Parallel machine problems with a single server and release times are generalizations of classical parallel machine problems. Before processing, each job must be loaded on a machine, which takes a certain release times...Parallel machine problems with a single server and release times are generalizations of classical parallel machine problems. Before processing, each job must be loaded on a machine, which takes a certain release times and a certain setup times. All these setups have to be done by a single server, which can handle at most one job at a time. In this paper, we continue studying the complexity result for parallel machine problem with a single and release times. New complexity results are derived for special cases.展开更多
Considering the importance of the prediction of rock burst disasters, and in order to grasp the law of acoustic emission(AE) of coal samples in different dynamic destruction time, the SH-II AE monitoring system was ad...Considering the importance of the prediction of rock burst disasters, and in order to grasp the law of acoustic emission(AE) of coal samples in different dynamic destruction time, the SH-II AE monitoring system was adopted to monitor the failure process of coal samples. The study of the change rule of the AE numbers, energy, ‘b' value and spectrum in the micro crack propagation process of the coal samples shows that as dynamic damage time went by, AE presented high-energy counts and the accumulated counts increased during the compression phase. The AE energy and cumulative counts increased during the elastic stage. The AE blank area increased gradually and the blank lines were more and more obvious in the molding stage. The AE counts and energy showed a trend of decrease in the residual damage phase.AE ‘b' values gradually became sparse, and the large scale cracks percentage compared with micro cracks decreased and the degree of damage decreased. The AE frequency spectrum peak went from the residual damage phase to the molding phase, and finally it was nearly stable, besides the bandwidth of the main frequency is gradually narrowed. Also, the frequency peak changed from single peak frequency to bi-peak frequency and to the single peak frequency. Uniaxial compressive strength is more sensitive than the elastic modulus to dynamic damage time.展开更多
This study focuses on the scheduling problem of unrelated parallel batch processing machines(BPM)with release times,a scenario derived from the moulding process in a foundry.In this process,a batch is initially formed...This study focuses on the scheduling problem of unrelated parallel batch processing machines(BPM)with release times,a scenario derived from the moulding process in a foundry.In this process,a batch is initially formed,placed in a sandbox,and then the sandbox is positioned on a BPM formoulding.The complexity of the scheduling problem increases due to the consideration of BPM capacity and sandbox volume.To minimize the makespan,a new cooperated imperialist competitive algorithm(CICA)is introduced.In CICA,the number of empires is not a parameter,and four empires aremaintained throughout the search process.Two types of assimilations are achieved:The strongest and weakest empires cooperate in their assimilation,while the remaining two empires,having a close normalization total cost,combine in their assimilation.A new form of imperialist competition is proposed to prevent insufficient competition,and the unique features of the problem are effectively utilized.Computational experiments are conducted across several instances,and a significant amount of experimental results show that the newstrategies of CICAare effective,indicating promising advantages for the considered BPMscheduling problems.展开更多
Failure of a safety critical system can lead to big losses. Very high software reliability is required for automating the working of systems such as aircraft controller and nuclear reactor controller software systems....Failure of a safety critical system can lead to big losses. Very high software reliability is required for automating the working of systems such as aircraft controller and nuclear reactor controller software systems. Fault-tolerant softwares are used to increase the overall reliability of software systems. Fault tolerance is achieved using the fault-tolerant schemes such as fault recovery （recovery block scheme）, fault masking （N-version programming （NVP）） or a combination of both （Hybrid scheme）. These softwares incorporate the ability of system survival even on a failure. Many researchers in the field of software engineering have done excellent work to study the reliability of fault-tolerant systems. Most of them consider the stable system reliability. Few attempts have been made in reliability modeling to study the reliability growth for an NVP system. Recently, a model was proposed to analyze the reliability growth of an NVP system incorporating the effect of fault removal efficiency. In this model, a proportion of the number of failures is assumed to be a measure of fault generation while an appropriate measure of fault generation should be the proportion of faults removed. In this paper, we first propose a testing efficiency model incorporating the effect of imperfect fault debugging and error generation. Using this model, a software reliability growth model （SRGM） is developed to model the reliability growth of an NVP system. The proposed model is useful for practical applications and can provide the measures of debugging effectiveness and additional workload or skilled professional required. It is very important for a developer to determine the optimal release time of the software to improve its performance in terms of competition and cost. In this paper, we also formulate the optimal software release time problem for a 3VP system under fuzzy environment and discuss a the fuzzy optimization technique for solving the problem with a numerical illustration.展开更多
