Locating distribution centers optimally is a crucial and systematic task for decision-makers.Optimally located distribution centers can significantly improve the logistics system's efficiency and reduce its operat...Locating distribution centers optimally is a crucial and systematic task for decision-makers.Optimally located distribution centers can significantly improve the logistics system's efficiency and reduce its operational costs.However,it is not an easy task to optimize distribution center locations and previous studies focused primarily on location optimization of a single distribution center.With growing logistics demands,multiple distribution centers become necessary to meet customers' requirements,but few studies have tackled the multiple distribution center locations(MDCLs) problem.This paper presents a comprehensive algorithm to address the MDCLs problem.Fuzzy integration and clustering approach using the improved axiomatic fuzzy set(AFS) theory is developed for location clustering based on multiple hierarchical evaluation criteria.Then,technique for order preference by similarity to ideal solution(TOPSIS) is applied for evaluating and selecting the best candidate for each cluster.Sensitivity analysis is also conducted to assess the influence of each criterion in the location planning decision procedure.Results from a case study in Guiyang,China,reveals that the proposed approach developed in this study outperforms other similar algorithms for MDCLs selection.This new method may easily be extended to address location planning of other types of facilities,including hospitals,fire stations and schools.展开更多
This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorit...This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorithm (IGA) was proposed to solve the problem. The improvement of IGA is based on the idea of adjusting crossover probability and mutation probability. The IGA is supplied by heuristic rules too. The simulation results show that the IGA is better than the standard GA(SGA) in search efficiency and equality.展开更多
In the light of the practical situation of logistics distribution of agricultural products,we primarily select transportation factor,economic factor,environment factor,and other factors,to establish evaluation index s...In the light of the practical situation of logistics distribution of agricultural products,we primarily select transportation factor,economic factor,environment factor,and other factors,to establish evaluation index system of site selection of distribution center of agricultural products.And then we adopt the analytic hierarchy process method to calculate weight of site selection of distribution center of agricultural products.Under the circumstance that the evaluation information is interval number,we use uncertain and multiple attribute decision making method to establish site selection model of distribution center of agricultural products.Finally,taking one city as an example,we discuss the application of this model in site selection of distribution center of agricultural products.The results of empirical analysis show that the model we established fully considers the randomness and uncertainty in the process of evaluation,so as to make the results of evaluation more objective,in line with reality.So the effect of evaluation is better as against the former real number evaluation calibration.展开更多
This paper studies the location of Wuhan steel logistics distribution center. First of all, according to Wuhan Iron and Steel Plant sales in Hunan Province and the relative position of the city, the transport costs ar...This paper studies the location of Wuhan steel logistics distribution center. First of all, according to Wuhan Iron and Steel Plant sales in Hunan Province and the relative position of the city, the transport costs are calculated from Wuhan Iron and Steel Plant to the demand point. We further analyze the necessity of establishing steel logistics distribution center, using the precise center of gravity to determine the actual location of the distribution center. After the establishment of distribution center, the total freight is reduced by 15.46 million yuan from Wuhan Iron and Steel Plant to each city in Hunan province via distribution center each year. The results of this paper can provide theoretical basis for the logistics node planning of related enterprises.展开更多
A supply chain is a network that performs the procurement of raw material, the transportation of raw material to intermediate and end products, and the distribution of end products to retailers or customers. Installat...A supply chain is a network that performs the procurement of raw material, the transportation of raw material to intermediate and end products, and the distribution of end products to retailers or customers. Installation and operation of distribution centers and all downstream members play a vital role in fulfilling the customers demand and have a great impact for supply chain management performance. In this paper we address a new approach for solving a supply chain optimization model to decide distribution centers based on environmental consideration.展开更多
