At the stage of preliminary scheme and algorithm design for spaceborne navigation systems, a precise and high-fidelity software global positioning system （GPS） simulator is a necessary and feasible testing facility ...At the stage of preliminary scheme and algorithm design for spaceborne navigation systems, a precise and high-fidelity software global positioning system （GPS） simulator is a necessary and feasible testing facility in laboratory environments, with consideration of the tradeoffs where possible. This article presents a software GPS measurements simulator on the L1 C/A code and carrier signal for space-oriented navigation system design. The simulator, coded in MATLAB language, generates both C/A code pseudorange and carrier phase measurements. Mathematical models in the Earth centered inertial （ECI） frame are formulated to simulate the GPS constellation and to generate GPS measurements. A series of efficient measures are investigated and utilized to rationalize the enhanced simulator, in terms of ephemeris data selection, space ionospheric model and range rate calculation, etc. Such an enhanced simulator has been facilitating our current work for designing a space integrated GPS/inertial navigation system （INS） navigation system. Consequently, it will promote our future research on space-oriented navigation system.展开更多
This paper establishes a very important scientific solution to science of complexity for physicists, and presents a multidisciplinary involved physics and engineering. The innovative solution for complex systems prese...This paper establishes a very important scientific solution to science of complexity for physicists, and presents a multidisciplinary involved physics and engineering. The innovative solution for complex systems presented here is verified on the basis of principles in engineering such as feed-back-system analysis using the classical control theory. This paper proposes that a complex system is a closed-loop system with a negative feedback element and is a solvable problem. A complex system can be analyzed using the system analysis theory in control engineering, and its behavior can be realized using a specially designed simulator.展开更多
This paper provides a clarification of the advanced solution for the mission of complexity in science, which was previously published in 2015;but the new solution is too difficult to scientists;for this, this paper de...This paper provides a clarification of the advanced solution for the mission of complexity in science, which was previously published in 2015;but the new solution is too difficult to scientists;for this, this paper describes the academic reasoning and the relevant scientific background behind solution. Moreover, it shows that the solution can be simulated the complex systems by the computer program MATLAB Simulink or an analog-type simulator under virtual circumstances. Thus, this paper verifies that the new solution has validity and superiority;additionally, it must replace the established older chaos theory with the advanced solution in future, so that this new solution is disadvantageous to many chaos physicists and the famous organization SFI, and others. However, they must suspend their work on complexity, because the complexity is a solvable problem in science.展开更多
Modern science has solved the systematic dynamic problems involving complexity such as complex systems by logical solution algebraically such as the old chaos theory derived from algebraic statistics based on determin...Modern science has solved the systematic dynamic problems involving complexity such as complex systems by logical solution algebraically such as the old chaos theory derived from algebraic statistics based on determinism. It is very vague and difficult for us. Moreover, modern science treats systems dynamic problems as logical static problems according to determinism. However, this study proposes a novel solution for systematic problems, it is accomplished by systems analysis theory based on a third science (indeterminism) as it is more precise and easier to understand compared to chaos theory. Furthermore, it is suitable for non-physicists, because it is supported by computer simulations without any mathematical processing. Thus, it can be solved especially regressive systems solution. Therefore, this provided an innovative scientific result to non-physicists for their unsolved systematic problems in modern science.展开更多
This paper presents an innovative solution regarding complex systems to scientists, and prepares a novel system simulator for complex systems. A complex system in nature is not a black box but a solvable systematic pr...This paper presents an innovative solution regarding complex systems to scientists, and prepares a novel system simulator for complex systems. A complex system in nature is not a black box but a solvable systematic problem. The solution is not derived from conventional physics based on reductionism, but rather from engineering sciences such as the feedback systems analysis method and engineering principles. Furthermore, this paper presents the conception of the solution to scientists for solving the problem. Moreover, nobody can doubt this research based on simulator. Complex systems are not mysterious science and not black box.展开更多
