

    In this paper, we first apply a generalized car-following model to study the commuter trip cost without late arrival from an analytical perspective; and then use the full velocity difference (FVD) model to verify the analytical results and explore the corresponding traffic properties from a numerical perspective. Finally, we explore the evolutions of traffic flow on a road with an open boundary under three traffic situations (i.e., the number of commuters is low, moderate, and high) and find that the evolution of traffic flow is related to the number of commuters. The numerical results are qualitatively consistent with the analytical results and illustrate that car-following models can be used to study each commuter's trip cost without late arrival and that the car-following model can accurately quantify each commuter's trip cost.

  18. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars-Part I: Model structure, simulation of bounded rationality, and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Michel G. [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland); Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland)], E-mail: peter.dehaan@env.ethz.ch

    2009-03-15

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated.

  19. A new car-following model with consideration of the velocity difference between the current speed and the historical speed of the leading car

    Science.gov (United States)

    Liu, Fangxun; Cheng, Rongjun; Ge, Hongxia; Yu, Chenyan

    2016-12-01

    In this study, a new car-following model is proposed based on taking the effect of the leading vehicle's velocity difference between the current speed and the historical speed into account. The model's linear stability condition is obtained via the linear stability theory. The time-dependent Ginzburg-Landau (TDGL) equation and the modified Korteweg-de Vries (mKdV) equation are deduced through the nonlinear analysis. The kink-antikink soliton can interpret the traffic jams near the critical point. In addition, the connection between the TDGL and the mKdV equations is also given. Numerical simulation shows that the new model can improve the stability of traffic flow, which is consistent with the theoretical analysis correspondingly.

  20. Models of the Post-Racial World? Rhetorics of Race among U.S. Military Brats

    OpenAIRE

    2015-01-01

    The U.S. military has long been claimed as a model for racial integration, having been integrated by executive order before the general population; significantly, too, the military is constantly shuffling but organized by service branch and rank, and so installation neighborhoods are more prone to organized diversity than their civilian counterparts, which tend toward homogeneity based on race and class. For the estimated two million children growing up in this system,1 such experiences of di...

  1. Co-evolution model of Colletotrichum lindemuthianum (melanconiaceae, melanconiales) races that occur in some Brazilian regions

    OpenAIRE

    Ana Lilia Alzate-Marin; Everaldo Gonçalves de Barros; Maurílio Alves Moreira

    1999-01-01

    Colletotrichum lindemuthianum, the causal agent of anthracnose in the common bean (Phaseolus vulgaris L.), displays a high level of virulence diversity, which explains the large number of existing pathotypes. Several lines of evidence indicate that such diversity is, at least in part, due to plant and pathogen co-evolution. A co-evolution model based on the binary classification of 25 races identified in Brazil by inoculation of differential cultivars and random amplified polymorphic DNA (RAP...

  2. Empirical evidence and stability analysis of the linear car-following model with gamma-distributed memory effect

    Science.gov (United States)

    Pei, Xin; Pan, Yan; Wang, Haixin; Wong, S. C.; Choi, Keechoo

    2016-05-01

    Car-following models, which describe the reactions of the driver of a following car to the changes of the leading car, are essential for the development of traffic flow theory. A car-following model with a stochastic memory effect is considered to be more realistic in modeling drivers' behavior. Because a gamma-distributed memory function has been shown to outperform other forms according to empirical data, in this study, we thus focus on a car-following model with a gamma-distributed memory effect; analytical and numerical studies are then conducted for stability analysis. Accordingly, the general expression of undamped and stability points is achieved by analytical study. The numerical results show great agreement with the analytical results: introducing the effect of the driver's memory causes the stable regions to weaken slightly, but the metastable region is obviously enlarged. In addition, a numerical study is performed to further analyze the variation of the stable and unstable regions with respect to the different profiles of gamma distribution.

  3. Rodent models in neuroscience research: is it a rat race?

    Directory of Open Access Journals (Sweden)

    Bart Ellenbroek

    2016-10-01

    Full Text Available Rodents (especially Mus musculus and Rattus norvegicus have been the most widely used models in biomedical research for many years. A notable shift has taken place over the last two decades, with mice taking a more and more prominent role in biomedical science compared to rats. This shift was primarily instigated by the availability of a much larger genetic toolbox for mice, particularly embryonic-stem-cell-based targeting technology for gene disruption. With the recent emergence of tools for altering the rat genome, notably genome-editing technologies, the technological gap between the two organisms is closing, and it is becoming more important to consider the physiological, anatomical, biochemical and pharmacological differences between rats and mice when choosing the right model system for a specific biological question. The aim of this short review and accompanying poster is to highlight some of the most important differences, and to discuss their impact on studies of human diseases, with a special focus on neuropsychiatric disorders.

  4. An extended car-following model accounting for the average headway effect in intelligent transportation system

    Science.gov (United States)

    Kuang, Hua; Xu, Zhi-Peng; Li, Xing-Li; Lo, Siu-Ming

    2017-04-01

    In this paper, an extended car-following model is proposed to simulate traffic flow by considering average headway of preceding vehicles group in intelligent transportation systems environment. The stability condition of this model is obtained by using the linear stability analysis. The phase diagram can be divided into three regions classified as the stable, the metastable and the unstable ones. The theoretical result shows that the average headway plays an important role in improving the stabilization of traffic system. The mKdV equation near the critical point is derived to describe the evolution properties of traffic density waves by applying the reductive perturbation method. Furthermore, through the simulation of space-time evolution of the vehicle headway, it is shown that the traffic jam can be suppressed efficiently with taking into account the average headway effect, and the analytical result is consistent with the simulation one.

  5. Optimal Observer Control Approach To Quarter Car Model With Active Suspension

    Directory of Open Access Journals (Sweden)

    Dinçer Maden

    2013-08-01

    Full Text Available As technological advances in automotive industry and roads construction techniques have made transportation faster, new comfort and safety matters have become the subject of engineering. Many vibrations caused by internal and external factors affect comfort and safety in negative ways. To damp these vibrations, active suspensions requiring controllers because of their complex structures are widely used. In this study, firstly ¼ car model having active suspension has been modeled with Luenberger observer, used on the occasions state variables cannot be determined efficiently. Then, the system has been combined with optimal feedback controller according to certain performance criteria. This new controller has been designed in MATLAB / SIMULINK environment, and the system response has been evaluated after applying roads disturbance inputs.

  6. An extended car-following model with consideration of speed guidance at intersections

    Science.gov (United States)

    Zhao, Jing; Li, Peng

    2016-11-01

    The main motivation of this paper is to analyze the influences of speed guidance strategies on the driving behaviors under four different traffic signalized conditions and to investigate an extended car-following model to explore how the speed guidance affects two different vehicle types that are intelligent vehicles and traditional vehicles during the phase-change periods. The numerical results show that the proposed model can qualitatively describe the impacts of the speed guidance strategies on vehicle's movement trail including the acceleration strategy, smooth braking strategy, and deceleration strategy. Moreover, the benefits of the speed guidance could be enhanced by lengthening the guiding space range, expanding permitted guiding speed range, and increasing the percentage of the intelligent vehicles.

  7. Kink antikink density wave of an extended car-following model in a cooperative driving system

    Science.gov (United States)

    Yu, Lei; Shi, Zhongke; Zhou, Bingchang

    2008-12-01

    We propose an extended optimal velocity model applicable to cooperative driving control system by considering the headway of arbitrary number of cars that precede and the relative velocity. The stability condition of the extended model is obtained by using the linear stability theory. The modified Korteweg-de Vries (mKdV) equation is derived to describe the traffic behavior near the critical point by applying the nonlinear analysis. Thus the traffic jams can be described by the kink-antikink density wave which is the solution of the mKdV equation. The simulation results confirm the analytical results and show that the traffic jams are suppressed more efficiently with considering not only the headway of more vehicles ahead but also the relative velocity.

  8. Effects of asymmetrical damping on a 2 DOF quarter-car model under harmonic excitation

    Science.gov (United States)

    Silveira, M.; Wahi, P.; Fernandes, J. C. M.

    2017-02-01

    The objective of this work is to study the dynamical behavior of vehicle suspension systems employing asymmetrical viscous damping, with a focus on improving passenger comfort. Previous studies have shown that the use of asymmetrical dampers in these types of systems can be advantageous with regard to comfort of the passengers. The modeling and the behavior of a quarter-car model with asymmetrical viscous damping under harmonic excitation is presented. The response is obtained with an analytical approximation via the method of Harmonic Balance. The choice of the asymmetry ratio diminishes the effects that the uneven road causes on the displacement and acceleration of the sprung mass. Although current systems usually adopt larger damping during the expansion phase, it is shown in this work that, for lower frequencies, smaller damping in this phase results in better comfort.

  9. Handleiding CAR Parking

    NARCIS (Netherlands)

    Gofferje D; LLO

    1997-01-01

    The CAR-Parking computer program, for which this manual has been written, was developed for calculating the air quality in the vicinity of parking garages and for testing the concentration of benzene against the standards for this compound. The model calculates the emission of benzene from cars insi

  10. Simulating the 'other-race' effect with autoassociative neural networks: further evidence in favor of the face-space model.

    Science.gov (United States)

    Caldara, Roberto; Hervé, Abdi

    2006-01-01

    Other-race (OR) faces are less accurately recognized than same-race (SR) faces, but faster classified by race. This phenomenon has often been reported as the 'other-race' effect (ORE). Valentine (1991 Quarterly Journal of Experimental Psychology A: Human Experimental Psychology 43 161-204) proposed a theoretical multidimensional face-space model that explained both of these results, in terms of variations in exemplar density between races. According to this model, SR faces are more widely distributed across the dimensions of the space than OR faces. However, this model does not quantify nor state the dimensions coded within this face space. The aim of the present study was to test the face-space explanation of the ORE with neural network simulations by quantifying its dimensions. We found the predicted density properties of Valentine's framework in the face-projection spaces of the autoassociative memories. This was supported by an interaction for exemplar density between the race of the learned face set and the race of the faces. In addition, the elaborated face representations showed optimal responses for SR but not for OR faces within SR face spaces when explored at the individual level, as gender errors occurred significantly more often in OR than in SR face-space representations. Altogether, our results add further evidence in favor of a statistical exemplar density explanation of the ORE as suggested by Valentine, and question the plausibility of such coding for faces in the framework of recent neuroimaging studies.

  11. CoCAR: An Online Synchronous Training Model for Empowering ICT Capacity of Teachers of Chinese as a Foreign Language

    Science.gov (United States)

    Lan, Yu-Ju; Chang, Kuo-En; Chen, Nian-Shing

    2012-01-01

    In response to the need to cultivate pre-service Chinese as a foreign language (CFL) teachers' information and communication technology (ICT) competency in online synchronous environments, this research adopted a three-stage cyclical model named "cooperation-based cognition, action, and reflection" (CoCAR). The model was implemented in an 18-week…

  12. Race differences: modeling the pharmacodynamics of rosuvastatin in Western and Asian hypercholesterolemia patients

    Institute of Scientific and Technical Information of China (English)

    Juan YANG; Lu-jin LI; Kun WANG; Ying-chun HE; Yu-cheng SHENG; Ling XU; Xiao-hui HUANG; Feng GUO; Qing-shan ZHENG

    2011-01-01

    Aim: To evaluate race differences in the pharmacodynamics of rosuvastatin in Western and Asian hypercholesterolemia patients using a population pharmacodynamic (PPD) model generated and validated using published clinical efficacy trials.Methods: Published studies randomized trials with rosuvastatin treatment for at least 4 weeks in hypercholesterolemia patients were used for model building and validation. Population pharmacodynamic analyses were performed to describe the dose-response relationship with the mean values of LDL-C reduction (%) from dose-ranging trials using NONMEM software. Baseline LDL-C and race were analyzed as the potential covariates. Model robustness was evaluated using the bootstrap method and the data-splitting method,and Monte Carlo simulation was performed to assess the predictive performance of the PPD model with the mean effects from the onedose trials.Results: Of the 36 eligible trials,14 dose-ranging trials were used in model development and 22 one-dose trials were used for model prediction. The dose-response of rosuvastatin was successfully described by a simple Emax model with a fixed E0,which provided a common Emax and an approximate twofold difference in ED50 for Westerners and Asians. The PPD model was demonstrated to be stable and predictive.Conclusion: The race differences in the pharmacodynamics of rosuvastatin are consistent with those observed in the pharmacokinetics of the drug,confirming that there is no significant difference in the exposure-response relationship for LDL-C reduction between Westerners and Asians. The study suggests that for a new compound with a mechanism of action similar to that of rosuvastatin,its efficacy in Western populations plus its pharmacokinetics in bridging studies in Asian populations may be used to support a registration of the new compound in Asian countries.

  13. CERN Relay Race

    CERN Multimedia

    2008-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 5 June starting at 12:15 p.m. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on how to register your team for the relay race are given on the Staff Association Bulletin web site. You can access the online registration form at: http://cern.ch/club-running-relay/form.html

  14. CERN Relay Race

    CERN Multimedia

    2011-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 19 May starting at 12-15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details of the course and of how to register your team for the relay race can be found here. Some advice for all runners from the Medical Service can also be found here.   

  15. CERN Relay Race

    CERN Multimedia

    2007-01-01

    The CERN relay race will take place around the Meyrin site on Wednesday 23 May starting at 12:15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on how to register your team for the relay race are given on the Staff Association Bulletin web site. You can access the online registration form at: http://cern.ch/club-running-relay/form.html

  16. Stabilization strategies of a general nonlinear car-following model with varying reaction-time delay of the drivers.

    Science.gov (United States)

    Li, Shukai; Yang, Lixing; Gao, Ziyou; Li, Keping

    2014-11-01

    In this paper, the stabilization strategies of a general nonlinear car-following model with reaction-time delay of the drivers are investigated. The reaction-time delay of the driver is time varying and bounded. By using the Lyapunov stability theory, the sufficient condition for the existence of the state feedback control strategy for the stability of the car-following model is given in the form of linear matrix inequality, under which the traffic jam can be well suppressed with respect to the varying reaction-time delay. Moreover, by considering the external disturbance for the running cars, the robust state feedback control strategy is designed, which ensures robust stability and a smaller prescribed H∞ disturbance attenuation level for the traffic flow. Numerical examples are given to illustrate the effectiveness of the proposed methods.

  17. Prevision of vehicle headway effect on urban traffic with a new car-following model

    Science.gov (United States)

    Peng, Guanghan; Lu, Weizhen; He, Hongdi; Gu, Zhenghua

    2017-04-01

    In this study, a new car-following model is established aiming to predict the variation of vehicle headways on urban road. The linear stability condition is derived corresponding to the prevision of headway in moving. The modified Korteweg-de Vries (mKdV) equation is deduced through the nonlinear analysis. The kink-antikink soliton solution of the mKdV equation can interpret the urban traffic jams near the critical point under the prevision of vehicle headway. Moreover, it is clear that the prevision of headway effect did improve the stability of urban traffic flow since the traffic jams are alleviated efficiently by taking into account the prevision of headway term in numerical simulations, which are consistent with the theoretical analysis.

  18. Calibrating the Local and Platoon Dynamics of Car-following Models on the Reconstructed NGSIM Data

    CERN Document Server

    Kurtc, Valentina

    2016-01-01

    The NGSIM trajectory data are used to calibrate two car-following models - the IDM and the FVDM. We used the I80 dataset which has already been reconstructed to eliminate outliers, unphysical data, and internal and platoon inconsistencies contained in the original data.We extract from the data leader-follower pairs and platoons of up to five consecutive vehicles thereby eliminating all trajectories that are too short or contain lane changes. Four error measures based on speed and gap deviations are considered. Furthermore, we apply three calibration methods: local or direct calibration, global calibration, and platoon calibration. The last approach means that a platoon of several vehicles following a data-driven leader is simulated and compared to the observed dynamics.

  19. Feedback control for car following model based on two-lane traffic flow

    Science.gov (United States)

    Ge, Hong-xia; Meng, Xiang-pei; Zhu, Hui-bing; Li, Zhi-Peng

    2014-08-01

    In the paper, two-lane traffic flow considering lane changing behaviors has been discussed based on the control theory, and the friction interference which is from the neighbor lane has been taken into account. By using the control method, the stability condition is derived. The feedback signals, which include vehicular information from both lanes, acting on the two-lane traffic system have been introduced into the Full Velocity Difference car-following model. In the end, simulations are conducted to examine the validity and reasonability of the control method. It is proven that lane changing behaviors can aggravate the traffic perturbation. The traffic flow congestion could be suppressed by using the control method and the simulation results are in good agreement with the theoretical analysis.

  20. Application for certification 1993 model year light-duty vehicles - Jaguar cars

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    Every year, each manufacturer of passenger cars, light-duty trucks, motorcycles, or heavy-duty engines submits to EPA an application for certification. In the application, the manufacturer gives a detailed technical description of the vehicles or engines he intends to market during the upcoming model year. These engineering data include explanations and/or drawings which describe engine/vehicle parameters such as basic engine design, fuel systems, ignition systems and exhaust and evaporative emission control systems. It also provides information on emission test procedures, service accumulation procedures, fuels to be used, and proposed maintenance requirements to be followed during testing. Section 16 of the application contains the results of emission testing, a statement of compliance to the regulations, production engine parameters, and a Summary Sheet Input Form on which issuance of a Certificate of Conformity is based.

  1. Suppression of chaotic vibrations in a nonlinear half-car model

    Science.gov (United States)

    Tusset, Ángelo Marcelo; Piccirillo, Vinícius; Janzen, Frederic Conrad; Lenz, Wagner Barth; Balthazar, José Manoel; da Fonseca Brasil, Reyolando M. L. R.

    2014-12-01

    The present work investigates the nonlinear response of a half-car model. The disturbances of the road are assumed to be sinusoidal. After constructing the bifurcation diagram, we using the 0-1 test for identify the chaotic motion. The principal objective of this study is to eliminate the chaotic behaviour of the chassis and reduce its vibration, and for this reason a control system for semi-active vehicle suspension with magnetorheological damper is proposed. The control mechanism is designed based on SDRE technique, where the control parameter is the voltage applied to the coil of the damper. Numerical results show that the proposed control method is effective in significantly reducing of the chassis vibration, increasing therefore, passenger comfort.

  2. Feedback control scheme of traffic jams based on the coupled map car-following model

    Science.gov (United States)

    Zhou, Tong; Sun, Di-Hua; Zhao, Min; Li, Hua-Min

    2013-09-01

    Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.

  3. GENERAL: A control method for congested traffic in the coupled map car-following model

    Science.gov (United States)

    Shen, Fei-Ying; Ge, Hong-Xia; Zhang, Hui; Yu, Han-Mei; Lei, Li

    2009-10-01

    Based on the pioneer work of Konishi et al, a new control method is presented to suppress the traffic congestion in the coupled map (CM) car-following model under an open boundary. A control signal concluding the velocity differences of the two vehicles in front is put forward. The condition under which the traffic jam can be contained is analyzed. The results are compared with that presented by Konishi et al [Phys. Rev. 1999 E 60 4000-4007]. The simulation results show that the temporal behavior obtained by our method is better than that by the Konishi's et al. method, although both the methods could suppress the traffic jam. The simulation results are consistent with the theoretical analysis.

  4. An extended car-following model based on intelligent transportation system application

    Science.gov (United States)

    Ge, H. X.; Dai, S. Q.; Dong, L. Y.

    2006-06-01

    The jams in the congested traffic reveal various density waves. Some of them are described by the nonlinear wave equations: the Korteweg-de-Vries (KdV) equation, the Burgers equation and the modified KdV equation. An extended car following model are proposed in previous work, and the kink-antikink solution has been obtained from the mKdV equation. We continue to derive the KdV equation near the neutral stability line by applying the reductive perturbation method. The traffic jam could be thus described by the soliton solution, and the analysis result is consistent with the previous one. From the numerical simulations results, the soliton waves are found, and traffic jam is suppressed efficiently as encounter big disturbances.

  5. A control method for congested traffic in the coupled map car-following model

    Institute of Scientific and Technical Information of China (English)

    Shen Fei-Ying; Ge Hong-Xia; Zhang Hui; Yu Han-Mei; Lei Li

    2009-01-01

    Based on the pioneer work of Konishi et al, a new control method is presented to suppress the traffic congestion in the coupled map (CM) car-following model under an open boundary. A control signal concluding the velocity differences of the two vehicles in front is put forward. The condition under which the traffic jam can be contained is analyzed. The results are compared with that presented by Konishi et al [Phys. Rev. 1999 E 60 4000-4007]. The simulation results show that the temporal behavior obtained by our method is better than that by the Konishi's et al. method, although both the methods could suppress the traffic jam. The simulation results are consistent with the theoretical analysis.

  6. Suppression of chaotic vibrations in a nonlinear half-car model

    Energy Technology Data Exchange (ETDEWEB)

    Tusset, Ângelo Marcelo, E-mail: tusset@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: wagner-barth@hotmail.com; Piccirillo, Vinícius, E-mail: tusset@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: wagner-barth@hotmail.com; Janzen, Frederic Conrad, E-mail: tusset@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: wagner-barth@hotmail.com; Lenz, Wagner Barth, E-mail: tusset@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: wagner-barth@hotmail.com [UTFPR- PONTA GROSSA, PR (Brazil); Balthazar, José Manoel, E-mail: jmbaltha@rc.unesp.br [UNESP-BAURU, SP (Brazil); Fonseca Brasil, Reyolando M. L. R. da, E-mail: reyolando.brasil@ufabc.edu.br [UFABC-SANTO ANDRE, SP (Brazil)

    2014-12-10

    The present work investigates the nonlinear response of a half-car model. The disturbances of the road are assumed to be sinusoidal. After constructing the bifurcation diagram, we using the 0-1 test for identify the chaotic motion. The principal objective of this study is to eliminate the chaotic behaviour of the chassis and reduce its vibration, and for this reason a control system for semi-active vehicle suspension with magnetorheological damper is proposed. The control mechanism is designed based on SDRE technique, where the control parameter is the voltage applied to the coil of the damper. Numerical results show that the proposed control method is effective in significantly reducing of the chassis vibration, increasing therefore, passenger comfort.

  7. Traffic stability of a car-following model considering driver’s desired velocity

    Science.gov (United States)

    Zhang, Geng; Sun, Di-Hua; Liu, Wei-Ning; Liu, Hui

    2015-07-01

    In this paper, a new car-following model is proposed by considering driver’s desired velocity according to Transportation Cyber Physical Systems. The effect of driver’s desired velocity on traffic flow has been investigated through linear stability theory and nonlinear reductive perturbation method. The linear stability condition shows that driver’s desired velocity effect can enlarge the stable region of traffic flow. From nonlinear analysis, the Burgers equation and mKdV equation are derived to describe the evolution properties of traffic density waves in the stable and unstable regions respectively. Numerical simulation is carried out to verify the analytical results, which reveals that traffic congestion can be suppressed efficiently by taking driver’s desired velocity effect into account.

  8. A new car-following model considering the related factors of a gyroidal road

    Science.gov (United States)

    Zhu, Wen-Xing; Yu, Rui-Ling

    2014-01-01

    A novel car-following model was proposed to describe the motion of the vehicles on a single lane gyroidal road. We explore the related effects of gyroidal road upon uniform traffic flow analytically and numerically. The analytical result shows that the related factors of gyroidal road including the friction coefficient, radius of curvature and slope have great influences on the stability of the uniform flow respectively. The modified KdV (Korteweg-de Vries) equation is derived in the unstable area and the kink solution is obtained near the critical point. A series of simulations are conducted to verify the effects upon uniform traffic flow under different road conditions. It is shown that the amplitudes of the headway oscillation wave were affected by the friction coefficient, radius of curvature and slope respectively. The numerical results are in good agreement with the analytical results.

  9. Areal rainfall estimation using moving cars - computer experiments including hydrological modeling

    Science.gov (United States)

    Rabiei, Ehsan; Haberlandt, Uwe; Sester, Monika; Fitzner, Daniel; Wallner, Markus

    2016-09-01

    The need for high temporal and spatial resolution precipitation data for hydrological analyses has been discussed in several studies. Although rain gauges provide valuable information, a very dense rain gauge network is costly. As a result, several new ideas have emerged to help estimating areal rainfall with higher temporal and spatial resolution. Rabiei et al. (2013) observed that moving cars, called RainCars (RCs), can potentially be a new source of data for measuring rain rate. The optical sensors used in that study are designed for operating the windscreen wipers and showed promising results for rainfall measurement purposes. Their measurement accuracy has been quantified in laboratory experiments. Considering explicitly those errors, the main objective of this study is to investigate the benefit of using RCs for estimating areal rainfall. For that, computer experiments are carried out, where radar rainfall is considered as the reference and the other sources of data, i.e., RCs and rain gauges, are extracted from radar data. Comparing the quality of areal rainfall estimation by RCs with rain gauges and reference data helps to investigate the benefit of the RCs. The value of this additional source of data is not only assessed for areal rainfall estimation performance but also for use in hydrological modeling. Considering measurement errors derived from laboratory experiments, the result shows that the RCs provide useful additional information for areal rainfall estimation as well as for hydrological modeling. Moreover, by testing larger uncertainties for RCs, they observed to be useful up to a certain level for areal rainfall estimation and discharge simulation.

  10. Development of a Refined Quarter Car Model for the Analysis of Discomfort due to Vibration

    Directory of Open Access Journals (Sweden)

    A. N. Thite

    2012-01-01

    Full Text Available In the automotive industry, numerous expensive and time-consuming trials are used to “optimize” the ride and handling performance. Ideally, a reliable virtual prototype is a solution. The practical usage of a model is linked and restricted by the model complexity and reliability. The object of this study is development and analysis of a refined quarter car suspension model, which includes the effect of series stiffness, to estimate the response at higher frequencies; resulting Maxwell's model representation does not allow straightforward calculation of performance parameters. Governing equations of motion are manipulated to calculate the effective stiffness and damping values. State space model is arranged in a novel form to find eigenvalues, which is a unique contribution. Analysis shows the influence of suspension damping and series stiffness on natural frequencies and regions of reduced vibration response. Increase in the suspension damping coefficient beyond optimum values was found to reduce the modal damping and increase the natural frequencies. Instead of carrying out trial simulations during performance optimization for human comfort, an expression is developed for corresponding suspension damping coefficient. The analysis clearly shows the influence of the series stiffness on suspension dynamics and necessity to incorporate the model in performance predictions.

  11. Development of Tsunami Numerical Model Considering the Disaster Debris such as Cars, Ships and Collapsed Buildings

    Science.gov (United States)

    Kozono, Y.; Takahashi, T.; Sakuraba, M.; Nojima, K.

