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Ek Peng Chew - One of the best experts on this subject based on the ideXlab platform.
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short term space allocation for Storage Yard management in a transshipment hub port
OR Spectrum, 2014Co-Authors: Xinjia Jiang, Ek Peng Chew, Loo Hay Lee, Kok Choon TanAbstract:In transshipment ports, the containers to the same destination vessel are usually stored together to facilitate the loading process, which is called the "consignment". During operation, the actual containers that will come in are only known for a short period in advance. Thus, short-term space allocation is needed to assign incoming containers taking into account the transporting vehicles, Yard cranes and Storage space. Currently, the space is allocated based on the experience of port operators. To balance the current and future impacts of short-term planning, we develop a systematic method called "space allocation given long-term plan (SALP)". The corresponding MIP model is formulated to utilize not only the short-term information, which includes the existing containers and the actual incoming containers, but also the given long-term plan, which provides a forecast of future requirements. The SALP method is evaluated under two Storage strategies to achieve consignment, namely, the "non-sharing strategy" and the "flexible space-sharing strategy". The numerical experiments show that the SALP method improves operational efficiency, but its performance is affected by the portion of long-term plan under consideration. The SALP method performs well under both Storage strategies when space is sufficient. However, the performance under the "flexible space-sharing strategy" is better than the "non-sharing strategy" when space is tight.
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flexible space sharing strategy for Storage Yard management in a transshipment hub port
OR Spectrum, 2013Co-Authors: Xinjia Jiang, Ek Peng Chew, Loo Hay Lee, Kok Choon TanAbstract:In this paper, a Storage Yard planning problem is studied for a transshipment port with limited space and high-throughput level. Generally, the consignment strategy is used in the Yard for a transshipment port, where containers to the same destination vessel are stored together. This is to facilitate faster loading process as it reduces reshuffles as well as long distance movements of Yard cranes. However, the consignment strategy is known to be inefficient in space utilization since each Storage location must be dedicated to a particular vessel. To improve the space utilization while retaining the advantage of consignment, a new approach named the "flexible space-sharing strategy" is proposed. The idea is that the container space can be shared by two different vessels as long as their containers do not occupy the space at the same time. This strategy allows the same Storage location to be reserved for two vessels. The amount of space will only be allocated to a specific vessel on the arrival of corresponding containers. By controlling where to stack the containers in the Storage locations, the containers to each vessel are not mixed and the consignment feature can be preserved. This strategy is first formulated as a mixed integer program (MIP). As the MIP model has a block diagonal structure, we develop a search algorithm which combines MIP and heuristics to find the solution. The numerical experiments show that the "flexible space-sharing strategy" can handle much more containers within the same Storage space compared with the "non-sharing strategy".
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a container Yard Storage strategy for improving land utilization and operation efficiency in a transshipment hub port
European Journal of Operational Research, 2012Co-Authors: Xinjia Jiang, Ek Peng ChewAbstract:This paper studies the Storage Yard management problem in a busy transshipment hub, where intense loading and unloading activities have to be considered at the same time. The need to handle huge volumes of container traffic and the scarcity of land in the container port area pose serious challenges for the port operator to provide efficient services. A consignment strategy with a static Yard template has been used to reduce the level of reshuffles in the Yard, but it sacrifices on land utilization because of exclusive Storage space reservation. Two space-sharing approaches are proposed to improve on the land utilization through dynamic reservation of Storage space for different vessels during different shifts. Meanwhile, workload assignment among reserved spaces will also satisfy the high-low workload balancing protocol to reduce traffic congestion in the Yard. A framework which integrates space reservation and workload assignment is proposed. Experimental results show that the framework is able to provide solutions for containers handling within much less Storage space, while guarantee the least Yard crane deployment.
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A SIMULATION STUDY ON THE USES OF SHUTTLE CARRIERS IN THE CONTAINER Yard
2010Co-Authors: S. G. Henderson, Ek Peng Chew, B. Biller, -h. M. Hsieh, J. Shortle, J. D. Tew, R. R. Barton, Loo Hay Lee, Kok Choon Tan, Huei Chuen HuangAbstract:In this paper, we investigate how two main factors affect the efficiency of the port operation. The two main factors are type of transport vehicles and layout of the Storage Yard. Two different types of transport vehicles (i.e., prime mover and shuttle carrier) and two different types of layouts (i.e., with or without chassis lane beside the container blocks) are modeled in this study. A total of four simulation models are created to conduct this study. To evaluate the performance, the gross crane rate is used as the main performance measure, which is defined as the number of containers moved per quay crane per working hour. In this paper, it has been shown that the incorporation of the chassis lane improves the gross crane rate for both prime movers and shuttle carriers. The improvement is more substantial when the port utilizes shuttle carriers.
