A method of combining the valve system program with the engine cycle modeling software to form a full set of working process modeling is submitted,not only considering the system as an independent part,but also as a p...A method of combining the valve system program with the engine cycle modeling software to form a full set of working process modeling is submitted,not only considering the system as an independent part,but also as a part of working process to evaluate comprehensively and indicate directly if the design is good or not.The designers can optimize the design by changing the engine structure,operation and the basic parameters of the cam on condition that the sysem should be stable so as to save large amounts of time and cost.Practical examples show that such a software package is an effective tool in optimizing the valve systems and performance of the machine.展开更多
The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarde...The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarded as control objectives,is used to establish the statistical model.The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data.The percentages of absolute relative error(below 15%,20%,30%) are 44.4%,66.7%,100%(turbidity) and 33.3%,44.4%,77.8%(Fe) on the 4th sampling point;77.8%,88.9%,88.9%(turbidity) and 44.4%,55.6%,66.7%(Fe) on the 5th sampling point.展开更多
A protection system using a multi-agent concept for power distribution networks is proposed.Every digital over current relay(OCR)is developed as an agent by adding its own intelligence,self-tuning and communication ab...A protection system using a multi-agent concept for power distribution networks is proposed.Every digital over current relay(OCR)is developed as an agent by adding its own intelligence,self-tuning and communication ability.The main advantage of the multi-agent concept is that a group of agents work together to achieve a global goal which is beyond the ability of each individual agent.In order to cope with frequent changes in the network operation condition and faults,an OCR agent,proposed in this paper,is able to detect a fault or a change in the network and find its optimal parameters for protection in an autonomous manner considering information of the whole network obtained by communication between other agents.Through this kind of coordination and information exchanges,not only a local but also a global protective scheme is completed.Simulations in a simple distribution network show the effectiveness of the proposed protection system.展开更多
In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed, accordin...In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed, according to the fact that the light of coal mine is uneven, the strength of light changes greatly, the direction of belt movement is constant, and the position of camera was fixed, various algorithms of speed measurement by video were studied, and algorithm for template matching based on sum of absolute differences (SAD) and correlation coefficient was proposed and improved, besides, the tracking of feature regions was realized. Then, a camera calibration method using the invariance of the cross-ratio was adopted and the real-time measurement of belt speed by the hardware platform based on DM642 was realized. Finally, experiment results show that this method not only has advantages of high precision and strong anti-jamming capability but also can real-time reflect the changes of belt speed, so it has a comprehensive applicability.展开更多
This paper investigates the achievable uplink spectral efficiency(SE) of a massive multi-input multi-output(MIMO) system with a mixed analog-to-digital converter(ADC) receiver architecture, in which some antennas are ...This paper investigates the achievable uplink spectral efficiency(SE) of a massive multi-input multi-output(MIMO) system with a mixed analog-to-digital converter(ADC) receiver architecture, in which some antennas are equipped with full-resolution ADCs while others are deployed with low-resolution ADCs. We derive the theoretical results and corresponding approximate expressions of the achievable SE in multi-cell systems with maximum ratio combining(MRC) detector and in single-cell systems with zero-forcing(ZF) detector. Based on approximated results, the effects of physical parameters, including the transmit power, the number of antennas, the proportion of full-resolution ADCs and the quantization precision of the low-resolution ADCs on the achievable SE are revealed. Furthermore, we propose the power allocation algorithms based on the lower bound and upper bound of approximate achievable SE. Our results show that the total achievable SE improves by increasing the number of BS antennas, the signal-to-noise ratio(SNR), and the quantization precision. Results showcase that proposed power allocation algorithms remarkably improve the total achievable SE comparing to the equal power allocation algorithm, which verifies the effectiveness of our proposed schemes.展开更多
Discrete-event system simulation technology is used to analyze distribution system reliability in this paper. A simulation model, including entity state models, system state models, state transition models, reliabilit...Discrete-event system simulation technology is used to analyze distribution system reliability in this paper. A simulation model, including entity state models, system state models, state transition models, reliability criterion model, is established. ‘Next happen event’ is taken as impulse principle of simulator clock to determine the sequence of random event occurrence dynamically. The results show this method is feasible.展开更多