    2016-12-01

    A lot of debris by tsunami, such as cars, ships and collapsed buildings were generated in the 2011 Tohoku tsunami. It is useful for rescue and recovery after tsunami disaster to predict the amount and final position of disaster debris. The transport form of disaster debris varies as drifting, rolling and sliding. These transport forms need to be considered comprehensively in tsunami simulation. In this study, we focused on the following three points. Firstly, the numerical model considering various transport forms of disaster debris was developed. The proposed numerical model was compared with the hydraulic experiment by Okubo et al. (2004) in order to verify transport on the bottom surface such as rolling and sliding. Secondly, a numerical experiment considering transporting on the bottom surface and drifting was studied. Finally, the numerical model was applied for Kesennuma city where serious damage occurred by the 2011 Tohoku tsunami. In this model, the influence of disaster debris was considered as tsunami flow energy loss. The hydraulic experiments conducted in a water tank which was 10 m long by 30 cm wide. The gate confined water in a storage tank, and acted as a wave generator. A slope was set at downstream section. The initial position of a block (width: 3.2 cm, density: 1.55 g/cm3) assuming the disaster debris was placed in front of the slope. The proposed numerical model simulated well the maximum transport distance and the final stop position of the block. In the second numerical experiment, the conditions were the same as the hydraulic experiment, except for the density of the block. The density was set to various values (from 0.30 to 4.20 g/cm3). This model was able to estimate various transport forms including drifting and sliding. In the numerical simulation of the 2011 Tohoku tsunami, the condition of buildings was modeled as follows: (i)the resistance on the bottom using Manning roughness coefficient (conventional method), and (ii)structure of

  12. ONE-DIMENSIONAL CELLULAR AUTOMATON MODEL OF TRAFFIC FLOW BASED ON CAR-FOLLOWING IDEA

    Institute of Scientific and Technical Information of China (English)

    董力耘; 薛郁; 戴世强

    2002-01-01

    An improved one-dimensional CA (Cellular Automaton) traffic model was proposed to describe the highway traffic under the periodic boundary conditions. This model was based on the idea of the car-following model, which claims that the motion of a vehicle at one time step depends on both its headway and the synchronous motion of the front vehicle,thus including indirectly the influence of its sub-neighboring vehicle. In addition, the socalled safety distance was introduced to consider the deceleration behavior of vehicles and the stochastic factor was taken into account by introducing the deceleration probability.Meanwhile, the conditional deceleration in the model gives a better description of the phenomena observed on highways. It is found that there exists the metastability and hysteresis effect of traffic flow in the neighborhood of critical density under different initial conditions.Since this model gives a reasonable depiction of the motion of a single vehicle, it is easy to be extended to the case of traffic flow under the control of traffic lights in cities.

  13. First Principles Modeling of the Performance of a Hydrogen-Peroxide-Driven Chem-E-Car

    Science.gov (United States)

    Farhadi, Maryam; Azadi, Pooya; Zarinpanjeh, Nima

    2009-01-01

    In this study, performance of a hydrogen-peroxide-driven car has been simulated using basic conservation laws and a few numbers of auxiliary equations. A numerical method was implemented to solve sets of highly non-linear ordinary differential equations. Transient pressure and the corresponding traveled distance for three different car weights are…

  14. Demonstrating the Conservation of Angular Momentum Using Model Cars Moving along a Rotating Rod

    Science.gov (United States)

    Abdul-Razzaq, Wathiq; Golubovic, Leonardo

    2013-01-01

    We have developed an exciting non-traditional experiment for our introductory physics laboratories to help students to understand the principle of conservation of angular momentum. We used electric toy cars moving along a long rotating rod. As the cars move towards the centre of the rod, the angular velocity of this system increases.…

  15. First Principles Modeling of the Performance of a Hydrogen-Peroxide-Driven Chem-E-Car

    Science.gov (United States)

    Farhadi, Maryam; Azadi, Pooya; Zarinpanjeh, Nima

    2009-01-01

    In this study, performance of a hydrogen-peroxide-driven car has been simulated using basic conservation laws and a few numbers of auxiliary equations. A numerical method was implemented to solve sets of highly non-linear ordinary differential equations. Transient pressure and the corresponding traveled distance for three different car weights are…

  16. Real-world emissions from model year 1993, 2000, and 2010 passenger cars

    Energy Technology Data Exchange (ETDEWEB)

    Ross, M.; Goodwin, R.; Watkins, R. [and others

    1995-11-01

    Air pollution by cars and light trucks is a major problem in metropolitan areas in the United States and around the world. Much of the discussion of this issue is based on the emissions per vehicle mile as determined under somewhat artificial testing conditions. The pollutants actually emitted vary considerably with the particular vehicle and the way it is driven, but the average emissions per mile are much higher than the test values. This report concerns the sources and levels of excess emissions, and the potential for reducing them. The history of automotive emissions regulation reveals remarkable success in reducing the emissions of carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NO{sub x}) from new automobiles - as measured in certification tests. The grams-per-mile (g/mile) standards for these tests are stringent, with 96% reductions mandated in comparison to the estimated pre-control (mid-1960s) levels for CO and HC; and 75% reductions mandated for NO{sub x}. Powerful new technologies have been developed and incorporated into every new vehicle in order to accomplish these reductions. Most noteworthy are the catalytic converter and closed-loop engine controls; the latter includes sensors before and after the engine proper, and computer analysis of the information leading to real-time control of fuel injection, with the principal objective of maintaining just the right chemical balance of fuel and air. The average lifetime real-world g/mile emissions associated with conventional gasoline fueled cars for model years 1993, 2000, and 2010 have been projected. Results are discussed.

  17. The influence of the non-motor vehicles for the car-following model considering traffic jerk

    Science.gov (United States)

    Liu, Yi; Cheng, Rong-jun; Lei, Li; Ge, Hong-xia

    2016-12-01

    The influence of the non-motor vehicles and traffic jerk is considered for the car-following model in this paper. The control method is used to analyze the stability of the model. A control signal which is the velocity difference between the target vehicle and the following vehicle is added into the model and the stability condition is obtained. Numerical simulation is used to display the results for the stability of the model with and without control signal.

  18. Modeling the Dynamic Failure of Railroad Tank Cars Using a Physically Motivated Internal State Variable Plasticity/Damage Nonlocal Model

    Directory of Open Access Journals (Sweden)

    Fazle R. Ahad

    2013-01-01

    Full Text Available We used a physically motivated internal state variable plasticity/damage model containing a mathematical length scale to idealize the material response in finite element simulations of a large-scale boundary value problem. The problem consists of a moving striker colliding against a stationary hazmat tank car. The motivations are (1 to reproduce with high fidelity finite deformation and temperature histories, damage, and high rate phenomena that may arise during the impact accident and (2 to address the material postbifurcation regime pathological mesh size issues. We introduce the mathematical length scale in the model by adopting a nonlocal evolution equation for the damage, as suggested by Pijaudier-Cabot and Bazant in the context of concrete. We implement this evolution equation into existing finite element subroutines of the plasticity/failure model. The results of the simulations, carried out with the aid of Abaqus/Explicit finite element code, show that the material model, accounting for temperature histories and nonlocal damage effects, satisfactorily predicts the damage progression during the tank car impact accident and significantly reduces the pathological mesh size effects.

  19. Optimization of damping in the passive automotive suspension system with using two quarter-car models

    Science.gov (United States)

    Lozia, Z.; Zdanowicz, P.

    2016-09-01

    The paper presents the optimization of damping in the passive suspension system of a motor vehicle moving rectilinearly with a constant speed on a road with rough surface of random irregularities, described according to the ISO classification. Two quarter-car 2DoF models, linear and non-linear, were used; in the latter, nonlinearities of spring characteristics of the suspension system and pneumatic tyres, sliding friction in the suspension system, and wheel lift-off were taken into account. The smoothing properties of vehicle tyres were represented in both models. The calculations were carried out for three roads of different quality, with simulating four vehicle speeds. Statistical measures of vertical vehicle body vibrations and of changes in the vertical tyre/road contact force were used as the criteria of system optimization and model comparison. The design suspension displacement limit was also taken into account. The optimum suspension damping coefficient was determined and the impact of undesirable sliding friction in the suspension system on the calculation results was estimated. The results obtained make it possible to evaluate the impact of the structure and complexity of the model used on the results of the optimization.

  20. Mixed Skyhook and FxLMS Control of a Half-Car Model with Magnetorheological Dampers

    Directory of Open Access Journals (Sweden)

    Piotr Krauze

    2016-01-01

    Full Text Available The problem of vibration attenuation in a semiactive vehicle suspension is considered. The proposed solution is based on usage of the information about the road roughness coming from the sensor installed on the front axle of the vehicle. It does not need any preview sensor to measure the road roughness as other preview control strategies do. Here, the well-known Skyhook algorithm is used for control of the front magnetorheological (MR damper. This algorithm is tuned to a quarter-car model of the front part of the vehicle. The rear MR damper is controlled by the FxLMS (Filtered-x LMS taking advantage of the information about the motion of the front vehicle axle. The goal of this algorithm is to minimize pitch of the vehicle body. The strategy is applied for a four-degree-of-freedom (4-DOF vehicle model equipped with magnetorheological dampers which were described using the Bouc-Wen model. The suspension model was subjected to the road-induced excitation in the form of a series of bumps within the frequency range 1.0–10 Hz. Different solutions are compared based on the transmissibility function and simulation results show the usefulness of the proposed solution.

  1. Psychological elements in car-following models: Mental workload in case of incidents in the other driving lane

    NARCIS (Netherlands)

    Hoogendoorn, R.G.; Hoogendoorn, S.P.; Brookhuis, K.A.; Daamen, W.

    2010-01-01

    Estimations of parameter values of car-following models show considerable differences between individuals and experiments. These differences may be caused by a different effect of external circumstances on mental workload of drivers. This effect may especially play a considerable role in case of

  2. MODEL BASED ON KEY PERFORMANCE INDICATORS FOR ASSESSING THE MARKET POSITION OF A COMPANY. CASE STUDY IN A CAR RENTAL COMPANY

    OpenAIRE

    URSACESCU Minodora; Mihai CIOC

    2012-01-01

    The present paper is the result of a research approach realized on the Romanian car rental services` market. Beginning from the characteristics of this economic sector and from the activity`s specificities of the car rental companies, the present study intends to develop an evaluation model of the position on the competitive market of a Romanian company in the car rental industry, based on Key Performance Indicators and Balanced Scorecard. The research`s objectives reside in defining an indic...

  3. Do Methodological Choices in Environmental Modeling Bias Rebound Effects? A Case Study on Electric Cars.

    Science.gov (United States)

    Font Vivanco, David; Tukker, Arnold; Kemp, René

    2016-10-18

    Improvements in resource efficiency often underperform because of rebound effects. Calculations of the size of rebound effects are subject to various types of bias, among which methodological choices have received particular attention. Modellers have primarily focused on choices related to changes in demand, however, choices related to modeling the environmental burdens from such changes have received less attention. In this study, we analyze choices in the environmental assessment methods (life cycle assessment (LCA) and hybrid LCA) and environmental input-output databases (E3IOT, Exiobase and WIOD) used as a source of bias. The analysis is done for a case study on battery electric and hydrogen cars in Europe. The results describe moderate rebound effects for both technologies in the short term. Additionally, long-run scenarios are calculated by simulating the total cost of ownership, which describe notable rebound effect sizes-from 26 to 59% and from 18 to 28%, respectively, depending on the methodological choices-with favorable economic conditions. Relevant sources of bias are found to be related to incomplete background systems, technology assumptions and sectorial aggregation. These findings highlight the importance of the method setup and of sensitivity analyses of choices related to environmental modeling in rebound effect assessments.

  4. The Theory of Visual Attention without the race: a new model of visual selection

    DEFF Research Database (Denmark)

    Andersen, Tobias; Kyllingsbæk, Søren

    2012-01-01

    The Theory of Visual Attention (TVA; Bundesen, 1990) is a comprehensive quantitative account of visual attention, which accounts for many empirical findings and has been extensively applied to clinical studies of attention. According to TVA, perceptual processing of objects occurs in parallel...... constrained by a limited processing capacity or rate, which is distributed among target and distractor objects with distractor objects receiving a smaller proportion of resources due to attentional filtering. Encoding into a limited visual short-term memory is implemented as a race model. Given its major...

  5. Hysteria, race, and phlogiston. A model of ontological elimination in the human sciences.

    Science.gov (United States)

    Ludwig, David

    2014-03-01

    Elimination controversies are ubiquitous in philosophy and the human sciences. For example, it has been suggested that human races, hysteria, intelligence, mental disorder, propositional attitudes such as beliefs and desires, the self, and the super-ego should be eliminated from the list of respectable entities in the human sciences. I argue that eliminativist proposals are often presented in the framework of an oversimplified "phlogiston model" and suggest an alternative account that describes ontological elimination on a gradual scale between criticism of empirical assumptions and conceptual choices.

  6. Race-related cognitive test bias in the active study: a mimic model approach.

    Science.gov (United States)

    Aiken Morgan, Adrienne T; Marsiske, Michael; Dzierzewski, Joseph M; Jones, Richard N; Whitfield, Keith E; Johnson, Kathy E; Cresci, Mary K

    2010-10-01

    The present study investigated evidence for race-related test bias in cognitive measures used in the baseline assessment of the ACTIVE clinical trial. Test bias against African Americans has been documented in both cognitive aging and early life span studies. Despite significant mean performance differences, Multiple Indicators Multiple Causes (MIMIC) models suggested most differences were at the construct level. There was little evidence that specific measures put either group at particular advantage or disadvantage and little evidence of cognitive test bias in this sample. Small group differences in education, cognitive status, and health suggest positive selection may have attenuated possible biases.

  7. Co-evolution model of Colletotrichum lindemuthianum (melanconiaceae, melanconiales races that occur in some Brazilian regions

    Directory of Open Access Journals (Sweden)

    Ana Lilia Alzate-Marin

    1999-03-01

    Full Text Available Colletotrichum lindemuthianum, the causal agent of anthracnose in the common bean (Phaseolus vulgaris L., displays a high level of virulence diversity, which explains the large number of existing pathotypes. Several lines of evidence indicate that such diversity is, at least in part, due to plant and pathogen co-evolution. A co-evolution model based on the binary classification of 25 races identified in Brazil by inoculation of differential cultivars and random amplified polymorphic DNA (RAPD data is proposed. In this model, races 8 and 64 that infected bean cultivar Cornell 49-242 (Are gene and Mexico 222 (Mexico I gene are considered to be sources of two important evolutionary routes. Inferences about undescribed races from Brazil could be made.Colletotrichum lindemuthianum (Sacc. & Magn. Scrib., agente causal da antracnose do feijoeiro comum (Phaseolus vulgaris L., possui alto nível de diversidade de virulência, o que explica o elevado número de patótipos existentes. A partir de trabalhos anteriores sobre a classificação binária de 25 raças identificadas no Brasil e sua relação com agrupamentos RAPD, foi possível construir um modelo de evolução de tais raças. As raças 8 e 64, que foram compatíveis com os cultivares Cornell 49-242 (gene Are e México 222 (gene México I, se apresentam como possíveis origens de duas importantes rotas de evolução. Inferências de raças ainda não detectadas no Brasil puderam ser feitas.

  8. Applying Critical Race Theory to Group Model Building Methods to Address Community Violence.

    Science.gov (United States)

    Frerichs, Leah; Lich, Kristen Hassmiller; Funchess, Melanie; Burrell, Marcus; Cerulli, Catherine; Bedell, Precious; White, Ann Marie

    2016-01-01

    Group model building (GMB) is an approach to building qualitative and quantitative models with stakeholders to learn about the interrelationships among multilevel factors causing complex public health problems over time. Scant literature exists on adapting this method to address public health issues that involve racial dynamics. This study's objectives are to (1) introduce GMB methods, (2) present a framework for adapting GMB to enhance cultural responsiveness, and (3) describe outcomes of adapting GMB to incorporate differences in racial socialization during a community project seeking to understand key determinants of community violence transmission. An academic-community partnership planned a 1-day session with diverse stakeholders to explore the issue of violence using GMB. We documented key questions inspired by critical race theory (CRT) and adaptations to established GMB "scripts" (i.e., published facilitation instructions). The theory's emphasis on experiential knowledge led to a narrative-based facilitation guide from which participants created causal loop diagrams. These early diagrams depict how violence is transmitted and how communities respond, based on participants' lived experiences and mental models of causation that grew to include factors associated with race. Participants found these methods useful for advancing difficult discussion. The resulting diagrams can be tested and expanded in future research, and will form the foundation for collaborative identification of solutions to build community resilience. GMB is a promising strategy that community partnerships should consider when addressing complex health issues; our experience adapting methods based on CRT is promising in its acceptability and early system insights.

  9. Drag reduction of a car model by linear genetic programming control

    Science.gov (United States)

    Li, Ruiying; Noack, Bernd R.; Cordier, Laurent; Borée, Jacques; Harambat, Fabien

    2017-08-01

    We investigate open- and closed-loop active control for aerodynamic drag reduction of a car model. Turbulent flow around a blunt-edged Ahmed body is examined at ReH≈ 3× 105 based on body height. The actuation is performed with pulsed jets at all trailing edges (multiple inputs) combined with a Coanda deflection surface. The flow is monitored with 16 pressure sensors distributed at the rear side (multiple outputs). We apply a recently developed model-free control strategy building on genetic programming in Dracopoulos and Kent (Neural Comput Appl 6:214-228, 1997) and Gautier et al. (J Fluid Mech 770:424-441, 2015). The optimized control laws comprise periodic forcing, multi-frequency forcing and sensor-based feedback including also time-history information feedback and combinations thereof. Key enabler is linear genetic programming (LGP) as powerful regression technique for optimizing the multiple-input multiple-output control laws. The proposed LGP control can select the best open- or closed-loop control in an unsupervised manner. Approximately 33% base pressure recovery associated with 22% drag reduction is achieved in all considered classes of control laws. Intriguingly, the feedback actuation emulates periodic high-frequency forcing. In addition, the control identified automatically the only sensor which listens to high-frequency flow components with good signal to noise ratio. Our control strategy is, in principle, applicable to all multiple actuators and sensors experiments.

  10. Analysis of car-following model considering driver’s physical delay in sensing headway

    Science.gov (United States)

    Zhu, H. B.; Dai, S. Q.

    2008-05-01

    An extended car-following model is proposed by taking into account the delay of the driver’s response in sensing headway. The stability condition of this model is obtained by using the linear stability theory. The results show that the stability region decreases when the driver’s physical delay in sensing headway increases. The KdV equation and mKdV equation near the neutral stability line and the critical point are respectively derived by applying the reductive perturbation method. The traffic jams could be thus described by soliton solution and kink-antikink soliton solution for the KdV equation and mKdV equation respectively. The numerical results in the form of the space-time evolution of headway show that the stabilization effect is weakened when the driver’s physical delay increases. It confirms the fact that the delay of driver’s response in sensing headway plays an important role in jamming transition, and the numerical results are in good agreement with the theoretical analysis.

  11. Proportional-differential effects in traffic car-following model system

    Science.gov (United States)

    Zhang, Li-Dong; Zhu, Wen-Xing; Liu, Jian-lei

    2014-07-01

    Traffic flow system's stability analysis can be seen as a typical control system problem, which has three kinds of damping ratio properties from the viewpoint of control theory. To discover the damping ratio characteristics of traffic flow system under sudden outer impulse, firstly, we proposed a new method to build the traffic flow model based on state space theory. Secondly, we deduced one form of state transfer matrix from system closed-loop transfer function reversely. Lastly, we fully investigated the proportional-differential effects in the traffic car-following model system analytically and numerically. For unsteady traffic flow system with the proportional-differential (PD) term, in order to suppress the traffic jam, we derived a kind of decoupled delay-feedback control algorithm, which used H∞-norm and the numerical simulation method to find the feedback gain k and delay time τ. The traffic flow system's transient performance formula was presented with and without PD term, and we found out the important impact of PD term on traffic flow system' stability. The numerical simulation results substantiate our theoretical and analytical results.

  12. Drag reduction of a car model by linear genetic programming control

    CERN Document Server

    Li, Ruiying; Cordier, Laurent; Borée, Jacques; Harambat, Fabien; Kaiser, Eurika; Duriez, Thomas

    2016-01-01

    We investigate open- and closed-loop active control for aerodynamic drag reduction of a car model. Turbulent flow around a blunt-edged Ahmed body is examined at $Re_{H}\\approx3\\times10^{5}$ based on body height. The actuation is performed with pulsed jets at all trailing edges combined with a Coanda deflection surface. The flow is monitored with pressure sensors distributed at the rear side. We apply a model-free control strategy building on Dracopoulos & Kent (Neural Comput. & Applic., vol. 6, 1997, pp. 214-228) and Gautier et al. (J. Fluid Mech., vol. 770, 2015, pp. 442-457). The optimized control laws comprise periodic forcing, multi-frequency forcing and sensor-based feedback including also time-history information feedback and combination thereof. Key enabler is linear genetic programming as simple and efficient framework for multiple inputs (actuators) and multiple outputs (sensors). The proposed linear genetic programming control can select the best open- or closed-loop control in an unsupervis...

  13. Modelling the Emission And/or Absorption Features in the High Resolution Spectra of the Southern Binary System: HH Car

    Science.gov (United States)

    Koseoglu, Dogan; Bakış, Hicran

    2016-07-01

    High-resolution spectra (R=48000) of the southern close binary system, HH Car, has been analyzed with modern analysis techniques. Precise absolute parameters were derived from the simultaneous solution of the radial velocity, produced in this study and the light curves, published. According to the results of these analyses, the primary component is an O9 type main sequence star while the secondary component is a giant/subgiant star with a spectral type of B0. Hα emissions can be seen explicitly in the spectra of HH Car. These features were modelled using the absolute parameters of the components. Since components of HH Car are massive early-type stars, mass loss through stellar winds can be expected. This study revealed that the components of HH Car have stellar winds and the secondary component loses mass to the primary. Stellar winds and the gas stream between the components were modelled as a hot shell around the system. It is determined that the interaction between the winds and the gas stream leads to formation of a high temperature impact region.

  14. The New Cloud Absorption Radiometer (CAR) Software: One Model for NASA Remote Sensing Virtual Instruments

    Science.gov (United States)

    Roth, Don J.; Rapchun, David A.; Jones, Hollis H.

    2001-01-01

    The Cloud Absorption Radiometer (CAR) instrument has been the most frequently used airborne instrument built in-house at NASA Goddard Space Flight Center, having flown scientific research missions on-board various aircraft to many locations in the United States, Azores, Brazil, and Kuwait since 1983. The CAR instrument is capable of measuring scattered light by clouds in fourteen spectral bands in UV, visible and near-infrared region. This document describes the control, data acquisition, display, and file storage software for the new version of CAR. This software completely replaces the prior CAR Data System and Control Panel with a compact and robust virtual instrument computer interface. Additionally, the instrument is now usable for the first time for taking data in an off-aircraft mode. The new instrument is controlled via a LabVIEW v5. 1.1-developed software interface that utilizes, (1) serial port writes to write commands to the controller module of the instrument, and (2) serial port reads to acquire data from the controller module of the instrument. Step-by-step operational procedures are provided in this document. A suite of other software programs has been developed to complement the actual CAR virtual instrument. These programs include: (1) a simulator mode that allows pretesting of new features that might be added in the future, as well as demonstrations to CAR customers, and development at times when the instrument/hardware is off-location, and (2) a post-experiment data viewer that can be used to view all segments of individual data cycles and to locate positions where 'start' and stop' byte sequences were incorrectly formulated by the instrument controller. The CAR software described here is expected to be the basis for CAR operation for many missions and many years to come.

  15. Multibody dynamics modelling and system identification of a quarter-car test rig with McPherson strut suspension

    Science.gov (United States)

    Sandu, Corina; Andersen, Erik R.; Southward, Steve

    2011-02-01

    In this paper, we develop a multibody dynamics model of a quarter-car test-rig equipped with a McPherson strut suspension and we apply a system identification technique on it. Constrained equations of motion in the Lagrange multiplier form are derived and employed to characterise the dynamic behaviour of the test rig modelled once as a linear system and once as a non-linear system. The system of differential algebraic equations is integrated using a Hilber-Hughes-Taylor integrator. The responses of both models (linear and non-linear) to a given displacement input are obtained and compared with the experimental response recorded using the physical quarter-car test rig equipped with a McPherson strut suspension. The system identification is performed for control purposes. The results, as well as the performance and area of applicability of the test rig models derived, are discussed.

  16. The Old Jalopy Races into the Future.

    Science.gov (United States)

    Considine, Tim

    1993-01-01

    Discusses alternative transportation technological advances in speed, range, battery strategies, and safety facilitated by motor car racing. Presents a historical perspective of the development of steam, electric and gas-powered vehicles and modern versions of electric, and mixed power source cars being tested today. (MCO)

  17. Multiphysics modelling of multibody systems: application to car semi-active suspensions

    Science.gov (United States)

    Docquier, N.; Poncelet, A.; Delannoy, M.; Fisette, P.

    2010-12-01

    The goal of the present article is to analyse the performances of a modern vehicle equipped with a novel suspension system linking front, rear, right and left cylinders via a semi-active hydraulic circuit, developed by the Tenneco Automotive company. In addition to improving the vehicle's vertical performances (in terms of comfort), both the stiff roll motion of the carbody and the soft wrap motion of the rear/front wheel-axle units can be obtained and tuned via eight electrovalves. The proposed system avoids the use of classical anti-roll bars, which would be incompatible with the wrap performance. A major problem of the project is to produce a realistic and efficient 3D multibody dynamic model of an Audi A6 coupled, at the equational level, with an hydraulic model of the suspension including cylinders, accumulators, valve characteristics, oil compressibility and pipe dynamics. As regards the hydraulic submodel, a particular attention is paid to assemble resistive components properly without resorting to the use of artificial volumes, as proposed by some software dealing with the dynamics of hydraulic systems. According to Tenneco Automotive requirements, this model must be produced in a Matlab/Simulink form, in particular for control purposes. Thanks to the symbolic approach underlying our multibody program; a unified hybrid model can be obtained as a unique plant dynamic block to be real-time integrated in the Simulink environment on a standard computer. Simulation results highlight the advantages of this new suspension system, in particular regarding the behaviour of the car which can remain stiff in roll for curve negotiation, while maintaining a soft wrap behaviour on uneven surfaces.

  18. A simple model for predicting sprint-race times accounting for energy loss on the curve

    Science.gov (United States)

    Mureika, J. R.

    1997-11-01

    The mathematical model of J. Keller for predicting World Record race times, based on a simple differential equation of motion, predicted quite well the records of the day. One of its shortcoming is that it neglects to account for a sprinter's energy loss around a curve, a most important consideration particularly in the 200m--400m. An extension to Keller's work is considered, modeling the aforementioned energy loss as a simple function of the centrifugal force acting on the runner around the curve. Theoretical World Record performances for indoor and outdoor 200m are discussed, and the use of the model at 300m is investigated. Some predictions are made for possible 200m outdoor and indoor times as run by Canadian 100m WR holder Donovan Bailey, based on his 100m final performance at the 1996 Olympic Games in Atlanta.

  19. A Simple Model for Predicting Sprint Race Times Accounting for Energy Loss on the Curve

    CERN Document Server

    Mureika, J R

    1997-01-01

    The mathematical model of J. Keller for predicting World Record race times, based on a simple differential equation of motion, predicted quite well the records of the day. One of its shortcoming is that it neglects to account for a sprinter's energy loss around a curve, a most important consideration particularly in the 200m--400m. An extension to Keller's work is considered, modeling the aforementioned energy loss as a simple function of the centrifugal force acting on the runner around the curve. Theoretical World Record performances for indoor and outdoor 200m are discussed, and the use of the model at 300m is investigated. Some predictions are made for possible 200m outdoor and indoor times as run by Canadian 100m WR holder Donovan Bailey, based on his 100m final performance at the 1996 Olympic Games in Atlanta.