Objective: to explore the influence of optimizing hospital sensing and control management of static distribution center on infusion quality. Methods: 80 patients were selected as subjects in a hospital. In order to hi...Objective: to explore the influence of optimizing hospital sensing and control management of static distribution center on infusion quality. Methods: 80 patients were selected as subjects in a hospital. In order to highlight the research results, the selected subjects were equally divided into experimental group and control group, and different nursing measures were used for the patients in the two groups. Tthe patients in the control group used routine nursing methods in the process of infusion treatment, while the experimental group took measures to optimize hospital sensing and control on the basis of routine nursing methods. On the premise of ensuring that other conditions of the two groups of patients do not change, after taking different nursing measures for the two groups of patients, compare the infusion satisfaction of the two groups of patients and the probability of adverse infusion events. Results: the incidence of adverse infusion events was 15.00% in the control group and 2.50% in the experimental group;The satisfaction of infusion nursing in the control group was 77.50%, while that in the experimental group was 95.00% (P < 0.05). Conclusion: the application of optimized hospital sensing and control management method in the static distribution center can improve patients infusion satisfaction and reduce the probability of adverse infusion reactions. Therefore, this method is worthy of comprehensive promotion and application in the hospital.展开更多
The location selection of the logistics distribution center for a supply and demand network(SDN)enterprises directly affected the efficiency of the logistics system operation and the customer service level.In this pap...The location selection of the logistics distribution center for a supply and demand network(SDN)enterprises directly affected the efficiency of the logistics system operation and the customer service level.In this paper,we present a location selection model of the logistics distribution center for SDN enterprises.In order to improve the optimization effectiveness of the traditional methods in solving the location selection problem,an improved firefly algorithm was presented.By introducing a coordination factor,the search step can be automatically adjusted,and the accuracy of the algorithm can be improved.By introducing a chaotic search strategy,the diversity of firefly populations and the global optimization ability of the algorithm can be improved.The simulation experiments showed that the improved firefly algorithm achieved a more favorable effectiveness than three other algorithms we tested.展开更多
Symbol Technologies, Inc., The Enterprise Mobility Company, today announced that it had been selected by ODIN technologies, the leader in the physics of RFID testing, software and deployment, to support its recent con...Symbol Technologies, Inc., The Enterprise Mobility Company, today announced that it had been selected by ODIN technologies, the leader in the physics of RFID testing, software and deployment, to support its recent contract win with the United States Defense Logistics Agency (DLA), the United States Department of Defense’s (DoD) logistics combat support agency that provides supplies and services to America’s military forces worldwide.展开更多
The composition distribution (CD) and microisotacticity distribution (ID) of propene/1-hexene copolymer synthesized by MgCl2/DIBP/TiCl4 (DIBP: diisobutyl phthalate) were determined by fractionating the copolymers acco...The composition distribution (CD) and microisotacticity distribution (ID) of propene/1-hexene copolymer synthesized by MgCl2/DIBP/TiCl4 (DIBP: diisobutyl phthalate) were determined by fractionating the copolymers according to crystallinity and characterizing the fractions by (CNMR)-C-13. The effects of two alkoxysilane donors, triethoxyphenylsilane (PTES) and dimethoxydi-tert-butylsilane (TBMS), on CD and ID of the copolymers were compared. Three main parts in the CD diagram of each copolymer were distinguished, which were correlated to active center distribution (ACD) based on three groups of different active centers. By studying the changes in l-hexene content, microisotacticity and reactivity ratio product of three typical fractions, the effects of external donor on ACD were better elucidated. It was found that TBMS shows much stronger effects on ACD than PTES. In the former system, most fractions were produced on active centers with relatively lower r(1)r(2), higher reactivity to I-hexene, and higher stereospecificity as compared to the system without external donor. It is concluded that the observed very extensive changes in ACD are mainly resulted by the formation of new types of active centers, possibly by coordination of external donor to certain positions on the catalyst.展开更多
Distribution of active centers(ACD)of ethylene or 1-hexene homopolymerization and ethylene-1-hexene copolymerization with a MgCl_2/TiCl_4 type Z-N catalyst were studied by deconvolution of the polymer molecular weight...Distribution of active centers(ACD)of ethylene or 1-hexene homopolymerization and ethylene-1-hexene copolymerization with a MgCl_2/TiCl_4 type Z-N catalyst were studied by deconvolution of the polymer molecular weight distribution into multiple Flory components.Each Flory component is thought to be formed by a certain type of active center. ACD of ethylene-1-hexene copolymer with very low 1-hexene incorporation was compared with that of ethylene homopolymer to see the effect of introducingα-olefin on ethyle...展开更多
In recent years,Danyang in Jiangsu Province-one of China’s key eyewear manufacturing and distribution centers-has leveraged its“small glasses”to power a“big industry.”