This paper presents a two-agent framework to build a natural langua g e query interface for IC information system, focusing more on scope queries in a single English sentence. The first agent, parsing agent, syntact...This paper presents a two-agent framework to build a natural langua g e query interface for IC information system, focusing more on scope queries in a single English sentence. The first agent, parsing agent, syntactically p rocesses and semantically interprets natural language sentence to construct a fu zzy structured query language (SQL) statement. The second agent, defuzzif ying agent, defuzzifies the imprecise part of the fuzzy SQL statement into its e quivalent executable precise SQL statement based on fuzzy rules. The first agent can also actively ask the user some necessary questions when it manages to disa mbiguate the vague retrieval requirements. The adaptive defuzzification approach employed in the defuzzifying agent is discussed in detail. A prototype interface has been implemented to demonstrate the effectiveness.展开更多
This paper presents a scenario of forest fire suppression using UAVs (Unmanned Aerial Vehicles) and addresses task assignment algorithm to coordinate UAVs. Forest fires are a major problem in many nations and fast e...This paper presents a scenario of forest fire suppression using UAVs (Unmanned Aerial Vehicles) and addresses task assignment algorithm to coordinate UAVs. Forest fires are a major problem in many nations and fast extinguishing forest fires brings a lot of ecological advantages so proper use of firefighting resources is very critical. In this sense, multi UAVs forest fire suppression system can be effective way to prevent fire outbreaks. In multi agent system, an appropriate task assignment according to the SA (Situational Awareness) is the most essential to conduct mission. We should consider real time re-planning or re-scheduling of multi UAVs team because environmental situations such as wind are changeable and that changes affect the forest fire spreading. Furthermore, we have to think about convergence to a consistent SA because it may take too much time. CBBA (Consensus-Based Bundle Algorithm) is robust decentralized task assignment tool so it can be implemented in real time re-planning application. A simulation model which is the main topic in this paper shows that multi UAVs can be properly operated to suppress forest fires even if there are unpredictable random factors and partial disconnection. The simulation model includes concrete operating scenarios and recursive task re-assign algorithm until fires in the whole area are suppressed.展开更多
The paper presents a technical solution which provides energy saving at full speed, as well as duplication of screw propeller and main propulsion system incase it's out of order. The description of the corresponding ...The paper presents a technical solution which provides energy saving at full speed, as well as duplication of screw propeller and main propulsion system incase it's out of order. The description of the corresponding device, designed for transport refrigerator ship, is shown as well as its location on board. Value of energy saving from the use of contra propeller is estimated. The results of the assessment required power to move the ship at low speed by the action of the contra propeller operating in the reactive mode are demonstrated. It is shown, that the ship equipped with the proposed device will get the additional class notation related to the redundancy or duplication of the propulsion system of Russian Maritime Register of Shipping.展开更多
A diagnostic signal current trace detecting based single phase-to-ground fault line identifica- tion and section location method for non-effectively grounded distribution systems is presented in this paper.A special d...A diagnostic signal current trace detecting based single phase-to-ground fault line identifica- tion and section location method for non-effectively grounded distribution systems is presented in this paper.A special diagnostic signal current is injected into the fault distribution system,and then it is detected at the outlet terminals to identify the fault line and at the sectionalizing or branching point along the fault line to locate the fault section.The method has been put into application in actual distribution network and field experience shows that it can identify the fault line and locate the fault section correctly and effectively.展开更多
A color based system using multiple templates was developed and implem ented for detecting human faces in color images. The algorithm consists of three image processing steps. The first step is human skin color stati...A color based system using multiple templates was developed and implem ented for detecting human faces in color images. The algorithm consists of three image processing steps. The first step is human skin color statistics. Then it separates skin regions from non-skin regions. After that, it locates the fronta l human face(s) within the skin regions. In the first step, 250 skin samples from persons of different ethnicities are used to determine the color distribution o f human skin in chromatic color space in order to get a chroma chart showing lik elihoods of skin colors. This chroma chart is used to generate, from the origina l color image, a gray scale image whose gray value at a pixel shows its likelih ood of representing the skin. The algorithm uses an adaptive thresholding proces s to achieve the optimal threshold value for dividing the gray scale image into separate skin regions from non skin regions. Finally, multiple face templates ma tching is used to determine if a given skin region represents a frontal human fa ce or not. Test of the system with more than 400 color images showed that the re sulting detection rate was 83%, which is better than most color-based face dete c tion systems. The average speed for face detection is 0.8 second/image (400×300 pixels) on a Pentium 3 (800MHz) PC.展开更多