  20. Introducing the Literary Critic: The CARS Model in the Introductions of Academic Papers in Literary Criticism

    Directory of Open Access Journals (Sweden)

    Balázs Sánta

    2015-05-01

    Full Text Available Genre analysis as a “meta-study” is a topic that has been deeply investigated in the field of applied linguistics, one of its more specific areas of interest being research article introductions (RAIs. However, there are still certain kinds of scholarly activity that have received relatively little attention in this regard, such as literary criticism. The paper presents and discusses the results of a small-scale study of the introductions of ten academic essays in this field. The paper’s aim is to see how Swales’ (1990 CARS model can be applied to the rhetorical structure of these RAIs. It is found that at the cost of certain modifications necessitated by the structure of the essays in the corpus, it is not impossible to analyze critical texts produced by scholars belonging in the latter area. The demonstration of this has significance in fulfilling a perceived need for literary criticism to be considered among those disciplines that are worthy of the attention of applied linguistic research.

  1. An investigation of merging and diverging cars on a multi-lane road using a cellular automation model

    Science.gov (United States)

    Jetto, K.; Ez-Zahraouy, H.; Benyoussef, A.

    2012-11-01

    In this paper, we have investigated two observed situations in a multi-lane road. The first one concerns a fast merging vehicle. The second situation is related to the case of a fast vehicle leaving the fastest lane back into the slowest lane and targeting a specific way out. We are interested in the relaxation time τ, i.e., which is the time that the merging (diverging) vehicle spends before reaching the desired lane. Using analytical treatment and numerical simulations for the NaSch model, we have found two states, namely, the free state in which the merging (diverging) vehicle reaches the desired lane, and the trapped state in which τ diverges. We have established phase diagrams for several values of the braking probability. In the second situation, we have shown that diverging from the fast lane targeting a specific way out is not a simple task. Even if the diverging vehicle is in the free phase, two different states can be distinguished. One is the critical state, in which the diverging car can probably reach the desired way out. The other is the safe state, in which the diverging car can surely reach the desired way out. In order to be in the safe state, we have found that the driver of the diverging car must know the critical distance (below which the way out will be out of his reach) in each lane. Furthermore, this critical distance depends on the density of cars, and it follows an exponential law.

  2. Modeling violations of the race model inequality in bimodal paradigms: co-activation from decision and non-decision components

    Directory of Open Access Journals (Sweden)

    Michael eZehetleitner

    2015-03-01

    Full Text Available The redundant-signals paradigm (RSP is designed to investigate response behavior in perceptual tasks in which response-relevant targets are defined by either one or two features, or modalities. The common finding is that responses are speeded for redundantly compared to singly defined targets. This redundant-signals effect (RSE can be accounted for by race models if the response times do not violate the race model inequality (RMI. When there are violations of the RMI, race models are effectively excluded as a viable account of the RSE. The common alternative is provided by co-activation accounts, which assume that redundant target signals are integrated at some processing stage. However, ‘co-activation’ has mostly been only indirectly inferred and the accounts have only rarely been explicitly modeled; if they were modeled, the RSE has typically been assumed to have a decisional locus. Yet, there are also indications in the literature that the RSE might originate, at least in part, at a non-decisional or motor stage. In the present study, using a distribution analysis of sequential-sampling models (ex-Wald and Ratcliff Diffusion model, the locus of the RSE was investigated for two bimodal (audio-visual detection tasks that strongly violated the RMI, indicative of substantial co-activation. Three model variants assuming different loci of the RSE were fitted to the quantile reaction time proportions: a decision, a non-decision, and a combined variant both to vincentized group as well as individual data. The results suggest that for the two bimodal detection tasks, co-activation has a shared decisional and non-decisional locus. These findings point to the possibility that the mechanisms underlying the RSE depend on the specifics (task, stimulus, conditions, etc. of the experimental paradigm.

  3. Modeling violations of the race model inequality in bimodal paradigms: co-activation from decision and non-decision components.

    Science.gov (United States)

    Zehetleitner, Michael; Ratko-Dehnert, Emil; Müller, Hermann J

    2015-01-01

    The redundant-signals paradigm (RSP) is designed to investigate response behavior in perceptual tasks in which response-relevant targets are defined by either one or two features, or modalities. The common finding is that responses are speeded for redundantly compared to singly defined targets. This redundant-signals effect (RSE) can be accounted for by race models if the response times do not violate the race model inequality (RMI). When there are violations of the RMI, race models are effectively excluded as a viable account of the RSE. The common alternative is provided by co-activation accounts, which assume that redundant target signals are integrated at some processing stage. However, "co-activation" has mostly been only indirectly inferred and the accounts have only rarely been explicitly modeled; if they were modeled, the RSE has typically been assumed to have a decisional locus. Yet, there are also indications in the literature that the RSE might originate, at least in part, at a non-decisional or motor stage. In the present study, using a distribution analysis of sequential-sampling models (ex-Wald and Ratcliff Diffusion model), the locus of the RSE was investigated for two bimodal (audio-visual) detection tasks that strongly violated the RMI, indicative of substantial co-activation. Three model variants assuming different loci of the RSE were fitted to the quantile reaction time proportions: a decision, a non-decision, and a combined variant both to vincentized group as well as individual data. The results suggest that for the two bimodal detection tasks, co-activation has a shared decisional and non-decisional locus. These findings point to the possibility that the mechanisms underlying the RSE depend on the specifics (task, stimulus, conditions, etc.) of the experimental paradigm.

  4. The Lognormal Race: A Cognitive-Process Model of Choice and Latency with Desirable Psychometric Properties.

    Science.gov (United States)

    Rouder, Jeffrey N; Province, Jordan M; Morey, Richard D; Gomez, Pablo; Heathcote, Andrew

    2015-06-01

    We present a cognitive process model of response choice and response time performance data that has excellent psychometric properties and may be used in a wide variety of contexts. In the model there is an accumulator associated with each response option. These accumulators have bounds, and the first accumulator to reach its bound determines the response time and response choice. The times at which accumulator reaches its bound is assumed to be lognormally distributed, hence the model is race or minima process among lognormal variables. A key property of the model is that it is relatively straightforward to place a wide variety of models on the logarithm of these finishing times including linear models, structural equation models, autoregressive models, growth-curve models, etc. Consequently, the model has excellent statistical and psychometric properties and can be used in a wide range of contexts, from laboratory experiments to high-stakes testing, to assess performance. We provide a Bayesian hierarchical analysis of the model, and illustrate its flexibility with an application in testing and one in lexical decision making, a reading skill.

  5. Imaging Race

    Science.gov (United States)

    Eberhardt, Jennifer L.

    2005-01-01

    Researchers have recently begun to use the tools of neuroscience to examine the social psychological responses associated with race. This article serves as a review of the developing literature in this area. It advances the argument that neuroscience studies of race have the potential to shape fundamental assumptions about race, and the interplay…

  6. The Feedback Control Strategy of the Takagi-Sugeno Fuzzy Car-Following Model with Two Delays

    Directory of Open Access Journals (Sweden)

    Cong Zhai

    2016-01-01

    Full Text Available Considering the driver’s sensing the headway and velocity the different time-varying delays exist, respectively, and the sensitivity of drivers changes with headway and speed. Introducing the fuzzy control theory, a new fuzzy car-following model with two delays is presented, and the feedback control strategy of the new fuzzy car-following model is studied. Based on the Lyapunov function theory and linear matrix inequality (LMI approach, the sufficient condition that the existence of the fuzzy controller is given making the closed-loop system is asymptotic, stable; namely, traffic congestion phenomenon can effectively be suppressed, and the controller gain matrix can be obtained via solving linear matrix inequality. Finally, the simulation examples verify that the method which suppresses traffic congestion and reduces fuel consumption and exhaust emissions is effective.

  7. Time-dependent Ginzburg-Landau equation in a car-following model considering the driver's physical delay

    Science.gov (United States)

    Ge, Hong-xia; Meng, Xiang-pei; Cheng, Rong-jun; Lo, Siu-Ming

    2011-10-01

    In this paper, an extended car-following model considering the delay of the driver's response in sensing headway is proposed to describe the traffic jam. It is shown that the stability region decreases when the driver's physical delay in sensing headway increases. The phase transition among the freely moving phase, the coexisting phase, and the uniformly congested phase occurs below the critical point. By applying the reductive perturbation method, we get the time-dependent Ginzburg-Landau (TDGL) equation from the car-following model to describe the transition and critical phenomenon in traffic flow. We show the connection between the TDGL equation and the mKdV equation describing the traffic jam.

  8. A control method for congested traffic induced by bottlenecks in the coupled map car-following model

    Science.gov (United States)

    Zhao, Xiaomei; Gao, Ziyou

    2006-07-01

    We present a simple control method to suppress the traffic congestion in the coupled map car-following model under open boundary, based on the pioneer work of Konishi et al. [Coupled map car-following model and its delayed-feedback control, Phys. Rev. E 60 (1999) 4000-4007]. Theoretically, it is proven that the congested traffic in the traffic system could be suppressed by using the method. Comparison between our method and the method of Konishi et al. is carried out. The simulation results show the temporal behavior obtained by our method is better than that by the method of Konishi et al., although both the methods can suppress the traffic jam. The simulation results demonstrate that the traffic system can move into a homogeneous phase and the flux has great increases by the introduction of the control signal. The simulation results are in good agreement with the theoretical analysis.

  9. Nonlinear analysis of a new car-following model accounting for the global average optimal velocity difference

    Science.gov (United States)

    Peng, Guanghan; Lu, Weizhen; He, Hongdi

    2016-09-01

    In this paper, a new car-following model is proposed by considering the global average optimal velocity difference effect on the basis of the full velocity difference (FVD) model. We investigate the influence of the global average optimal velocity difference on the stability of traffic flow by making use of linear stability analysis. It indicates that the stable region will be enlarged by taking the global average optimal velocity difference effect into account. Subsequently, the mKdV equation near the critical point and its kink-antikink soliton solution, which can describe the traffic jam transition, is derived from nonlinear analysis. Furthermore, numerical simulations confirm that the effect of the global average optimal velocity difference can efficiently improve the stability of traffic flow, which show that our new consideration should be taken into account to suppress the traffic congestion for car-following theory.

  10. Validation of alternative models in genetic evaluation of racing performance in North Swedish and Norwegian cold-blooded trotters.

    Science.gov (United States)

    Olsen, H F; Klemetsdal, G; Odegård, J; Arnason, T

    2012-04-01

    There have been several approaches to the estimation of breeding values of performance in trotters, and the objective of this study was to validate different alternatives for genetic evaluation of racing performance in the North Swedish and Norwegian cold-blooded trotters. The current bivariate approach with the traits racing status (RACE) and earnings (EARN) was compared with a threshold-linear animal model and the univariate alternative with the performance trait only. The models were compared based on cross-validation of standardized earnings, using mean-squared errors of prediction (MSEP) and the correlation between the phenotype (Y) and the estimated breeding value (EBV). Despite possible effects of selection, a rather high estimate of heritability of EARN was found in our univariate analysis. The genetic trend estimate for EARN was clearly higher in the bivariate specification than in the univariate model, as a consequence of the considerable size of estimated heritability of RACE and its high correlation with EARN (approximately 0.8). RACE is highly influenced by ancestry rather than the on-farm performance of the horse itself. Consequently, the use of RACE in the genetic analysis may inflate the genetic trend of EARN because of a double counting of pedigree information. Although, because of the higher predictive ability of the bivariate specification, the improved ranking of animals within a year-class and the inability to discriminate between models for genetic trend, we propose to base prediction of breeding values on the current bivariate model. © 2011 Blackwell Verlag GmbH.

  11. Analysis of Urban Car Owners Commute Mode Choice Based on Evolutionary Game Model

    Directory of Open Access Journals (Sweden)

    Huawei Gong

    2015-01-01

    Full Text Available With the aggravation of the traffic congestion in the city, car owners will have to give up commuting with private cars and take the public transportation instead. The paper uses the replication dynamic mechanism to simulate the learning and adjustment mechanism of the automobile owners commuting mode selection. The evolutionary stable strategy is used to describe the long-term evolution of competition game trend. Finally we simulate equilibrium and stability of an evolution of the game under a payoff imbalance situation. The research shows that a certain proportion of car owners will choose public transit under the pressure of public transport development and heavy traffic, and the proportion will be closely related to the initial conditions and urban transportation development policy.

  12. From a Competition for Self-Driving Miniature Cars to a Standardized Experimental Platform: Concept, Models, Architecture, and Evaluation

    OpenAIRE

    Berger, Christian

    2014-01-01

    Context: Competitions for self-driving cars facilitated the development and research in the domain of autonomous vehicles towards potential solutions for the future mobility. Objective: Miniature vehicles can bridge the gap between simulation-based evaluations of algorithms relying on simplified models, and those time-consuming vehicle tests on real-scale proving grounds. Method: This article combines findings from a systematic literature review, an in-depth analysis of results and technical ...

  13. General Design of Model ZG-1 Track Car%ZG-1型轨道车总体设计

    Institute of Scientific and Technical Information of China (English)

    赵瑞杰

    2013-01-01

      重点介绍了ZG -1型轨道车的总体设计思路及技术方案,简要阐述了该车的各系统性能及组成。%This paper introduces the general design thought and scheme of Model ZG‐1 Track Car ,and describes the performance and composition of each subsystem .

  14. DETERMINATION ALGORITHM OF OPTIMAL GEOMETRICAL PARAMETERS FOR COMPONENTS OF FREIGHT CARS ON THE BASIS OF GENERALIZED MATHEMATICAL MODELS

    Directory of Open Access Journals (Sweden)

    O. V. Fomin

    2013-10-01

    Full Text Available Purpose. Presentation of features and example of the use of the offered determination algorithm of optimum geometrical parameters for the components of freight cars on the basis of the generalized mathematical models, which is realized using computer. Methodology. The developed approach to search for optimal geometrical parameters can be described as the determination of optimal decision of the selected set of possible variants. Findings. The presented application example of the offered algorithm proved its operation capacity and efficiency of use. Originality. The determination procedure of optimal geometrical parameters for freight car components on the basis of the generalized mathematical models was formalized in the paper. Practical value. Practical introduction of the research results for universal open cars allows one to reduce container of their design and accordingly to increase the carrying capacity almost by100 kg with the improvement of strength characteristics. Taking into account the mass of their park this will provide a considerable economic effect when producing and operating. The offered approach is oriented to the distribution of the software packages (for example Microsoft Excel, which are used by technical services of the most enterprises, and does not require additional capital investments (acquisitions of the specialized programs and proper technical staff training. This proves the correctness of the research direction. The offered algorithm can be used for the solution of other optimization tasks on the basis of the generalized mathematical models.

  15. Lightweight robotic mobility: template-based modeling for dynamics and controls using ADAMS/car and MATLAB

    Science.gov (United States)

    Adamczyk, Peter G.; Gorsich, David J.; Hudas, Greg R.; Overholt, James

    2003-09-01

    The U.S. Army is seeking to develop autonomous off-road mobile robots to perform tasks in the field such as supply delivery and reconnaissance in dangerous territory. A key problem to be solved with these robots is off-road mobility, to ensure that the robots can accomplish their tasks without loss or damage. We have developed a computer model of one such concept robot, the small-scale "T-1" omnidirectional vehicle (ODV), to study the effects of different control strategies on the robot's mobility in off-road settings. We built the dynamic model in ADAMS/Car and the control system in Matlab/Simulink. This paper presents the template-based method used to construct the ADAMS model of the T-1 ODV. It discusses the strengths and weaknesses of ADAMS/Car software in such an application, and describes the benefits and challenges of the approach as a whole. The paper also addresses effective linking of ADAMS/Car and Matlab for complete control system development. Finally, this paper includes a section describing the extension of the T-1 templates to other similar ODV concepts for rapid development.

  16. Car Shoe

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    历史悠久的意大利制鞋商Car Shoe为日本爱知世界博览会意大利展团迎宾小姐设计的两款皮鞋,轻松休闲又不失高雅,完美再现Car Shoe的设计理念,其中一款舒适大方“Driving”软底鞋,白1963年上市至今,始终风靡全球,成为一代经典。布满黑色胶皮钉的鞋底,是Car Shoe鞋子的标志性特点,另有一款3.5厘米的矮跟 鞋,尽显女性独特魅力。

  17. A decision tree model for the implementation of a safety strategy in the horse-racing industry.

    Science.gov (United States)

    Hitchens, Peta L; Curry, Beverley; Blizzard, C Leigh; Palmer, Andrew J

    2015-04-01

    The profession of a horse-racing jockey is a dangerous one. We developed a decision tree model quantifying the effects of implementing different safety strategies on jockey fall and injury rates and their associated costs. Data on race-day falls were obtained from stewards' reports from August 2002 to July 2009. Insurance claim data were provided by Principal Racing Authorities and workers' compensation authorities in each jurisdiction. Fall and claim incidence data were used as baseline rates. The model considered (1) the status quo, in which policy was unchanged; and (2) compared it with four hypothetical changes in policy that restricted apprentice jockeys from riding less-accomplished horses, with the aim of improving safety by reducing incidence of injurious jockey falls. Second-order Monte Carlo simulations were conducted to account for uncertainties. The point estimate for mean costs of falls under the status quo was $30.73/ride, with falls by apprentice jockeys with race rides riding horses with less than five race starts contributing the highest costs ($98.49/ride). The hypothetical safety strategies resulted in a 1.04%-5.07% decrease in fall rates versus status quo. For three of the four strategies, significant reductions of 8.74%-13.13% in workers' compensation costs over one single race season were predicted. Costs were highly sensitive to large claims. This model is a useful instrument for comparing potential changes in cost and risks associated with implementing new safety strategies in the horseracing industry. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Testing Self-Segregation: Multiple-Group Structural Modeling of College Students' Interracial Friendship by Race

    Science.gov (United States)

    Kim, Young K.; Park, Julie J.; Koo, Katie K.

    2015-01-01

    Using structural equation modeling, this study examined the effects of peer environments on collegiate interracial friendship and how such effects vary by students' race. The results show that the peer environment of Greek life mediated the relationship between structural diversity and interracial friendship in college, in that students…

  19. Kinematic and dynamic analysis of the McPherson suspension with a planar quarter-car model

    Science.gov (United States)

    Hurel, Jorge; Mandow, Anthony; García-Cerezo, Alfonso

    2013-09-01

    McPherson suspension modelling poses a challenging problem due to its nonlinear asymmetric behaviour. The paper proposes a planar quarter-car analytical model that not only considers vertical motion of the sprung mass (chassis) but also: (i) rotation and translation for the unsprung mass (wheel assembly), (ii) wheel mass and its inertia moment about the longitudinal axis, and (iii) tyre damping and lateral deflection. This kinematic-dynamic model offers a solution to two important shortcomings of the conventional quarter-car model: it accounts for geometry and for tyre modelling. The paper offers a systematic development of the planar model as well as the complete set of mathematical equations. This analytical model can be suitable for fast computation in hardware-in-the-loop applications. Furthermore, a reproducible Simulink implementation is given. The model has been compared with a realistic Adams/View simulation to analyse dynamic behaviour for the jounce and rebound motion of the wheel and two relevant kinematic parameters: camber angle and track width variation.

  20. Noise Reduction in Car Speech

    OpenAIRE

    V. Bolom

    2009-01-01

    This paper presents properties of chosen multichannel algorithms for speech enhancement in a noisy environment. These methods are suitable for hands-free communication in a car cabin. Criteria for evaluation of these systems are also presented. The criteria consider both the level of noise suppression and the level of speech distortion. The performance of multichannel algorithms is investigated for a mixed model of speech signals and car noise and for real signals recorded in a car

  1. Noise Reduction in Car Speech

    Directory of Open Access Journals (Sweden)

    V. Bolom

    2009-01-01

    Full Text Available This paper presents properties of chosen multichannel algorithms for speech enhancement in a noisy environment. These methods are suitable for hands-free communication in a car cabin. Criteria for evaluation of these systems are also presented. The criteria consider both the level of noise suppression and the level of speech distortion. The performance of multichannel algorithms is investigated for a mixed model of speech signals and car noise and for real signals recorded in a car

  2. An investigation of merging and diverging cars on a multi-lane road using a cellular automation model

    Institute of Scientific and Technical Information of China (English)

    K.Jetto; H.Ez-Zahraouy; A.Benyoussef

    2012-01-01

    In this paper,we have investigated two observed situations in a multi-lane road.The first one concerns a fast merging vehicle.The second situation is related to the case of a fast vehicle leaving the fastest lane back into the slowest lane and targeting a specific way out.We are interested in the relaxation time τ,i.e.,which is the time that the merging (diverging) vehicle spends before reaching the desired lane.Using analytical treatment and numerical simulations for the NaSch model,we have found two states,namely,the free state in which the merging (diverging) vehicle reaches the desired lane,and the trapped state in which τ diverges.We have established phase diagrams for several values of the braking probability.In the second situation,we have shown that diverging from the fast lane targeting a specific way out is not a simple task.Even if the diverging vehicle is in the free phase,two different states can be distinguished.One is the critical state,in which the diverging car can probably reach the desired way out.The other is the safe state,in which the diverging car can surely reach the desired way out.In order to be in the safe state,we have found that the driver of the diverging car must know the critical distance (below which the way out will be out of his reach) in each lane.Furthermore,this critical distance depends on the density of cars,and it follows an exponential law.

  3. Impacts of the driver's bounded rationality on the traffic running cost under the car-following model

    Science.gov (United States)

    Tang, Tie-Qiao; Luo, Xiao-Feng; Liu, Kai

    2016-09-01

    The driver's bounded rationality has significant influences on the micro driving behavior and researchers proposed some traffic flow models with the driver's bounded rationality. However, little effort has been made to explore the effects of the driver's bounded rationality on the trip cost. In this paper, we use our recently proposed car-following model to study the effects of the driver's bounded rationality on his running cost and the system's total cost under three traffic running costs. The numerical results show that considering the driver's bounded rationality will enhance his each running cost and the system's total cost under the three traffic running costs.

  4. Creating the finite element models of car seats with passive head restraints to meet the requirements of passive safety

    Directory of Open Access Journals (Sweden)

    D. Yu. Solopov

    2014-01-01

    Full Text Available A problem solution to create the car chairs using modern software complexes (CAE based on the finite elements is capable to increase an efficiency of designing process significantly. Designing process is complicated by the fact that at present there are no available techniques focused on this sort of tasks.This article shows the features to create the final element models (FEM of the car chairs having three levels of complexity. It assesses a passive safety, which is ensured by the developed chair models with passive head restraints according to requirements of UNECE No 25 Regulations, and an accuracy of calculation results compared with those of full-scale experiments.This work is part of the developed technique, which allows effective development of the car chair designs both with passive, and with active head restraints, meeting the requirements of passive safety.By results of calculations and experiments it was established that at assessment by an UNECE No 25 technique the "rough" FEM (the 1st and 2nd levels can be considered as rational (in terms of effort to its creation and task solution and by the errors of results, and it is expedient to use them for preliminary and multiple calculations. Detailed models (the 3rd level provide the greatest accuracy (for accelerations the relative error makes 10%, for movements it is 11%, while in comparison with calculations, the relative error for a model of head restraint only decreases by 5% for accelerations and for 9% for movements.The materials presented in the article are used both in research activities and in training students at the Chair of Wheel Vehicles of the Scientific and Educational Complex "Special Mechanical Engineering" of Bauman Moscow State Technical University.

  5. Characterizing the Effects of Race/Ethnicity on Acetaminophen Pharmacokinetics Using Physiologically Based Pharmacokinetic Modeling.

    Science.gov (United States)

    Zurlinden, Todd J; Reisfeld, Brad

    2017-02-01

    Acetaminophen (APAP, paracetamol) is currently the principal cause of acute liver failure in both the USA and the UK. However, relatively little is known about the influence of genes and race/ethnicity on the disposition of APAP and the extent to which genetic variation and ethnicity may predispose individuals to a higher risk of APAP-induced hepatotoxicity. The objective of this research was to develop subpopulation-specific physiologically based pharmacokinetic (PBPK) models for two genetically different groups (Western Europeans and East Asians) and then use the models to quantify the difference in absorption, distribution, metabolism, and excretion (ADME) of APAP between these groups. A comprehensive set of human pharmacokinetic data mined from the literature was divided into two groups based on ethnicity as an indicator of the expected abundance of phenol-metabolizing alleles. Using these datasets and a Bayesian hierarchical framework, subpopulation-specific physiologically based pharmacokinetic models for APAP were developed and tested for the two groups. Model simulations were in good agreement with experimental data for both time-dependent parent and metabolite concentrations and summary pharmacokinetic parameters. In addition, simulations were conducted to characterize the difference between ADME in these groups with regard to urinary excretion and APAP area under the curve (AUC) in the liver. Although not dramatic at therapeutic dosing levels, these results demonstrated the divergence in the liver-specific APAP concentrations and AUC between the two groups and suggested that differences in glucuronidation capacity may play a role in this disparity. Overall, the models developed in this study, and others created using this type of hierarchical methodology, are expected to be useful in quantifying ADME in a subpopulation-specific manner and reducing prediction uncertainty compared to that from generalized PBPK modeling approaches.

  6. Nonlinear Modeling of Azimuth Error for 2D Car Navigation Using Parallel Cascade Identification Augmented with Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Umar Iqbal

    2010-01-01

    Full Text Available Present land vehicle navigation relies mostly on the Global Positioning System (GPS that may be interrupted or deteriorated in urban areas. In order to obtain continuous positioning services in all environments, GPS can be integrated with inertial sensors and vehicle odometer using Kalman filtering (KF. For car navigation, low-cost positioning solutions based on MEMS-based inertial sensors are utilized. To further reduce the cost, a reduced inertial sensor system (RISS consisting of only one gyroscope and speed measurement (obtained from the car odometer is integrated with GPS. The MEMS-based gyroscope measurement deteriorates over time due to different errors like the bias drift. These errors may lead to large azimuth errors and mitigating the azimuth errors requires robust modeling of both linear and nonlinear effects. Therefore, this paper presents a solution based on Parallel Cascade Identification (PCI module that models the azimuth errors and is augmented to KF. The proposed augmented KF-PCI method can handle both linear and nonlinear system errors as the linear parts of the errors are modeled inside the KF and the nonlinear and residual parts of the azimuth errors are modeled by PCI. The performance of this method is examined using road test experiments in a land vehicle.

  7. An extended car-following model with consideration of vehicle to vehicle communication of two conflicting streams

    Science.gov (United States)

    Zhao, Jing; Li, Peng

    2017-05-01

    In this paper, we propose a car-following model to explore the influences of V2V communication on the driving behavior at un-signalized intersections with two crossing streams and to explore how the speed guidance strategy affects the operation efficiency. The numerical results illustrate that the benefits of the guidance strategy could be enhanced by lengthening the guiding space range and increasing the maximum speed limitation, and that the guidance strategy is more suitable under low to medium traffic density and small safety interval condition.