ARINC653 systems, which have been widely used in avionics industry, are an important class of safety-critical applications. Partitions are the core concept in the Arinc653 system architecture. Due to the existence of ...ARINC653 systems, which have been widely used in avionics industry, are an important class of safety-critical applications. Partitions are the core concept in the Arinc653 system architecture. Due to the existence of partitions, the system designer must allocate adequate time slots statically to each partition in the design phase. Although some time slot allocation policies could be borrowed from task scheduling policies, no existing literatures give an optimal allocation policy. In this paper, we present a partition configuration policy and prove that this policy is optimal in the sense that if this policy fails to configure adequate time slots to each partition, nor do other policies. Then, by simulation, we show the effects of different partition configuration policies on time slot allocation of partitions and task response time, respectively.展开更多
The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants.However,research about delayed seed dispersal species in the desert of the United Arab Emirates...The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants.However,research about delayed seed dispersal species in the desert of the United Arab Emirates(UAE)is lacking.This study aims to identify these delayed seed dispersal species and assess the relationships of the presence of delayed seed dispersal with plant growth form,habit,spatial dispersal,antitelechoric mechanism,and seed release time.The relationships between the presence of delayed seed dispersal and the above studied traits were assessed by using the Pearson Chi-square test and Nonlinear Principal Components Analysis(NLPCA).Results showed that a total of 46 delayed seed dispersal species were recorded(15.0%of 307 studied species)and the highest incidence occurred in the Fabaceae family(17.4%).Delayed seed dispersal species were predominantly perennial plants(73.9%)with spatial restricted dispersal(67.4%),which released seed in the dry season(45.7%).The dominant groups of delayed seed dispersal species were persistent fruits species and synaptospermy(28.3%).All graminoids showed persistent lignified fruits,while prostrate annuals were basicarpic species with myxospermy.Sandy habitats had the highest number of delayed seed dispersal species(54.3%),whereas salt flats had the lowest(23.9%).In the desert of the UAE,delayed seed dispersal species spread seeds until the end of the dry and windy season,thus breaking seed dormancy at this time and ensuring seed germination in the next arrival of the rainy season.This morphological and ecological adaptation of delayed dispersal species is essential to the survival and sustainable development of vegetation in desert environments.展开更多
The problem of scheduling jobs with release and delivery time subject to machine eligibility constraints is considered.The eligible sets of the jobs are nested,and pre-emptions are not allowed.The goal is to minimize ...The problem of scheduling jobs with release and delivery time subject to machine eligibility constraints is considered.The eligible sets of the jobs are nested,and pre-emptions are not allowed.The goal is to minimize the maximum delivery completion time,i.e.,the time by which all jobs are delivered.For the special case of equal release time,a 2-approximation algorithm is presented whose running time depends linearly on the number of jobs.For the general case of unequal release time,a polynomial time approximation scheme is derived.展开更多
This paper considers the parallel machines scheduling problem where jobs are subject to different release times. A constructive heuristic is first proposed to solve the problem in a modest amount of computer time. In ...This paper considers the parallel machines scheduling problem where jobs are subject to different release times. A constructive heuristic is first proposed to solve the problem in a modest amount of computer time. In general, the quality of the solutions provided by heuristics degrades with the increase of the probiem’s scale. Combined the global search ability of genetic algorithm, this paper proposed a hybrid heuristic to improve the quality of solutions further. The computational results show that the hybrid heuristic combines the advantages of heuristic and genetic algorithm effectively and can provide very good solutions to some large problems in a reasonable amount of computer time.展开更多
