Warehouse operations have a significant role to survive in today's competitive world. Hence, companies introduce various solutions to improve efficiency of warehouses which is mainly affected by the performance of...
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Warehouse operations have a significant role to survive in today's competitive world. Hence, companies introduce various solutions to improve efficiency of warehouses which is mainly affected by the performance of storage operations. This study deals with a real-life storage location and assignment problem encountered in a fastener company where several orders consisting steel coils are to be assigned into storage areas. Three individual objective functions;minimizing the number of lanes to be used, minimizing area usage, and maximizing volume utilization are considered. For the investigated problem, first, an integer linear programming (ILP) model is developed. Then, a greedy randomized adaptive search procedure (GRASP) which provides quick and efficient solutions is proposed. The proposed methods are applied to the real problem case and the results are compared with the current storage assignment. Moreover, through an extensive computational study, the performances of proposed methods are evaluated on a set of test problems with different range of characteristics. The computational results show that the ILP model proves optimality in most of the problem instances within reasonable computation times, while the GRASP gives quick solutions with small optimality gaps.
This paper presents a new procedure for solving the integer linear programming problem when the objective function is a linear function and the set of constraints is in the form of linear inequality constraints. The p...
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This paper presents a new procedure for solving the integer linear programming problem when the objective function is a linear function and the set of constraints is in the form of linear inequality constraints. The proposed procedure is based on the conjugate gradient projection method together with the use of the spirit of Gomory cut. The main idea behind our method is to move through the feasible region through a sequence of points in the direction that improves the objective function. Since methods based on vertex information may have difficulties as the problem size increases, therefore, the present method can be considered as an interior point method, which had been proved to be less sensitive to problem size. A simple production example is given to clarify the theory of this new procedure.
The authors are to be commended for adding a new technique to the seemingly replete arsenal of optimization procedures for this problem. But this is not indeed a new technique. In fact so far only evolutionary algorit...
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The authors are to be commended for adding a new technique to the seemingly replete arsenal of optimization procedures for this problem. But this is not indeed a new technique. In fact so far only evolutionary algorithms have been proved to deal with the discrete nature of commercial pipe diameters without resorting to rounding continuous diameters or splitting the pipe reach into two segments.
This article presents an inventory management model for profit maximization in a Peruvian retail company (FIDEL) using linearprogramming techniques and the Branch and Bound algorithm. To introduce this paper we refut...
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This article presents an inventory management model for profit maximization in a Peruvian retail company (FIDEL) using linearprogramming techniques and the Branch and Bound algorithm. To introduce this paper we refute, through a review of previous studies in the same field, the use of this approach for its effectiveness in business decision-making. Gathering data on costs, demand and the available capital for the company’s different product lines was done through the use of interviews. The proposed model aims to maximize revenue based on the quantities of goods purchased, while considering minimum demand and capital constraints. Validation was performed with Lingo software to confirm the consistency and feasibility of the model. The resulting values revealed a significant increase in projected profits compared to actual data.
This paper shows an optimization method for redemption and due date matching which assigns the receivables to the payments date under the pre-defined constraints which related companies specified. Our proposed method ...
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ISBN:
(纸本)9789898111586
This paper shows an optimization method for redemption and due date matching which assigns the receivables to the payments date under the pre-defined constraints which related companies specified. Our proposed method determines the pairs of the receivables and the payment with proper new settlement date which closes the fluid assets of companies to their target amounts by extending/shortening the redemption/due date. This paper shows that this matching program is categorized in integer linear programming. By applying this matching mechanism, transferors could utilize credit of issuers and also reduce fluid assets for payments. Effectiveness of our optimization method is shown by executing simulation which emulates the issuing and receiving status of receivables in Japanese companies.
A new global routing method is proposed for sea-of-gates (SOG) arrays and custom logic arrays based on a zero-one linearintegerprogramming technique. This method overcomes the various difficulties due to numerous ph...
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A new global routing method is proposed for sea-of-gates (SOG) arrays and custom logic arrays based on a zero-one linearintegerprogramming technique. This method overcomes the various difficulties due to numerous physical constraints faced by many heuristic routing algorithms. In the proposed approach, all the physical constraints are rigorously modeled in the constraint equations. Alternatives for all the nets are considered simultaneously with the routing environment, instead of being routed in a particular net-ordering. An optimal set of global paths routing all the nets is found with well established zero-one linearintegerprogramming methods. The global router has run successfully on industrial SOG circuits, including 108 000 transistor circuits with 9400 nets, achieving 100% routing and high packing densities, which compare favorably with recently reported results.