This paper sums up the research situation. At the influence of friction, a simulator exists the phenomenon of low-speed stick-slip. The character of low-speed of simulator is affected seriously. According to the phase...This paper sums up the research situation. At the influence of friction, a simulator exists the phenomenon of low-speed stick-slip. The character of low-speed of simulator is affected seriously. According to the phase plane method, algebra analyzing method and Lyapunov theory, the paper gives a criterion about overcoming low-speed stick-slip. Making use of the criterion, we can conclude the relationship between system parameters and low-speed stick-slip, and determine the condition where the parameters of PID controller should satisfy, for the purpose of overcoming low-speed stick-slip and has not the phenomenon of low-speed stick-slip. This method is simple and easy to carry out and the experiments show that the condition is correct.展开更多
It is difficult to model human behavior because of the variability in driving styles and driving skills. However, for some driver assistance systems, it is necessary to have knowledge of that behavior to discriminate ...It is difficult to model human behavior because of the variability in driving styles and driving skills. However, for some driver assistance systems, it is necessary to have knowledge of that behavior to discriminate potentially hazardous situations, such as distraction, fatigue or drowsiness. Many of the systems that look for driver distraction or drowsiness are based on intrusive means （analysis of the electroencephalogram--EEG） or highly sensitive to operating conditions and expensive equipment （eye movements analysis through artificial vision）. A solution that seeks to avoid the above drawbacks is the use of driving parameters This article presents the conclusions obtained after a set of driving simulator tests with professional drivers with two main objectives using driving variables such as speed profile, steering wheel angle, transversal position on the lane, safety distance, etc., that are available in a non-intrusive way： （1） To analyze the differences between the driving patterns of individual drivers; and （2） To analyze the effect of distraction and drowsiness on these parameters. Different scenarios have been designed, including sequences with distractions and situations that cause fatigue. The analysis of the results is carried out in time and frequency domains in order to identify situations of loss of attention and to study whether the evolution of the analyzed variables along the time could be considered independent of the driver.展开更多
籽粒蛋白质积累过程的准确模拟对黄土丘陵区旱地小麦优质生产的有效调控有重要意义。利用甘肃省定西市安定区凤翔镇安家沟村2016-2017年大田试验数据及定西市安定区1971-2017年气象资料,建立基于APSIM(agricultural production systems ...籽粒蛋白质积累过程的准确模拟对黄土丘陵区旱地小麦优质生产的有效调控有重要意义。利用甘肃省定西市安定区凤翔镇安家沟村2016-2017年大田试验数据及定西市安定区1971-2017年气象资料,建立基于APSIM(agricultural production systems simulator)的旱地小麦籽粒蛋白质含量模型,采用相关性分析方法检验,并定量分析了耕作方式(传统耕作、传统耕作+秸秆覆盖、免耕及免耕+秸秆覆盖)和播期(正常播期、早播、晚播)对小麦籽粒蛋白质含量的影响。结果表明:3个播期处理和4种耕作方式下,产量和籽粒蛋白质含量模拟值和观测值之间的均方根误差(RMSE)分别为66.4~121.9 kg·hm-2和0.2%~1.1%;归一化均方根误差(NRMSE)分别为1.23%~9.66%和1.31%~9.94%,模型模拟精度较高。播期对旱地小麦籽粒蛋白质含量的影响显著,正常播期的蛋白质含量最高,晚播明显降低了蛋白质含量。4种耕作方式的小麦产量与籽粒蛋白质含量均呈开口向下的二次曲线关系,随着蛋白质含量的升高,产量呈先增加后减少的态势,经过秸秆覆盖的耕作方式(传统耕作+秸秆覆盖和免耕+秸秆覆盖)比不覆盖的耕作方式(传统耕作和免耕)更利于小麦籽粒蛋白质含量的提高。展开更多
基金Research Fund of Shanghai Academy of Spaceflight Technology
文摘At the stage of preliminary scheme and algorithm design for spaceborne navigation systems, a precise and high-fidelity software global positioning system （GPS） simulator is a necessary and feasible testing facility in laboratory environments, with consideration of the tradeoffs where possible. This article presents a software GPS measurements simulator on the L1 C/A code and carrier signal for space-oriented navigation system design. The simulator, coded in MATLAB language, generates both C/A code pseudorange and carrier phase measurements. Mathematical models in the Earth centered inertial （ECI） frame are formulated to simulate the GPS constellation and to generate GPS measurements. A series of efficient measures are investigated and utilized to rationalize the enhanced simulator, in terms of ephemeris data selection, space ionospheric model and range rate calculation, etc. Such an enhanced simulator has been facilitating our current work for designing a space integrated GPS/inertial navigation system （INS） navigation system. Consequently, it will promote our future research on space-oriented navigation system.
文摘This paper establishes a very important scientific solution to science of complexity for physicists, and presents a multidisciplinary involved physics and engineering. The innovative solution for complex systems presented here is verified on the basis of principles in engineering such as feed-back-system analysis using the classical control theory. This paper proposes that a complex system is a closed-loop system with a negative feedback element and is a solvable problem. A complex system can be analyzed using the system analysis theory in control engineering, and its behavior can be realized using a specially designed simulator.
