An evaluation approach for the response time probability distribution of workflows based on the fluid stochastic Petri net formalism is presented. Firstly, some problems about stochastic workflow net modeling are disc...An evaluation approach for the response time probability distribution of workflows based on the fluid stochastic Petri net formalism is presented. Firstly, some problems about stochastic workflow net modeling are discussed. Then how to convert a stochastic workflow net model into a fluid stochastic Petri net model is described. The response time distribution can be obtained directly upon the transient state solution of the fluid stochastic Petri net model. In the proposed approach, there are not any restrictions on the structure of workflow models, and the processing times of workflow tasks can be modeled by using arbitrary probability distributions. Large workflow models can be efficiently tackled by recursively using a net reduction technique.展开更多
A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machi...A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine （HEDSM） motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis.展开更多
In order to effectively control the random tasks submitted and executed in grid workflow,a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net,colored petri-net and g...In order to effectively control the random tasks submitted and executed in grid workflow,a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net,colored petri-net and general petri-net. Therein random petri-net declares the relationship between the number of grid users' random tasks and the size of service window and computes the server intensity of grid system. Colored petri-net sets different color for places with grid services and provides the valid interfaces for grid resource allocation and task scheduling. The experiment indicated that the model presented in this letter could compute the valve between the number of users' random tasks and the size of grid service window in grid workflow management system.展开更多
In view of the airborne application characteristics such as flexible flight, large error of altimeter, large initial error of inertial navigation system, etc., a new terrain matching system architecture which is suita...In view of the airborne application characteristics such as flexible flight, large error of altimeter, large initial error of inertial navigation system, etc., a new terrain matching system architecture which is suitable for airborne application is presented. The key techniques in terrain matching system realizing process including system workflow, terrain matching algorithm and selection criterion of matching region are expatiated. The experimental results prove the rationality and feasibility of the proposed solution.展开更多
Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be util...Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.展开更多
Artificial intelligence(AI) is intrinsically data-driven.It calls for the application of statistical concepts through human-machine collaboration during the generation of data,the development of algorithms,and the eva...Artificial intelligence(AI) is intrinsically data-driven.It calls for the application of statistical concepts through human-machine collaboration during the generation of data,the development of algorithms,and the evaluation of results.This paper discusses how such human-machine collaboration can be approached through the statistical concepts of population,question of interest,representativeness of training data,and scrutiny of results(PQRS).The PQRS workflow provides a conceptual framework for integrating statistical ideas with human input into AI products and researches.These ideas include experimental design principles of randomization and local control as well as the principle of stability to gain reproducibility and interpretability of algorithms and data results.We discuss the use of these principles in the contexts of self-driving cars,automated medical diagnoses,and examples from the authors' collaborative research.展开更多
The characteristics of the confined bubble and elongated bubble in subcooled flow boiling in a single horizontal rectangular microchannel with hydraulic diameter Dh=1mm are studied experimentally. The channel with 1 &...The characteristics of the confined bubble and elongated bubble in subcooled flow boiling in a single horizontal rectangular microchannel with hydraulic diameter Dh=1mm are studied experimentally. The channel with 1 ×1mm cross section is fabricated in a thin copper plate whose confinement number is Co=2.8 and the degassed deionized water is used as the working fluid. Visualization on the confined and elongated bubbles inside the microchannel is carded out by employing a high-speed CCD camera with a rnicrolens. The recorded images are carefully analyzed to illustrate the behaviors of the confinement and elongation processes of the bubble. The boiling number is used as an adjustable parameter to regulate the operating conditions which is eventually found to take a vital role in the bubble elongation process. Two formation patterns of the confined and elongated bubble are identified and the interactions between the neighboring confined and elongated bubbles are elucidated.展开更多
Flexibility plays an important part in the application of the workflow management system and has become one of the major research hotspots in this field recently. When adapting a workflow process definition to specifi...Flexibility plays an important part in the application of the workflow management system and has become one of the major research hotspots in this field recently. When adapting a workflow process definition to specific needs or changing the structure of the workflow process as a result of evolutionary change, coarse-grained reuse of work- flow is of significance to the reduction of the work effort, modeling system and enhancing the reliability of their work. Based on decomposition of workflow tasks and teamwork, this paper proposes an approach to describing interoperability behavior between roles in teamwork by using activity-pattern. In activity-pattern, abstract mechanisms of activity specialization and activity aggregation are presented, enabling reuse of workflow by means of reuse of interoperability behavior between roles. The experimental system shows that our approach presented is feasible.展开更多
基金The National Natural Science Foundation of China(No.60175027).