With the limited resources such as the number of classrooms and instructors in educational institutions, course planning can be challenged in terms of determining which courses to offer to students in each term. The c...
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ISBN:
(纸本)9781450365994
With the limited resources such as the number of classrooms and instructors in educational institutions, course planning can be challenged in terms of determining which courses to offer to students in each term. The course planner needs to offer a minimum number of appropriate courses by examining the course sequences and the enrolled courses of every students in each term. The proposed problem formulation for an optimization with conditional constraints based on integer linear programming establishes an approach for efficient course planning. A course advising process assisted by this optimization allows students to enroll in appropriate courses in every terms. In this paper, students are enrolled in each term a set of 3 courses following the course sequence defined by the study plan such that every individual student can complete the program within 4 terms. The simulation carries out for 4 consecutive terms on students from 3 study programs with varied number of students in each term to quantitatively demonstrate that the high advising quality can achieved in spite of several resource constraints. A proposed evaluation index %Q is developed to confirm the advising quality.
The opportunity of finding conserved segments in different species has increased with the increasing availability of completely sequenced genomes. Similarity of different parts or regions of different genomes suggests...
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ISBN:
(纸本)9781728149592
The opportunity of finding conserved segments in different species has increased with the increasing availability of completely sequenced genomes. Similarity of different parts or regions of different genomes suggests evolutionary relationships among different species and might foretell functional roles which prevented genes to separate. These similar segments are called conserved gene clusters or gene clusters. Approximate Gene Cluster Discovery Problem (AGCDP) is the problem of finding genes that are kept together in different species. Presented in this study is an integer linear programming (ILP) formulation of the AGCDP. Since ILP is proven to be NP-complete, the study also made use of LP Relaxation since linearprogramming problems can be solved in polynomial time. The software used Java for the interface and other functionalities and R for solving ILP. InteGene, the tool produced by the study, can provide the user the best clusters given a set of data and input constraints which can be further tested for biological significance.
Process mining is based on event logs. Traditionally, an event log is a sequence of events. Yet, there is a growing amount of work in the literature that suggests we should extend the notion of an event log and use pa...
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ISBN:
(纸本)9783031336195;9783031336201
Process mining is based on event logs. Traditionally, an event log is a sequence of events. Yet, there is a growing amount of work in the literature that suggests we should extend the notion of an event log and use partially ordered logs as a basis for process mining. Thus, the need for algorithms able to handle these partially ordered logs will grow in the upcoming years. In this paper, we adapt an existing, classical process discovery algorithm to be able to handle partially ordered logs. We use the ILP Miner [1] as a basis and replace its region theory part by compact tokenflow regions [2] to introduce the ILP2 Miner. This ILP2 Miner handles sequential event logs just like the ILP Miner but, in addition, is able to directly process partially ordered logs. We prove that the ILP2 Miner provides the same guarantees regarding structural and behavioral properties of the discovered process models as the ILP Miner. We implement the ILP2 Miner and show experimental results of its runtime using three well-known example log files from the process mining community literature.
Unwrapping is a crucial step when analyzing ground displacements with InSAR techniques. Formulations of unwrapping as integer linear programming (ILP) problem suitable for PSInSAR were given by Costantini et al. under...
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ISBN:
(纸本)9781509033324
Unwrapping is a crucial step when analyzing ground displacements with InSAR techniques. Formulations of unwrapping as integer linear programming (ILP) problem suitable for PSInSAR were given by Costantini et al. under the name redundant integration of finite differences and by Shanker et al. under the name edge list algorithm. They allow the treatment of "4D"-graphs, in the sense of making use of the redundancy both in the PS-net and temporal graph, in a consistent way. This important advantage is paid for by a high computational load, which for large graphs even might prevent the algorithm from finishing in an acceptable time. The approach presented in this paper suggests subdividing the graph into spatio-temporal regions, thereby maintaining the advantage of redundancy, and solving the corresponding ILPs. This results in a considerable acceleration. Besides explaining our approach we report on results obtained for simulated and real data.
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