  8. Stability analysis in a car-following model with reaction-time delay and delayed feedback control

    Science.gov (United States)

    Jin, Yanfei; Xu, Meng

    2016-10-01

    The delayed feedback control in terms of both headway and velocity differences has been proposed to guarantee the stability of a car-following model including the reaction-time delay of drivers. Using Laplace transformation and transfer function, the stable condition is derived and appropriate choices of time delay and feedback gains are designed to stabilize traffic flow. Meanwhile, an upper bound on explicit time delay is determined with respect to the response of desired acceleration. To ensure the string stability, the explicit time delay cannot over its upper bound. Numerical simulations indicate that the proposed control method can restraint traffic congestion and improve control performance.

  9. Influences of vehicles’ fuel consumption and exhaust emissions on the trip cost without late arrival under car-following model

    Science.gov (United States)

    Tang, Tie-Qiao; Yu, Qiang

    2016-07-01

    In this paper, we use car-following model to explore the influences of the vehicle’s fuel consumption and exhaust emissions on each commuter’s trip cost without late arrival on one open road. Our results illustrate that considering the vehicle’s fuel cost and emission cost only enhances each commuter’s trip cost and the system’s total cost, but has no prominent impacts on his optimal time headway at the origin of each open road under the minimum total cost.

  10. Experimental Validation of Switching Strategy for Tracking Control with Collision Avoidance in Non-Cooperative Situation Using Toy Model Cars

    Science.gov (United States)

    Kogiso, Kiminao; Noguchi, Makoto; Hatada, Kazuyoshi; Kida, Naoki; Hirade, Naofumi; Sugimoto, Kenji

    This paper presents some experimental validation results of an already-proposed switching control method for simultaneous achievement of collision avoidance and tracking control for a vehicle in a non-cooperative situation. To validate the method, an experimental control system is made, in which the vehicle is a toy model car possible to remotely control via infrared ray and a camera is used to measure the vehicle's state. After presenting the constructed control system, the effectiveness of the method is investigated with the results obtained from the several control experiments.

  11. CD19 CAR-targeted T cells induce long-term remission and B Cell Aplasia in an immunocompetent mouse model of B cell acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Marco L Davila

    Full Text Available Although many adults with B cell acute lymphoblastic leukemia (B-ALL are induced into remission, most will relapse, underscoring the dire need for novel therapies for this disease. We developed murine CD19-specific chimeric antigen receptors (CARs and an immunocompetent mouse model of B-ALL that recapitulates the disease at genetic, cellular, and pathologic levels. Mouse T cells transduced with an all-murine CD3ζ/CD28-based CAR that is equivalent to the one being used in our clinical trials, eradicate B-ALL in mice and mediate long-term B cell aplasias. In this model, we find that increasing conditioning chemotherapy increases tumor eradication, B cell aplasia, and CAR-modified T cell persistence. Quantification of recipient B lineage cells allowed us to estimate an in vivo effector to endogenous target ratio for B cell aplasia maintenance. In mice exhibiting a dramatic B cell reduction we identified a small population of progenitor B cells in the bone marrow that may serve as a reservoir for long-term CAR-modified T cell stimulation. Lastly, we determine that infusion of CD8+ CAR-modified T cells alone is sufficient to maintain long-term B cell eradication. The mouse model we report here should prove valuable for investigating CAR-based and other therapies for adult B-ALL.

  12. Service Capacity Reserve under Uncertainty by Hospital’s ER Analogies: A Practical Model for Car Services

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Pérez Salaverría

    2014-01-01

    Full Text Available We define a capacity reserve model to dimension passenger car service installations according to the demographic distribution of the area to be serviced by using hospital’s emergency room analogies. Usually, service facilities are designed applying empirical methods, but customers arrive under uncertain conditions not included in the original estimations, and there is a gap between customer’s real demand and the service’s capacity. Our research establishes a valid methodology and covers the absence of recent researches and the lack of statistical techniques implementation, integrating demand uncertainty in a unique model built in stages by implementing ARIMA forecasting, queuing theory, and Monte Carlo simulation to optimize the service capacity and occupancy, minimizing the implicit cost of the capacity that must be reserved to service unexpected customers. Our model has proved to be a useful tool for optimal decision making under uncertainty integrating the prediction of the cost implicit in the reserve capacity to serve unexpected demand and defining a set of new process indicators, such us capacity, occupancy, and cost of capacity reserve never studied before. The new indicators are intended to optimize the service operation. This set of new indicators could be implemented in the information systems used in the passenger car services.

  13. Car-2-Car Communication Consortium - Manifesto

    OpenAIRE

    Baldessari, Roberto; Bödekker, Bert; Deegener, Matthias; Festag, Andreas; Franz, Walter; Kellum, C. Christopher; Kosch, Timo; Kovacs, Andras; Lenardi, Massimiliano; Menig, Cornelius; Peichl, Timo; Röckl, Matthias; Seeberger, Dieter; Straßberger, Markus; Stratil, Hannes

    2007-01-01

    This document summarizes and describes the main building blocks of the Car2X Communication System as it is pursued by the Car2Car Communication Consortium (C2C-CC). “Car2X” means interactions among cars, between cars and infrastructures, and viceversa. It provides interested readers with an introduction to Car2X communications. It is intended to be a living document which will be complemented according to the progress of the work of the C2C-CC. One main objective of this document is to give i...

  14. 车辆跟驰的分子动力学特性及其模型%Molecular kinetics behavior of car-following and its model

    Institute of Scientific and Technical Information of China (English)

    曲大义; 杨建; 陈秀锋; 卞晓华

    2012-01-01

    应用分子动力学研究了车辆跟驰特性,探索了车辆跟驰的需求安全距离及其应用模型构建。通过赋予跟驰模型多个刺激项的反应权重,运用数学演绎方法,推导出驾驶员对各种刺激反应同向性的状态方程。在此基础上提出了描述跟驰变化过程的分子跟驰模型。数据验证和试验对比分析结果表明,分子跟驰模型对跟驰状态的描述更加全面和贴切,弥补了速度跟驰模型的不足,完善了交通流跟驰理论。%The car-following behavior was studied by molecular kinetics,the required safe distance was explored and an application model was built.By giving the reaction weights to various stimuli,a state equation for the isodirectionality of the responses of the driver to various stimuli was derived using the mathematical deduction.Based on this equation,a molecular car-following model was built to describe the car-following behavior.The results of analyses from the data validation and the experimental comparison showed that the proposed molecular car-following model describes the car-following behavior more completely and appropriately,makes up the deficiency of the speed-based car-following models,and improves the car-following theory.

  15. Inducible activation of MyD88 and CD40 in CAR T-cells results in controllable and potent antitumor activity in preclinical solid tumor models.

    Science.gov (United States)

    Mata, Melinda; Gerken, Claudia; Nguyen, Phuong; Krenciute, Giedre; Spencer, David M; Gottschalk, Stephen

    2017-08-11

    Adoptive immunotherapy with T-cells expressing chimeric antigen receptors (CARs) has had limited success for solid tumors in early phase clinical studies. We reasoned that introducing into CAR T-cells an inducible co-stimulatory (iCO) molecule consisting of a chemical inducer of dimerization (CID)-binding domain and the MyD88 and CD40 signaling domains would improve and control CAR T-cell activation. In the presence of CID, T-cells expressing HER2-CARζ and a MyD88/CD40-based iCO molecule (HER2ζ.iCO T-cells) had superior T-cell proliferation, cytokine production, and ability to sequentially kill targets in vitro relative to HER2ζ.iCO T-cells without CID and T-cells expressing HER2-CAR.CD28ζ. HER2ζ.iCO T-cells with CID also significantly improved survival in vivo in two xenograft models. Repeat injections of CID were able to further increase the antitumor activity of HER2ζ.iCO T-cells in vivo. Thus, expressing MyD88/CD40-based iCO molecules in CAR T-cells has the potential to improve the efficacy of CAR T-cell therapy approaches for solid tumors. Copyright ©2017, American Association for Cancer Research.

  16. Mean-field theory for car accidents

    Science.gov (United States)

    Huang, Ding-Wei; Tseng, Wei-Chung

    2001-11-01

    We study analytically the occurrence of car accidents in the Nagel-Schreckenberg traffic model. We obtain exact results for the occurrence of car accidents Pac as a function of the car density ρ and the degree of stochastic braking p1 in the case of speed limit vmax=1. Various quantities are calculated analytically. The nontrivial limit p1-->0 is discussed.

  17. Stabilization effect of traffic flow in an extended car-following model based on an intelligent transportation system application.

    Science.gov (United States)

    Ge, H X; Dai, S Q; Dong, L Y; Xue, Y

    2004-12-01

    An extended car following model is proposed by incorporating an intelligent transportation system in traffic. The stability condition of this model is obtained by using the linear stability theory. The results show that anticipating the behavior of more vehicles ahead leads to the stabilization of traffic systems. The modified Korteweg-de Vries equation (the mKdV equation, for short) near the critical point is derived by applying the reductive perturbation method. The traffic jam could be thus described by the kink-antikink soliton solution for the mKdV equation. From the simulation of space-time evolution of the vehicle headway, it is shown that the traffic jam is suppressed efficiently with taking into account the information about the motion of more vehicles in front, and the analytical result is consonant with the simulation one.

  18. CAR STICKERS

    CERN Multimedia

    Access and Control Service

    2004-01-01

    Following to the operational circular No2 title III. Conditions of access, paragraph 21 . Except in the case of exemptions authorized by the Director-General, all drivers must facilitate the identification of their vehicle. For CERN car stickers to be valid in 2004, they must have the numbers 04 printed on them. As of Monday, March 15th, the security agents on duty at the various access points will have no alternative but to refuse entry to vehicles which do not have a valid sticker. Anyone in this situation is requested to follow the regularization procedure either by logging on to the web site, or by going in person to the registration service in bldg. 55, first floor, between 07h30 et 16h30, Monday through Friday. Access and Control Service - FM Group, TS Department

  19. Active suspension control of a one-wheel car model using single input rule modules fuzzy reasoning and a disturbance observer

    Institute of Scientific and Technical Information of China (English)

    YOSHIMURA Toshio; TERAMURA Itaru

    2005-01-01

    This paper presents the construction of an active suspension control of a one-wheel car model using fuzzy reasoning and a disturbance observer. The one-wheel car model to be treated here can be approximately described as a nonlinear two degrees of freedom system subject to excitation from a road profile. The active control is designed as the fuzzy control inferred by using single input rule modules fuzzy reasoning, and the active control force is released by actuating a pneumatic actuator. The excitation from the road profile is estimated by using a disturbance observer, and the estimate is denoted as one of the variables in the precondition part of the fuzzy control rules. A compensator is inserted to counter the performance degradation due to the delay of the pneumatic actuator. The experimental result indicates that the proposed active suspension system improves much the vibration suppression of the car model.

  20. Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities

    Science.gov (United States)

    Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

    2013-01-01

    Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

  1. Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities

    Science.gov (United States)

    Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

    2013-01-01

    Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

  2. Pervasive Adaptation in Car Crowds

    Science.gov (United States)

    Ferscha, Alois; Riener, Andreas

    Advances in the miniaturization and embedding of electronics for microcomputing, communication and sensor/actuator systems, have fertilized the pervasion of technology into literally everything. Pervasive computing technology is particularly flourishing in the automotive domain, exceling the “smart car”, embodying intelligent control mechanics, intelligent driver assistance, safety and comfort systems, navigation, tolling, fleet management and car-to-car interaction systems, as one of the outstanding success stories of pervasive computing. This paper raises the issue of the socio-technical phenomena emerging from the reciprocal interrelationship between drivers and smart cars, particularly in car crowds. A driver-vehicle co-model (DVC-model) is proposed, expressing the complex interactions between the human driver and the in-car and on-car technologies. Both explicit (steering, shifting, overtaking), as well as implicit (body posture, respiration) interactions are considered, and related to the drivers vital state (attentive, fatigue, distracted, aggressive). DVC-models are considered as building blocks in large scale simulation experiments, aiming to analyze and understand adaptation phenomena rooted in the feed-back loops among individual driver behavior and car crowds.

  3. Prediction of Swedish Harness Racing.

    OpenAIRE

    Josefsson, Jonas; Hellander, Martin

    2013-01-01

    Harness racing is a sport where betting most often is done based on historical performances and known conditions from each horse. With up to 12-15 horses in each race and with a quite large set of data for each horse, harness racing seemed to be very suitable for some statistical modeling and regression analysis. The main goal of this project was to construct a model that predicts the outcome of a race better than the odds. To achieve this, many dierent covariates, and combinations of them, h...

  4. Jet Car Track Site

    Data.gov (United States)

    Federal Laboratory Consortium — Located in Lakehurst, New Jersey, the Jet Car Track Site supports jet cars with J57 engines and has a maximum jet car thrust of 42,000 pounds with a maximum speed of...

  5. CONDENSED MATTER: STRUCTURE, THERMAL AND MECHANICAL PROPERTIES: Multiple car-following model of traffic flow and numerical simulation

    Science.gov (United States)

    Peng, Guang-Han; Sun, Di-Hua

    2009-12-01

    On the basis of the full velocity difference (FVD) model, an improved multiple car-following (MCF) model is proposed by taking into account multiple information inputs from preceding vehicles. The linear stability condition of the model is obtained by using the linear stability theory. Through nonlinear analysis, a modified Korteweg-de Vries equation is constructed and solved. The traffic jam can thus be described by the kink-antikink soliton solution for the mKdV equation. The improvement of this new model over the previous ones lies in the fact that it not only theoretically retains many strong points of the previous ones, but also performs more realistically than others in the dynamical evolution of congestion. Furthermore, numerical simulation of traffic dynamics shows that the proposed model can avoid the disadvantage of negative velocity that occurs at small sensitivity coefficients λ in the FVD model by adjusting the information on the multiple leading vehicles. No collision occurs and no unrealistic deceleration appears in the improved model.

  6. Ride Performance Analysis of Half-Car Model for Semi-Active System Using RMS as Performance Criteria

    Directory of Open Access Journals (Sweden)

    S.I. Ihsan

    2009-01-01

    Full Text Available The work aims to study the root mean square (RMS responses to acceleration input for four state variables: the ms vertical acceleration, the ms pitch angular acceleration and the front and rear deflections of the suspensions. A half-car two degree-of-freedom model of semi-active control scheme is analyzed and compared with the conventional passive suspension system. Frequency response of the transfer function for the heave, pitch of the sprung mass and suspension deflections are initially compared and then mean square analysis is utilized to see the effect of semi-active scheme. Results indicate that significant improvements were achieved in the sprung mass heave and pitch responses using semi-active control scheme. However results for the rear and front suspension deflection show that there are limiting values of damping coefficient beyond which, the semi-active scheme becomes disadvantageous than the passive system.

  7. Car Club

    CERN Multimedia

    Automobile Club

    2012-01-01

    The Car Club wishes all its members Good road and Happy New Year 2012. It is time to think about renewing your subscription for this year, at a cost of 50 CHF, unchanged since several years. For those of you who are regular users of our equipment and who know all the advantages that the club is in a position to offer, it seems pointless to going to more details, as we are sure that many of you have made use of them and are satisfied. Therefore don’t forget to fill in the payment slip to continue to be a part of our large family. We remind you that everyone who works on the CERN site can be members of our club, this includes industrial support personnel and the personnel of companies which have a contract with CERN. If you are not yet a member, come and visit us! We will be happy to welcome you and show you the installations, alternatively you can visit our web site: http://club-acc.web.cern.ch/club-acc/ The use of the club’s installations is strictly reserved for members. Pour t...

  8. Usability of car stereo.

    Science.gov (United States)

    Razza, Bruno Montanari; Paschoarelli, Luis Carlos

    2012-01-01

    Automotive sound systems vary widely in terms of functions and way of use between different brands and models what can bring difficulties and lack of consistency to the user. This study aimed to analyze the usability of car stereo commonly found in the market. Four products were analyzed by task analysis and after use reports and the results indicate serious usability issues with respect to the form of operation, organization, clarity and quality of information, visibility and readability, among others.

  9. Combined control effects of brake and active suspension control on the global safety of a full-car nonlinear model

    Science.gov (United States)

    Tchamna, Rodrigue; Youn, Edward; Youn, Iljoong

    2014-05-01

    This paper focuses on the active safety of a full-vehicle nonlinear model during cornering. At first, a previously developed electronic stability controller (ESC) based on vehicle simplified model is applied to the full-car nonlinear model in order to control the vehicle yaw rate and side-slip angle. The ESC system was shown beneficial not only in tracking the vehicle path as close as possible, but it also helped in reducing the vehicle roll angle and influences ride comfort and road-holding capability; to tackle that issue and also to have better attitude motion, making use of optimal control theory the active suspension control gain is developed from a vehicle linear model and used to compute the active suspension control force of the vehicle nonlinear model. The active suspension control algorithm used in this paper includes the integral action of the suspension deflection in order to make zero the suspension deflection steady state and keep the vehicle chassis flat. Keeping the chassis flat reduces the vehicle load transfer and that is helpful for road holding and yaw rate tracking. The effects of the two controllers when they work together are analysed using various computer simulations with different steering wheel manoeuvres.

  10. CERN Relay Race

    CERN Document Server

    2005-01-01

    The CERN Relay Race will take place around the Meyrin site on Wednesday 18 May between 12.15 and 12.35. This year, weather permitting, there will be some new attractions in the start/finish area on the field behind the Main Building. You will be able to: listen to music played by the CERN Jazz Club; buy drinks at the bar organised by the CERN Running Club; buy lunch served directly on the terrace by the restaurant Novae. ATTENTION: concerning traffic, the recommendations are the same as always: If possible, please avoid driving on the site during this 20 minute period. If you do meet runners in your car, please STOP until they all have passed. Thank you for your understanding.

  11. RELAY RACE

    CERN Multimedia

    Staff Association

    2013-01-01

    Well done to all runners, the fans and the organizers of this great race which took place on Thursday 23rd May! You were many to participate in the run or by supporting your colleagues. The Staff Association contributed with its team of runners and also with its information stall where you could meet with your delegates.  

  12. Transcending race?

    DEFF Research Database (Denmark)

    Wilson, Fiona

    2007-01-01

    Using accounts of militant schoolteachers from a province in the central sierra of Peru, this article attempts to show how and why concepts of race and political commitment among teachers changed at three critical moments in Peruvian history: agrarian reform, mass unionisation, and Maoist insurge...

  13. Downhill Races

    Science.gov (United States)

    Melvin, Cruse

    2002-04-01

    Discussions of downhill races have been evolving in introductory texts. This article presents a logical sequence to guide students through the essential factors in this multifaceted topic. Comparative examples and a technical supplement are provided to reinforce the logic. Slipping, surface compressions, bounces, wobble, and internal material shifts are considered adverse effects.

  14. Motor racing accidents at Brands Hatch, 1988/9.

    Science.gov (United States)

    Chapman, M A; Oni, J

    1991-09-01

    Little is known about the incidence of injury to race track motor-cyclists and car drivers. In a 1-year study at Brands Hatch, 70 of 33,184 competitors required hospital treatment. We found this injury rate to be higher than on the public highway. However, the anatomical distribution of injury caused by motor-bike accidents is similar to that found on the public highway. Motor-cyclists are more likely than car drivers to sustain limb trauma requiring outpatient treatment only. The number of participants requiring admission to hospital is broadly similar for car and bike races, being less than 0.1%.

  15. 车辆跟驰行为建模的回顾与展望%Review and Outlook of Modeling of Car Following Behavior

    Institute of Scientific and Technical Information of China (English)

    王殿海; 金盛

    2012-01-01

    系统地回顾了跟驰理论60年的发展历程,依据建模思想将跟驰行为模型分为交通工程角度和统计物理角度。交通工程角度的跟驰模型包括刺激-反应类、安全距离类、心理-生理类及人工智能类模型;统计物理角度的跟驰模型包括优化速度模型、智能驾驶模型和元胞自动机模型。针对各类模型分别阐述了其建模思路、模型结构、参数标定及其扩展研究。最后,展望了跟驰行为建模的发展趋势与研究方向,为建立适合中国交通流特点的跟驰模型提供参考。%Authors reviewed the development of car following theory from a system point of view.Based on the modeling ideas,car following models were divided into point of view of traffic engineering and statistical physics.In the point of view of traffic engineering,car following models were classified into stimulus-response models,safety distance models,psycho-physical models and artificial intelligence models.In the point of view of statistical physics,car following models were classified into optimal velocity models,intelligent driver models,and cellular automata models.Then,various types of modeling ideas,model structure,parameter calibration,and related research were elaborated.Finally,development trends and research directions of car following models were proposed.It can provide reference for car following modeling of considering traffic flow characteristics in China.

  16. Markov chain modelling analysis of HIV/AIDS progression: A race-based forecast in the United States

    Directory of Open Access Journals (Sweden)

    S Lee

    2014-01-01

    Full Text Available HIV/AIDS has reached a pandemic level across the world with more than 33 million people who are living with HIV. In the United States, more than half a million people have been victims of AIDS. This study investigates the most vulnerable racial minority population (the African Americans in the United States and the second least affected (the Caucasians in order to predict the trends of the epidemic. A Markov chain analysis was used to model the progression of the disease among vulnerable people, infective people and AIDS cases for the two races separately, based on the 2009 Centers of Disease Control and Prevention HIV/AIDS Surveillance Report. Based on the Markov model, our study predicts that the number of African American people living with AIDS diagnosis and HIV infection and dead due to HIV/AIDS will be 662.2, 1225.3 and 62.9 in 2015 and 794.9, 1566.5 and 79.2 in 2030, respectively. The number of Caucasian people living with AIDS diagnosis and HIV infection and dead due to HIV/AIDS will be 96.4, 160 and 6.5 in 2015 and 118.6, 206.9 and 8.3 in 2030, respectively. The numbers of deaths due to HIV/AIDS are quite stable over the years in both the races. There is an increasing trend in the number of people living with HIV infection and AIDS diagnosis in Caucasians compared with African Americans. The absolute number of Caucasians living with AIDS diagnosis and HIV infection is quite smaller compared with African Americans. The results reveal discrepancy in HIV infection, AIDS diagnosis and deaths due to HIV/AIDS among the African Americans and the Caucasians races. There is a need for interventions focusing on HIV/AIDS prevention and management, optimum resource allocation and development of antiAIDS campaigns to reduce the infection rate.

  17. Markov Chain Modelling Analysis of HIV/AIDS Progression: A Race-based Forecast in the United States.

    Science.gov (United States)

    Lee, S; Ko, J; Tan, Xi; Patel, Isha; Balkrishnan, R; Chang, J

    2014-03-01

    HIV/AIDS has reached a pandemic level across the world with more than 33 million people who are living with HIV. In the United States, more than half a million people have been victims of AIDS. This study investigates the most vulnerable racial minority population (the African Americans) in the United States and the second least affected (the Caucasians) in order to predict the trends of the epidemic. A Markov chain analysis was used to model the progression of the disease among vulnerable people, infective people and AIDS cases for the two races separately, based on the 2009 Centers of Disease Control and Prevention HIV/AIDS Surveillance Report. Based on the Markov model, our study predicts that the number of African American people living with AIDS diagnosis and HIV infection and dead due to HIV/AIDS will be 662.2, 1225.3 and 62.9 in 2015 and 794.9, 1566.5 and 79.2 in 2030, respectively. The number of Caucasian people living with AIDS diagnosis and HIV infection and dead due to HIV/AIDS will be 96.4, 160 and 6.5 in 2015 and 118.6, 206.9 and 8.3 in 2030, respectively. The numbers of deaths due to HIV/AIDS are quite stable over the years in both the races. There is an increasing trend in the number of people living with HIV infection and AIDS diagnosis in Caucasians compared with African Americans. The absolute number of Caucasians living with AIDS diagnosis and HIV infection is quite smaller compared with African Americans. The results reveal discrepancy in HIV infection, AIDS diagnosis and deaths due to HIV/AIDS among the African Americans and the Caucasians races. There is a need for interventions focusing on HIV/AIDS prevention and management, optimum resource allocation and development of antiAIDS campaigns to reduce the infection rate.

  18. Connected Car: Quantified Self becomes Quantified Car

    Directory of Open Access Journals (Sweden)

    Melanie Swan

    2015-02-01

    Full Text Available The automotive industry could be facing a situation of profound change and opportunity in the coming decades. There are a number of influencing factors such as increasing urban and aging populations, self-driving cars, 3D parts printing, energy innovation, and new models of transportation service delivery (Zipcar, Uber. The connected car means that vehicles are now part of the connected world, continuously Internet-connected, generating and transmitting data, which on the one hand can be helpfully integrated into applications, like real-time traffic alerts broadcast to smartwatches, but also raises security and privacy concerns. This paper explores the automotive connected world, and describes five killer QS (Quantified Self-auto sensor applications that link quantified-self sensors (sensors that measure the personal biometrics of individuals like heart rate and automotive sensors (sensors that measure driver and passenger biometrics or quantitative automotive performance metrics like speed and braking activity. The applications are fatigue detection, real-time assistance for parking and accidents, anger management and stress reduction, keyless authentication and digital identity verification, and DIY diagnostics. These kinds of applications help to demonstrate the benefit of connected world data streams in the automotive industry and beyond where, more fundamentally for human progress, the automation of both physical and now cognitive tasks is underway.

  19. A control method applied to mixed traffic flow for the coupled-map car-following model

    Science.gov (United States)

    Cheng, Rong-Jun; Han, Xiang-Lin; Lo, Siu-Ming; Ge, Hong-Xia

    2014-03-01

    In light of previous work [Phys. Rev. E 60 4000 (1999)], a modified coupled-map car-following model is proposed by considering the headways of two successive vehicles in front of a considered vehicle described by the optimal velocity function. The non-jam conditions are given on the basis of control theory. Through simulation, we find that our model can exhibit a better effect as p = 0.65, which is a parameter in the optimal velocity function. The control scheme, which was proposed by Zhao and Gao, is introduced into the modified model and the feedback gain range is determined. In addition, a modified control method is applied to a mixed traffic system that consists of two types of vehicle. The range of gains is also obtained by theoretical analysis. Comparisons between our method and that of Zhao and Gao are carried out, and the corresponding numerical simulation results demonstrate that the temporal behavior of traffic flow obtained using our method is better than that proposed by Zhao and Gao in mixed traffic systems.

  20. Construction and evaluation of thoracic injury risk curves for a finite element human body model in frontal car crashes.

    Science.gov (United States)

    Mendoza-Vazquez, Manuel; Davidsson, Johan; Brolin, Karin

    2015-12-01

    There is a need to improve the protection to the thorax of occupants in frontal car crashes. Finite element human body models are a more detailed representation of humans than anthropomorphic test devices (ATDs). On the other hand, there is no clear consensus on the injury criteria and the thresholds to use with finite element human body models to predict rib fractures. The objective of this study was to establish a set of injury risk curves to predict rib fractures using a modified Total HUman Model for Safety (THUMS). Injury criteria at the global, structural and material levels were computed with a modified THUMS in matched Post Mortem Human Subjects (PMHSs) tests. Finally, the quality of each injury risk curve was determined. For the included PMHS tests and the modified THUMS, DcTHOR and shear stress were the criteria at the global and material levels that reached an acceptable quality. The injury risk curves at the structural level did not reach an acceptable quality.

