As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new appro...As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workflow models using π calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS (Labeled Transition Semantics) semantics of π calculus. The main advantage of the workflow model's formal semantic is that it allows for verification of the model's properties, such as deadlock free and normal termination. Moreover, the equivalence of workflow models can be checked through weak bisimulation theorem in the π calculus, thus facilitating the optimization of business processes.展开更多
The goal of this paper is to analyze and propose a reconstruction of functional possibilities and database requirements of a Web based Educational Information system. For the research the Information system of the Tec...The goal of this paper is to analyze and propose a reconstruction of functional possibilities and database requirements of a Web based Educational Information system. For the research the Information system of the Technology School ＂electronic Systems＂ （TUES） associated with the Technical University of Sofia is on focus. The modules for admission of students, specialty classification, and graduation of students, management of the student＇s work in computer classrooms and lecturers＇ data management have been analyzed, developed and implemented. The additionally developed modules concern mainly the management of educational process and do not affect the e-learning or the official part modules. That led to the idea that the functionality for managing educational process has to be organized in a separate module defined as module for administrative services of educational process. Such restructuring of the system will bring flexibility in further growth of the system--for example students＇ admission or selection for different purposes.展开更多
CVAM-based management accounting emphasizes that enterprises should make efforts not only to provide goods or service to customers but also to create value for customers. In practice, customer value should be measured...CVAM-based management accounting emphasizes that enterprises should make efforts not only to provide goods or service to customers but also to create value for customers. In practice, customer value should be measured reasonably first. Then according to its condition, enterprise can apply the CVAM-based management accounting method by improving management quality, perfecting costing planning, brand operation and business innovation to create value for customers thus achieving increase of corporate value as well as social value.展开更多
To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and pre...To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.展开更多
This paper firstly introduces the structure and working principle of turbine sail. Numerical model of a turbine sail is established with Gambit software. The aerodynamic characteristics of the turbine sail are describ...This paper firstly introduces the structure and working principle of turbine sail. Numerical model of a turbine sail is established with Gambit software. The aerodynamic characteristics of the turbine sail are described with RNG k-e turbulence model and the numerical simulation is carded out with Fluent software. The influence of sail＇s structure is analyzed including plate, separation type and height/width ratio. The lift coefficients and drag coefficients of the simulated turbine sail are calculated under different rotation angles, suction intensity and separation plate position. The calculated results are compared with the wind tunnel experimental results, which verifies the feasibility of the numerical results and establishes a foundation for the optimal design of turbine sails.展开更多
This paper discusses a distributed design for clustering based on the K-means algorithm in a switching multi-agent network, for the case when data are decentralized stored and unavailable to all agents. The authors pr...This paper discusses a distributed design for clustering based on the K-means algorithm in a switching multi-agent network, for the case when data are decentralized stored and unavailable to all agents. The authors propose a consensus-based algorithm in distributed case, that is, the double- clock consensus-based K-means algorithm （DCKA）. With mild connectivity conditions, the authors show convergence of DCKA to guarantee a distributed solution to the clustering problem, even though the network topology is time-varying. Moreover, the authors provide experimental results on vari- ous clustering datasets to illustrate the effectiveness of the fully distributed algorithm DCKA, whose performance may be better than that of the centralized K-means algorithm.展开更多
文摘As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workflow models using π calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS (Labeled Transition Semantics) semantics of π calculus. The main advantage of the workflow model's formal semantic is that it allows for verification of the model's properties, such as deadlock free and normal termination. Moreover, the equivalence of workflow models can be checked through weak bisimulation theorem in the π calculus, thus facilitating the optimization of business processes.
文摘The goal of this paper is to analyze and propose a reconstruction of functional possibilities and database requirements of a Web based Educational Information system. For the research the Information system of the Technology School ＂electronic Systems＂ （TUES） associated with the Technical University of Sofia is on focus. The modules for admission of students, specialty classification, and graduation of students, management of the student＇s work in computer classrooms and lecturers＇ data management have been analyzed, developed and implemented. The additionally developed modules concern mainly the management of educational process and do not affect the e-learning or the official part modules. That led to the idea that the functionality for managing educational process has to be organized in a separate module defined as module for administrative services of educational process. Such restructuring of the system will bring flexibility in further growth of the system--for example students＇ admission or selection for different purposes.
文摘CVAM-based management accounting emphasizes that enterprises should make efforts not only to provide goods or service to customers but also to create value for customers. In practice, customer value should be measured reasonably first. Then according to its condition, enterprise can apply the CVAM-based management accounting method by improving management quality, perfecting costing planning, brand operation and business innovation to create value for customers thus achieving increase of corporate value as well as social value.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50578048)
文摘To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.
文摘This paper firstly introduces the structure and working principle of turbine sail. Numerical model of a turbine sail is established with Gambit software. The aerodynamic characteristics of the turbine sail are described with RNG k-e turbulence model and the numerical simulation is carded out with Fluent software. The influence of sail＇s structure is analyzed including plate, separation type and height/width ratio. The lift coefficients and drag coefficients of the simulated turbine sail are calculated under different rotation angles, suction intensity and separation plate position. The calculated results are compared with the wind tunnel experimental results, which verifies the feasibility of the numerical results and establishes a foundation for the optimal design of turbine sails.
基金supported by the National Key Research and Development Program of China under Grant No.2016YFB0901902the National Natural Science Foundation of China under Grant Nos.61573344,61333001,61733018,and 61374168
文摘This paper discusses a distributed design for clustering based on the K-means algorithm in a switching multi-agent network, for the case when data are decentralized stored and unavailable to all agents. The authors propose a consensus-based algorithm in distributed case, that is, the double- clock consensus-based K-means algorithm （DCKA）. With mild connectivity conditions, the authors show convergence of DCKA to guarantee a distributed solution to the clustering problem, even though the network topology is time-varying. Moreover, the authors provide experimental results on vari- ous clustering datasets to illustrate the effectiveness of the fully distributed algorithm DCKA, whose performance may be better than that of the centralized K-means algorithm.