文摘An evaluation approach for the response time probability distribution of workflows based on the fluid stochastic Petri net formalism is presented. Firstly, some problems about stochastic workflow net modeling are discussed. Then how to convert a stochastic workflow net model into a fluid stochastic Petri net model is described. The response time distribution can be obtained directly upon the transient state solution of the fluid stochastic Petri net model. In the proposed approach, there are not any restrictions on the structure of workflow models, and the processing times of workflow tasks can be modeled by using arbitrary probability distributions. Large workflow models can be efficiently tackled by recursively using a net reduction technique.
文摘A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine （HEDSM） motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis.
基金the National Natural Science Foundation of China (No.60573141, 70271050)the Natural Science Foundation of Jiangsu Province (No.BK2005146)+3 种基金the High Technology Research Programme of Jiangsu Prov-ince (No.BG2005037, BG2005038, BG2006001)the High Technology Research Programme of Nanjing (No. 2006RZ105)the Foundation of National Laboratory for Modern Communications (No.9140C1101010603)the Key Laboratory of Information Technology Processing of Jiangsu Province (No.kjs05001, kjs0606).
文摘In order to effectively control the random tasks submitted and executed in grid workflow,a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net,colored petri-net and general petri-net. Therein random petri-net declares the relationship between the number of grid users' random tasks and the size of service window and computes the server intensity of grid system. Colored petri-net sets different color for places with grid services and provides the valid interfaces for grid resource allocation and task scheduling. The experiment indicated that the model presented in this letter could compute the valve between the number of users' random tasks and the size of grid service window in grid workflow management system.
基金This work was supported by the National Key Basic Research and Development （973） Program of China （Grant No. 2010CB731806） and Aeronautical Science Foundation of China （Grant No. 20100818018）.
文摘In view of the airborne application characteristics such as flexible flight, large error of altimeter, large initial error of inertial navigation system, etc., a new terrain matching system architecture which is suitable for airborne application is presented. The key techniques in terrain matching system realizing process including system workflow, terrain matching algorithm and selection criterion of matching region are expatiated. The experimental results prove the rationality and feasibility of the proposed solution.
文摘Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.
基金supported by the Army Research Office(No.W911NF1710005)the National Science Foundation(Nos.DMS-1613002 and IIS 1741340)+1 种基金the Center for Science of Information,a US National Science Foundation Science and Technology Center(No.CCF-0939370)the National Library of Medicine of the NIH(No.T32LM012417)
文摘Artificial intelligence(AI) is intrinsically data-driven.It calls for the application of statistical concepts through human-machine collaboration during the generation of data,the development of algorithms,and the evaluation of results.This paper discusses how such human-machine collaboration can be approached through the statistical concepts of population,question of interest,representativeness of training data,and scrutiny of results(PQRS).The PQRS workflow provides a conceptual framework for integrating statistical ideas with human input into AI products and researches.These ideas include experimental design principles of randomization and local control as well as the principle of stability to gain reproducibility and interpretability of algorithms and data results.We discuss the use of these principles in the contexts of self-driving cars,automated medical diagnoses,and examples from the authors' collaborative research.
基金supported by National Natural Science Foundation of China (No. 51176008)the Fundamental Research Funds for the Central Universities (No.2011YJS267)Jiangsu Key Laboratory of Process Enhancement & New Energy Equipment Technology(Nanjing University of Technology)
文摘The characteristics of the confined bubble and elongated bubble in subcooled flow boiling in a single horizontal rectangular microchannel with hydraulic diameter Dh=1mm are studied experimentally. The channel with 1 ×1mm cross section is fabricated in a thin copper plate whose confinement number is Co=2.8 and the degassed deionized water is used as the working fluid. Visualization on the confined and elongated bubbles inside the microchannel is carded out by employing a high-speed CCD camera with a rnicrolens. The recorded images are carefully analyzed to illustrate the behaviors of the confinement and elongation processes of the bubble. The boiling number is used as an adjustable parameter to regulate the operating conditions which is eventually found to take a vital role in the bubble elongation process. Two formation patterns of the confined and elongated bubble are identified and the interactions between the neighboring confined and elongated bubbles are elucidated.
基金This research is supported by National Natural Science Foundation of China （60574028） the Key Projects of Natural Science Foundation of Edtication Department of Anhui Province of China （2006kj016A, 2005kj065）
文摘Flexibility plays an important part in the application of the workflow management system and has become one of the major research hotspots in this field recently. When adapting a workflow process definition to specific needs or changing the structure of the workflow process as a result of evolutionary change, coarse-grained reuse of work- flow is of significance to the reduction of the work effort, modeling system and enhancing the reliability of their work. Based on decomposition of workflow tasks and teamwork, this paper proposes an approach to describing interoperability behavior between roles in teamwork by using activity-pattern. In activity-pattern, abstract mechanisms of activity specialization and activity aggregation are presented, enabling reuse of workflow by means of reuse of interoperability behavior between roles. The experimental system shows that our approach presented is feasible.