  1. 基于品牌形象的汽车造型研究%Research of Car Modeling Based on Brand Image

    Institute of Scientific and Technical Information of China (English)

    胡昆

    2015-01-01

    The contemporary trend and future trend of the car modeling were analyzed by history re⁃searching, and the development of well-known car brands abroad was researched by case studying. The important role of the brand image decided by brand culture in the car modeling design was elaborated. The implementation methods of the brand strategy in the car modeling design were summarized.%通过史论研究方法分析当代汽车造型的潮流和未来趋势;通过个案调查法研究当代国外知名汽车品牌的发展历程,阐述由品牌文化决定的品牌形象在汽车造型设计中发挥的重要作用。归纳总结出品牌策略在汽车造型设计中的实施方法。

  2. Women and Cars

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    JUST a decade ago, private cars were far too luxurious for Chinese people; most of them never even dreamed of having a car. In the Chinese language, a car is called "jiao che", which literally means "sedan automobile." The fact that a car is referred to as a sedan, a luxury only available to officials in old China, reveals Chinese people’s idea that cars are separated by an impassable gulf from ordinary people.

  3. Safety of children in cars: A review of biomechanical aspects and human body models

    Directory of Open Access Journals (Sweden)

    Karin Brolin

    2015-03-01

    To study how children interact with restraints during on-road driving and during pre- and in-crash events, numerical child models implementing age-specific anthropometric features will be essential. The review of human whole body models covers multi body models (age 1.5 to 15 years and finite element models (ages 3, 6, and 10 years. All reviewed child models are developed for crash scenarios. The only finite element models to implement age dependent anthropometry details for the spine and pelvis were a 3 year-old model and an upcoming 10 year-old model. One ongoing project is implementing active muscles response in a 6 year-old multi body model to study pre-crash scenarios. These active models are suitable for the next important step in providing the automotive industry with adequate tools for development and assessment of future restraint systems in the full sequence of events from pre- to in-crash.

  4. Testing the race inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias; Heckel, A.

    2008-01-01

    In speeded response tasks with redundant signals, parallel processing of the redundant signals is generally tested using the so-called race inequality. The race inequality states that the distribution of fast responses for a redundant stimulus never exceeds the summed distributions of fast...... responses for the single stimuli. It has been pointed out that fast guesses (e.g. anticipatory responses) interfere with this test, and a correction procedure ('kill-the-twin' procedure) has been suggested. In this note we formally derive this procedure and extend it to the case in which redundant stimuli...... are presented with onset asynchrony. We demonstrate how the kill-the-twin procedure is used in a statistical test of the race model prediction....

  5. Matrix Solution of Coupled Differential Equations and Looped Car Following Models

    Science.gov (United States)

    McCartney, Mark

    2008-01-01

    A simple mathematical model for the behaviour of how vehicles follow each other along a looped stretch of road is described. The resulting coupled first order differential equations are solved using appropriate matrix techniques and the physical significance of the model is discussed. A number possible classroom exercises are suggested to help…

  6. Hexavalent Chromium Removal from Model Water and Car Shock Absorber Factory Effluent by Nanofiltration and Reverse Osmosis Membrane

    Directory of Open Access Journals (Sweden)

    Amine Mnif

    2017-01-01

    Full Text Available Nanofiltration and reverse osmosis are investigated as a possible alternative to the conventional methods of Cr(VI removal from model water and industrial effluent. The influences of feed concentration, water recovery, pH, and the coexisting anions were studied. The results have shown that retention rates of hexavalent chromium can reach 99.7% using nanofiltration membrane (NF-HL and vary from 85 to 99.9% using reverse osmosis membrane (RO-SG depending upon the composition of the solution and operating conditions. This work was also extended to investigate the separation of Cr(VI from car shock absorber factory effluent. The use of these membranes is very promising for Cr(VI water treatment and desalting industry effluent. Spiegler-Kedem model was applied to experimental results in the aim to determine phenomenological parameters, the reflection coefficient of the membrane (σ, and the solute permeability coefficient (Ps. The convective and diffusive parts of the mass transfer were quantified with predominance of the diffusive contribution.

  7. Hexavalent Chromium Removal from Model Water and Car Shock Absorber Factory Effluent by Nanofiltration and Reverse Osmosis Membrane

    Science.gov (United States)

    Bejaoui, Imen; Mouelhi, Meral; Hamrouni, Béchir

    2017-01-01

    Nanofiltration and reverse osmosis are investigated as a possible alternative to the conventional methods of Cr(VI) removal from model water and industrial effluent. The influences of feed concentration, water recovery, pH, and the coexisting anions were studied. The results have shown that retention rates of hexavalent chromium can reach 99.7% using nanofiltration membrane (NF-HL) and vary from 85 to 99.9% using reverse osmosis membrane (RO-SG) depending upon the composition of the solution and operating conditions. This work was also extended to investigate the separation of Cr(VI) from car shock absorber factory effluent. The use of these membranes is very promising for Cr(VI) water treatment and desalting industry effluent. Spiegler-Kedem model was applied to experimental results in the aim to determine phenomenological parameters, the reflection coefficient of the membrane (σ), and the solute permeability coefficient (Ps). The convective and diffusive parts of the mass transfer were quantified with predominance of the diffusive contribution. PMID:28819360

  8. Analytical studies on an extended car following model for mixed traffic flow with slow and fast vehicles

    Science.gov (United States)

    Li, Zhipeng; Xu, Xun; Xu, Shangzhi; Qian, Yeqing; Xu, Juan

    2016-07-01

    The car-following model is extended to take into account the characteristics of mixed traffic flow containing fast and slow vehicles. We conduct the linear stability analysis to the extended model with finding that the traffic flow can be stabilized with the increase of the percentage of the slow vehicle. It also can be concluded that the stabilization of the traffic flow closely depends on not only the average value of two maximum velocities characterizing two vehicle types, but also the standard deviation of the maximum velocities among all vehicles, when the percentage of the slow vehicles is the same as that of the fast ones. With increase of the average maximum velocity, the traffic flow becomes more and more unstable, while the increase of the standard deviation takes negative effect in stabilizing the traffic system. The direct numerical results are in good agreement with those of theoretical analysis. Moreover, the relation between the flux and the traffic density is investigated to simulate the effects of the percentage of slow vehicles on traffic flux in the whole density regions.

  9. PLC Based Automatic Multistoried Car Parking System

    OpenAIRE

    2014-01-01

    This project work presents the study and design of PLC based Automatic Multistoried Car Parking System. Multistoried car parking is an arrangement which is used to park a large number of vehicles in least possible place. For making this arrangement in a real plan very high technological instruments are required. In this project a prototype of such a model is made. This prototype model is made for accommodating twelve cars at a time. Availability of the space for parking is detecte...

  10. An averaging battery model for a lead-acid battery operating in an electric car

    Science.gov (United States)

    Bozek, J. M.

    1979-01-01

    A battery model is developed based on time averaging the current or power, and is shown to be an effective means of predicting the performance of a lead acid battery. The effectiveness of this battery model was tested on battery discharge profiles expected during the operation of an electric vehicle following the various SAE J227a driving schedules. The averaging model predicts the performance of a battery that is periodically charged (regenerated) if the regeneration energy is assumed to be converted to retrievable electrochemical energy on a one-to-one basis.

  11. Cost-Benefit Analysis of Implementing a Car-Sharing Model to the Navy’s Passenger Vehicle Fleet

    Science.gov (United States)

    2016-12-01

    segment within a base operation. Table 1 lists the pilots considered and accepted for review based on the following pilot acceptance criteria...owned fleet using commercial car-sharing companies in a pre-established car-sharing market instead of implementing fleet management hardware... market and the number is growing at a steady rate. Some of the major auto manufacturers are getting their hands into the sharing market , including Ford

  12. A velocity-difference-separation model for car-following theory

    Science.gov (United States)

    Li, Zhi-Peng; Liu, Yun-Cai

    2006-07-01

    We introduce a velocity-difference-separation model that modifies the previous models in the literature. The improvement of this new model over the previous ones lies in that it not only theoretically retains many strong points of the previous ones, but also performs more realistically than others in the dynamical evolution of congestion. Furthermore, the proposed model is investigated with analytic and numerical methods, with the finding that it can demonstrate some complex physical features observed in real traffic such as the existence of three phases: free flow, synchronized flow, and wide moving jam; sudden flow drop in flow-density plane; and traffic hysteresis in transition between the free and the synchronized flow.

  13. A velocity-difference-separation model for car-following theory

    Institute of Scientific and Technical Information of China (English)

    Li Zhi-Peng; Liu Yun-Cai

    2006-01-01

    We introduce a velocity-difference-separation model that modifies the previous models in the literature. The improvement of this new model over the previous ones lies in that it not only theoretically retains many strong points of the previous ones, but also performs more realistically than others in the dynamical evolution of congestion. Furthermore,the proposed model is investigated with analytic and numerical methods, with the finding that it can demonstrate some complex physical features observed in real traffic such as the existence of three phases: free flow, synchronized flow, and wide moving jam; sudden flow drop in flow-density plane; and traffic hysteresis in transition between the free and the synchronized flow.

  14. Simulation and comparison of quarter-car passive suspension system with Bingham and Bouc-Wen MR semi-active suspension models

    Science.gov (United States)

    Perescu, A.; Bereteu, L.

    2013-11-01

    In this paper we want to transposion the suspension system in MATLAB, Simulink®, based on equation of motion. Consider only vertical movement of the car, neglecting roll and pitch. All movements of the car axes are modeled as having equal amplitude. The characteristic equations that describe the behavior of dynamical systems based on FBD (Free Body Diagram) of automotive suspension. It will make two models, one passive and one Bingham semi-active. Their responses will be compared between them, and with another Bouc-Wen semi-active model, more complex. Semi-active suspension systems have received significant attention in recent years because they offer the adaptability of active control devices without requiring large power sources. Given that both passive and semi-active dampers are in mass production will follow the normal parameters and their economic efficiency. These models are used for initial design of suspension system.

  15. Dipole model analysis of F2cc¯${m{F}}_2^{{m{car c}}} $ derived from the new D* data in DIS at HERA

    Directory of Open Access Journals (Sweden)

    Luszczak Agnieszka

    2012-12-01

    Full Text Available I analyse the new D* deep inelastic scattering data from HERA with the help of dipole models. I calculate F2cc¯${m{F}}_2^{{m{car c}}} $ from the GBW [1] and BGK [2] saturation models. I compare results with the last values determined by H1 at low Q2. I find good agreement with the data.

  16. Progresses in computer modelling, characterization and foaming of comfort car seats; Fortschritte in der Computermodellierung, Charakterisierung und Schaumentwicklung fuer Komfort-Autositze

    Energy Technology Data Exchange (ETDEWEB)

    Leenslag, J.W.; Tan, A. [Huntsman Polyurethanes, Everberg (Belgium); Jostmeyer, H. [Huntsman Polyurethanes, Deggendorf (Germany)

    2000-07-01

    Manufacture of comfort car seats is concerned: The seats are cushioned with PUR soft foams based on MDI, which exhibit high seat-comfort and resilience. Several aspects are discussed: the comfort model; polyurethane chemistry and foam morphology; 3D computer simulation; mechanical properties of the foam; non-linear compression behavior; dynamic creeping; vibrational behavior; FEA; validation of the comfort model; OEM foam specification; thinner foam layers.

  17. Car battery model study%车用电池模型研究

    Institute of Scientific and Technical Information of China (English)

    李多晴

    2015-01-01

    As the requirement of society and environment,the scale of electronic vehicle market increase,and so does the research of battery.The research of battery model plays a key roel role among this ,because it has a strong relationship with the accuracy of the description of SOC,SOH and running parameter bight.Forthermore,it relates to the execution of relative control strategy and vehicle parameter and function .This passage introduces 3 battery model——simplied electrochemical model , equivalent circuit model and NNs model. Simplied electrochemical model describes reaction in the battery using math tools, equivalent circuit model simulates dynamic model by electric circuit and NNs model sumulates work of battery using artificial intelligence. Unlinear,multiply-inputed ,multiply-outputed and generalized NNs is specially fit for describing quite unlinear system—battery,so it is a key point for researching and applying.%由于社会和环境的需求,电动汽车市场规模不断扩大,对车用电池的研究也在不断加深。其中,电池模型的研究起着十分关键的作用,它关系到电池系统对 SOC、SOH、工作参数曲线等信息的描述准确与否,进而关系到相关控制策略的执行,影响整车的参数和性能。文章介绍了三类电池模型——简化电化学模型、等效电路模型和神经网络模型。简化电化学模型采用数学方法描述电池内部的反应过程,等效电路模型使用电路网络模拟电池动态模型,神经网络模型是利用人工智能的方法模拟电池的运行。神经网络非线性、多输入多输出、泛化能力强的特点,尤为有利于描述电池这一高度非线性系统,是研究和应用的重点。

  18. Do Methodological Choices in Environmental Modeling Bias Rebound Effects? : A Case Study on Electric Cars

    NARCIS (Netherlands)

    Font Vivanco, D.; Tukker, A.; Kemp, R.

    2016-01-01

    Improvements in resource efficiency often underperform because of rebound effects. Calculations of the size of rebound effects are subject to various types of bias, among which methodological choices have received particular attention. Modellers have primarily focused on choices related to changes i

  19. KdV and kink antikink solitons in car-following models

    Science.gov (United States)

    Ge, H. X.; Cheng, R. J.; Dai, S. Q.

    2005-11-01

    The jams in the congested traffic are related with various density waves, which might be governed by the nonlinear wave equations, such as the Korteweg-de-Vries (KdV) equation, the Burgers equation and the modified Korteweg-de-Vries (mKdV) equation. Three different versions of optimal velocity models are examined. The stability conditions of the models are obtained by using the linear stability theory. The KdV equation near the neutral stability line and the mKdV equation around the critical point are derived by applying the reductive perturbation method, respectively. The traffic jams could be thus described by the KdV and kink-antikink soliton solutions for the two kinds of equations. The general solutions are given for, which can lead to specific solutions in previous work. Moreover, they are applied to solve a new model-the full velocity difference model and the corresponding KdV and kink-antikink soliton solutions could be quickly obtained, which demonstrates the general solutions presented herein are useful.

  20. XMM-Newton observations of OY Car III: OM light curve modelling, X-ray timing and spectral studies

    CERN Document Server

    Hakala, P; Hakala, Pasi; Ramsay, Gavin

    2003-01-01

    We revisit the XMM-Newton observations of the dwarf nova OY Car taken in July 2000 which occured shortly after an outburst. Ramsay et al (2001a) found a prominent energy dependent modulation at a period of 2240 sec: this modulation was only seen for app. 1/3 of the observation duration. In our new analysis, we examine this time interval in greater detail. In addition to the 2240 sec period we find evidence for other periods, the most prominent being near 3500 sec. Both these modulations are most likely due to changes in photoelectric absorption over this period: this is supported by phase-resolved spectroscopy. This may indicate the presence of matter above the accretion disc or a presence of a magnetic accretion curtain. In this case the 2240 sec period could represent a spin period of the white dwarf and the 3500 sec period a beat period between the spin and orbital periods. We also model the B band and UV eclipse profiles and light curves using a new technique to map the spatial extent of the accretion dis...

  1. FSE赛车永磁同步电机的设计仿真与验证%Design Simulation and Verification of Permanent Magnet Synchronous Motor of FSE Racing

    Institute of Scientific and Technical Information of China (English)

    冯勇; 阳林; 吴发亮; 陈楠楠

    2015-01-01

    Drive motor is a mechanical power source FSE car,and has a significant impact on the racing competition results.Based on research ob-j ect FSE electric car,the permanent magnet syn-chronous motor of FSE racing car is designed. Then,in order to verify the operating parameters of the motor,a motor model in Ansoft electromagnet-ic field analysis software is created,and the motor load characteristics and performance characteristics at rated load are calculated.At last,the prototype is installed on the FSE racing car ,the power per-formance of the car is measuredaccording to proj ect power performance testing racing contest.The re-sults show that the racing car has excellent dynam-ic performance,and thedesign of the motor proto-typemeet the requirements well.%驱动电机是 FSE 赛车的机械动力源,对赛车的参赛成绩有重大影响。以 FSE 赛车为对象,设计了FSE赛车永磁同步电机,在Ansoft Maxwell电磁场分析软件中创建电机模型,对电机的空载特性、额定负载特性进行计算,验证电机运行的重要参数。将样机装配FSE赛车,按照大赛项目对赛车性能进行实测,赛车实测数据表明:赛车动力性能优异,电机设计成功,满足赛车正式比赛争先的要求。

  2. Modelling mode choice in short trips - shifting from car to bicycle

    DEFF Research Database (Denmark)

    Halldórsdóttir, Katrín; Christensen, Linda; Jensen, Thomas Christian

    2011-01-01

    This paper investigates the mode choice behaviour of Danish population from the Greater Copenhagen Area when travelling short trips. Data from the Danish National Transport Survey identify the travel behaviour of the Danish population through interviews collecting travel diaries and socio...... available for each period of the day in which the trip was conducted. The present study estimates a mixed logit model able to capture taste variations and differentiates travel time parameters across modes. The mixed logit model allows investigating the effect of level of service variables, individual...... characteristics of the travellers, purpose of the trips and environmental conditions. Results suggest heterogeneity among cyclists in the sensitivity to travel time, temperature and hilliness. The cost parameter is not significant, probably because of difficulties in the calculation, but possibly because of lower...

  3. Car accidents and number of stopped cars due to road blockage on a one-lane highway

    Science.gov (United States)

    Boccara, N.; Fuks, H.; Zeng, Q.

    1997-05-01

    Within the framework of a simple model of car traffic on a one-lane highway, we study the probability of the occurrence of car accidents when drivers do not respect the safety distance between cars, and, as a result of the blockage during the time T necessary to clear the road, we determine the number of stopped cars as a function of car density. We give a simple theory in good agreement with our numerical simulations.

  4. Car accidents and number of stopped cars due to road blockage on a one-lane highway

    CERN Document Server

    Boccara, N; Zeng, Q

    1997-01-01

    Within the framework of a simple model of car traffic on a one-lane highway, we study the probability for car accidents to occur when drivers do not respect the safety distance between cars, and, as a result of the blockage during the time $T$ necessary to clear the road, we determine the number of stopped cars as a function of car density. We give a simple theory in good agreement with our numerical simulations.

  5. The Contrast Simulative Analysis of Intake Flow-limiting Valve on FSAE Racing Car%FSAE赛车进气限流阀的对比仿真分析

    Institute of Scientific and Technical Information of China (English)

    冯勇; 阳林; 彭仁杰; 周永光

    2014-01-01

    In this paper, the influence of intake flow-limiting valve on FSAE racing car’s performance is analyzed. Then three intake flow-limiting valve solutions with different diffuser cone angle of 6°、7°、8°are analyzed based on Fluent software. Finally, the best solution is chosen according to the result of comparison analysis, and thus a certain reference for optimizing the diffuser cone angle of intake flow-limiting valve.%本文分析了进气限流阀对赛车性能的影响,并利用Fluent软件对6°、7°、8°扩散器锥角的三种限流阀方案进行分析和比较,根据对比分析结果最终选出最优的限流阀方案,为以后对限流阀扩散器锥角的优选提供了一种参考方法。

  6. Patent Races and Market Value

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Hussinger, Katrin; Leten, Bart;

    Patent races are models of strategic interactions between firms competing to develop an invention. The winning firm secures a patent, protecting the invention from imitation. This paper tests the assumption made about the reward structure in patent races, both in discrete and complex industries. We...... identify patent race winners using detailed information from the patent examination reports at the European Patent Office (EPO). Estimates of a market value equation featuring large, R&D-intensive U.S., European and Japanese firms, show that if firms win patent races, their market value increases...... significantly. We further show that the gain in market value is significantly larger for patent race winners in discrete industries than for firms in complex industries....

  7. Local stability conditions and calibrating procedure for new car-following models used in driving simulators

    CERN Document Server

    Kurtc, Valentina

    2015-01-01

    This book continues the biannual series of conference proceedings, which has become a classical reference resource in traffic and granular research alike, and addresses the latest developments at the intersection of physics, engineering and computational science. These involve complex systems, in which multiple simple agents, be they vehicles or particles, give rise to surprising and fascinating phenomena. The contributions collected in these proceedings cover several research fields, all of which deal with transport. Topics include highway, pedestrian and internet traffic; granular matter; biological transport; transport networks; data acquisition; data analysis and technological applications. Different perspectives, i.e., modeling, simulations, experiments, and phenomenological observations are considered.    

  8. Prevaba: a Bayesian Model to Predict the Existence of Victims in car accidents

    Directory of Open Access Journals (Sweden)

    TELLES, M.J.

    2015-12-01

    Full Text Available Road safety is an area which is concerned with both the reduction of accidents as with the care provided to the victims. Several initiatives are proposed to assist with reducing the number of accidents, such as surveillance, awareness campaigns and support equipment to drivers. Other initiatives for prevention and protection are proposed by vehicle manufacturers in terms of requirements of governament entities. As a final resort, that is, in the event of the accident and the victim needs medical attention, this should be done as quickly as possible. To assist in identifying the existence of the victim and the need for medical care, we propose a Bayesian model, called Prevaba, which uses Bayesian Networks (BN, which aims to predict the existence of victims in traffic accidents. In order to validate the model, we developed a prototype that performed the actual data classification in Porto Alegre - RS for the year 2013. The prototype made the classification based on the previous year's data (2012, showing an index above 90% accuracy, taking into account the incorrect classications are only classified as victimless, but actually was has a victim.

  9. The Socialist Car

    DEFF Research Database (Denmark)

    Christensen, Lars K.

    2013-01-01

    Review of L.H. Siegelbaum (ed.) The Socialist Car. Automobility in the Eastern Block. Cornell University Press, 2011.......Review of L.H. Siegelbaum (ed.) The Socialist Car. Automobility in the Eastern Block. Cornell University Press, 2011....

  10. Relay race

    CERN Multimedia

    Staff Association

    2012-01-01

    The CERN Relay Race will take place around the Meyrin site on Thursday 24th May at 12:00. This annual event is for teams of six runners covering distances of 1000 m, 800 m, 800 m, 500 m, 500 m and 300 m respectively. Teams may be entered in the Seniors, Veterans, Ladies, Mixed or Open categories. There will also this year be a Nordic Walking event, as part of the Medical Service’s initiative “Move more, eat better!” The registration fee is 10 CHF per runner, and each runner will receive a souvenir prize. There will be a programme of entertainment from 12:00 on the arrival area (the lawn in front of Restaurant 1): 12:00 - 12:45  Music from the Old Bottom Street band 12:15 Start of the race 12:45 - 13h Demonstrations by the Fitness club and Dancing club 13:00 Results and prize giving (including a raffle to win an iPad2 3G offered by the Micro club) 13:20 à 14:00 Music from “What’s next” And many information st...

  11. Cars, Cycles, and Consumers.

    Science.gov (United States)

    Idleman, Hillis K. Ed.

    The purpose of this consumer education module is to provide information and skills, and the ability to raise questions and find answers, while seeking the best automobile or motorcycle buy available for the money. The module may be used for a full or part semester course. The five sections (cars and the consumer, renting and leasing cars, cars and…

  12. Recognition of car model based on support vector machine%基于支持向量机的轿车车型识别

    Institute of Scientific and Technical Information of China (English)

    冯超; 贺俊吉; 史立

    2011-01-01

    为了从轿车图像中快速、准确地识别出轿车车型,采用支持向量机(Support Vector Machine,SVM)方法作为分类器,以轿车的长、宽、高和轴距等4个特征参数作为输入特征向量,并根据这些特征向量对不同车型进行分类和识别.实验结果表明,对11个品牌15种车型的识别准确率达100%.本研究表明,在正确选取轿车的特征参数基础上,采用SVM方法识别轿车车型可以达到很好的效果,SVM方法在智能交通管理系统等领域具有较高的应用价值.%To recognize models from the car pictures quickly and accurately, the Support Vector Machine ( SVM) method is used as classifier, and four feature parameters of cars, including length, width, height and wheelbase, are chosen as the input of characteristic vectors, and variant car models are classified and identified according to the characteristic vectors. The experimental results show that accuracy rate of recognition reaches 100% for as many as 15 various models of 11 brands. The experiment indicates that car model recognition based on the right selection of feature parameters is of good performance by using the SVM method. This SVM method has a high application value in the intelligent traffic management systems and other relative fields.

  13. Car use within the household

    DEFF Research Database (Denmark)

    de Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    2013-01-01

    , respectively. When we do take into account the substitution effect, these figures reduce to, respectively, -0.32 and -0.45. We further estimate an alternative version of the model to test the hypothesis that substitution in response to higher fuel prices will be predominantly from the least to the most fuel...... efficient car, finding partial support for the underlying hypothesis. More importantly, the results of this extended model emphasize the importance of behavioural differences related to the position of the most fuel efficient car in the household, suggesting that households’ fuel efficiency choices...

  14. Intelligent Car System

    Directory of Open Access Journals (Sweden)

    Qasim Siddique

    2009-01-01

    Full Text Available In modern life the road safety has becomes the core issue. One single move of a driver can cause horrifying accident. The main goal of intelligent car system is to make communication with other cars on the road. The system is able to control to speed, direction and the distance between the cars the intelligent car system is able to recognize traffic light and is able to take decision according to it. This paper presents a framework of the intelligent car system. I validate several aspect of our system using simulation.

  15. Intelligent Car System

    CERN Document Server

    Siddique, Qasim

    2012-01-01

    In modern life the road safety has becomes the core issue. One single move of a driver can cause horrifying accident. The main goal of intelligent car system is to make communication with other cars on the road. The system is able to control to speed, direction and the distance between the cars the intelligent car system is able to recognize traffic light and is able to take decision according to it. This paper presents a framework of the intelligent car system. I validate several aspect of our system using simulation.

  16. CERN Relay Race: information for drivers

    CERN Multimedia

    2012-01-01

    The CERN relay race will take place around the Meyrin site on Thursday, 24 May starting at 12.15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. In addition, there will be a Nordic Walking event which will finish around 12.50. This should not block the roads, but please drive carefully during this time. Thank you for your cooperation. Details on how to register your team for the relay race can be found here.

  17. Arms race between selfishness and policing: two-trait quantitative genetic model for caste fate conflict in eusocial Hymenoptera.

    Science.gov (United States)

    Dobata, Shigeto

    2012-12-01

    Policing against selfishness is now regarded as the main force maintaining cooperation, by reducing costly conflict in complex social systems. Although policing has been studied extensively in social insect colonies, its coevolution against selfishness has not been fully captured by previous theories. In this study, I developed a two-trait quantitative genetic model of the conflict between selfish immature females (usually larvae) and policing workers in eusocial Hymenoptera over the immatures' propensity to develop into new queens. This model allows for the analysis of coevolution between genomes expressed in immatures and workers that collectively determine the immatures' queen caste fate. The main prediction of the model is that a higher level of polyandry leads to a smaller fraction of queens produced among new females through caste fate policing. The other main prediction of the present model is that, as a result of arms race, caste fate policing by workers coevolves with exaggerated selfishness of the immatures achieving maximum potential to develop into queens. Moreover, the model can incorporate genetic correlation between traits, which has been largely unexplored in social evolution theory. This study highlights the importance of understanding social traits as influenced by the coevolution of conflicting genomes. © 2012 The Author. Evolution© 2012 The Society for the Study of Evolution.