The development of the assistive abilities regarding the decision-making process o fan Intelligent Control System (ICS) like a fuzzy expert system implies the development of its functionality and its ability of spec...The development of the assistive abilities regarding the decision-making process o fan Intelligent Control System (ICS) like a fuzzy expert system implies the development of its functionality and its ability of specification. Fuzzy expert systems can model fuzzy controllers, i.e., the knowledge representation and the abilities of making decisions corresponding to fuzzy expert systems are much more complicated that in the case of standard fuzzy controllers. The expert system acts also as a supervisor, creating meta-level reasoning on a set of fuzzy controllers, in order to choose the best one for the management of the process. Knowledge Management Systems (KMSs) is a new development paradigm of Intelligent Systems which has resulted from a synergy between fuzzy sets, artificial neural networks, evolutionary computation, machine learning, etc., broadening computer science, physics, economics, engineering, mathematics. This paper presents, after a synergic new paradigm of intelligent systems, as a practical case study the fuzzy and temporal properties of knowledge formalism embedded in an ICS. We are not dealing high with level reasoning methods, because we think that real-time problems can only be solved by rather low-level reasoning. Solving the match-time predictability problem would allow us to build much more powerful reasoning techniques.展开更多
Being a safe and highly-efficient mining method, fully mechanized mining with sublevel caving (FMMSC) was extensively employed in Chinese coal mines with thick seam. In order to make drawing top-coal furthest to par...Being a safe and highly-efficient mining method, fully mechanized mining with sublevel caving (FMMSC) was extensively employed in Chinese coal mines with thick seam. In order to make drawing top-coal furthest to parallel work with shearer cutting coal, decrease failure ratio of rear scraper conveyor and increase safe production capacity of equipments, based on production technology, set up the mating model of safe production capacity of equipments for the system of drawing top-coal and shearer cutting coal in coal face with sublevel caving. It is mean capability of drawing top-coal adapted to the capability of shearer cutting coal in a working circle in the coal face that was deduced. The type selection of equipment of rear scraper conveyor can be tackled with this mating model. The model was applied in FMMSC in Yangcun Coal Mine, Yima Coal Group of China. With the mating light-equipments, the coal output in coal face attained 1.05 Mt in 2004. It gained better technical-economic benefit.展开更多
Nowadays, in a household PV (photovoltaic) generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wron...Nowadays, in a household PV (photovoltaic) generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wrong MPPT (maximum power point tracking) to all modules and a power decreasing of the whole system. Aiming at this problem, this paper presents the idea which improves the MPPT without changing the conventional power-conditioner, by adding a Buck type DC-DC (direct current) converter behind each module. Simulations of PSIM (power simulation) and experiments are taken to prove this theory. The result shows that, by this idea, the generated power of the conventional PV generation system can be greatly increased under the condition of mismatch.展开更多
With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal speci...With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal specification and model finding techniques.In this paper,we pay more attention to formal specifications of network information,i.e.,exploring principles and algorithm to map network information(topology,devices and status,etc.) to Alloy specifications.We first model network information in relational form,which is easy to realize because of the structured feature of network information in nature.Then we map the relational data to Alloy specifications according to our novel data mapping principles and algorithm.Based on the transition of relational data,it is possible to automatically map network information to Alloy specifications.We evaluate our data mapping principles and algorithm by applying them to a practical application scenario.The results illustrate that we can find a model for the task within a tolerant time interval,which implies that our novel approach can convert relational data to Alloy specifications correctly and efficiently.展开更多
The allocation of control and stock in venture capital is the key point of the venture capital project.This paper develops a dynamic model of control and stock and profoundly analyses how to allocate the control betwe...The allocation of control and stock in venture capital is the key point of the venture capital project.This paper develops a dynamic model of control and stock and profoundly analyses how to allocate the control between the entrepreneur and the venture capitalist.The model reveals the relationship of control and stock's structure,the time and the degree of imparting the control to the entrepreneur or the venture capitalist,the condition of retracting the control and compensation accordingly.展开更多