In this paper, the inhomogeneous structure of generalized seismic strain release time series (GSSRTS) of earth- quakes in East, West China and their subtectonic regions as Xinjiang, Qinghai-Xizang (Tibetan) Plateau, N...In this paper, the inhomogeneous structure of generalized seismic strain release time series (GSSRTS) of earth- quakes in East, West China and their subtectonic regions as Xinjiang, Qinghai-Xizang (Tibetan) Plateau, Northeast China, North China, South China and Taiwan have been analyzed by using the method of significant analysis on zero crossings of derivatives (SiZer). Results show that when index η for estimating GSSRTS is close to zero and bandwidth is large enough, GSSRTSs feature significant increasing in Xinjiang, Northeast China, South China and Taiwan tectonic regions and decreasing in Qinghai-Xizang (Tibetan Platean) and North China tectonic regions from January 1, 1970 to January 1, 2000. While with the dwindling of bandwidth GSSRTSs in all the above tec- tonic regions characterize clustering, that is to say, significant increasing and decreasing emerge alternatively. When η is large enough, GSSRTSs would have no significant statistical variation in most of above tectonic regions except Qinghai-Xizang (Tibetan Platean) and Taiwan where significant increasing or decreasing hold in several time intervals within limited bandwidths.展开更多
According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets： common faults and fatal faults. Common faults cause slight loss when they are ...According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets： common faults and fatal faults. Common faults cause slight loss when they are activated. A fatal fault can lead to significant loss, and even damage the safety-crltical system entirely when it is activated. A software reliability growth model for safety-critical systems is developed based on G - 0 model. And a software cost model is proposed too. The cost model considers maintenance and risk costs due to software failures. The optimal release policies are discussed to minimize the total software cost. A numerical exampie is provided to illustrate how to use the results we obtained.展开更多
The“13th Five-Year Plan”for the Construction of Municipal Infrastructures in Cities of China that was compiled by the Ministry of Housing and Urban-Rural Development and the National Development and Reform Commissio...The“13th Five-Year Plan”for the Construction of Municipal Infrastructures in Cities of China that was compiled by the Ministry of Housing and Urban-Rural Development and the National Development and Reform Commission was released for enforcement on May 26,2017.It is a first state-level and comprehensive plan for municipal infrastructures construction,which changes the conventional method of compiling different plans in different domains.As a systematic integration of展开更多
文摘Parallel machine problems with a single server and release times are generalizations of classical parallel machine problems. Before processing, each job must be loaded on a machine, which takes a certain release times and a certain setup times. All these setups have to be done by a single server, which can handle at most one job at a time. In this paper, we continue studying the complexity result for parallel machine problem with a single and release times. New complexity results are derived for special cases.
基金provided by the National Natural Science Foundation of China (No.51374097)the Science Foundation General Projects of Chinese Postgraduate (No.2014M561384)Key Project of Science and Technology Research of Department of Education in Heilongjiang Province (No.12541z009)
文摘Considering the importance of the prediction of rock burst disasters, and in order to grasp the law of acoustic emission(AE) of coal samples in different dynamic destruction time, the SH-II AE monitoring system was adopted to monitor the failure process of coal samples. The study of the change rule of the AE numbers, energy, ‘b' value and spectrum in the micro crack propagation process of the coal samples shows that as dynamic damage time went by, AE presented high-energy counts and the accumulated counts increased during the compression phase. The AE energy and cumulative counts increased during the elastic stage. The AE blank area increased gradually and the blank lines were more and more obvious in the molding stage. The AE counts and energy showed a trend of decrease in the residual damage phase.AE ‘b' values gradually became sparse, and the large scale cracks percentage compared with micro cracks decreased and the degree of damage decreased. The AE frequency spectrum peak went from the residual damage phase to the molding phase, and finally it was nearly stable, besides the bandwidth of the main frequency is gradually narrowed. Also, the frequency peak changed from single peak frequency to bi-peak frequency and to the single peak frequency. Uniaxial compressive strength is more sensitive than the elastic modulus to dynamic damage time.
