• 전기학회논문지
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• 제64권7호
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• pp.1125-1129
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• 2015

Increasing peak load is one of the major concerns about operation of urban railroad systems. Since ESSs (Energy Storage Systems) have a great potential for shaving the peak load, there has been a growing interest in the use of ESS for peak load reduction. Also, ESS can be optimally scheduled to minimize the electricity purchasing cost under a given ToU (Time-of-Use) tariff by taking advantage of electricity price difference between peak and off-peak time. This paper presents a Mixed Integer Programming (MIP)-based ESS scheduling method to minimize the electricity purchasing cost under a ToU tariff for an urban railroad system.

• Management Science and Financial Engineering
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• 제11권1호
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• pp.63-78
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• 2005

Disassembly scheduling is the problem of determining the ordering and disassembly schedules of used or end-of-life products while satisfying the demand of their parts or components over a certain planning horizon. This paper considers the case of the assembly product structure for the cost-based objective of minimizing the sum of purchase, setup, inventory holding, and disassembly operation costs. To represent and solve the problem optimally, this paper presents an integer programming model, which is a reversed form of the multi-level lot sizing formulation. Computational experiments on an example derived from the literature and a number of randomly generated test problems are done and the results are reported.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.51-51
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• 2000

The ambiguity resolution is an essential task for the precise carrier phase differential GPS. In practice, however, there are still many problems in resolving the ambiguity in kinematic mode, especially in the urban areas. The multipath in received signal, the frequent change in visible satellites, and the cyclic slips make the ambiguity resolution very difficult task in real-time operation. In this paper, we consider a differential positioning with the float ambiguity that is free from the integer constraint. The float ambiguity estimation if carried out by the Kalman filter. The float and fixed ambiguities are combined together to determine the position in real-time kinematic mode.

• 한국국방경영분석학회지
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• 제30권2호
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• pp.133-140
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• 2004

In this paper, with the limited range of ammunition supply point(ASP) at ammunition battalion in specific corps and light automobile battalion(LAB) directly supports its vehicle for ammunition supply, we propose optimal model to minimize transportation time and logistics cost using integer programming(IP) for efficient ammunition resupply allocation during a given operation period of front combat unit. And then, we consider ammunition treatment and supply capacity of ammunition supply point(ASP), constraint elements of transportation ability considering time and cost, ammunition storage capacity of combat unit, combat situation and unit mission to propose this model. Finally, through numerical example, we examine the applicable feasibility of proposed model.

• 지능정보연구
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• 제4권1호
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• pp.1-10
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• 1998

Process planning is a very complex task and requires the dynamic informatioon of shop foor and market situations. Process plan selection is one of the main problems in the process planning. In this paper, we propose a new process plan selection model considering operation flexibility for the computer aided process planing. The model is formulated as a 0-1 integer programming considering realistic shop factors such as production volume, machining time, machine capacity, transportation time and capacity of tractors such as production volume, machining time, machine capacity, transportation time capacity of transfer device. The objective of the model is to minimize the sum of the processing and transportation time for all parts. A genetic algorithm a, pp.oach is developed to solve the model. The efficiency of the proposed a, pp.oach is verified with numerical examples.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.762-763
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• 2016

동형 암호화 시스템을 구현하는 데 있어, encrypt, decrypt, recrypt 연산은 큰 골격을 이루는 연산이다. 각각에 있어 공통된 가장 중요한 연산은 백만 비트가 넘는 큰 정수에 대한 법 곱셈이며, 이것은 푸리에 변환을 반복적으로 수행하여 얻을 수 있는 매우 큰 정수에 대한 곱셈 연산과 곱셈 결과에 대한 법 간소화를 요구한다. 본 논문에서는 Schonhage-Strassen이 제안한 큰 정수에 대한 법 곱셈을 수행하는 알고리즘을 응용하여, 이를 다시 메모리를 절약할 수 있는 효율적인 알고리즘을 제안하고 구현한다. 제안한 정수 푸리에 변환 구조는 FPGA에 구현하여 성능을 비교하였다.

• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.253-262
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• 2021

Global Navigation Satellite Systems (GNSS) based precise positioning using Real Time Kinematic (RTK) technique has been proposed as an enabler of the formation operation of moving vehicles. In RTK methods, the integer ambiguity of GNSS carrier phase measurements must be resolved. Although there have been many proposed algorithms for the integer ambiguity resolution, the widelane combination of carrier phase measurements and LAMBDA methods have gained the most popularity in literatures when dual frequency GNSS measurements were used. In this paper, we evaluated five alternative methods to determine relative positions of moving base and rover receivers; the round-off scheme of widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with dual frequency measurements. The paper presented the performance of each method using flight test data, which showed their strength and weakness in the aspects of time-to-first-fix, ambiguity resolution success ratio, and relative position errors. Based on that, we provided practical recommendations of RTK operations for moving vehicles.

• 한국항해항만학회지
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• 제43권5호
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• pp.273-280
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• 2019

This study developed an optimization model, defined as the IPS (Itinerary for Passenger Satisfaction), for a cruise ship to identify an itinerary that maximizes passenger satisfaction. A 0-1 integer programming model was developed to provide an optimal sequence of ports of call, assigning a destination to each day of the cruise. The concepts of the destination access network and the neighborhood of a destination were designed and manipulated to organize the complex network of destinations so that each next destination is selected within a practical overnight sail. The developed model can also be viewed as a reduced variant of the traveling salesperson problem with less constraints. A set of example tests shows that practical scenarios of the IPS with moderate cruise duration can be easily solved with light computation loads. Considering cruise ship passengers usually make their decisions not relying on only one destination but on an itinerary in its entirety, the purpose of this study was to identify itinerary alternatives to attract potential cruise passengers for attaining maximum occupancy level.

• 경영과학
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• 제12권1호
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• pp.1-17
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• 1995

The success of cell manufacturing applications in FMS rests on the effective cell formation to maintain the independent relations both between machine cells and between part families. This paper presents an integrated method for concurrent formation of cells and families with no E.E (Exceptional Element) in FMS with alternative routings. To determine the maximum number of cell and family with no E.E, mathematical conditions and properties are derived. New concept of nonsimilarity is introduced for each machine and part based on machine-operation incidence matrix and part-operation incidence matrix. To concurrently form the cells and families, integer programming based mathematical models are developed. For the predetermined number of cell or family, model I is used to identify whether E.E exists or not. Model II forms cells and families considering only nonsimilarity. But model III can consider nonsimilarity and processing times. The proposed method is tested and proved by using numerical examples.

• 품질경영학회지
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• 제41권3호
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• pp.371-380
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• 2013

Purpose: This study analyzes the optimal operation scheme of childcare centers in Korea to maximize the quality of childcare service by determining the number of children and number of teachers. Methods: This study employs a mathematical programming methodology called 'nonlinear integer programming (NLIP)' to solve the optimization problems and compare the quality of childcare service of optimal solutions with those of present operation scheme. Results: It is very successful in obtaining the optimal solutions for alternative capacities and they guarantee the substantial improvement in the quality of childcare service. Conclusion: Though more variables should be adapted for defining the quality of childcare service robustly, it is possible to conclude that childcare centers should modify their operation scheme to improve the quality of childcare service.