  18. An Amusing Car Accident

    Institute of Scientific and Technical Information of China (English)

    倪俊

    2001-01-01

    @@ It was about midnight. My son was riding in the back seat with a friend of his in a car driven by a Chinese schoolmate, when a police car suddenly approached from behind with its siren sounding ominously. The driver immediately stopped his car by the roadside and stepped out to see what was happening. Just at that moment, he seemed to hear a policeman shouting to him: “Back your car!” (Actually, his order was: “Go back into your car!”) Then the student set about backing his car. In a flurry, he went so far as to bump into the police car, which made the cops very much alarmed.

  19. Common feature of concave growth pattern of oscillations in terms of speed, acceleration, fuel consumption and emission in car following: experiment and modeling

    CERN Document Server

    Tian, Junfang; Treiber, Martin; Ma, Shoufeng; Jia, Bin; Zhang, Wenyi

    2016-01-01

    This paper has investigated the growth pattern of traffic oscillations by using vehicle trajectory data in a car following experiment. We measured the standard deviation of acceleration, emission and fuel consumption of each vehicle in the car-following platoon. We found that: (1) Similar to the standard deviation of speed, these indices exhibit a common feature of concave growth pattern along vehicles in the platoon; (2) The emission and fuel consumption of each vehicle decrease remarkably when the average speed of the platoon increases from low value; However, when reaches 30km/h, the change of emission and fuel consumption with is not so significant; (3), the correlations of emission and fuel consumption with both the standard deviation of acceleration and the speed oscillation are strong. Simulations show that with the memory effect of drivers taken into account, the improved two-dimensional intelligent driver model is able to reproduce the common feature of traffic oscillation evolution quite well.

  20. 5 kHz thermometry in a swirl-stabilized gas turbine model combustor using chirped probe pulse femtosecond CARS. Part 1: Temporally resolved swirl-flame thermometry

    KAUST Repository

    Dennis, Claresta N.

    2016-06-20

    Single-laser-shot temperature measurements at 5 kHz were performed in a gas turbine model combustor using femtosecond (fs) coherent anti-Stokes Raman scattering (CARS). The combustor was operated at two conditions; one exhibiting a low level of thermoacoustic instability and the other a high level of instability. Measurements were performed at 73 locations within each flame in order to resolve the spatial flame structure and compare to previously published studies. The measurement procedures, including the procedure for calibrating the laser system parameters, are discussed in detail. Despite the high turbulence levels in the combustor, signals were obtained on virtually every laser shot, and these signals were strong enough for spectral fitting analysis for determination of flames temperatures. The spatial resolution of the single-laser shot temperature measurements was approximately 600 µm, the precision was approximately ±2%, and the estimated accuracy was approximately ±3%. The dynamic range was sufficient for temperature measurements ranging from 300 K to 2200 K, although some detector saturation was observed for low temperature spectra. These results demonstrate the usefulness of fs-CARS for the investigation of highly turbulent combustion phenomena. In a companion paper, the time-resolved fs CARS data are analyzed to provide insight into the temporal dynamics of the gas turbine model combustor flow field.

  1. 基于顾客保留的汽车服务链整合%The Integration of Car Service Chain Based on Analytical Kano Model

    Institute of Scientific and Technical Information of China (English)

    耿立校; 徐静娟

    2016-01-01

    现阶段,以汽车4S店为核心的汽车经销企业顾客流失率很高,文章首先分析了汽车经销商集团在打造一体化汽车服务链上的优势。并基于分析型Kano模型的原理,对顾客的服务需求要素进行了分类。通过分析型Kano模型的决策指标,确定了服务属性提升的优先顺序。最后对顾客需求要素进行了重新整合。该研究对于汽车经销企业实现大规模定制服务,提高的顾客满意度,进而实现顾客保留效果有一定意义。%Nowadays, car 4S shops as the core of the car dealership companies have a high customer reduction rate. First, the paper analyzed the advantage of car dealership in creating an-integrated automotive service chain. Based on the principle of analytical Kano model, classified the customer de-mand of service elements. Determining the priorities of service by decision index of analytical Kano model. Finally, re-inte-grated the elements of the customer demand factors. The re-search is significant on the car dealership companies in achieving mass customization services, improving customer sat-isfaction, achieving the customer retention.

  2. CAR2 - Czech Database of Car Speech

    Directory of Open Access Journals (Sweden)

    P. Sovka

    1999-12-01

    Full Text Available This paper presents new Czech language two-channel (stereo speech database recorded in car environment. The created database was designed for experiments with speech enhancement for communication purposes and for the study and the design of a robust speech recognition systems. Tools for automated phoneme labelling based on Baum-Welch re-estimation were realised. The noise analysis of the car background environment was done.

  3. High-performance turbocharger for motor sports cars; Motor sports yo turbo ni tsuibe

    Energy Technology Data Exchange (ETDEWEB)

    Koike, T. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    2000-02-01

    Motor sports car with a turbo-charged gasoline or diesel engine ranges over racing car, prototype car and production cars from light vehicle to large truck. Not only a large output power but also a high torque ranging from a low- revolution region of engines to a high-revolution region are required for turbochargers for racing cars. The turbocharger for racing cars requires the following features: (1) The latest fluid performance for achieving a high pressure ratio, high efficiency and large capacity, (2) a high reliability for bearing high exhaust temperature, (3) a high-response rotation part with low inertia moment, (4) a loss reduction bearing for improving a response and total performance, and (5) the small light-weight turbocharger for balancing a car with an engine. The turbocharger for motor sports cars has developed various advanced technologies concretely for achieving a high running performance and low fuel consumption required for automobiles. Such advanced technologies developed for motor races will also contribute to the growth of an automobile industry in the future. (NEDO)

  4. CRISPR Meets CAR T-cell Therapy.

    Science.gov (United States)

    2017-03-21

    Using CRISPR/Cas9 technology, researchers have devised a method to deliver a CAR gene to a specific locus, TRAC, in T cells. This targeted approach yielded therapeutic cells that were more potent even at low doses; in a mouse model of acute lymphoblastic leukemia, they outperformed CAR T cells created with a randomly integrating retroviral vector.

  5. Design review of gondola car

    Directory of Open Access Journals (Sweden)

    S. V. Myamlin

    2014-12-01

    . The generalization of theoretical, scientific and methodological, experimental studies aimed at further improving the technical and economic parameters of gondola cars are urgent when improving the body structure of the gondola cars. The above mentioned design features of the bodies of some models of modern gondola cars have practical value and can be used in further developments.

  6. A Race to the Bottom: MOOCs and Higher Education Business Models

    Science.gov (United States)

    Kalman, Yoram M.

    2014-01-01

    This is a critical examination of the claims that innovations such as massive open online courses (MOOCs) will disrupt the business models of the higher education sector. It describes what business models are, analyses the business model of free MOOCs offered by traditional universities and compares that model to that of paid online courses…

  7. A Race to the Bottom: MOOCs and Higher Education Business Models

    Science.gov (United States)

    Kalman, Yoram M.

    2014-01-01

    This is a critical examination of the claims that innovations such as massive open online courses (MOOCs) will disrupt the business models of the higher education sector. It describes what business models are, analyses the business model of free MOOCs offered by traditional universities and compares that model to that of paid online courses…

  8. Development of aerodynamics for solar cars; Solar Car no kuryoku kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, S.; Ozawa, H.; Higashida, D.; Arai, S.; Ozawa, K.; Aoki, T. [Honda Research and Development Co. Ltd., Saitama (Japan)

    1997-04-01

    In the worldwide attempts for environmental problem, various researches and developments have also been executed on vehicles used the new energies. Among them solar cars using solar cell activated effectively solar energy thought to be unlimited for their energy source are also given many attentions for one of the future cars. In this paper, transition of aerodynamic development of Honda`s `Dream` joined since 1990 to the World solar challenge held in Australia in each three year, ranged to 3,000 km of running distance and positioned at the biggest race in the world was introduced. The `Dream` of `96 could be won a victory of the 4th solar car race in 1996 with new record of the race as aimed. The last aerodynamic resistance of the `Dream` of `96 was promoted 11% in C{sub D}{times}A value in comparison with that of the `Dream` of `93, which also established its aim of performance. In shape of vehicle at super low air resistance, shape improvement around tires and finish accuracy of the body surface became also an important point for improvement of aerodynamic features. 2 refs., 13 figs., 4 tabs.

  9. Influence of mobile air-conditioning on vehicle emissions and fuel consumption: a model approach for modern gasoline cars used in Europe.

    Science.gov (United States)

    Weilenmann, Martin F; Vasic, Ana-Marija; Stettler, Peter; Novak, Philippe

    2005-12-15

    The influence of air-conditioning activity on the emissions and fuel consumption of passenger cars is an important issue, since fleet penetration and use of these systems have reached a high level. Apart from the MOBILE6 study in the United States, little data is available on the impact of air-conditioning devices (A/Cs). Since weather conditions and A/C technologies both differ from those in the U. S., a test series was designed for the European setting. A fleet of six modern gasoline passenger cars was tested in different weather conditions. Separate test series were carried out for the initial cooldown and for the stationary situation of keeping the interior of the vehicle cool. As assumed, CO2 emissions and fuel consumption rise with the thermal load. This also causes a notable rise in CO and hydrocarbons (HCs). Moreover, A/Cs do not stop automatically at low ambient temperatures; if necessary, they produce dry air to demist the windscreen. A model is proposed that shows a constant load for lower temperatures and a linear trend for higher temperatures. The initial cooldown tests highlight significant differences among cars but show that A/C operation for the initial cooling of an overheated passenger compartment does not result in any extra emissions for the fleet as a whole.

  10. Optimization Of Car Rim

    Directory of Open Access Journals (Sweden)

    Mr. Sushant K. Bawne

    2015-10-01

    Full Text Available The essential of car wheel rim is to provide a firm base on which to fit the tyre. Its dimensions, shape should be suitable to adequately accommodate the particular tyre required for the vehicle. In this project a tyre of car wheel rim belonging to the disc wheel category is considered. Design is an important industrial activity which influences the quality of the product. The wheel rim is modeled by using modeling software catiav5r17. By using this software the time spent in producing the complex 3- D models and the risk involved in the design and manufacturing process can be easily minimized. So the modeling of the wheel rim is made by using CATIA. Later this CATIA modal is imported to ANSYS WORKBENCH 14.5 for analysis work. ANSYS WORKBENCH 14.5 is the latest software used for simulating the different forces, pressure acting on the component and also calculating and viewing the results. By using ANSYS WORKBENCH 14.5 software reduces the time compared with the method of mathematical calculations by a human. ANSYS WORKBENCH 14.5 static structural analysis work is carried out by considered three different materials namely aluminum alloy ,magnesium alloy and structural steel and their relative performances have been observed respectively. In addition to wheel rim is subjected to modal analysis, a part of dynamic analysis is carried out its performance is observed. In this analysis by observing the results of both static and dynamic analysis obtained magnesium alloy is suggested as best material.

  11. Breaking car use habits

    DEFF Research Database (Denmark)

    Thøgersen, John; Møller, Berit Thorup

    2008-01-01

    Based on calls for innovative ways of reducing car traffic and research indicating that car driving is often the result of habitual decision-making and choice processes, this paper reports on a field experiment designed to test a tool aimed to entice drivers to skip the habitual choice of the car...... and consider using-or at least trying-public transport instead. About 1,000 car drivers participated in the experiment either as experimental subjects, receiving a free one-month travelcard, or as control subjects. As predicted, the intervention had a significant impact on drivers' use of public transport...... and it also neutralized the impact of car driving habits on mode choice. However, in the longer run (i.e., four months after the experiment) experimental subjects did not use public transport more than control subjects. Hence, it seems that although many car drivers choose travel mode habitually, their final...

  12. Space race functional responses.

    Science.gov (United States)

    Sjödin, Henrik; Brännström, Åke; Englund, Göran

    2015-02-22

    We derive functional responses under the assumption that predators and prey are engaged in a space race in which prey avoid patches with many predators and predators avoid patches with few or no prey. The resulting functional response models have a simple structure and include functions describing how the emigration of prey and predators depend on interspecific densities. As such, they provide a link between dispersal behaviours and community dynamics. The derived functional response is general but is here modelled in accordance with empirically documented emigration responses. We find that the prey emigration response to predators has stabilizing effects similar to that of the DeAngelis-Beddington functional response, and that the predator emigration response to prey has destabilizing effects similar to that of the Holling type II response. A stability criterion describing the net effect of the two emigration responses on a Lotka-Volterra predator-prey system is presented. The winner of the space race (i.e. whether predators or prey are favoured) is determined by the relationship between the slopes of the species' emigration responses. It is predicted that predators win the space race in poor habitats, where predator and prey densities are low, and that prey are more successful in richer habitats.

  13. 基于MATLAB的轿车悬架系统模型简化%Simplified Car Suspension System Model Based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    李慧娟

    2014-01-01

    悬架系统是汽车系统中非常重要的一部分,它在汽车行驶平顺性和操作稳定性方面起着至关重要的作用。通过对轿车悬架模型的简化,得出独立悬架传递函数。为验证传递函数的正确性以及模型简化的合理性,在参数取值范围内,任意选取一组参数值,应用MATLAB中M 函数进行测试。测试结果证明,该传递函数正确,该模型合理,可作为今后研制、开发轿车悬架系统的一种测试、检验模型。%Suspension system is a very important part of the vehicle system ,it greatly affects the ride performance and operation stability of vehicles .In this paper ,the independent suspension transfer function for a car is set up after the car suspension model is simplified .To verify the correctness of the transfer function and the rationality of the simplified model ,a set of parameter values is freely chosen within the scope of the parameter selection ,and the simulation test is carried out by use of M function of MATLAB . Test results show that the transfer function is correct and the model is reasonable .This model can be used as a testing and inspection model in the development of car suspension system in the future .

  14. Buying a New Car?

    Institute of Scientific and Technical Information of China (English)

    Paul; Maghielse

    2000-01-01

    You read it here first, folks: a car buying processthat first counsels its readers not to buy a car! Why?Because, no matter what mystical incantations a carsalesperson may whisper in your ear, cars are notinvestments. Certainly, there are a few exceptions to that rule,but in general. vehicles are what the accountantsamong us call depreciating assets. Think of a vehiclepurchase in comparison with the other big-ticketpurchases we make during our lifetimes. Buying a

  15. Linking community, parenting, and depressive symptom trajectories: testing resilience models of adolescent agency based on race/ethnicity and gender.

    Science.gov (United States)

    Williams, Amanda L; Merten, Michael J

    2014-09-01

    Family stress models illustrate how communities affect youth outcomes through effects on parents and studies consistently show the enduring effects of early community context. The present study takes a different approach identifying human agency during adolescence as a potentially significant promotive factor mediating the relationship between community, parenting, and mental health. While agency is an important part of resilience, its longitudinal effects are unknown, particularly based on gender and race/ethnicity. The purpose of this research was to model the long-term effects of community structural adversity and social resources as predictors of adolescent depressive symptom trajectories via indirect effects of parental happiness, parent-child relationships, and human agency. Latent growth analyses were conducted with 1,796 participants (53% female; 56% White) across four waves of the National Longitudinal Study of Adolescent Health spanning adolescence (Wave 1) through adulthood (Wave 4). The results identified agency as an important promotive factor during adolescence with long-term mental health benefits, but only for White and male participants. For these individuals, community social resources and the quality of the parent-child relationship were related to higher levels of agency and more positive mental health trajectories. Although community social resources similarly benefitted parenting and agency among females and non-White participants, there were no significant links between agency and depressive symptoms for these youth. The results suggest that agency remains an important, but poorly understood concept and additional work is necessary to continue unpacking its meaning for diverse groups of youth.

  16. Ethnogenetic layering (EL): an alternative to the traditional race model in human variation and health disparity studies.

    Science.gov (United States)

    Jackson, F L C

    2008-01-01

    Traditionally, studies in human biodiversity, disease risk, and health disparities have defined populations in the context of typological racial models. However, such racial models are often imprecise generalizations that fail to capture important local patterns of human biodiversity. More explicit, detailed, and integrated information on relevant geographic, environmental, cultural, genetic, historical, and demographic variables are needed to understand local group expressions of disease inequities. This paper details the methods used in ethnogenetic layering (EL), a non-typological alternative to the current reliance of the biological racial paradigm in public health, epidemiology, and biomedicine. EL is focused on geographically identified microethnic groups or MEGs, a more nuanced and sensitive level of analysis than race. Using the MEG level of analysis, EL reveals clinical variations, details the causes of health disparities, and provides a foundation for bioculturally effective intervention strategies. EL relies on computational approaches by using GIS-facilitated maps to produce horizontally stratified geographical regional profiles which are then stacked and evaluated vertically. Each horizontal digital map details local geographic variation in the attributes of a particular database; usually this includes data on local historical demography, genetic diversity, cultural patterns, and specific chronic disease risks (e.g. dietary and toxicological exposures). Horizontal visual display of these layered maps permits vertical analysis at various geographic hot spots. From these analyses, geographical areas and their associated MEGs with highly correlated chronic disease risk factors can be identified and targeted for further study.

  17. Education effect of solar car for technical high school student; Kogyo kokosei ni taisuru solar car no kyoiku koka

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, T.

    1998-09-30

    The solar car race which technical high school students can join in was determined to be held at Ogata village, Akita prefecture. To join in the solar bicycle race, the author working in Ofuna technical high school called on 3 schools of Yokosuka, Fujisawa and Kanagawa technical high schools which joined in World Solar-Car Rally in Akita (WSR) in 1997, before fabrication of a racing bicycle. This paper describes the survey results at the above technical high schools, and the spirit as the teacher of Ofuna technical high school on joining in the race and fabrication of the solar bicycle, and the past, current and future situations. Club activities of high school students incline too toward sports such as soccer, baseball, volleyball and rugby, and are apt to keep honest cultural events and technical events at a distance. The author says that the challenge spirit to the solar car race using environment-friendly solar energy by both dedicated teachers and students of technical high schools summoned up the author`s courage. 15 figs.

  18. Car stickers for 2011

    CERN Multimedia

    GS Department

    2010-01-01

    The 2011 car stickers are now available. Holders of blue car stickers will receive their 2011 car stickers by internal mail as of 15 December.   Holders of red car stickers are kindly requested to come to the Registration Service (Building 55,1st floor) to renew their 2011 stickers. This service is open from Monday to Friday from 7.30 am to 5.30 pm non-stop. Documents for the vehicles concerned must be presented. Reception and Access Control Service – GS/ISG/SIS General Infrastructure Services Department

  19. Car stickers for 2012

    CERN Multimedia

    GS Department

    2011-01-01

    The 2012 car stickers are now available. Holders of blue car stickers will receive by internal mail their 2012 car stickers as of 5 December. Holders of red car stickers are kindly requested to come to the Registration Service (Building 55,1st floor) to renew their 2011 stickers. This service is open from Monday to Friday from 7.30 am to 5.30 pm non-stop. Documents related to the vehicles concerned are mandatory. Reception and Access Control Service – GS/IS/SIS General Infrastructure Services Department

  20. Use of car crashes resulting in fatal and serious injuries to analyze a safe road transport system model and to identify system weaknesses.

    Science.gov (United States)

    Stigson, Helena; Hill, Julian

    2009-10-01

    The objective of this study was to evaluate a model for a safe road transport system, based on some safety performance indicators regarding the road user, the vehicle, and the road, by using crashes with fatally and seriously injured car occupants. The study also aimed to evaluate whether the model could be used to identify system weaknesses and components (road user, vehicles, and road) where improvements would yield the highest potential for further reductions in serious injuries. Real-life car crashes with serious injury outcomes (Maximum Abbreviated Injury Scale 2+) were classified according to the vehicle's safety rating by Euro NCAP (European New Car Assessment Programme) and whether the vehicle was fitted with ESC (Electronic Stability Control). For each crash, the road was also classified according to EuroRAP (European Road Assessment Programme) criteria, and human behavior in terms of speeding, seat belt use, and driving under the influence of alcohol/drugs. Each crash was compared and classified according to the model criteria. Crashes where the safety criteria were not met in more than one of the 3 components were reclassified to identify whether all the components were correlated to the injury outcome. In-depth crash injury data collected by the UK On The Spot (OTS) accident investigation project was used in this study. All crashes in the OTS database occurring between 2000 and 2005 with a car occupant with injury rated MAIS2+ were included, for a total of 101 crashes with 120 occupants. It was possible to classify 90 percent of the crashes according to the model. Eighty-six percent of the occupants were injured when more than one of the 3 components were noncompliant with the safety criteria. These cases were reclassified to identify whether all of the components were correlated to the injury outcome. In 39 of the total 108 cases, at least two components were still seen to interact. The remaining cases were only related to one of the safety criteria

  1. Summary on Dynamics Simulation Tire Models of FSAE Racing Car%FSAE赛车动力学仿真中轮胎模型应用

    Institute of Scientific and Technical Information of China (English)

    倪俊

    2012-01-01

    FSAE赛车的研发周期较短,应用仿真手段对其操纵性能进行模拟及优化是FSAE赛车设计中的重要过程,其中轮胎力学特性的准确表达是保证仿真准确度的重要基础.总结了FSAE赛车动力学仿真研究过程中UA轮胎模型、Fiala轮胎模型及魔术公式轮胎模型的选择及应用方法,简述了其建模机理,并给出了若干可以指导工程应用的结论.

  2. Modeling and Kinematics Optimization of Front Suspension for FSAE Racing Car%FSAE赛车前悬架建模与运动学优化

    Institute of Scientific and Technical Information of China (English)

    秦玉英; 孙明浩; 侯志国; 桂军

    2013-01-01

    为提高FSAE赛车设计水平,利用Adams/Car建立赛车双横臂前悬架仿真模型,通过双轮同向跳动仿真试验,对悬架的外倾角、主销后倾角、主销内倾角及前束角等运动学参数进行分析.利用Adams/Insight对悬架的运动学特性进行优化,结果表明,优化后,悬架的整体性能得到较大提高,有助于提高整车操纵稳定性.另外,对悬架在实车装配中涉及到运动学的问题进行说明,对提高FSAE赛车的性能具有一定的实际参考价值.

  3. Effect of Meat Price on Race and Gender Disparities in Obesity, Mortality and Quality of Life in the US: A Model-Based Analysis

    Science.gov (United States)

    Pitt, Allison; Bendavid, Eran

    2017-01-01

    Introduction There are large differences in the burden and health implications of obesity by race and gender in the US. It is unclear to what extent policies modifying caloric consumption change the distribution of the burden of obesity and related health outcomes. Meat is a large component of the American diet. We investigate how changing meat prices (that may result from policies or from exogenous factors that reduce supply) might impact the burden of obesity by race and gender. Methods We construct a microsimulation model that evaluates the 15-year body-mass index (BMI) and mortality impact of changes in meat price (5, 10, 25, and 50% increase) in the US adult population stratified by age, gender, race, and BMI. Results Under each price change evaluated, relative to the status quo, white males, black males, and black females are expected to realize more dramatic reduction in 2030 obesity prevalence than white females. Life expectancy gains are also projected to differ by subpopulation, with black males far less likely to benefit from an increase in meat prices than other groups. Conclusions Changing meat prices has considerable potential to affect population health differently by race and gender. In designing interventions that alter the price of foods to consumers, it is not sufficient to assess health effects based solely on the population as a whole, since differential effects across subpopulations may be substantial. PMID:28045931

  4. Microparticle-mediated transfer of the viral receptors CAR and CD46, and the CFTR channel in a CHO cell model confers new functions to target cells.

    Directory of Open Access Journals (Sweden)

    Gaëlle Gonzalez

    Full Text Available Cell microparticles (MPs released in the extracellular milieu can embark plasma membrane and intracellular components which are specific of their cellular origin, and transfer them to target cells. The MP-mediated, cell-to-cell transfer of three human membrane glycoproteins of different degrees of complexity was investigated in the present study, using a CHO cell model system. We first tested the delivery of CAR and CD46, two monospanins which act as adenovirus receptors, to target CHO cells. CHO cells lack CAR and CD46, high affinity receptors for human adenovirus serotype 5 (HAdV5, and serotype 35 (HAdV35, respectively. We found that MPs derived from CHO cells (MP-donor cells constitutively expressing CAR (MP-CAR or CD46 (MP-CD46 were able to transfer CAR and CD46 to target CHO cells, and conferred selective permissiveness to HAdV5 and HAdV35. In addition, target CHO cells incubated with MP-CD46 acquired the CD46-associated function in complement regulation. We also explored the MP-mediated delivery of a dodecaspanin membrane glycoprotein, the CFTR to target CHO cells. CFTR functions as a chloride channel in human cells and is implicated in the genetic disease cystic fibrosis. Target CHO cells incubated with MPs produced by CHO cells constitutively expressing GFP-tagged CFTR (MP-GFP-CFTR were found to gain a new cellular function, the chloride channel activity associated to CFTR. Time-course analysis of the appearance of GFP-CFTR in target cells suggested that MPs could achieve the delivery of CFTR to target cells via two mechanisms: the transfer of mature, membrane-inserted CFTR glycoprotein, and the transfer of CFTR-encoding mRNA. These results confirmed that cell-derived MPs represent a new class of promising therapeutic vehicles for the delivery of bioactive macromolecules, proteins or mRNAs, the latter exerting the desired therapeutic effect in target cells via de novo synthesis of their encoded proteins.

  5. Expression of Human CAR Splicing Variants in BAC-Transgenic Mice

    OpenAIRE

    Zhang, Yu-Kun Jennifer; Lu, Hong; Klaassen, Curtis D.

    2012-01-01

    The nuclear receptor constitutive androstane receptor (CAR) is a key regulator for drug metabolism in liver. Human CAR (hCAR) transcripts are subjected to alternative splicing. Some hCAR splicing variants (SVs) have been shown to encode functional proteins by reporter assays. However, in vivo research on the activity of these hCAR SVs has been impeded by the absence of a valid model. This study engineered an hCAR-BAC-transgenic (hCAR-TG) mouse model by integrating the 8.5-kbp hCAR gene as wel...

  6. AFSC/RACE/GAP/Laman: Model Results of Aleutian Island POP distributions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data supporting the "Model Results of Aleutian Island POP distributions" manuscript are distribution and abundance of Pacific ocean perch from RACEBase,...

  7. Juan Yacht Design:ITesting LES turbulence models in race boat sails

    OpenAIRE

    Herbert Owen

    2014-01-01

    The objective of this project is to implement LES turbulence models outside the academic world to simulate flow around sailsIto replace RANS models that are the standard in the industry. The implementation and testing in the finite code ALYA is done by the Barcelona Supercomputing Center so that Juan Yatch Design SL (JYD) can appreciate the advantages of using a LES formulation for their problem.The obtained results show that LES can provide significant advantages over RANS simula...

  8. APF-Based Car Following Behavior Considering Lateral Distance

    OpenAIRE

    Zhao-Sheng Yang; Yao Yu; De-Xin Yu; Hu-Xing Zhou; Xiang-Lun Mo

    2013-01-01

    Considering the influence of lateral distance on consecutive vehicles, this paper proposes a new car following model based on the artificial potential field theory (APF). Traditional car following behaviors all assume that the vehicles are driving along the middle of a lane. Different from the traditional car following principles, this incorporation of APF offers a potential breakthrough in the fields of car following theory. The individual vehicle can be represented as a unit point charge in...