基金the National Natural Science Foundation of China(Grant Number 61573264).
文摘This study focuses on the scheduling problem of unrelated parallel batch processing machines(BPM)with release times,a scenario derived from the moulding process in a foundry.In this process,a batch is initially formed,placed in a sandbox,and then the sandbox is positioned on a BPM formoulding.The complexity of the scheduling problem increases due to the consideration of BPM capacity and sandbox volume.To minimize the makespan,a new cooperated imperialist competitive algorithm(CICA)is introduced.In CICA,the number of empires is not a parameter,and four empires aremaintained throughout the search process.Two types of assimilations are achieved:The strongest and weakest empires cooperate in their assimilation,while the remaining two empires,having a close normalization total cost,combine in their assimilation.A new form of imperialist competition is proposed to prevent insufficient competition,and the unique features of the problem are effectively utilized.Computational experiments are conducted across several instances,and a significant amount of experimental results show that the newstrategies of CICAare effective,indicating promising advantages for the considered BPMscheduling problems.
文摘Failure of a safety critical system can lead to big losses. Very high software reliability is required for automating the working of systems such as aircraft controller and nuclear reactor controller software systems. Fault-tolerant softwares are used to increase the overall reliability of software systems. Fault tolerance is achieved using the fault-tolerant schemes such as fault recovery （recovery block scheme）, fault masking （N-version programming （NVP）） or a combination of both （Hybrid scheme）. These softwares incorporate the ability of system survival even on a failure. Many researchers in the field of software engineering have done excellent work to study the reliability of fault-tolerant systems. Most of them consider the stable system reliability. Few attempts have been made in reliability modeling to study the reliability growth for an NVP system. Recently, a model was proposed to analyze the reliability growth of an NVP system incorporating the effect of fault removal efficiency. In this model, a proportion of the number of failures is assumed to be a measure of fault generation while an appropriate measure of fault generation should be the proportion of faults removed. In this paper, we first propose a testing efficiency model incorporating the effect of imperfect fault debugging and error generation. Using this model, a software reliability growth model （SRGM） is developed to model the reliability growth of an NVP system. The proposed model is useful for practical applications and can provide the measures of debugging effectiveness and additional workload or skilled professional required. It is very important for a developer to determine the optimal release time of the software to improve its performance in terms of competition and cost. In this paper, we also formulate the optimal software release time problem for a 3VP system under fuzzy environment and discuss a the fuzzy optimization technique for solving the problem with a numerical illustration.
基金supported by the National Natural Science Foundation of China under Grant No. 90718019the National High-Tech Research and Development Plan of China under Grant No. 2007AA010304
文摘ARINC653 systems, which have been widely used in avionics industry, are an important class of safety-critical applications. Partitions are the core concept in the Arinc653 system architecture. Due to the existence of partitions, the system designer must allocate adequate time slots statically to each partition in the design phase. Although some time slot allocation policies could be borrowed from task scheduling policies, no existing literatures give an optimal allocation policy. In this paper, we present a partition configuration policy and prove that this policy is optimal in the sense that if this policy fails to configure adequate time slots to each partition, nor do other policies. Then, by simulation, we show the effects of different partition configuration policies on time slot allocation of partitions and task response time, respectively.
文摘The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants.However,research about delayed seed dispersal species in the desert of the United Arab Emirates(UAE)is lacking.This study aims to identify these delayed seed dispersal species and assess the relationships of the presence of delayed seed dispersal with plant growth form,habit,spatial dispersal,antitelechoric mechanism,and seed release time.The relationships between the presence of delayed seed dispersal and the above studied traits were assessed by using the Pearson Chi-square test and Nonlinear Principal Components Analysis(NLPCA).Results showed that a total of 46 delayed seed dispersal species were recorded(15.0%of 307 studied species)and the highest incidence occurred in the Fabaceae family(17.4%).Delayed seed dispersal species were predominantly perennial plants(73.9%)with spatial restricted dispersal(67.4%),which released seed in the dry season(45.7%).The dominant groups of delayed seed dispersal species were persistent fruits species and synaptospermy(28.3%).All graminoids showed persistent lignified fruits,while prostrate annuals were basicarpic species with myxospermy.Sandy habitats had the highest number of delayed seed dispersal species(54.3%),whereas salt flats had the lowest(23.9%).In the desert of the UAE,delayed seed dispersal species spread seeds until the end of the dry and windy season,thus breaking seed dormancy at this time and ensuring seed germination in the next arrival of the rainy season.This morphological and ecological adaptation of delayed dispersal species is essential to the survival and sustainable development of vegetation in desert environments.