The paper presents a preview controller design for ATS (active trailer steering) systems to improve high-speed stability of AHVs (articulated heavy vehicles). An AHV consists of a towing unit, namely tractor or tr...The paper presents a preview controller design for ATS (active trailer steering) systems to improve high-speed stability of AHVs (articulated heavy vehicles). An AHV consists of a towing unit, namely tractor or truck, and one or more towed units which called trailers. Individual units are connected to one another at articulated joints by mechanical couplings. Due to the multi-unit configurations, AHVs exhibit unique unstable motion modes, including jack-knifing, trailer swing and rollover. These unstable motion modes are the leading cause of highway accidents. To prevent these unstable motion modes, the preview controller, namely the LPDP (lateral position deviation preview) controller, is proposed. For a truck/full-trailer combination, the LPDP controller is designed to control the steering of the front and rear axle wheels of the trailing unit. The calculation of the corrective steering angle of the trailer front axle wheels is based on the preview information of the lateral position deviation of the trajectory of the axle center from that of the truck front axle center. Similarly, the steering angle of the trailer rear axle wheels is calculated by using the lateral position deviation of the trajectory of the axle center from that of the truck front axle. To perform closed-loop dynamic simulations and evaluate the vehicle performance measure, a driver model is introduced and it 'derives' the AHV model based on well-defined testing specifications. The proposed preview control scheme in the continuous time domain is developed by using the LQR (linear quadratic regular) technique. The closed-loop simulation results indicate that the performance of the AHV with the LPDP controller is improved by decreasing rearward amplification ratio from the baseline value of 1.28 to 0.98 and reducing transient off-tracking by 95.03%. The proposed LPDP control algorithm provides an alternative method for the design optimization of AHVs with ATS systems.展开更多
The CIM (common information model) is an abstract information model that can be used to model an electrical network and various equipments used on the network. By using a common model, utilities and vendors can redu...The CIM (common information model) is an abstract information model that can be used to model an electrical network and various equipments used on the network. By using a common model, utilities and vendors can reduce their integration costs, which should allow more resources to be applied toward increased functionality for managing and optimizing the electrical system. As a part of smart grid, the SPG (smart power grid) was built on Jeju Island. The SPG consists of IDAS (intelligent distribution automation system), substation automation system, intelligent transmission system, and active telemetrics system. To integrate these systems which have different operating systems and platforms CIM standard was used. But IDAS has many functions and advanced algorithms not defined in CIM. In this paper, the authors introduce how to develop and extend the CIM model for managing the IDAS.展开更多
Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for...Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for a rectangular domain that exhibits interesting symmetry properties.We also demonstrate the procedure for performing a center manifold reduction on the system to extract a set of coordinates which capture the long term dynamics when the system is close to a bifurcation.Bifurcations of the system restricted to the center manifold are then classified and compared to numerical results.Although we analyze a specific set-up,these methods can in principle be applied to any bifurcation point of any equilibrium for any domain.展开更多
文摘A method of combining the valve system program with the engine cycle modeling software to form a full set of working process modeling is submitted,not only considering the system as an independent part,but also as a part of working process to evaluate comprehensively and indicate directly if the design is good or not.The designers can optimize the design by changing the engine structure,operation and the basic parameters of the cam on condition that the sysem should be stable so as to save large amounts of time and cost.Practical examples show that such a software package is an effective tool in optimizing the valve systems and performance of the machine.
基金Supported by National Natural Science Foundation of China (No.50478086)Tianjin Special Scientific Innovation Foundation (No.06FZZDSH00900)
文摘The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarded as control objectives,is used to establish the statistical model.The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data.The percentages of absolute relative error(below 15%,20%,30%) are 44.4%,66.7%,100%(turbidity) and 33.3%,44.4%,77.8%(Fe) on the 4th sampling point;77.8%,88.9%,88.9%(turbidity) and 44.4%,55.6%,66.7%(Fe) on the 5th sampling point.
文摘A protection system using a multi-agent concept for power distribution networks is proposed.Every digital over current relay(OCR)is developed as an agent by adding its own intelligence,self-tuning and communication ability.The main advantage of the multi-agent concept is that a group of agents work together to achieve a global goal which is beyond the ability of each individual agent.In order to cope with frequent changes in the network operation condition and faults,an OCR agent,proposed in this paper,is able to detect a fault or a change in the network and find its optimal parameters for protection in an autonomous manner considering information of the whole network obtained by communication between other agents.Through this kind of coordination and information exchanges,not only a local but also a global protective scheme is completed.Simulations in a simple distribution network show the effectiveness of the proposed protection system.