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a Yard Storage strategy for minimizing traffic congestion in a marine container transshipment hub
OR Spectrum, 2008Co-Authors: Ek Peng ChewAbstract:This paper studies a Storage Yard management problem in a transshipment hub where the loading and unloading activities are both heavy and concentrated. In order to reduce the number of reshuffles, which helps to reduce the vessel turnaround time, the port operator uses the consignment strategy to group export and transshipment containers according to their destination vessel. To reduce the potential traffic congestion of prime movers, a high–low workload balancing protocol is used. A mixed integer programming model is formulated to determine the Storage locations of incoming containers, the number of incoming containers and the smallest number of Yard cranes to deploy in each shift. An iterative improvement method is developed to solve the problem, in which a tabu search based heuristic algorithm is used to generate an initial Yard template, and then the generated Yard template is improved by an improvement algorithm iteratively until an optimal or a satisfactory solution is obtained. Experiment results show that the proposed method can generate excellent results within a reasonable time, even for the extreme cases.
Xinjia Jiang - One of the best experts on this subject based on the ideXlab platform.
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short term space allocation for Storage Yard management in a transshipment hub port
OR Spectrum, 2014Co-Authors: Xinjia Jiang, Ek Peng Chew, Loo Hay Lee, Kok Choon TanAbstract:In transshipment ports, the containers to the same destination vessel are usually stored together to facilitate the loading process, which is called the "consignment". During operation, the actual containers that will come in are only known for a short period in advance. Thus, short-term space allocation is needed to assign incoming containers taking into account the transporting vehicles, Yard cranes and Storage space. Currently, the space is allocated based on the experience of port operators. To balance the current and future impacts of short-term planning, we develop a systematic method called "space allocation given long-term plan (SALP)". The corresponding MIP model is formulated to utilize not only the short-term information, which includes the existing containers and the actual incoming containers, but also the given long-term plan, which provides a forecast of future requirements. The SALP method is evaluated under two Storage strategies to achieve consignment, namely, the "non-sharing strategy" and the "flexible space-sharing strategy". The numerical experiments show that the SALP method improves operational efficiency, but its performance is affected by the portion of long-term plan under consideration. The SALP method performs well under both Storage strategies when space is sufficient. However, the performance under the "flexible space-sharing strategy" is better than the "non-sharing strategy" when space is tight.
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flexible space sharing strategy for Storage Yard management in a transshipment hub port
OR Spectrum, 2013Co-Authors: Xinjia Jiang, Ek Peng Chew, Loo Hay Lee, Kok Choon TanAbstract:In this paper, a Storage Yard planning problem is studied for a transshipment port with limited space and high-throughput level. Generally, the consignment strategy is used in the Yard for a transshipment port, where containers to the same destination vessel are stored together. This is to facilitate faster loading process as it reduces reshuffles as well as long distance movements of Yard cranes. However, the consignment strategy is known to be inefficient in space utilization since each Storage location must be dedicated to a particular vessel. To improve the space utilization while retaining the advantage of consignment, a new approach named the "flexible space-sharing strategy" is proposed. The idea is that the container space can be shared by two different vessels as long as their containers do not occupy the space at the same time. This strategy allows the same Storage location to be reserved for two vessels. The amount of space will only be allocated to a specific vessel on the arrival of corresponding containers. By controlling where to stack the containers in the Storage locations, the containers to each vessel are not mixed and the consignment feature can be preserved. This strategy is first formulated as a mixed integer program (MIP). As the MIP model has a block diagonal structure, we develop a search algorithm which combines MIP and heuristics to find the solution. The numerical experiments show that the "flexible space-sharing strategy" can handle much more containers within the same Storage space compared with the "non-sharing strategy".
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a container Yard Storage strategy for improving land utilization and operation efficiency in a transshipment hub port
European Journal of Operational Research, 2012Co-Authors: Xinjia Jiang, Ek Peng ChewAbstract:This paper studies the Storage Yard management problem in a busy transshipment hub, where intense loading and unloading activities have to be considered at the same time. The need to handle huge volumes of container traffic and the scarcity of land in the container port area pose serious challenges for the port operator to provide efficient services. A consignment strategy with a static Yard template has been used to reduce the level of reshuffles in the Yard, but it sacrifices on land utilization because of exclusive Storage space reservation. Two space-sharing approaches are proposed to improve on the land utilization through dynamic reservation of Storage space for different vessels during different shifts. Meanwhile, workload assignment among reserved spaces will also satisfy the high-low workload balancing protocol to reduce traffic congestion in the Yard. A framework which integrates space reservation and workload assignment is proposed. Experimental results show that the framework is able to provide solutions for containers handling within much less Storage space, while guarantee the least Yard crane deployment.