基金This work was supported by the National Natural Science Foundation of China(No.11771251)Key project of Shandong Provincial Natural Science Foundation of China(No.ZR2015GZ009)Shandong Provincial Education Reform Project(No.2015M098).
文摘The problem of scheduling jobs with release and delivery time subject to machine eligibility constraints is considered.The eligible sets of the jobs are nested,and pre-emptions are not allowed.The goal is to minimize the maximum delivery completion time,i.e.,the time by which all jobs are delivered.For the special case of equal release time,a 2-approximation algorithm is presented whose running time depends linearly on the number of jobs.For the general case of unequal release time,a polynomial time approximation scheme is derived.
文摘This paper considers the parallel machines scheduling problem where jobs are subject to different release times. A constructive heuristic is first proposed to solve the problem in a modest amount of computer time. In general, the quality of the solutions provided by heuristics degrades with the increase of the probiem’s scale. Combined the global search ability of genetic algorithm, this paper proposed a hybrid heuristic to improve the quality of solutions further. The computational results show that the hybrid heuristic combines the advantages of heuristic and genetic algorithm effectively and can provide very good solutions to some large problems in a reasonable amount of computer time.
基金Natural Science Foundation of Shandong Province (Y2002E01), Key Project for Earthquake Prevention and Disaster Mitigation in Shandong (SD10503-02-05) and Project of China-Greece International Cooperation of Science and Technology from 2003 to 2005.
文摘In this paper, the inhomogeneous structure of generalized seismic strain release time series (GSSRTS) of earth- quakes in East, West China and their subtectonic regions as Xinjiang, Qinghai-Xizang (Tibetan) Plateau, Northeast China, North China, South China and Taiwan have been analyzed by using the method of significant analysis on zero crossings of derivatives (SiZer). Results show that when index η for estimating GSSRTS is close to zero and bandwidth is large enough, GSSRTSs feature significant increasing in Xinjiang, Northeast China, South China and Taiwan tectonic regions and decreasing in Qinghai-Xizang (Tibetan Platean) and North China tectonic regions from January 1, 1970 to January 1, 2000. While with the dwindling of bandwidth GSSRTSs in all the above tec- tonic regions characterize clustering, that is to say, significant increasing and decreasing emerge alternatively. When η is large enough, GSSRTSs would have no significant statistical variation in most of above tectonic regions except Qinghai-Xizang (Tibetan Platean) and Taiwan where significant increasing or decreasing hold in several time intervals within limited bandwidths.
基金Sponsored by the Ph.D. Programs Foundation of Ministry of Education of China (Grant No. 20020213017).
文摘According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets： common faults and fatal faults. Common faults cause slight loss when they are activated. A fatal fault can lead to significant loss, and even damage the safety-crltical system entirely when it is activated. A software reliability growth model for safety-critical systems is developed based on G - 0 model. And a software cost model is proposed too. The cost model considers maintenance and risk costs due to software failures. The optimal release policies are discussed to minimize the total software cost. A numerical exampie is provided to illustrate how to use the results we obtained.
文摘The“13th Five-Year Plan”for the Construction of Municipal Infrastructures in Cities of China that was compiled by the Ministry of Housing and Urban-Rural Development and the National Development and Reform Commission was released for enforcement on May 26,2017.It is a first state-level and comprehensive plan for municipal infrastructures construction,which changes the conventional method of compiling different plans in different domains.As a systematic integration of
