Papers by Keyword: Heuristic Algorithm

Abstract: Well maintenance (well service and workover) is an operation needed by oil company to guarantee the optimum productionof its oil well.Well maintenance is performed using large equipment called hydraulic workover unit (HWU-Rig) which is available in limited number. Scheduling sequence of the HWU-Rig to do well service must meet the goal of the maintenance that is to minimize the loss of oil well production due to well breakdown. Thus minimizing breakdown time of well with high rate production is a priority. However, scheduling secuence of the HWU-Rig to perform its task for few days ahead become complicated due to the numerous alternatives of secuence to choose. Each alternatives of sequence yields a certain production loss. Arbitrarily scheduling sequence may not yield the goal og minimizing the loss of well production. This research was done by analyzing workover scheduling system and data from Kondur Petroleum such as well location, well production rate, and service time needed to be performed on wells. Algorithm to create schedulling sequence was developed in the research. The algorithm was then implemented in discrete simulation software, and yield the result of absolute global optimal solution, near optimal solution and local optimal solution of the HWU scheduling problem.

Abstract: In this paper, the analysis of the general tendencies of line building of cottage settlement is carried out by houses. The analysis of domestic and foreign development showed that many questions connected with formation of schedules of building of objects of settlement and calculation of parameters of works taking into account restriction on resources at development of local plans of settlement by houses, now finally aren't solved.As practice of construction of settlement shows further improvement of a technique of scheduling of building of settlement by houses has to go on an alternative basis and a choice among them the most effective on economic indicators because of modern computer technologies. The calculation procedure and optimization of options of the line organization of construction of houses because of modern computer technologies is offered.The technique of a technical and economic assessment of optimizing solutions of cottage building is offered. In this paper data on application to the developed technique for scheduling of construction of houses of settlement. The developed techniques can find application when developing projects of the organization of mass building of cottage settlement by houses.

Abstract: This paper uses VB software and accounting information transparency to improve BOT investment mode and establishes computer accounting algorithm using the form of software programming. It also uses the least squares SCF criterion to improve this algorithm and gets the BOT investment accounting information platform after the optimization. The platform mainly focuses on openness of accounting information transparency and account investment efficiency and economic benefit of BOT investment mode using the form of computer array computing. At last, through the calculation, this paper concludes the convergence curve of risk aversion and economic efficiency and analyzes the benefits of BOT investment in risk management and supply chain which provides a theoretical reference for the study of accounting information transparency.

Abstract: Service restoration which is an important part in smart distribution network has become more important in improving the reliability to customers and reducing the interruption loss. The mathematical model including objective functions and electrical constraints are overviewed in the paper. Three algorithms based on heuristic search, artificial intelligence and combinational method are elaborated separately. Finally, the problems needing to solve in future are discussed combining with the research status and the recent advance in distribution network.

Abstract: High-speed Railway Energy-saving Operation is a NP complete problem and it’s difficult to seek the optimal solution by tradition method. In this paper, considering the influence braking utilization to train operation, we established a high-speed railway minimum energy cost model, in which the optimization objective are maximizing the Interval efficiency and minimizing the total energy consumption. Then the model is solved by heuristic algorithm and the operation strategies are gotten. The simulation experiment result showed that when the braking utilization is equal to 0, the energy will be largely saved if the operation time is increased slightly; with the increasing of braking utilization, the percentage of saved energy will decrease correspondingly. So, the high-speed railway energy-saving operation strategy based on heuristic algorithm performed well.

Abstract: In the uncertain environment, the cycle re-claimer and logistics distribution cross warehouse scheduling is important and it should be optimized. The mathematical programming model is constructed, and the proposed two-stage heuristic algorithm is proposed, the optimal solution of heuristic algorithm is used as the initial value. And the taboo search algorithm is designed to improve the initial solution. In order to verify the availability of the method, the Monte Carlo simulation method is used for numerical experiment. The experiment results show that the new method can solve the suboptimal solution which close to the optimal solution in fast, and the taboo searching algorithm can improve the solution of heuristic algorithm, it has significantly improvement performance for new method, and it has good application value in practice.

Abstract: This paper considers the m-machine flow shop problem to minimize weighted completion time. A heuristic algorithm is presented to deal with the problem for large size problem. At the end of the paper, some numerical experiments show the effectiveness of the heuristic.

Abstract: This paper investigates the scheduling of the multi-crane operations in batch annealing process in an iron and steel enterprise so that the completion time of the last annealed coil (makespan) is minimized. The annealing process of each coil consists of two-stage: heating and cooling. To start heating (cooling) for each coil, a special machine named furnace (cooler) must be loaded on. Once the heating (cooling) is completed, the furnace (cooler) must be unloaded immediately without any delay by crane (job no-wait constraint). The aim of our studied problem is to schedule finite machines (furnaces and coolers) by cranes to process jobs under the consideration for avoiding collision between two adjacent cranes and satisfying job no-wait constraint. For solving the problem, we present a heuristic algorithm combining earliest job requirement and closest crane first. Through the theoretical analysis, we show the absolute performance bound of the proposed heuristic algorithm.

Abstract: The problem of scheduling for electronic satellites is a serious problem involving a lot of complex constraints. Considering the specific constraints of electromagnetic detection electronic satellite, on the basis of rational hypothesis, a multi-objective mathematic model was established. Several basic scheduling strategies were proposed. Based on the roulette method and hierarchical optimization method, a heuristic algorithm based on the rules was designed. A comprehensive evaluation with Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) for the algorithm was offered. Finally, some experiments are conducted to verify the correctness and practicability of our scheduling model and algorithm.

Abstract: A Flexible Manufacturing System (FMS) is an integrated, computer-controlled system of machines, automated handling systems, and storage systems that can be used to simultaneously manufacture a variety of jobs. FMSs can be characterized as asynchronous, concurrent, distributed and parallel systems in which multiple operations share multiple resources so that the performance criteria are optimized. Petri nets (PNs) have recently become a promising approach for modeling FMSs. PNs are formal graphical modeling tool that can be efficiently utilized as a process analysis and modeling tool, because it shows graphically and dynamically to simulate a process in an integrated manner. It is a mathematical modeling technique that is useful for modeling concurrent, asynchronous, distributed, parallel, nondeterministic, and stochastic systems. Unreasonably the dispatching resources/jobs to machine in FMS may result in a deadlock situation and the situation is studied thoroughly and avoided through PN techniques. From the design and analysis point of view, the uses of nets have many advantages in modeling, performance evaluation, qualitative analysis and code generation. Scheduling a manufacturing system is usually a Non-Polynomial hard problem. This means that only heuristic algorithms can be used to provide near-optimal schedule when it is merged with PN. The merging of PNs with knowledge based heuristic techniques seems to be very promising to deal with large complex discrete event dynamic systems. This paper presents a comprehensive survey of FMS that combines PNs with other methods.