Peres, João Geraldo Molinari - One of the best experts on this subject based on the ideXlab platform.
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Viabilidade de utilização da serragem de couro para fins de obtenção de um material alternativo de construção
[s.n.], 2018Co-Authors: Peres, João Geraldo MolinariAbstract:Orientador: Wesley Jorge FreireDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia AgricolaResumo: Um dos grandes problemas hodiernos é o acentuado aumento populacional e, por conseguinte, a geração de uma enorme quantidade de materiais descartáveis, isto é, resíduos cumulativos da matéria-primajá utilizada, o que leva a se pensar em uma proposta de utilização destes diferentes resíduos para diversos fins. Os resíduos domiciliar e industrial na maioria das vezes são depositados em lixões a céu aberto e em aterros sanitários controlados, ou encaminhadosa usinas ou incineradores, muitas vezes sem qualquer tratamento prévio, podendo trazer conseqüências danosas para o ambiente e a saúde pública. As indústrias de curtimento de couro e a calçadista fazem parte daquelas que estão em constante evolução para atender à demanda crescente de consumo, e, ao mesmo tempo, forçadas a resolver os problemas gerados em função de sua própria atividade econômica, representados pelos resíduos originados de seu processo industrial. Dentre esses resíduos, pode-se citar os resíduos sólidos da indústria de curtimento de couro, mais conhecidos como "raspa de couro", "farelo de couro" ou "serragem de couro". São volumes consideráveis de materiais que, por falta de melhor alternativa, são encaminhados a aterros sanitários. Este trabalho foi desenvolvido, então, com a finalidade de estudar a possível utilização desses resíduos sólidos como adições em argamassas de cimento e areia visando a obtenção de um material alternativo de construção voltado, exclusivamente, à produção de pisos. Procurou-se não associar produtos ou materiais de reforço que, seguramente, confeririam melhores características fisico-mecânicas ao compósito obtido, a fim de que o efeito da incorporação dos resíduos estudados no desempenho da argamassa de cimento e areia não fosse mascarado. Para tal, foram confeccionados corpos-de-prova que, depois de devidamente curados, tiveram suas características fisicas e mecânicas determinadas através de ensaios não destrutivos de ultra-som, ensaios de compressão simples, análise da verificação dimensional, determinação do empeno, determinação da retitude lateral, determinação das curvaturas lateral e central, resistência ao impacto, resistência à flexão, determinação da absorção de água por capilaridade, determinação da absorção de água por imersão e resistência do material à abrasão profunda. Os resultados obtidos mostraram a viabilidade técnica do uso desse resíduo na produção de pisos, evidenciando, também, a necessidade de se dar continuidade a este trabalho, visando a melhoria das condições fisicas e mecânicas do material produzidoAbstract: Nowadays one of the most important Brazilian problems is the marked population increasing and therefore the generation of enormous volumes of disposable material like the cumulative used up raw material residues. This fact drives to the need for a proposal aiming at the utilization of these different kinds of residues. The domestic and industrial wastes in most cases are simply discarded in an open air Storage Yard, directed to a controlled sanitary landfill, or sent to incinerating plants uequently without any kind of previous treatment causing environrnentalharm and injury to public health. The leather tanning industry and the shoe manufacturing ones are among those evolutive industries trying to attend the increasing demand for their products; at the same time these industries are compelled to solve the problems generated by their ownecoflomical activity represented by their industrial processing refuses. The solid refuses obtained uom the leather tanning industry are commonly produced at considerable volumes which are usually directed to a controlled sanitary landfill. 80, this work was carried out in order to study the feasible utilization of the leather tanning refuse as a component of cement mortars for paving purposes. No chemical products or reinforcing materiaIs were used to ameliorate the physical and mechanical characteristics of the obtained composite so that the effect of the addition ofleather tanning refuse on the cement mortar was not hidden any way. For this purpose composite specimens were molded according to the previous established treatments and properly cured before being submitted to ultrasonic test, compressive test, dimensional checking, bending determination, lateral rectitude determination, lateral and central curvature determination, impact resistance, flexural strength, capillary water absorption test, immersion water absorption test and deep abrasion resistance.The results pointed out the technical feasibility of the leather tanning refuse addition to cement mortar for paving purposes making evident the need for new studies in order to obtain a material ofbetter physical and mechanical qualityMestradoConstruções Rurais e AmbienciaMestre em Engenharia Agrícol
João Geraldo Molinari Peres - One of the best experts on this subject based on the ideXlab platform.