Constructing circulation mode of high feasibility and good implementation effect is the key method to solve difficulties in the development of “Agricultural Super-Docking” at present in China. There are many problem...Constructing circulation mode of high feasibility and good implementation effect is the key method to solve difficulties in the development of “Agricultural Super-Docking” at present in China. There are many problems that exist in the process of the development of “Agricultural Super-Docking” by our analyzing from both the benefit of subjects and the whole supply chain perspectives. A large amount of relevant literature research shows that adopting the “cooperation between the government and the third party logistics enterprises to build distribution center” innovation model can solve these problems. This model can effectively remove obstacles between farmers and supermarkets. It is conducive to the development of small and medium-scale the farmer cooperatives, supermarkets and the third party logistics enterprises that don’t have a strong financial strength and a high degree of brand influence. In addition, it can also produce considerable social benefits. In order to ensure the implementation efficiency of the model to maximize, some management issues in the implementation process about the determination of core subject in supply chain, the method of evaluating the third party logistics enterprises grade, the planning of the number of customers for the distribution center, the mechanism of income distribution among multiple subjects and the implementation of relevant policies after the model into practice should be taken into account.展开更多
The paper study communication protocol, the structure of the circuit, antenna design of radio frequency identification technology （RFID）, and puts forward a scheme based on IOT application： RFID logistics tracking ...The paper study communication protocol, the structure of the circuit, antenna design of radio frequency identification technology （RFID）, and puts forward a scheme based on IOT application： RFID logistics tracking system. Finally, the paper study the logistics distribution center information management model from three aspects of the system design objectives, system function analysis and system architecture design based on RFID.展开更多
The evolution of spermatophytes(seed plants)is relatively well known in their evolutionary relationships over temporal changes,but their spatial evolution is another critical yet often neglected lens,especially using ...The evolution of spermatophytes(seed plants)is relatively well known in their evolutionary relationships over temporal changes,but their spatial evolution is another critical yet often neglected lens,especially using a taxon-based approach.Here,by integrating geographic distributions and origin locations across 429 spermatophyte families worldwide with unsupervised machine learning approaches,we constructed a Spermatophyte Spatial Evolutionary System(SSES)that classifies global spermatophytes into 18 distribution types and six distribution supertypes within three primary floristic elements:cosmopolitan,tropical,and temperate.We found that the three elements all primarily originated from Gondwana,with the cosmopolitan element being the youngest and the temperate element being the oldest in terms of origin.They primarily formed during the Tertiary,particularly between the Eocene and Miocene,driven mainly by climate,long-distance dispersal,and tectonic movement,while each exhibited distinct migration routes and formation models.Our results provide novel insights into the spatial evolution of global spermatophytes and highlight that similar distribution patterns of spermatophytes were driven by their comparable formation processes and mechanisms at the levels of floristic element,distribution supertype,and type.展开更多
A major concern is to locate manufacturing plants and/or distribution centers to serve the needs of consumers widely and rapidly with reasonably distributive cost and flexible delivery time. The purpose of this resear...A major concern is to locate manufacturing plants and/or distribution centers to serve the needs of consumers widely and rapidly with reasonably distributive cost and flexible delivery time. The purpose of this research is to help enhance a decision support for three distribution center locations with different ranges of area in order that the distributors are able to serve appropriately the retailers in twelve large cities or capitals of the nine countries in Asia-Pacific region. The researcher applies the theory of supply chain and logistics management systems with Excel, Visual Basic and Genetic Algorithms programs to find the research results. The research results revealed that the interfaces of Excel, Visual Basic, and Genetic Algorithms programs helped decision support in distribution range selection for 3 distribution center locations. Each of which had different ranges of area for distribution with a rapidly, flexibly distributed time. However, variables resulting in a decision-making should be adjusted under certain circumstances for more reliable, specific needs.展开更多