  9. Assessment of NHTSA’s Report “Relationships Between Fatality Risk, Mass, and Footprint in Model Year 2003-2010 Passenger Cars and LTVs”

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, Tom [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-06-01

    NHTSA recently completed a logistic regression analysis updating its 2003, 2010, and 2012 studies of the relationship between vehicle mass and US fatality risk per vehicle mile traveled (VMT; Kahane 2010, Kahane 2012, Puckett 2016). The new study updates the 2012 analysis using FARS data from 2005 to 2011 for model year 2003 to 2010. Using the updated databases, NHTSA estimates that reducing vehicle mass by 100 pounds while holding footprint fixed would increase fatality risk per VMT by 1.49% for lighter-than-average cars and by 0.50% for heavierthan- average cars, but reduce risk by 0.10% for lighter-than-average light-duty trucks, by 0.71% for heavier-than-average light-duty trucks, and by 0.99% for CUVs/minivans. Using a jack knife method to estimate the statistical uncertainty of these point estimates, NHTSA finds that none of these estimates are statistically significant at the 95% confidence level; however, the 1.49% increase in risk associated with mass reduction in lighter-than-average cars, and the 0.71% and 0.99% decreases in risk associated with mass reduction in heavier-than-average light trucks and CUVs/minivans, are statistically significant at the 90% confidence interval. The effect of mass reduction on risk that NHTSA estimated in 2016 is more beneficial than in its 2012 study, particularly for light trucks and CUVs/minivans. The 2016 NHTSA analysis estimates that reducing vehicle footprint by one square foot while holding mass constant would increase fatality risk per VMT by 0.28% in cars, by 0.38% in light trucks, and by 1.18% in CUVs and minivans.This report replicates the 2016 NHTSA analysis, and reproduces their main results. This report uses the confidence intervals output by the logistic regression models, which are smaller than the intervals NHTSA estimated using a jack-knife technique that accounts for the sampling error in the FARS fatality and state crash data. In addition to reproducing the NHTSA results, this report also examines the

  10. The kinematic advantage of electric cars

    Science.gov (United States)

    Meyn, Jan-Peter

    2015-11-01

    Acceleration of a common car with with a turbocharged diesel engine is compared to the same type with an electric motor in terms of kinematics. Starting from a state of rest, the electric car reaches a distant spot earlier than the diesel car, even though the latter has a better specification for engine power and average acceleration from 0 to 100 km h-1. A three phase model of acceleration as a function of time fits the data of the electric car accurately. The first phase is a quadratic growth of acceleration in time. It is shown that the tenfold higher coefficient for the first phase accounts for most of the kinematic advantage of the electric car.

  11. Driving an improved CAR for cancer immunotherapy.

    Science.gov (United States)

    Huang, Xiaopei; Yang, Yiping

    2016-08-01

    The recent clinical success of chimeric antigen receptor (CAR) T cell therapy for B cell malignancies represents a paradigm shift in cancer immunotherapy. Unfortunately, application of CAR T cell-mediated therapy for solid tumors has so far been disappointing, and the reasons for this poor response in solid tumors remain unknown. In this issue of the JCI, Cherkassky and colleagues report on their use of a murine model of human pleural mesothelioma to explore potential factors that limit CAR T cell efficacy. Their studies have uncovered the importance of the tumor microenvironment in the inhibition of CAR T cell functions, revealed a critical role for the programmed death-1 (PD-1) pathway in CAR T cell exhaustion within the tumor microenvironment, and demonstrated improved antitumor effects with a CAR T cell-intrinsic PD-1 blockade strategy using a dominant negative form of PD-1. Together, the results of this study lay the groundwork for further evaluation of mechanisms underlying CAR T cell immune evasion within the tumor microenvironment for the improvement of CAR T cell-mediated therapy for solid tumors.

  12. The Electric Cars Challenge

    Science.gov (United States)

    Roman, Harry T.

    2011-01-01

    Over 100 years ago, the great inventor Thomas Edison warned that gasoline cars would pollute the environment and lead to gasoline shortages. He preferred the use of clean electric vehicles. He also put his money where his mouth was and developed an entirely new alkaline storage battery system for his beloved cars, the nickel-iron storage battery.…

  13. The Electric Cars Challenge

    Science.gov (United States)

    Roman, Harry T.

    2011-01-01

    Over 100 years ago, the great inventor Thomas Edison warned that gasoline cars would pollute the environment and lead to gasoline shortages. He preferred the use of clean electric vehicles. He also put his money where his mouth was and developed an entirely new alkaline storage battery system for his beloved cars, the nickel-iron storage battery.…

  14. Estimation of genetic parameters for racing speed at different distances in young and adult Spanish Trotter horses using the random regression model.

    Science.gov (United States)

    Gómez, M D; Menendez-Buxadera, A; Valera, M; Molina, A

    2010-10-01

    A total of 71 522 records (from 3154 horses) with the times per kilometre (TPK), recorded in Spanish Trotter horses (individual races) from racing performances held from 1991 to 2007, were available for this study. The TPK values for the different age groups (young and adult horses) and different distances (1600-2700 m) were considered as different traits, and a bi character random regression model (RRM) was applied to estimate the (co)variance components throughout the trajectory of age groups and distances. The following effects were considered as fixed: the combination of hippodrome-date of race (404 levels); sex of the animals (3 levels); type of start (2 levels) and a fixed regression of Legendre polynomials (order 2). Those considered as random effects were the random regression Legendre polynomial (order 1) for animals (9201 animals in the pedigree); the individual environment permanent (3154 animals with data) and the driver (n = 957 levels). The residual variance was considered as heterogeneous with two classes (ages). The heritability estimated by distance ranged from 0.12 to 0.34, with a different trajectory for the two age groups. Within each age group, the genetic correlations between adjacent distances were high (>0.90), but decreased when the differences between them were over 400 metres for both age groups. The genetic correlations for the same distance across the age groups ranged from 0.47 to 0.78. Accordingly, the analysed trait (TPK) can be considered as positive genetic correlated but as different traits along the trajectory of distance and age. Therefore, some re-ranking should be expected in the breeding value of the horses at different characteristics of the racing. The use of RRM is recommended because it allows us to estimate the breeding value along the whole trajectory of race competition.

  15. Motor racing, tobacco company sponsorship, barcodes and alibi marketing

    OpenAIRE

    Grant-Braham, Bruce; Britton, John

    2012-01-01

    Background Sponsorship of Formula One (F1) motor racing, which has been used as an indirect medium of tobacco advertising for several decades, was prohibited by the 2005 European Union Tobacco Advertising Directive. Most F1 tobacco sponsorship of motor racing in the EU has since ceased, with the exception of the Scuderia Ferrari team, which continues to be funded by Philip Morris. In 2007, the Marlboro logo on Ferrari cars and other race regalia was replaced by an evolving ‘barcode’ design, w...

  16. Motor racing, tobacco company sponsorship, barcodes and alibi marketing

    OpenAIRE

    Grant-Banham, Bruce; Britton, John

    2011-01-01

    Abstract\\ud Background Sponsorship of Formula One (F1) motor racing, which has been used as an indirect medium of tobacco advertising for several decades, was prohibited by the 2005 European Union Tobacco Advertising Directive. Most F1 tobacco sponsorship of motor racing in the EU has since ceased, with the exception of the Scuderia Ferrari team, which continues to be funded by Philip Morris. In 2007, the Marlboro logo on Ferrari cars and other race regalia was replaced by an evolving ‘barcod...

  17. City Car = The City Car / Andres Sevtshuk

    Index Scriptorium Estoniae

    Sevtshuk, Andres, 1981-

    2008-01-01

    Massachusettsi Tehnoloogiainstituudi (MIT) meedialaboratooriumi juures tegutseva Targa Linna Grupi (Smart City Group) ja General Motorsi koostööna sündinud kaheistmelisest linnasõbralikust elektriautost City Car. Nimetatud töögrupi liikmed (juht William J. Mitchell, töögruppi kuulus A. Sevtshuk Eestist)

  18. City Car = The City Car / Andres Sevtshuk

    Index Scriptorium Estoniae

    Sevtshuk, Andres, 1981-

    2008-01-01

    Massachusettsi Tehnoloogiainstituudi (MIT) meedialaboratooriumi juures tegutseva Targa Linna Grupi (Smart City Group) ja General Motorsi koostööna sündinud kaheistmelisest linnasõbralikust elektriautost City Car. Nimetatud töögrupi liikmed (juht William J. Mitchell, töögruppi kuulus A. Sevtshuk Eestist)

  19. The Race to Nourish: Exploring resource equity in a coupled human coastline model

    Science.gov (United States)

    Williams, Z. C.; McNamara, D.; Murray, A.; Smith, M.

    2011-12-01

    Many coastal communities are faced with eroding shorelines due to gradients in the alongshore transport of sediment and rising sea level. These communities often employ a beach nourishment mitigation strategy to counter erosion from natural forces. These nourishment activities provide economic benefits in the form of protection from storms and enhanced recreation on the stabilized beach. Previous work has shown that economically optimal nourishment decisions indicate that rising nourishment costs can lead to more frequent nourishment. Given that the cost of nourishing is likely to rise as offshore sediment borrow sites become more scarce, this suggests a positive feedback whereby nourishment that dwindles offshore borrow sites causes more frequent nourishment. We explore the dynamics of this feedback in a coupled economic-coastline model and how resulting long term shoreline and economic patterns respond to forcing changes in the form of increased sea level rise and changing storminess along both a straight shoreline and a cuspate Carolina like shoreline. The economic model utilizes myopic manager agents that inform a community of the optimal nourishment interval based on the current cost of sand and locally observed erosion rate since the last nourishment episode. Communities nourish independently but can affect the erosion rate of adjacent communities through alongshore sediment transport dynamics. The coastline model tracks large-scale coastline change via alongshore sediment transport calculations and erosion due to rising sea level. Model experiments show that when the economic model is coupled to a flat coastline, the feedback in sand cost leads to resource inequity as communities that become caught in the feedback nourish frequently while adjacent communities maintain coastline position by "free riding" on these neighbor towns. Model experiments also show that on cuspate coastlines, the emergent cuspate features enhance the cost feedback and create unequal

  20. Electric cars for Germany; Deutschland stromert

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, Karsten

    2010-09-15

    The German government has defined eight model regions in which electric cars will be funded. Results are not available as yet, but there are experts who criticize the focus on electric-powered vehicles. (orig.)

  1. Modeling and Forecasting of Depletion of Additives in Car Engine Oils Using Attenuated Total Reflectance Fast Transform Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ronald Nguele

    2014-11-01

    Full Text Available On average, additives make up to 7% of a typical lubricant base. Commonly, they are blended with lube oils to enhance specific features thereby improving their qualities. Ultimately, additives participate in the performance of car engine oils. Using an analytical tool, attenuated total reflectance fast transform infrared spectroscopy, various grades of car engine oils, at different mileages, were analyzed. Sulfate oxidation and wear were found to trigger chemical processes which, in the long run, cause lubricant degradation while carbonyl oxidation was observed to occur only at a slow rate. Based upon data obtained from infrared spectra and using a curve fitting technique, mathematical equations predicting the theoretical rates of chemical change due to the aforementioned processes were examined. Additive depletions were found to obey exponential regression rather than polynomial. Moreover, breakpoint (breakpoint is used here to denote the initiation of deterioration of additives and critical mileage (critical mileage defines the distance at which the lubricant is chemically unusable of both samples were determined.

  2. Modeling Design of Children Car Safety Seat%儿童汽车安全座椅造型设计

    Institute of Scientific and Technical Information of China (English)

    陈文利

    2013-01-01

      本文通过对目前儿童汽车安全座椅进行系统地分析和研究,提出了产品造型设计在遵循安全性的原则下,应从人性化(使用、储放等)和审美化的方面来体现设计理念,使得儿童汽车安全座椅设计更加合理,并且能够适合不同年龄段的儿童使用。不仅对整车及零配件企业研发中心有借鉴意义,而且有利于儿童汽车安全座椅的普及推广。%Based on the systematic analysis and study of current children's car sa fety seat, the paper proposed the product design to follow the safety principle which is from the human (use, storage etc.) and aesthetic aspects to reflect the design concept, make the child car seat design more reasonable, what’s more, can be suitable for different age of the children. It not only has the reference significance to the research and development center of vehicle and parts enterprises, but also is conducive to the popularization of child safety seat in automobile.

  3. 改进的基于安全距离的车辆跟驰模型%Improved Safe Distance Car-following Model

    Institute of Scientific and Technical Information of China (English)

    杨达; 蒲云; 祝俪菱; 杨飞; Ran Bin

    2013-01-01

    Gipps' model,the well-known safe distance car-following model,has a strict restriction on the car-following behavior,that is,the following vehicle has to maintain the exact safe distance with the leading vehicle to avoid accident.However,this restriction is not consistent with the reality.Owning to this reson,an enhanced safe distance car-following model was proposed first,and then evaluated by comparing with Gipps' model.Furthermore,simulations were conducted to analyze the characteristics of the new model.The results of evaluation and simulation illustrate that the proposed model has more accurate prediction result than Gipps' model,and can reproduce the stable flow and shockwave that are very common in real traffic flow.In addition,the enhanced model can stabilize traffic flow.%由于经典的基于安全距离的车辆跟驰模型Gipps模型要求车辆行驶时恰好与前车保持安全距离,这是一个对车辆跟驰行为过分严格的约束,不符合实际情况,根据实际情况提出车辆跟驰距离是有关安全距离和前后车相对速度的函数,并据此建立了改进的基于安全距离的车辆跟驰模型.NGSIM数据经过处理后被用来标定Gipps 模型和改进后的模型,在标定结果的基础上对模型进行了统计意义上和仿真预测能力上的模型评价.结果显示:改进后的基于安全距离的车辆跟驰模型比Gipps模型有更高的仿真精确,可以再现出宏观交通中的稳定交通流和冲击波等常见的交通现象,并且改进模型在一定程度上使交通流变得更加稳定.

  4. An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints.

    Science.gov (United States)

    Wang, Shiyao; Deng, Zhidong; Yin, Gang

    2016-02-24

    A high-performance differential global positioning system (GPS)  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS-inertial measurement unit (IMU)/dead reckoning (DR) data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA) equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car.

  5. An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints

    Directory of Open Access Journals (Sweden)

    Shiyao Wang

    2016-02-01

    Full Text Available A high-performance differential global positioning system (GPS  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS–inertial measurement unit (IMU/dead reckoning (DR data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car.

  6. An Accurate GPS-IMU/DR Data Fusion Method for Driverless Car Based on a Set of Predictive Models and Grid Constraints

    Science.gov (United States)

    Wang, Shiyao; Deng, Zhidong; Yin, Gang

    2016-01-01

    A high-performance differential global positioning system (GPS)  receiver with real time kinematics provides absolute localization for driverless cars. However, it is not only susceptible to multipath effect but also unable to effectively fulfill precise error correction in a wide range of driving areas. This paper proposes an accurate GPS–inertial measurement unit (IMU)/dead reckoning (DR) data fusion method based on a set of predictive models and occupancy grid constraints. First, we employ a set of autoregressive and moving average (ARMA) equations that have different structural parameters to build maximum likelihood models of raw navigation. Second, both grid constraints and spatial consensus checks on all predictive results and current measurements are required to have removal of outliers. Navigation data that satisfy stationary stochastic process are further fused to achieve accurate localization results. Third, the standard deviation of multimodal data fusion can be pre-specified by grid size. Finally, we perform a lot of field tests on a diversity of real urban scenarios. The experimental results demonstrate that the method can significantly smooth small jumps in bias and considerably reduce accumulated position errors due to DR. With low computational complexity, the position accuracy of our method surpasses existing state-of-the-arts on the same dataset and the new data fusion method is practically applied in our driverless car. PMID:26927108

  7. Cars and socio-economics: understanding neighbourhood variations in car characteristics from administrative data

    Directory of Open Access Journals (Sweden)

    Guy Lansley

    2016-01-01

    Full Text Available There were 30.7 million registered cars in Great Britain in 2011, outnumbering the total number of households recorded by the census. Despite this, the Driving and Vehicle Licensing Agency’s (DVLA database of car model registrations remains underexplored as an indicator of socio-economic characteristics. In the past, car ownership itself has been frequently considered as a census proxy variable for affluence. However, this is an increasingly dated interpretation as ownership has become more widespread across society and the value of cars varies considerably. Understanding the geography of different car types, however, is likely to be more informative of local population characteristics as the choice of model is dependent on several factors, notably including the cost and the purpose of the vehicle. In partnership with the Department for Transport (DfT, a car segmentation was produced that grouped every car model registered in England and Wales in 2011 into 10 distinctive categories based on the vehicle’s key characteristics. Data representing the total number of registered cars for each car segment and three age groups were made available at a small area geography (known as lower layer super output areas – LSOAs to be analysed for this study. It revealed that each car segment is uniquely distributed across London, and the rest of England and Wales. The patterns were then compared with key 2011 Census variables on socio-economics to understand the extent to which spatial patterns of broad car characteristics correspond with variances in indicators of social make-up.

  8. The Race Race: Assimilation in America

    Science.gov (United States)

    Balis, Andrea; Aman, Michael

    2013-01-01

    Can race and assimilation be taught? Interdisciplinary pedagogy provides a methodology, context, and use of nontraditional texts culled from American cultural history such as from, theater and historical texts. This approach and these texts prove useful for an examination of race and assimilation in America. The paper describes a course that while…

  9. Careers in Auto Racing: Work in the Fast Lane

    Science.gov (United States)

    Lawhorn, William

    2009-01-01

    Long before most people had seen an automobile, thrill-seekers across the globe were driving cars competitively. The speed of racecars has accelerated steadily, as has the popularity of the sport. In public opinion polls of sports popularity, in fact, auto racing consistently finishes near the top. Racecar drivers may be the star of their event,…

  10. Race to the Top

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The global race in developing and deploying green energy technology can be a win-win game "Clean energy race" has become a catchphrase for journalists and bloggers to attract reader eyes. Googling that, one will be

  11. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  12. Breaking car use habits

    DEFF Research Database (Denmark)

    Thøgersen, John; Møller, Berit Thorup

    2008-01-01

    and consider using-or at least trying-public transport instead. About 1,000 car drivers participated in the experiment either as experimental subjects, receiving a free one-month travelcard, or as control subjects. As predicted, the intervention had a significant impact on drivers' use of public transport...... and it also neutralized the impact of car driving habits on mode choice. However, in the longer run (i.e., four months after the experiment) experimental subjects did not use public transport more than control subjects. Hence, it seems that although many car drivers choose travel mode habitually, their final...

  13. Substitution between cars within the household

    DEFF Research Database (Denmark)

    De Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    2016-01-01

    .98 and 1.41 for the primary and secondary cars, respectively. Accounting for substitution effects, these figures reduce to, respectively, 0.32 and 0.45. Consistent with substitution behaviour, we find that the fuel price elasticity of fuel demand exceeds the elasticity of kilometre demands with respect...... to the fuel price; the difference strongly increases at the highest deciles of the distribution of kilometre demand. Extending the model to account for driver heterogeneity and the role of car characteristics confirmed the relevance of substitution between cars within the household. We found strong evidence......’ fuel efficiency choices are related to their price sensitivity....

  14. An Improved Car-Following Dynamic Model%一种改进的车辆跟驰动力学模型

    Institute of Scientific and Technical Information of China (English)

    曹宝贵; 杨兆升

    2011-01-01

    In order to overcome the shortcomings of current car-following models, a novel optimal velocity ( desired velocity) function is proposed and an improved car-following dynamic model is established based on the "stimulus-response" pattern. Then, the stability of this model is analyzed by using the Lyapunov stability theory on motion. Finally, the parameter calibration and application verification of the improved model are performed by using the measured data. The results show that the theoretical results of the improved model accord well with the experimental data in terms of starting acceleration, approximately uniform speed and deceleration, without unrealistic acceleration which occurs in other models.%针对现有跟驰模型存在的不足,文中提出了一种新的优化速度(期望速度)函数,基于“刺激—反应”模式建立了改进的车辆跟驰动力学模型,并运用李亚普诺夫运动稳定性理论对其进行了稳定性分析.最后运用实测数据对模型进行了参数标定和应用性验证.结果表明:改进模型在模拟交通流的启动加速、近似匀速和减速过程方面与实测数据都具有较高的一致性,没有出现已有模型的不切实际的加速度.

  15. Heritability of racing durability traits in the Australian and Hong Kong Thoroughbred racing populations.

    Science.gov (United States)

    Velie, B D; Hamilton, N A; Wade, C M

    2016-05-01

    Many attempts have been made to improve the well-being of racing Thoroughbreds through improvements in management and veterinary care. However, these attempts are often limited by the industry's ability to regulate a large number of environmental variables and as a result have arguably had limited success in providing long-lasting change for the breed. To identify heritable durability traits for Thoroughbred horses racing in Australia and Hong Kong. Heritability analysis of a longitudinal dataset. Performance data on the Thoroughbred populations racing in Australia and Hong Kong between 2000 and 2011 (n = 168,993) were used to estimate the heritabilities and probability values of fixed effects and covariates for a range of racing durability traits. Heritabilities for all durability traits were estimated using a single trait animal model. Each model included, as a minimum, the effects of sex and trainer. Racing longevity (0.12 ± 0.01), racing persistence (0.10 ± 0.01), racing frequency (0.03 ± 0.01), spells (a time period between consecutive races, official trials and/or jump-outs greater than 90 days in length) per year (0.05 ± 0.01), spells per 10 starts (0.03 ± 0.01) and variation of days between races (0.08 ± 0.03) were all significantly heritable for horses racing in Australia. Racing longevity (0.08 ± 0.02), racing persistence (0.04 ± 0.02), spells per year (0.06 ± 0.02) and spells per 10 starts (0.11 ± 0.04) were significantly heritable for horses racing in Hong Kong. The heritabilities estimated for durability traits in this study provide support for the successful and practical application of genetic selection methodologies to improving the well-being of racing Thoroughbreds. © 2015 EVJ Ltd.

  16. Statistical Properties of Car Following: Theory and Driving Simulator Experiments

    CERN Document Server

    Ando, Hiromasa; Zgonnikov, Arkady; Saito, Yoshiaki

    2015-01-01

    A fair simple car driving simulator was created based on the open source engine TORCS and used in car-following experiments aimed at studying the basic features of human behavior in car driving. Four subjects with different skill in driving real cars participated in these experiments. The subjects were instructed to drive a car without overtaking and losing sight of a lead car driven by computer at a fixed speed. Based on the collected data the distributions of the headway distance, the car velocity, acceleration, and jerk are constructed and compared with the available experimental data for the real traffic flow. A new model for the car-following is proposed to capture the found properties. As the main result, we draw a conclusion that human actions in car driving should be categorized as generalized intermittent control with noise-driven activation. Besides, we hypothesize that the car jerk together with the car acceleration are additional phase variables required for describing the dynamics of car motion g...

  17. Simulation Models of the Effects of Race- and Socioeconomic-Based Affirmative Action Policies on Elite College Enrollment Patterns

    Science.gov (United States)

    Reardon, Sean; Baker, Rachel; Kasman, Matt; Townsend, Joe; Klasik, Daniel

    2014-01-01

    The creation of racially diverse colleges at all levels of selectivity has proven to be no small task, even with the legal use of race-conscious affirmative action. As evidenced in the postsecondary destinations of the high school class of 2004, very selective schools (those with Barron's Selectivity rankings of 1, 2 or 3) have many more White,…

  18. Equal Pay for Equal Qualifications? A Model for Determining Race or Sex Discrimination in Salaries. AIR Forum Paper 1978.

    Science.gov (United States)

    Muffo, John; And Others

    Equal pay for equal work by persons of equal qualifications is the concept behind laws against race and sex discrimination in salaries in the United States. However, determining the existence and extent of discrimination is not a simple matter. A four-step procedure is recommended that attempts to uncover the existence of discrimination and begins…

  19. The Electric Car Challenge.

    Science.gov (United States)

    Diehl, Brian E.

    1997-01-01

    Describes the Electric Car Challenge during which students applied methods of construction to build lightweight, strong vehicles that were powered by electricity. The activity required problem solving, sheet metal work, electricity, design, and construction skills. (JOW)

  20. The benefits of improved car secondary safety.

    Science.gov (United States)

    Broughton, Jeremy

    2003-07-01

    The term 'secondary safety' refers to the protection that a vehicle provides its occupants when involved in an accident. This paper studies information from the British database of road accident reports between 1980 and 1998, to estimate the reduction in the number of occupant casualties over these years which may be attributed to improvements to secondary safety in cars. The paper shows that the proportion of driver casualties who are killed or seriously injured (KSI) is lower for modern cars than for older cars. The reduction of this proportion is used to assess the improvement in secondary safety. Statistical models are developed to represent the proportion with 'year of first registration' as one of the independent variables, although only an incomplete assessment of the benefits of improved secondary safety can be made with the available data. The assessment compares the number of casualties that would have been expected if secondary safety had remained at the level found in cars first registered in 1980 with the actual casualty numbers. It is estimated that improved secondary safety reduced the number of drivers KSI by at least 19.7% in 1998, in comparison with what might have occurred if all cars had had that lower level of secondary safety. This figure relates to all cars on the road in 1998, and rises to 33%, when confined to the most modern cars (those which were first registered in 1998).

  1. TANK CAR CONSTRUCTION REFINMENT

    Directory of Open Access Journals (Sweden)

    A. N. Soberzhansjkyj

    2010-06-01

    Full Text Available The increase of volume and load-carrying capacity of tank cars is an urgent task for improving the efficiency of transportation of liquid bulk cargoes. Variants of the constructive and technical approaches, which allow increasing the specified indices, are considered. After the analysis the most rational constructive scheme meeting the modern requirements for tank cars and allowing to raise their productivity is chosen.

  2. Analysis of multiple tank car releases in train accidents.

    Science.gov (United States)

    Liu, Xiang; Liu, Chang; Hong, Yili

    2017-10-01

    There are annually over two million carloads of hazardous materials transported by rail in the United States. The American railroads use large blocks of tank cars to transport petroleum crude oil and other flammable liquids from production to consumption sites. Being different from roadway transport of hazardous materials, a train accident can potentially result in the derailment and release of multiple tank cars, which may result in significant consequences. The prior literature predominantly assumes that the occurrence of multiple tank car releases in a train accident is a series of independent Bernoulli processes, and thus uses the binomial distribution to estimate the total number of tank car releases given the number of tank cars derailing or damaged. This paper shows that the traditional binomial model can incorrectly estimate multiple tank car release probability by magnitudes in certain circumstances, thereby significantly affecting railroad safety and risk analysis. To bridge this knowledge gap, this paper proposes a novel, alternative Correlated Binomial (CB) model that accounts for the possible correlations of multiple tank car releases in the same train. We test three distinct correlation structures in the CB model, and find that they all outperform the conventional binomial model based on empirical tank car accident data. The analysis shows that considering tank car release correlations would result in a significantly improved fit of the empirical data than otherwise. Consequently, it is prudent to consider alternative modeling techniques when analyzing the probability of multiple tank car releases in railroad accidents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. PLC Based Automatic Multistoried Car Parking System

    Directory of Open Access Journals (Sweden)

    Swanand S .Vaze

    2014-12-01

    Full Text Available This project work presents the study and design of PLC based Automatic Multistoried Car Parking System. Multistoried car parking is an arrangement which is used to park a large number of vehicles in least possible place. For making this arrangement in a real plan very high technological instruments are required. In this project a prototype of such a model is made. This prototype model is made for accommodating twelve cars at a time. Availability of the space for parking is detected by optical proximity sensor which is placed on the pallet. A motor controlled elevator is used to lift the cars. Elevator status is indicated by LED which is placed on ground floor. Controlling of the platforms and checking the vacancies is done by PLC. For unparking of car, keyboard is interfaced with the model for selection of required platform. Automation is done to reduce requirement of space and also to reduce human errors, which in-turn results in highest security and greatest flexibility. Due to these advantages, this system can be used in hotels, railway stations, airports where crowding of car is more.