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Viabilidade de utilização da serragem de couro para fins de obtenção de um material alternativo de construção
2014Co-Authors: João Geraldo Molinari PeresAbstract:Resumo: Um dos grandes problemas hodiernos é o acentuado aumento populacional e, por conseguinte, a geração de uma enorme quantidade de materiais descartáveis, isto é, resíduos cumulativos da matéria-primajá utilizada, o que leva a se pensar em uma proposta de utilização destes diferentes resíduos para diversos fins. Os resíduos domiciliar e industrial na maioria das vezes são depositados em lixões a céu aberto e em aterros sanitários controlados, ou encaminhadosa usinas ou incineradores, muitas vezes sem qualquer tratamento prévio, podendo trazer conseqüências danosas para o ambiente e a saúde pública. As indústrias de curtimento de couro e a calçadista fazem parte daquelas que estão em constante evolução para atender à demanda crescente de consumo, e, ao mesmo tempo, forçadas a resolver os problemas gerados em função de sua própria atividade econômica, representados pelos resíduos originados de seu processo industrial. Dentre esses resíduos, pode-se citar os resíduos sólidos da indústria de curtimento de couro, mais conhecidos como "raspa de couro", "farelo de couro" ou "serragem de couro". São volumes consideráveis de materiais que, por falta de melhor alternativa, são encaminhados a aterros sanitários. Este trabalho foi desenvolvido, então, com a finalidade de estudar a possível utilização desses resíduos sólidos como adições em argamassas de cimento e areia visando a obtenção de um material alternativo de construção voltado, exclusivamente, à produção de pisos. Procurou-se não associar produtos ou materiais de reforço que, seguramente, confeririam melhores características fisico-mecânicas ao compósito obtido, a fim de que o efeito da incorporação dos resíduos estudados no desempenho da argamassa de cimento e areia não fosse mascarado. Para tal, foram confeccionados corpos-de-prova que, depois de devidamente curados, tiveram suas características fisicas e mecânicas determinadas através de ensaios não destrutivos de ultra-som, ensaios de compressão simples, análise da verificação dimensional, determinação do empeno, determinação da retitude lateral, determinação das curvaturas lateral e central, resistência ao impacto, resistência à flexão, determinação da absorção de água por capilaridade, determinação da absorção de água por imersão e resistência do material à abrasão profunda. Os resultados obtidos mostraram a viabilidade técnica do uso desse resíduo na produção de pisos, evidenciando, também, a necessidade de se dar continuidade a este trabalho, visando a melhoria das condições fisicas e mecânicas do material produzidoAbstract: Nowadays one of the most important Brazilian problems is the marked population increasing and therefore the generation of enormous volumes of disposable material like the cumulative used up raw material residues. This fact drives to the need for a proposal aiming at the utilization of these different kinds of residues. The domestic and industrial wastes in most cases are simply discarded in an open air Storage Yard, directed to a controlled sanitary landfill, or sent to incinerating plants uequently without any kind of previous treatment causing environrnentalharm and injuryto public health. The leather tanning industry and the shoe manufacturing ones are among those evolutive industries trying to attend the increasing demand for their products; at the same time these industries are compelled to solve the problems generated by their ownecoflomical activity represented by their industrial processing refuses. The solid refuses obtained uom the leather tanning industry are commonly produced at considerable volumes which are usually directed to a controlled sanitary landfill. 80, this work was carried out in order to study the feasible utilization of the leathertanning refuse as a component of cement mortars for paving purposes. No chemical products or reinforcing materiaIs were used to ameliorate the physical and mechanical characteristics of the obtained composite so that the effect of the addition ofleather tanning refuse on the cement mortar was not hidden any way. For this purpose composite specimens were molded according to the previous established treatments and properly cured before being submitted to ultrasonic test, compressive test, dimensional checking, bending determination, lateral rectitude determination, lateral and central curvature determination, impact resistance, flexural strength, capillary water absorption test, immersion water absorption test and deep abrasionresistance.The results pointed out the technical feasibility of the leather tanning refuse addition to cement mortar for paving purposes making evident the need for new studies in order to obtain a material ofbetter physical and mechanical qualit
Jin Xin Cao - One of the best experts on this subject based on the ideXlab platform.
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Storage Yard management in maritime container terminals
Transportation Science, 2016Co-Authors: Jian Gang Jin, Derhorng Lee, Jin Xin CaoAbstract:This paper studies the daily Storage Yard manage problem arising in maritime container terminals, which integrates the space allocation and Yard crane deployment decisions together with the consideration of container traffic congestion in the Storage Yard. The integrated problem is formulated as an integer linear programming model with the objective of minimizing the Yard crane operating cost and the Yard crane interblock movement cost. A divide-and-conquer solution approach is designed to solve the problem in an efficient manner in which harmony search and constraint satisfaction techniques are employed. Numerical experiments are conducted to validate the performance of the solution approach and the improvement from the integrated optimization method.