The distribution control center(DCC)has evolved from a sideshow in the traditional distribution service center to a major centerpiece of the utility moving into the decentralized world.Mostly,this is the place where m...The distribution control center(DCC)has evolved from a sideshow in the traditional distribution service center to a major centerpiece of the utility moving into the decentralized world.Mostly,this is the place where much of the action is happening due to new forms of energy that are coining into the distribution system.This creates the flexibility of operation and in-creased complexity due to the need for increased coordination between the transmission control center and DCC.However,the US and European utilities have adapted to this change in very different ways.Firstly,we describe the research works done in a DCC and their evolutions from the perspectives of major US utilities,and those enhanced by the European perspective focusing on the coordination of distribution system operator and transmission system operator(DSO-TSO).We pres-ent the insights into the systems used in these control centers and the role of vendors in their evolution.Throughout this paper,we present the perspectives of challenges,operational capabilities,and the involvement of various parties who will be re-sponsible to make the transition successful.Key differences are pointed out on how distribution operations are conducted between the US and Europe.展开更多
A supported TiCl4/MgCl2 catalyst without internal electron donor （O-cat） was prepared firstly. Then it was modified by 2,6-diisopropylphenol to make a novel modified catalyst （M-cat）. These two catalysts were used...A supported TiCl4/MgCl2 catalyst without internal electron donor （O-cat） was prepared firstly. Then it was modified by 2,6-diisopropylphenol to make a novel modified catalyst （M-cat）. These two catalysts were used to catalyze ethylene/l-hexene copolymerization and l-hexene homopolymerization. The influence of cocatalyst and hydrogen on the catalytic behavior of these two catalysts was investigated. In ethylene/l-hexene copolymerization, the introduction of 2,6- iPr2C6H3O- groups did not deactivate the supported TiCl4/MgCl2 catalyst. Although the 1-hexene incorporation in ethylene/1- hexene copolymer prepared by M-cat was lower than that prepared by O-cat, the composition distribution of the former was narrower than that of the latter. Methylaluminoxane （MAO） was a more effective activator for M-cat than triisobutyl- aluminium （TIBA）. MAO led to higher yield and more uniform chain structure. In 1-hexene homopolymerization, the presence of 2,6-ipr2C6H3O- groups lowered the propagation rate constants. Two types of active centers with a chemically bonded 2,6-iprzCaH3O- group were proposed to explain the observed phenomena in M-cat.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 51028802 and 70902029)the PhD Programs Foundation of Ministry of Education of China (No. 20090092120045)
文摘Locating distribution centers optimally is a crucial and systematic task for decision-makers.Optimally located distribution centers can significantly improve the logistics system's efficiency and reduce its operational costs.However,it is not an easy task to optimize distribution center locations and previous studies focused primarily on location optimization of a single distribution center.With growing logistics demands,multiple distribution centers become necessary to meet customers' requirements,but few studies have tackled the multiple distribution center locations(MDCLs) problem.This paper presents a comprehensive algorithm to address the MDCLs problem.Fuzzy integration and clustering approach using the improved axiomatic fuzzy set(AFS) theory is developed for location clustering based on multiple hierarchical evaluation criteria.Then,technique for order preference by similarity to ideal solution(TOPSIS) is applied for evaluating and selecting the best candidate for each cluster.Sensitivity analysis is also conducted to assess the influence of each criterion in the location planning decision procedure.Results from a case study in Guiyang,China,reveals that the proposed approach developed in this study outperforms other similar algorithms for MDCLs selection.This new method may easily be extended to address location planning of other types of facilities,including hospitals,fire stations and schools.