文摘In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed, according to the fact that the light of coal mine is uneven, the strength of light changes greatly, the direction of belt movement is constant, and the position of camera was fixed, various algorithms of speed measurement by video were studied, and algorithm for template matching based on sum of absolute differences (SAD) and correlation coefficient was proposed and improved, besides, the tracking of feature regions was realized. Then, a camera calibration method using the invariance of the cross-ratio was adopted and the real-time measurement of belt speed by the hardware platform based on DM642 was realized. Finally, experiment results show that this method not only has advantages of high precision and strong anti-jamming capability but also can real-time reflect the changes of belt speed, so it has a comprehensive applicability.
基金supported in part by the National Science Foundation(NSFC)for Distinguished Young Scholars of China with Grant 61625106the National Natural Science Foundation of China under Grant 61531011+1 种基金the Hong Kong,Macao and Taiwan Science and Technology Cooperation Program of China(2016YFE0123100)the Guangzhou University project under Grant 27000503123
文摘This paper investigates the achievable uplink spectral efficiency(SE) of a massive multi-input multi-output(MIMO) system with a mixed analog-to-digital converter(ADC) receiver architecture, in which some antennas are equipped with full-resolution ADCs while others are deployed with low-resolution ADCs. We derive the theoretical results and corresponding approximate expressions of the achievable SE in multi-cell systems with maximum ratio combining(MRC) detector and in single-cell systems with zero-forcing(ZF) detector. Based on approximated results, the effects of physical parameters, including the transmit power, the number of antennas, the proportion of full-resolution ADCs and the quantization precision of the low-resolution ADCs on the achievable SE are revealed. Furthermore, we propose the power allocation algorithms based on the lower bound and upper bound of approximate achievable SE. Our results show that the total achievable SE improves by increasing the number of BS antennas, the signal-to-noise ratio(SNR), and the quantization precision. Results showcase that proposed power allocation algorithms remarkably improve the total achievable SE comparing to the equal power allocation algorithm, which verifies the effectiveness of our proposed schemes.
基金SupportedbyNationalNatureScienceFoundation No .5 0 1770 17
文摘Discrete-event system simulation technology is used to analyze distribution system reliability in this paper. A simulation model, including entity state models, system state models, state transition models, reliability criterion model, is established. ‘Next happen event’ is taken as impulse principle of simulator clock to determine the sequence of random event occurrence dynamically. The results show this method is feasible.
文摘This paper presents a two-agent framework to build a natural langua g e query interface for IC information system, focusing more on scope queries in a single English sentence. The first agent, parsing agent, syntactically p rocesses and semantically interprets natural language sentence to construct a fu zzy structured query language (SQL) statement. The second agent, defuzzif ying agent, defuzzifies the imprecise part of the fuzzy SQL statement into its e quivalent executable precise SQL statement based on fuzzy rules. The first agent can also actively ask the user some necessary questions when it manages to disa mbiguate the vague retrieval requirements. The adaptive defuzzification approach employed in the defuzzifying agent is discussed in detail. A prototype interface has been implemented to demonstrate the effectiveness.
文摘This paper presents a scenario of forest fire suppression using UAVs (Unmanned Aerial Vehicles) and addresses task assignment algorithm to coordinate UAVs. Forest fires are a major problem in many nations and fast extinguishing forest fires brings a lot of ecological advantages so proper use of firefighting resources is very critical. In this sense, multi UAVs forest fire suppression system can be effective way to prevent fire outbreaks. In multi agent system, an appropriate task assignment according to the SA (Situational Awareness) is the most essential to conduct mission. We should consider real time re-planning or re-scheduling of multi UAVs team because environmental situations such as wind are changeable and that changes affect the forest fire spreading. Furthermore, we have to think about convergence to a consistent SA because it may take too much time. CBBA (Consensus-Based Bundle Algorithm) is robust decentralized task assignment tool so it can be implemented in real time re-planning application. A simulation model which is the main topic in this paper shows that multi UAVs can be properly operated to suppress forest fires even if there are unpredictable random factors and partial disconnection. The simulation model includes concrete operating scenarios and recursive task re-assign algorithm until fires in the whole area are suppressed.