  4. 基于ADAMS/Car Ride的整车平顺性建模与仿真%Modeling and simulation of vehicle ride based on ADAMS/Car Ride

    Institute of Scientific and Technical Information of China (English)

    王南; 平恩顺; 岳龙山; 李伟

    2010-01-01

    利用机械系统动力学分析软件ADAMS/Car Ride模块建立整车虚拟样机模型,应用虚拟四柱试验台对整车模型进行随机输入和脉冲输入下的平顺性仿真试验.仿真结果表明:ADAMS/Car Ride可简洁有效地进行整车平顺性仿真试验,实现了在设计阶段对汽车进行平顺性预测与分析的目标,从而为车辆的前期开发提供设计依据.

  5. 电动汽车商业模式综合性分析与创新性思考%Electric car business model integrated analysis and innovative thinking

    Institute of Scientific and Technical Information of China (English)

    张泓

    2014-01-01

    本文对电动汽车现有商业模式进行了回顾与总结,全面分析了影响因素,并进行了思考,最后提出一种电动汽车创新商业模式的设想。%This paper reviewed and summarized the existing electric cars business model, a comprehensive analysis of the influencing factors, and thought, finally propose an electric car business model innovation.

  6. REPAIR TECHNOLOGY IMPROVEMENT OF SPECIALIZED FREIGHT CARS

    Directory of Open Access Journals (Sweden)

    V. M. Bubnov

    2016-02-01

    Full Text Available Purpose. The volume of cargo transportation demands the introduction of a new generation of cars that would be able to provide all the needs of carriers. But this is impossible without the implementation of renovation repair facilities with the introduction of new technologies and modernization of the repair process. Repair of rolling stock is a key factor that must proceed with the establishment of new cars, as not all of the inventions may be repaired in car-repair depots, most of which are obsolete. The purpose is to analyze the possibility of increasing the efficiency of the repair process by introducing new repair technologies or improving the existing ones. It will improve not only the quality of the repair, but also its rate. Methodology. Works on improving the designs of freight cars are held by many design organizations in almost all industrialized countries. It makes repair organizations (depots and car-repair plants to upgrade the repair process. Achievements of-this goal is possible by improving the technology renovation and reorganization through the use of flexible flow technologies, which to date are the most effective in the repair of rolling stock. Findings. When performing the analysis it was determined that there are different designs of cars. More of cars are all-purpose and their repair does not cause difficulties for car-repair business. However, the number of specialized cars is also significant, and the technology of their repair should be improved. One of the reasons is that many models, such as tank wagons for the carriage of sulfur, are intended for the carriage of dangerous goods and their failure at the time of motion is not permitted. Originality. Firstly the authors have defined direction at improving technologies of repair specialized cars. Practical value. Actual improvement in the construction of cars is to improve the existing repair facilities. In addition, the repair technology using nowadays when repairing

  7. Investigation on the Effectiveness of Holistic Multi-dimensional Treatment Model (HMTM) in Improvement of CARS Test Indicators in Children suffering from Autism Spectrum Disorder

    National Research Council Canada - National Science Library

    Maryam Hojjati; Ghasem Sadeghi Bejestani; Farah Ashrafzadeh

    2015-01-01

    ...) in improvement of CARS test indicators in children with Autism Spectrum Disorder (ASD) and it is done without pharmaceutical interventions, without names and accompanied by parental satisfaction questionnaire...

  8. Hydrogen bonding and induced dipole moments in water: predictions from the Gaussian charge polarizable model and Car-Parrinello molecular dynamics.

    Science.gov (United States)

    Dyer, Peter J; Cummings, Peter T

    2006-10-14

    We compare a new classical water model, which features Gaussian charges and polarizability (GCPM) with ab initio Car-Parrinello molecular dynamics (CPMD) simulations. We compare the total dipole moment, the total dipole moment distribution, and degree of hydrogen bonding at ambient to supercritical conditions. We also compared the total dipole moment calculated from both the electron density (partitioning the electron density among molecules based on a zero electron flux condition), and from the center of localized Wannier function centers (WFCs). Compared to CPMD, we found that GCPM overpredicts the dipole moment derived by partitioning the electron density and underpredicts that obtained from the WFCs, but exhibits similar trends and distribution of values. We also found that GCPM predicted similar degrees of hydrogen bonding compared to CPMD and has a similar structure.

  9. Production cars' featuring technologies derived from motor sports; Motor sports de hagukumareta shihansha no yoso gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    Many recent innovative automotive technologies are derived from motor racing. This paper focuses on some applications of these leading-edge technologies to production cars. (1) Mitsubishi's vehicle technology, derived from its World Rally Championship car 'LANCER'. (2) Toyota's racing engine technology. (3) Subaru's center differential technology, derived from its 4WD competition car 'IMPREZA'. (4) Nissan's aerodynamic and highly rigid body structure applied to 'SKYLINE'. (5) Hino's heavy duty truck air suspension system, derived from 'CAMION'. (author)

  10. 时滞车辆跟驰模型及其分岔现象%REVIEW OF TIME-DELAYED CAR FOLLOWING MODELS AND BIFURCATION PHENOMENA

    Institute of Scientific and Technical Information of China (English)

    徐鉴; 徐荣改

    2013-01-01

    In car following theory of traffic dynamics, human drivers need a finite period of time to process stimuli of preceding vehicles and make a decision, which is attributed to human physiological factors. Since mechanical devices also need time for sensing, computing and actuating, time delay seems unavoidable even in autonomous cruise control systems. As a result time delays should be considered as an inherent factor in car following theories of traffic dynamics. One of the key problems in need of study is how time delays affect the traffic flow patterns and their evolutions. In this paper, time-delayed car following models which are continuous in both time and space are firstly surveyed. Then the progress in the dynamic behaviors based on bifurcation theory is reviewed. Defects of these models and the corresponding bifurcation research are pointed out in this summary. Finally we conclude that research on dynamic behaviors of time-delayed car following models with traffic flow parameters based on bifurcation theory are of great significance and necessity. By means of such research, the underlying mechanisms of traffic jam formation and evolution can be better understood. Traffic jam patterns can be categorized from a synchronization perspective through classifying dynamic behaviors in parameter plane, and hence, different traffic control strategies can be put forward by traffic management department based on the above jam patterns.%交通流车辆跟驰理论中,由于生理因素,造成司机在处理前方车辆变化信息和采取应对措施之间存在时间滞后.即使是在自动巡航控制系统中,设备在感知信息、计算所需操作并最终作动车辆这一过程中时滞也不可避免.因此交通流跟驰理论的数学模型本质上应包含时滞.时滞的存在对各种交通模式的出现及其相互演化产生怎样的影响?这是值得我们关注的问题.本文首先综述了各类时间和空间连续的时滞车辆跟驰模型.

  11. Allocating Freight Empty Cars in Railway Networks with Dynamic Demands

    Directory of Open Access Journals (Sweden)

    Ce Zhao

    2014-01-01

    Full Text Available This paper investigates the freight empty cars allocation problem in railway networks with dynamic demands, in which the storage cost, unit transportation cost, and demand in each stage are taken into consideration. Under the constraints of capacity and demand, a stage-based optimization model for allocating freight empty cars in railway networks is formulated. The objective of this model is to minimize the total cost incurred by transferring and storing empty cars in different stages. Moreover, a genetic algorithm is designed to obtain the optimal empty cars distribution strategies in railway networks. Finally, numerical experiments are given to show the effectiveness of the proposed model and algorithm.

  12. Car stickers for 2009

    CERN Multimedia

    TS Department

    2008-01-01

    All members of the personnel holding a valid contract (except owners of cars with green or CD plates) can come to the Registration Service (Building 55, 1st floor) to obtain their 2009 car sticker, Mondays to Fridays from 7.30 a.m. to 4.00 p.m. non-stop. Please ensure you bring with you the documents relating to the vehicles(s) concerned. If you only wish to register one vehicle, you can obtain the 2009 sticker using the request form on the Web (via internet Explorer only). NB: This notice only applies to members of the personnel who obtained one or several blue car stickers for 2008. Reception and Access Control Service – TS/FM

  13. Toward a Social Psychology of Race and Race Relations for the Twenty-First Century.

    Science.gov (United States)

    Richeson, Jennifer A; Sommers, Samuel R

    2016-01-01

    The United States, like many nations, continues to experience rapid growth in its racial minority population and is projected to attain so-called majority-minority status by 2050. Along with these demographic changes, staggering racial disparities persist in health, wealth, and overall well-being. In this article, we review the social psychological literature on race and race relations, beginning with the seemingly simple question: What is race? Drawing on research from different fields, we forward a model of race as dynamic, malleable, and socially constructed, shifting across time, place, perceiver, and target. We then use classic theoretical perspectives on intergroup relations to frame and then consider new questions regarding contemporary racial dynamics. We next consider research on racial diversity, focusing on its effects during interpersonal encounters and for groups. We close by highlighting emerging topics that should top the research agenda for the social psychology of race and race relations in the twenty-first century.

  14. Affectivity and race

    DEFF Research Database (Denmark)

    of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...... on the role of feelings in the formation of subjectivities, how race and whiteness are affectively circulated in public life and the ways in which emotions contribute to regimes of inclusion and exclusion. As such it will appeal to scholars across the social sciences, with interests in sociology, anthropology...

  15. Motor racing, tobacco company sponsorship, barcodes and alibi marketing

    Science.gov (United States)

    Britton, John

    2012-01-01

    Background Sponsorship of Formula One (F1) motor racing, which has been used as an indirect medium of tobacco advertising for several decades, was prohibited by the 2005 European Union Tobacco Advertising Directive. Most F1 tobacco sponsorship of motor racing in the EU has since ceased, with the exception of the Scuderia Ferrari team, which continues to be funded by Philip Morris. In 2007, the Marlboro logo on Ferrari cars and other race regalia was replaced by an evolving ‘barcode’ design, which Ferrari later claimed was part of the livery of the car, and not a Marlboro advertisement. Objective To determine whether the ‘barcode’ graphics used by Ferrari represent ‘alibi’ Marlboro advertising. Methods Academic and grey literature, and online tobacco industry document archives, were searched using terms relevant to tobacco marketing and motorsport. Results Tobacco sponsorship of F1 motor racing began in 1968, and Philip Morris has sponsored F1 teams since 1972. Phillip Morris first used a ‘barcode’ design, comprising red vertical parallel lines below the word Marlboro on the British Racing Motors F1 car in 1972. Vertical or horizontal ‘barcode’ designs have been used in this way, latterly without the word Marlboro, ever since. The modern ‘barcode’ logos occupied the same position on cars and drivers' clothing as conventional Marlboro logos in the past. The shared use of red colour by Marlboro and Ferrari is also recognised by Philip Morris as a means of promoting brand association between Marlboro and Ferrari. Conclusion The Ferrari ‘barcode’ designs are alibi Marlboro logos and hence constitute advertising prohibited by the 2005 EU Tobacco Advertising Directive. PMID:21821820

  16. Bouncing Balls and Hot Rod Races.

    Science.gov (United States)

    Tibbs, Peggy; Sherrill, Donna

    This paper presents the Bouncing Ball Experiment which models quadratic and exponential functions, and the Hot Rod Races activity that explores velocity and acceleration. Activities include directions for the use of TI-82 and TI-83 calculators. (YDS)

  17. Car-use habits

    DEFF Research Database (Denmark)

    Møller, Berit Thorup; Thøgersen, John

    2008-01-01

    It is often claimed that many drivers use their private car rather habitually. The claim gains credibility from the fact that travelling to many everyday destinations fulfils all the prerequisites for habit formation: it is recurring, performed under stable circumstances and produces rewarding co...

  18. Cars submerged in water.

    NARCIS (Netherlands)

    2010-01-01

    Crashes in which cars are submerged in deep water or in a ditch are often complicated and serious. Considering their severity and the fact that approximately half the fatalities in this crash type are not due to drowning but to injury, preventive measures are to be preferred above measures that have

  19. Constraining CO2 tower measurements in an inhomogeneous area with anthropogenic emissions using a combination of car-mounted instrument campaigns, aircraft profiles, transport modeling and neural networks

    Science.gov (United States)

    Schmidt, A.; Rella, C.; Conley, S. A.; Goeckede, M.; Law, B. E.

    2013-12-01

    The NOAA CO2 observation network in Oregon has been enhanced by 3 new towers in 2012. The tallest tower in the network (270 m), located in Silverton in the Willamette Valley is affected by anthropogenic emissions from Oregon's busiest traffic routes and urban centers. In summer 2012, we conducted a measurement campaign using a car-mounted PICARRO CRDS CO2/CO analyzer. Over 3 days, the instrument was driven over 1000 miles throughout the northwestern portion of Oregon measuring the CO/ CO2 ratios on main highways, back roads in forests, agricultural sites, and Oregon's biggest urban centers. By geospatial analyses we obtained ratios of CO/ CO2 over distinct land cover types divided into 10 classes represented in the study area. Using the coupled WRF-STILT transport model we calculated the footprints of nearby CO/ CO2 observation towers for the corresponding days of mobile road measurements. Spatiotemporally assigned source areas in combination with the land use classification were then used to calculate specific ratios of CO (anthropogenic origins) and CO2 to separate the anthropogenic portion of CO2 from the mixing ratio time series measured at the tower in Silverton. The WRF modeled boundary layer heights used in out study showed some differences compared to the boundary layer heights derived from profile data of wind, temperature, and humidity measured with an airplane in August, September, and November 2012, repeatedly over 5 tower locations. A Bayesian Regularized Artificial Neural Network (BRANN) was used to correct the boundary layer height calculated with WRF with a temporal resolution of 20 minutes and a horizontal resolution of 4 km. For that purpose the BRANN was trained using height profile data from the flight campaigns and spatiotemporally corresponding meteorological data from WRF. Our analyses provide information needed to run inverse modeling of CO2 exchange in an area that is affected by sources that cannot easily be considered by biospheric models

  20. Design of an intelligent car

    Science.gov (United States)

    Na, Yongyi

    2017-03-01

    The design of simple intelligent car, using AT89S52 single chip microcomputer as the car detection and control core; The metal sensor TL - Q5MC induction to iron, to detect the way to send feedback to the signal of single chip microcomputer, make SCM according to the scheduled work mode to control the car in the area according to the predetermined speed, and the operation mode of the microcontroller choose different also can control the car driving along s-shaped iron; Use A44E hall element to detect the car speeds; Adopts 1602 LCD display time of car driving, driving the car to stop, take turns to show the car driving time, distance, average speed and the speed of time. This design has simple structure and is easy to implement, but are highly intelligent, humane, to a certain extent reflects the intelligence.

  1. New concepts for the comparison of tropospheric NO2 column densities derived from car-MAX-DOAS observations, OMI satellite observations and the regional model CHIMERE during two MEGAPOLI campaigns in Paris 2009/10

    Directory of Open Access Journals (Sweden)

    R. Shaiganfar

    2015-03-01

    Full Text Available We compare tropospheric column densities (vertically integrated concentrations of NO2 from three data sets for the metropolitan area of Paris during two extensive measurement campaigns (25 days in summer 2009 and 29 days in winter 2010 within the European research project MEGAPOLI. The selected data sets comprise a regional chemical transport model (CHIMERE as well as two observational data sets: ground based mobile Multi-AXis-Differential Optical Absorption Spectroscopy (car-MAX-DOAS measurements and satellite measurements from the Ozone Monitoring Instrument (OMI. On most days, car-MAX-DOAS measurements were carried out along large circles (diameter ~35 km around Paris. The car-MAX-DOAS results are compared to coincident data from CHIMERE and OMI. All three data sets have their specific strengths and weaknesses, especially with respect to their spatio-temporal resolution and coverage as well as their uncertainties. Thus we compare them in two different ways: first, we simply consider the original data sets. Second, we compare modified versions making synergistic use of the complementary information from different data sets. For example, profile information from the regional model is used to improve the satellite data, observations of the horizontal trace gas distribution are used to adjust the respective spatial patterns of the model simulations, or the model is used as a transfer tool to bridge the spatial scales between car-MAX-DOAS and satellite observations. Using the modified versions of the data sets, the comparison results substantially improve compared to the original versions. In general, good agreement between the data sets is found outside the emission plume, but inside the emission plumes the tropospheric NO2 VCDs are systematically underestimated by the CHIMERE model and the satellite observations (compared to the car-MAX-DOAS observations. One major result from our study is that for satellite validation close to strong emission

  2. Implementation of Secured Car Parking Management System Using Verilog HDL

    Directory of Open Access Journals (Sweden)

    Bhavana CHENDIKA

    2015-07-01

    Full Text Available Present days usage of motor vehicles are increased day by day, it causes the pollution, traffic congestion and parking place problems. In this paper we proposed a secured car parking management system using Verilog HDL. This system has two main modules Module-1: Slot identification for parking and LCD display screens, Module-2: Security indicator will provide security to the car, if unauthorized person want to vacant the car. These modules are modeled in Verilog HDL and implemented on FPGA.

  3. SOME ASPECTS OF MOTOR CAR COERCION COEFFICIENT DETERMINATION

    Directory of Open Access Journals (Sweden)

    О. Denysenko

    2010-01-01

    Full Text Available A short review of motor car coercion coefficient determination is presented. The models designed for the determination of motor car queues time intervals at the stop line is presented. The estimation of modeling results according to experimental data is carried out.

  4. SOME ASPECTS OF MOTOR CAR COERCION COEFFICIENT DETERMINATION

    OpenAIRE

    О. Denysenko; A. Filimonova

    2010-01-01

    A short review of motor car coercion coefficient determination is presented. The models designed for the determination of motor car queues time intervals at the stop line is presented. The estimation of modeling results according to experimental data is carried out.

  5. Prejudice and Race Relations.

    Science.gov (United States)

    Mack, Raymond W., Ed.

    Contents of this book comprises: Introduction--A decade of change; (1) Race and its consequences: Beliefs and acts; (2) Race relations in different societies: A comparative perspective; (3) Implementing discrimination: the institutional impact of prejudice; (4) Leaders in change: A set of profiles; and (5) Options facing Americans: Pathos to…

  6. Testing the race inequality

    DEFF Research Database (Denmark)

    Gondan, Matthias; Heckel, A.

    2008-01-01

    In speeded response tasks with redundant signals, parallel processing of the redundant signals is generally tested using the so-called race inequality. The race inequality states that the distribution of fast responses for a redundant stimulus never exceeds the summed distributions of fast...

  7. The Amazing Mathematical Race

    Science.gov (United States)

    Noblitt, Bethany A.; Buckley, Brooke E.

    2011-01-01

    Teams, pit stops, clues, time limits, fast forwards, challenges, and prizes are all components of the CBS hit show "The Amazing Race." They were also elements of the Amazing Mathematical Race sponsored by the Math and Stats Club at Northern Kentucky University in April 2009. Held in recognition of Math Awareness Month, which is advocated…

  8. The Kinesiology of Race

    Science.gov (United States)

    McAfee, Myosha

    2014-01-01

    In this research article, Myosha McAfee presents findings from her grounded theory and microethnographical study of math instruction in a racially and socioeconomically diverse public school. Her analysis puts forth a new theory-the kinesiology of race-which conceptualizes race as a verb rather than a noun. It centrally considers how racial…

  9. Study on behavior of car and driver in the very small commuter car made of FRP during collision using scale model. Under the consideration of thorax deformation of driver using airbag; FRP sei mokei ni yoru FRP sei chokeiryo jissha shototsuji no kuruma to join no anzensei ni kansuru kenkyu. Kyobu henkei tokusei wo yusuru join ni taisuru air gab no koka

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, H.; Morisawa, M.; Yoshino, T. [Musashi Institute of Technology, Tokyo (Japan); Sato, T. [Keio University, Tokyo (Japan); Ishizuki, H. [Satake Co., Tokyo (Japan)

    1997-10-01

    In this study, after having performed simulation which took up scale models substituting for full scale model of commuter car made of FRP, we carried out collision tests to barrier. Here, we made enquiries about the occupant safety by changing the collision speed and the deformation characteristics of the seat belt, during head-on barrier collision using one-fifth scale models. We sought for the occupant`s safe combinations among the deformation characteristics of airbag and the thorax deformation. In this case, the degree of the occupants injury were estimated using HIC values, 3msecG and maximum deformation of the thorax. 7 refs., 5 figs.

  10. Our Car as Power Plant

    NARCIS (Netherlands)

    Van Wijk, A.J.M.; Verhoef, L.

    2014-01-01

    Fuel cell cars can provide more efficient and cleaner transportation. However, we use our cars for transportation only 5% of the time. When parked, the fuel cell in the car can produce electricity from hydrogen, which is cleaner and more efficient than the current electricity system, generating usef

  11. Our Car as Power Plant

    NARCIS (Netherlands)

    Van Wijk, A.J.M.; Verhoef, L.

    2014-01-01

    Fuel cell cars can provide more efficient and cleaner transportation. However, we use our cars for transportation only 5% of the time. When parked, the fuel cell in the car can produce electricity from hydrogen, which is cleaner and more efficient than the current electricity system, generating

  12. Car boots: layers and drawers

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The car boot of practically any car appears to be pretty low on the list of items the manufacturer considers important.The world of glossy, state of the art and high-tech design seems to come to a halt behind the rear seat. Designers at Audi, the German car manufacturers, were well aware that this p

  13. Car boots: layers and drawers

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The car boot of practically any car appears to be pretty low on the list of items the manufacturer considers important.The world of glossy, state of the art and high-tech design seems to come to a halt behind the rear seat. Designers at Audi, the German car manufacturers, were well aware that this p

  14. DOES ELECTRIC CAR PRODUCE EMISSIONS?

    Directory of Open Access Journals (Sweden)

    Vladimír RIEVAJ

    2017-03-01

    Full Text Available This article focuses on the comparison of the amount of emissions produced by vehicles with a combustion engine and electric cars. The comparison, which is based on the LCA factor results, indicates that an electric car produces more emissions than a vehicle with combustion engine. The implementation of electric cars will lead to an increase in the production of greenhouse gases.

  15. Compatibility optimization of passenger cars

    NARCIS (Netherlands)

    Nastic, T.; Schoofs, A.J.G.; Mooi, H.G.

    1999-01-01

    Nowadays traffic safety and occupant protection get a lot of attention due to the large number of fatalities and injuries in car accidents. The occupant protection in two-vehicle crashes can be improved by car-to-car compatibility, which means well balanced crashworthiness characteristics of both

  16. Design optimization for car compatibility

    NARCIS (Netherlands)

    Nastic, T.; Schoofs, A.J.G.; Mooi, H.G.

    1999-01-01

    Nowadays traffic safety and occupant protection get a lot of attention due to the large number of fatalities and injuries in car accidents. The occupant protection in two-vehicle crashes can be improved by car-to-car compatibility, which means well balanced crashworthiness characteristics of both

  17. Car boots: layers and drawers

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The car boot of practically any car appears to be pretty low on the list of items the manufacturer considers important.The world of glossy, state of the art and high-tech design seems to come to a halt behind the rear seat. Designers at Audi, the German car manufacturers, were well aware that this

  18. ADULTEROUS BEHAVIOUR WITHIN THE CAR-OWNER COUPLE

    Directory of Open Access Journals (Sweden)

    Francis PAPON

    2008-01-01

    Full Text Available The objective of this paper was to analyse two activities: who rents a car and why? Which households share the driving of their cars? In order to do that, the Parc-Auto (Car-Fleet database, built from annual postal surveys conducted with a panel of 10,000 French households, has been processed. Among approximately one hundred questions in the survey, two key questions have been crossed against many social, economic, demographic, geographic or time variables. KQ1: “During the last 12 months, did you — or another person from your home — rent a car in France for personal purposes?” KQ2: “Is this car occasionally used by other persons?” Here are the main findings. Renting households are mainly working, high income households, living in the core of big cities, and in particular in Paris. Most of them have two wage-sheets and two cars, one of which is generally a recent, high power, high quality car. Car rental is mainly an occasional practice. Yet for a minority of renters, it is a sustained habit. Households with more licence holders than cars share the most: about three quarters of them share their cars. On the contrary, single driver-single car households have less opportunity to share: only 15% share. Household car sharing shed light on the gender role within households: while 58% of the main users of the shared cars are male, 55% of secondary users are female. Household car sharing is mainly a regular practice. Finally, without diminishing the merits of innovative transport solutions proposed here and there, it is not a waste of time to give some insight on self established behaviour within households. This reveals that complex patterns have been built over time by the people themselves, to cope with diverse situations that cannot be easily handled by straightforward classifications. The car cannot be reduced to a personal object. Household car sharing also carries strong links with the issue of car dependency. Sifting car

  19. Substitution between Cars within the Household

    DEFF Research Database (Denmark)

    de Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    , respectively. When we do take into account the substitution effect, these figures reduce to, respectively, -0.32 and -0.45. We further estimate an alternative version of the model to test the hypothesis that substitution in response to higher fuel prices will be predominantly from the least to the most fuel...... efficient car, finding partial support for the underlying hypothesis. More importantly, the results of this extended model emphasize the importance of behavioural differences related to the position of the most fuel efficient car in the household, suggesting that households’ fuel efficiency choices...

  20. 基于Benchmarking技术的汽车侧面碰撞建模与仿真试验%Modeling and Simulation Test of Car Side Impact Based on Benchmarking Technology

    Institute of Scientific and Technical Information of China (English)

    徐中明; 张亮; 范体强; 赵清江

    2012-01-01

    介绍了Benchmarking技术的概念和基本工作流程,并根据某车型所进行的Benchmarking数据,建立了包括车身结构、发动机和底盘系统在内的整车有限元分析模型.根据ECE R95法规进行了整车侧面碰撞仿真试验,通过对比仿真试验的结果与实车侧面碰撞试验的结果,验证了模型的有效性.本文的研究方法为Benchmarking技术在汽车碰撞安全分析上的应用提供了参考.%The concept and working process of benchmarking technology are introduced. According to a car benchmarking data,the finite element analysis model of a full-scale passenger car is developed, including body structure, engine and chassis system. Subsequently, the simulation test of the car side impact is conducted according to ECE R95 regulation. And the model is verified by comparing the results of simulation and test, reference of using benchmarking technology in the car crash safety analysis is provided by this research method.