文摘This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorithm (IGA) was proposed to solve the problem. The improvement of IGA is based on the idea of adjusting crossover probability and mutation probability. The IGA is supplied by heuristic rules too. The simulation results show that the IGA is better than the standard GA(SGA) in search efficiency and equality.
文摘In the light of the practical situation of logistics distribution of agricultural products,we primarily select transportation factor,economic factor,environment factor,and other factors,to establish evaluation index system of site selection of distribution center of agricultural products.And then we adopt the analytic hierarchy process method to calculate weight of site selection of distribution center of agricultural products.Under the circumstance that the evaluation information is interval number,we use uncertain and multiple attribute decision making method to establish site selection model of distribution center of agricultural products.Finally,taking one city as an example,we discuss the application of this model in site selection of distribution center of agricultural products.The results of empirical analysis show that the model we established fully considers the randomness and uncertainty in the process of evaluation,so as to make the results of evaluation more objective,in line with reality.So the effect of evaluation is better as against the former real number evaluation calibration.
文摘This paper studies the location of Wuhan steel logistics distribution center. First of all, according to Wuhan Iron and Steel Plant sales in Hunan Province and the relative position of the city, the transport costs are calculated from Wuhan Iron and Steel Plant to the demand point. We further analyze the necessity of establishing steel logistics distribution center, using the precise center of gravity to determine the actual location of the distribution center. After the establishment of distribution center, the total freight is reduced by 15.46 million yuan from Wuhan Iron and Steel Plant to each city in Hunan province via distribution center each year. The results of this paper can provide theoretical basis for the logistics node planning of related enterprises.
文摘A supply chain is a network that performs the procurement of raw material, the transportation of raw material to intermediate and end products, and the distribution of end products to retailers or customers. Installation and operation of distribution centers and all downstream members play a vital role in fulfilling the customers demand and have a great impact for supply chain management performance. In this paper we address a new approach for solving a supply chain optimization model to decide distribution centers based on environmental consideration.
文摘Objective: to explore the influence of optimizing hospital sensing and control management of static distribution center on infusion quality. Methods: 80 patients were selected as subjects in a hospital. In order to highlight the research results, the selected subjects were equally divided into experimental group and control group, and different nursing measures were used for the patients in the two groups. Tthe patients in the control group used routine nursing methods in the process of infusion treatment, while the experimental group took measures to optimize hospital sensing and control on the basis of routine nursing methods. On the premise of ensuring that other conditions of the two groups of patients do not change, after taking different nursing measures for the two groups of patients, compare the infusion satisfaction of the two groups of patients and the probability of adverse infusion events. Results: the incidence of adverse infusion events was 15.00% in the control group and 2.50% in the experimental group;The satisfaction of infusion nursing in the control group was 77.50%, while that in the experimental group was 95.00% (P < 0.05). Conclusion: the application of optimized hospital sensing and control management method in the static distribution center can improve patients infusion satisfaction and reduce the probability of adverse infusion reactions. Therefore, this method is worthy of comprehensive promotion and application in the hospital.
基金This work is supported by the National Natural Science Foundation of China[grant numbers 71132006,71421002,71171135].
文摘The location selection of the logistics distribution center for a supply and demand network(SDN)enterprises directly affected the efficiency of the logistics system operation and the customer service level.In this paper,we present a location selection model of the logistics distribution center for SDN enterprises.In order to improve the optimization effectiveness of the traditional methods in solving the location selection problem,an improved firefly algorithm was presented.By introducing a coordination factor,the search step can be automatically adjusted,and the accuracy of the algorithm can be improved.By introducing a chaotic search strategy,the diversity of firefly populations and the global optimization ability of the algorithm can be improved.The simulation experiments showed that the improved firefly algorithm achieved a more favorable effectiveness than three other algorithms we tested.