文摘The paper presents a technical solution which provides energy saving at full speed, as well as duplication of screw propeller and main propulsion system incase it's out of order. The description of the corresponding device, designed for transport refrigerator ship, is shown as well as its location on board. Value of energy saving from the use of contra propeller is estimated. The results of the assessment required power to move the ship at low speed by the action of the contra propeller operating in the reactive mode are demonstrated. It is shown, that the ship equipped with the proposed device will get the additional class notation related to the redundancy or duplication of the propulsion system of Russian Maritime Register of Shipping.
基金Postdoctoral Foundation of China(No.20070410755)PAN Zhencun,born in 1962,male,postdoctor researcher.
文摘A diagnostic signal current trace detecting based single phase-to-ground fault line identifica- tion and section location method for non-effectively grounded distribution systems is presented in this paper.A special diagnostic signal current is injected into the fault distribution system,and then it is detected at the outlet terminals to identify the fault line and at the sectionalizing or branching point along the fault line to locate the fault section.The method has been put into application in actual distribution network and field experience shows that it can identify the fault line and locate the fault section correctly and effectively.
文摘A color based system using multiple templates was developed and implem ented for detecting human faces in color images. The algorithm consists of three image processing steps. The first step is human skin color statistics. Then it separates skin regions from non-skin regions. After that, it locates the fronta l human face(s) within the skin regions. In the first step, 250 skin samples from persons of different ethnicities are used to determine the color distribution o f human skin in chromatic color space in order to get a chroma chart showing lik elihoods of skin colors. This chroma chart is used to generate, from the origina l color image, a gray scale image whose gray value at a pixel shows its likelih ood of representing the skin. The algorithm uses an adaptive thresholding proces s to achieve the optimal threshold value for dividing the gray scale image into separate skin regions from non skin regions. Finally, multiple face templates ma tching is used to determine if a given skin region represents a frontal human fa ce or not. Test of the system with more than 400 color images showed that the re sulting detection rate was 83%, which is better than most color-based face dete c tion systems. The average speed for face detection is 0.8 second/image (400×300 pixels) on a Pentium 3 (800MHz) PC.
文摘The development of the assistive abilities regarding the decision-making process o fan Intelligent Control System (ICS) like a fuzzy expert system implies the development of its functionality and its ability of specification. Fuzzy expert systems can model fuzzy controllers, i.e., the knowledge representation and the abilities of making decisions corresponding to fuzzy expert systems are much more complicated that in the case of standard fuzzy controllers. The expert system acts also as a supervisor, creating meta-level reasoning on a set of fuzzy controllers, in order to choose the best one for the management of the process. Knowledge Management Systems (KMSs) is a new development paradigm of Intelligent Systems which has resulted from a synergy between fuzzy sets, artificial neural networks, evolutionary computation, machine learning, etc., broadening computer science, physics, economics, engineering, mathematics. This paper presents, after a synergic new paradigm of intelligent systems, as a practical case study the fuzzy and temporal properties of knowledge formalism embedded in an ICS. We are not dealing high with level reasoning methods, because we think that real-time problems can only be solved by rather low-level reasoning. Solving the match-time predictability problem would allow us to build much more powerful reasoning techniques.
文摘Being a safe and highly-efficient mining method, fully mechanized mining with sublevel caving (FMMSC) was extensively employed in Chinese coal mines with thick seam. In order to make drawing top-coal furthest to parallel work with shearer cutting coal, decrease failure ratio of rear scraper conveyor and increase safe production capacity of equipments, based on production technology, set up the mating model of safe production capacity of equipments for the system of drawing top-coal and shearer cutting coal in coal face with sublevel caving. It is mean capability of drawing top-coal adapted to the capability of shearer cutting coal in a working circle in the coal face that was deduced. The type selection of equipment of rear scraper conveyor can be tackled with this mating model. The model was applied in FMMSC in Yangcun Coal Mine, Yima Coal Group of China. With the mating light-equipments, the coal output in coal face attained 1.05 Mt in 2004. It gained better technical-economic benefit.
文摘Nowadays, in a household PV (photovoltaic) generation system, it is generally connecting PV modules in series and then output to the power-conditioner. However, when PV modules are mismatched, it will lead to a wrong MPPT (maximum power point tracking) to all modules and a power decreasing of the whole system. Aiming at this problem, this paper presents the idea which improves the MPPT without changing the conventional power-conditioner, by adding a Buck type DC-DC (direct current) converter behind each module. Simulations of PSIM (power simulation) and experiments are taken to prove this theory. The result shows that, by this idea, the generated power of the conventional PV generation system can be greatly increased under the condition of mismatch.