文摘This paper provides a clarification of the advanced solution for the mission of complexity in science, which was previously published in 2015;but the new solution is too difficult to scientists;for this, this paper describes the academic reasoning and the relevant scientific background behind solution. Moreover, it shows that the solution can be simulated the complex systems by the computer program MATLAB Simulink or an analog-type simulator under virtual circumstances. Thus, this paper verifies that the new solution has validity and superiority;additionally, it must replace the established older chaos theory with the advanced solution in future, so that this new solution is disadvantageous to many chaos physicists and the famous organization SFI, and others. However, they must suspend their work on complexity, because the complexity is a solvable problem in science.
文摘Modern science has solved the systematic dynamic problems involving complexity such as complex systems by logical solution algebraically such as the old chaos theory derived from algebraic statistics based on determinism. It is very vague and difficult for us. Moreover, modern science treats systems dynamic problems as logical static problems according to determinism. However, this study proposes a novel solution for systematic problems, it is accomplished by systems analysis theory based on a third science (indeterminism) as it is more precise and easier to understand compared to chaos theory. Furthermore, it is suitable for non-physicists, because it is supported by computer simulations without any mathematical processing. Thus, it can be solved especially regressive systems solution. Therefore, this provided an innovative scientific result to non-physicists for their unsolved systematic problems in modern science.
文摘This paper presents an innovative solution regarding complex systems to scientists, and prepares a novel system simulator for complex systems. A complex system in nature is not a black box but a solvable systematic problem. The solution is not derived from conventional physics based on reductionism, but rather from engineering sciences such as the feedback systems analysis method and engineering principles. Furthermore, this paper presents the conception of the solution to scientists for solving the problem. Moreover, nobody can doubt this research based on simulator. Complex systems are not mysterious science and not black box.
基金This project was supported by the National Fund of Defense Pre research.
文摘This paper sums up the research situation. At the influence of friction, a simulator exists the phenomenon of low-speed stick-slip. The character of low-speed of simulator is affected seriously. According to the phase plane method, algebra analyzing method and Lyapunov theory, the paper gives a criterion about overcoming low-speed stick-slip. Making use of the criterion, we can conclude the relationship between system parameters and low-speed stick-slip, and determine the condition where the parameters of PID controller should satisfy, for the purpose of overcoming low-speed stick-slip and has not the phenomenon of low-speed stick-slip. This method is simple and easy to carry out and the experiments show that the condition is correct.
文摘It is difficult to model human behavior because of the variability in driving styles and driving skills. However, for some driver assistance systems, it is necessary to have knowledge of that behavior to discriminate potentially hazardous situations, such as distraction, fatigue or drowsiness. Many of the systems that look for driver distraction or drowsiness are based on intrusive means （analysis of the electroencephalogram--EEG） or highly sensitive to operating conditions and expensive equipment （eye movements analysis through artificial vision）. A solution that seeks to avoid the above drawbacks is the use of driving parameters This article presents the conclusions obtained after a set of driving simulator tests with professional drivers with two main objectives using driving variables such as speed profile, steering wheel angle, transversal position on the lane, safety distance, etc., that are available in a non-intrusive way： （1） To analyze the differences between the driving patterns of individual drivers; and （2） To analyze the effect of distraction and drowsiness on these parameters. Different scenarios have been designed, including sequences with distractions and situations that cause fatigue. The analysis of the results is carried out in time and frequency domains in order to identify situations of loss of attention and to study whether the evolution of the analyzed variables along the time could be considered independent of the driver.
文摘籽粒蛋白质积累过程的准确模拟对黄土丘陵区旱地小麦优质生产的有效调控有重要意义。利用甘肃省定西市安定区凤翔镇安家沟村2016-2017年大田试验数据及定西市安定区1971-2017年气象资料,建立基于APSIM(agricultural production systems simulator)的旱地小麦籽粒蛋白质含量模型,采用相关性分析方法检验,并定量分析了耕作方式(传统耕作、传统耕作+秸秆覆盖、免耕及免耕+秸秆覆盖)和播期(正常播期、早播、晚播)对小麦籽粒蛋白质含量的影响。结果表明:3个播期处理和4种耕作方式下,产量和籽粒蛋白质含量模拟值和观测值之间的均方根误差(RMSE)分别为66.4~121.9 kg·hm-2和0.2%~1.1%;归一化均方根误差(NRMSE)分别为1.23%~9.66%和1.31%~9.94%,模型模拟精度较高。播期对旱地小麦籽粒蛋白质含量的影响显著,正常播期的蛋白质含量最高,晚播明显降低了蛋白质含量。4种耕作方式的小麦产量与籽粒蛋白质含量均呈开口向下的二次曲线关系,随着蛋白质含量的升高,产量呈先增加后减少的态势,经过秸秆覆盖的耕作方式(传统耕作+秸秆覆盖和免耕+秸秆覆盖)比不覆盖的耕作方式(传统耕作和免耕)更利于小麦籽粒蛋白质含量的提高。