文摘Symbol Technologies, Inc., The Enterprise Mobility Company, today announced that it had been selected by ODIN technologies, the leader in the physics of RFID testing, software and deployment, to support its recent contract win with the United States Defense Logistics Agency (DLA), the United States Department of Defense’s (DoD) logistics combat support agency that provides supplies and services to America’s military forces worldwide.
文摘The composition distribution (CD) and microisotacticity distribution (ID) of propene/1-hexene copolymer synthesized by MgCl2/DIBP/TiCl4 (DIBP: diisobutyl phthalate) were determined by fractionating the copolymers according to crystallinity and characterizing the fractions by (CNMR)-C-13. The effects of two alkoxysilane donors, triethoxyphenylsilane (PTES) and dimethoxydi-tert-butylsilane (TBMS), on CD and ID of the copolymers were compared. Three main parts in the CD diagram of each copolymer were distinguished, which were correlated to active center distribution (ACD) based on three groups of different active centers. By studying the changes in l-hexene content, microisotacticity and reactivity ratio product of three typical fractions, the effects of external donor on ACD were better elucidated. It was found that TBMS shows much stronger effects on ACD than PTES. In the former system, most fractions were produced on active centers with relatively lower r(1)r(2), higher reactivity to I-hexene, and higher stereospecificity as compared to the system without external donor. It is concluded that the observed very extensive changes in ACD are mainly resulted by the formation of new types of active centers, possibly by coordination of external donor to certain positions on the catalyst.
基金the Major State Basic Research Programs(No.2005CB623804).
文摘Distribution of active centers(ACD)of ethylene or 1-hexene homopolymerization and ethylene-1-hexene copolymerization with a MgCl_2/TiCl_4 type Z-N catalyst were studied by deconvolution of the polymer molecular weight distribution into multiple Flory components.Each Flory component is thought to be formed by a certain type of active center. ACD of ethylene-1-hexene copolymer with very low 1-hexene incorporation was compared with that of ethylene homopolymer to see the effect of introducingα-olefin on ethyle...
文摘In recent years,Danyang in Jiangsu Province-one of China’s key eyewear manufacturing and distribution centers-has leveraged its“small glasses”to power a“big industry.”
文摘Constructing circulation mode of high feasibility and good implementation effect is the key method to solve difficulties in the development of “Agricultural Super-Docking” at present in China. There are many problems that exist in the process of the development of “Agricultural Super-Docking” by our analyzing from both the benefit of subjects and the whole supply chain perspectives. A large amount of relevant literature research shows that adopting the “cooperation between the government and the third party logistics enterprises to build distribution center” innovation model can solve these problems. This model can effectively remove obstacles between farmers and supermarkets. It is conducive to the development of small and medium-scale the farmer cooperatives, supermarkets and the third party logistics enterprises that don’t have a strong financial strength and a high degree of brand influence. In addition, it can also produce considerable social benefits. In order to ensure the implementation efficiency of the model to maximize, some management issues in the implementation process about the determination of core subject in supply chain, the method of evaluating the third party logistics enterprises grade, the planning of the number of customers for the distribution center, the mechanism of income distribution among multiple subjects and the implementation of relevant policies after the model into practice should be taken into account.