基金supported by the National Science Foundation for Distinguished Young Scholars of China under Grant No.61225012 and No.71325002the Specialized Research Fund of the Doctoral Program of Higher Education for the Priority Development Areas under Grant No.20120042130003the Liaoning BaiQianWan Talents Program under Grant No.2013921068
文摘With the challenges brought by the expansion of network scale,as well as the diversity of the equipments and the complexity of network protocols,many self-configurable systems have been proposed combining formal specification and model finding techniques.In this paper,we pay more attention to formal specifications of network information,i.e.,exploring principles and algorithm to map network information(topology,devices and status,etc.) to Alloy specifications.We first model network information in relational form,which is easy to realize because of the structured feature of network information in nature.Then we map the relational data to Alloy specifications according to our novel data mapping principles and algorithm.Based on the transition of relational data,it is possible to automatically map network information to Alloy specifications.We evaluate our data mapping principles and algorithm by applying them to a practical application scenario.The results illustrate that we can find a model for the task within a tolerant time interval,which implies that our novel approach can convert relational data to Alloy specifications correctly and efficiently.
文摘The allocation of control and stock in venture capital is the key point of the venture capital project.This paper develops a dynamic model of control and stock and profoundly analyses how to allocate the control between the entrepreneur and the venture capitalist.The model reveals the relationship of control and stock's structure,the time and the degree of imparting the control to the entrepreneur or the venture capitalist,the condition of retracting the control and compensation accordingly.
文摘The paper presents a preview controller design for ATS (active trailer steering) systems to improve high-speed stability of AHVs (articulated heavy vehicles). An AHV consists of a towing unit, namely tractor or truck, and one or more towed units which called trailers. Individual units are connected to one another at articulated joints by mechanical couplings. Due to the multi-unit configurations, AHVs exhibit unique unstable motion modes, including jack-knifing, trailer swing and rollover. These unstable motion modes are the leading cause of highway accidents. To prevent these unstable motion modes, the preview controller, namely the LPDP (lateral position deviation preview) controller, is proposed. For a truck/full-trailer combination, the LPDP controller is designed to control the steering of the front and rear axle wheels of the trailing unit. The calculation of the corrective steering angle of the trailer front axle wheels is based on the preview information of the lateral position deviation of the trajectory of the axle center from that of the truck front axle center. Similarly, the steering angle of the trailer rear axle wheels is calculated by using the lateral position deviation of the trajectory of the axle center from that of the truck front axle. To perform closed-loop dynamic simulations and evaluate the vehicle performance measure, a driver model is introduced and it 'derives' the AHV model based on well-defined testing specifications. The proposed preview control scheme in the continuous time domain is developed by using the LQR (linear quadratic regular) technique. The closed-loop simulation results indicate that the performance of the AHV with the LPDP controller is improved by decreasing rearward amplification ratio from the baseline value of 1.28 to 0.98 and reducing transient off-tracking by 95.03%. The proposed LPDP control algorithm provides an alternative method for the design optimization of AHVs with ATS systems.
文摘The CIM (common information model) is an abstract information model that can be used to model an electrical network and various equipments used on the network. By using a common model, utilities and vendors can reduce their integration costs, which should allow more resources to be applied toward increased functionality for managing and optimizing the electrical system. As a part of smart grid, the SPG (smart power grid) was built on Jeju Island. The SPG consists of IDAS (intelligent distribution automation system), substation automation system, intelligent transmission system, and active telemetrics system. To integrate these systems which have different operating systems and platforms CIM standard was used. But IDAS has many functions and advanced algorithms not defined in CIM. In this paper, the authors introduce how to develop and extend the CIM model for managing the IDAS.
文摘Motivated by an animal territoriality model,we consider a centroidal Voronoi tessellation algorithm from a dynamical systems perspective.In doing so,we discuss the stability of an aligned equilibrium configuration for a rectangular domain that exhibits interesting symmetry properties.We also demonstrate the procedure for performing a center manifold reduction on the system to extract a set of coordinates which capture the long term dynamics when the system is close to a bifurcation.Bifurcations of the system restricted to the center manifold are then classified and compared to numerical results.Although we analyze a specific set-up,these methods can in principle be applied to any bifurcation point of any equilibrium for any domain.