文摘The paper study communication protocol, the structure of the circuit, antenna design of radio frequency identification technology （RFID）, and puts forward a scheme based on IOT application： RFID logistics tracking system. Finally, the paper study the logistics distribution center information management model from three aspects of the system design objectives, system function analysis and system architecture design based on RFID.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2024QZKK0200)the National Natural Science Foundation of China(32322006 and 32100187)+2 种基金the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U23A20149)the Key R&D Program of Yunnan Province(202103AF140005 and 202101BC070002)the Strategic Biological Resources Capacity Building Project of Chinese Academy of Sciences(KFJBRP-017-08)。
文摘The evolution of spermatophytes(seed plants)is relatively well known in their evolutionary relationships over temporal changes,but their spatial evolution is another critical yet often neglected lens,especially using a taxon-based approach.Here,by integrating geographic distributions and origin locations across 429 spermatophyte families worldwide with unsupervised machine learning approaches,we constructed a Spermatophyte Spatial Evolutionary System(SSES)that classifies global spermatophytes into 18 distribution types and six distribution supertypes within three primary floristic elements:cosmopolitan,tropical,and temperate.We found that the three elements all primarily originated from Gondwana,with the cosmopolitan element being the youngest and the temperate element being the oldest in terms of origin.They primarily formed during the Tertiary,particularly between the Eocene and Miocene,driven mainly by climate,long-distance dispersal,and tectonic movement,while each exhibited distinct migration routes and formation models.Our results provide novel insights into the spatial evolution of global spermatophytes and highlight that similar distribution patterns of spermatophytes were driven by their comparable formation processes and mechanisms at the levels of floristic element,distribution supertype,and type.
文摘A major concern is to locate manufacturing plants and/or distribution centers to serve the needs of consumers widely and rapidly with reasonably distributive cost and flexible delivery time. The purpose of this research is to help enhance a decision support for three distribution center locations with different ranges of area in order that the distributors are able to serve appropriately the retailers in twelve large cities or capitals of the nine countries in Asia-Pacific region. The researcher applies the theory of supply chain and logistics management systems with Excel, Visual Basic and Genetic Algorithms programs to find the research results. The research results revealed that the interfaces of Excel, Visual Basic, and Genetic Algorithms programs helped decision support in distribution range selection for 3 distribution center locations. Each of which had different ranges of area for distribution with a rapidly, flexibly distributed time. However, variables resulting in a decision-making should be adjusted under certain circumstances for more reliable, specific needs.
基金MONKS,Sarajevo,FBiH,Bosnia and Herzegovina(No.27-02-11-41250-34/21).
文摘The distribution control center(DCC)has evolved from a sideshow in the traditional distribution service center to a major centerpiece of the utility moving into the decentralized world.Mostly,this is the place where much of the action is happening due to new forms of energy that are coining into the distribution system.This creates the flexibility of operation and in-creased complexity due to the need for increased coordination between the transmission control center and DCC.However,the US and European utilities have adapted to this change in very different ways.Firstly,we describe the research works done in a DCC and their evolutions from the perspectives of major US utilities,and those enhanced by the European perspective focusing on the coordination of distribution system operator and transmission system operator(DSO-TSO).We pres-ent the insights into the systems used in these control centers and the role of vendors in their evolution.Throughout this paper,we present the perspectives of challenges,operational capabilities,and the involvement of various parties who will be re-sponsible to make the transition successful.Key differences are pointed out on how distribution operations are conducted between the US and Europe.
基金supported by the National Natural Science Foundation of China (No. 20874084)the Special Research Fund for the Doctoral Program of Higher Education (No. 20100101110136)
文摘A supported TiCl4/MgCl2 catalyst without internal electron donor （O-cat） was prepared firstly. Then it was modified by 2,6-diisopropylphenol to make a novel modified catalyst （M-cat）. These two catalysts were used to catalyze ethylene/l-hexene copolymerization and l-hexene homopolymerization. The influence of cocatalyst and hydrogen on the catalytic behavior of these two catalysts was investigated. In ethylene/l-hexene copolymerization, the introduction of 2,6- iPr2C6H3O- groups did not deactivate the supported TiCl4/MgCl2 catalyst. Although the 1-hexene incorporation in ethylene/1- hexene copolymer prepared by M-cat was lower than that prepared by O-cat, the composition distribution of the former was narrower than that of the latter. Methylaluminoxane （MAO） was a more effective activator for M-cat than triisobutyl- aluminium （TIBA）. MAO led to higher yield and more uniform chain structure. In 1-hexene homopolymerization, the presence of 2,6-ipr2C6H3O- groups lowered the propagation rate constants. Two types of active centers with a chemically bonded 2,6-iprzCaH3O- group were proposed to explain the observed phenomena in M-cat.
