Earticle

In this paper, a hybrid method is proposed to design an air-core superconducting solenoid system for 6 T axial uniform magnetic field using Niobium Titanium (NbTi) superconducting wire. In order to minimize the volume of conductor, the hybrid optimization method including a linear programming and a nonlinear programming was adopted. The feasible space of solenoid is divided by several grids and the magnetic field at target point is approximated by the sum of magnetic field generated by an ideal current loop at the center of each grid. Using the linear programming, a global optimal current distribution in the feasible space can be indicated by non-zero current grids. Furthermore the clusters of the non-zero current grids also give the information of probable solenoids in the feasible space, such as the number, the shape, and so on. Applying these probable solenoids as the initial model, the final practical configuration of solenoids with integer layers can be obtained by the nonlinear programming. The design result illustrates the efficiency and the flexibility of the hybrid method. And this method can also be used for the magnet design which is required the high homogeneity within several ppm (parts per million).

본 연구는 기후변화로 초래될 수 있는 가뭄의 경제적 파급효과를 추정하고자 하였다. 아직 우리나라에는 수자원분야의 표준 시나리오가 없기 때문에 인위적으로 물부족을 가정하였으며, 분석은 수자원 투입산출 선형계획법(WIOLP)을 사용하였다. 추정결과, 경제내 필요한 수자원량 중 10%가 감소할 경우, 경제에 주는 피해액은 약 6조 4천억원으로 추정되었으며 물의 부족량에 따라 수자원의 잠재가격은 2,462원에서 76,902원까지 증가하는 것으로 추정되었다. 본 연구결과는 가뭄 등으로 인해 용수의 제약이 발생할 경우, 경제전체에 미치는 파급효과는 매우 클 수 있다는 것을 의미하며 수자원 관리의 필요성을 반영한다.

This study is to estimate economic damages of water shortage, especially drought. we assume scenarios of water shortage and use water input-output linear programming. The result is that economic damage is about 6.4 trillion won in the case of 10% water shortage. According to water shortage scenarios, the shadow price of water in Korea is increasing from 2,462 won to 76,902 won. This study indicates that water has a significant influence on the industrial production in Korea and provides the necessity of the climate change policy for water management.

본 연구는 국내 산업용수 이용량과 산업연관표를 연계하여 물 투입-산출 모형을 설정하고, 선형계획 법을 이용해 산업 부문(농업, 공업, 서비스업)별 수자원의 잠재가격을 추정하였다. 물 이용량과 산업 연관표 간의 통합을 위해 연동이 가능한 2014년 최근 자료(수자원통계 및 한국은행 산업연관표)를 적용하였으며, 산업용수 이용 업종 분류 체계에 맞추어 산업연관표의 30개 대분류를 12개 산업 부문 으로 재정의하였다. 각 부문별 물 투입 계수를 포함한 물 투입산출표를 설정한 뒤, 가용 수자원량과 업종 간 생산관계의 제약 속에서 각 용수의 잠재가격과 물 부족 시나리오에 따른 부문별 잠재가격 변화를 추정하였다. 주요 결과는 다음과 같다. 농업용수, 공업용수, 서비스업용수의 잠재가격은 각각 864원/㎥, 27,545원/㎥, 275,449원/㎥로 나타났으며, 물 부족 시나리오에 따른 잠재가격 변화 범위 (10% 제약~90% 제약)는 농업용수가 1,518원/㎥ ~ 2,369원/㎥, 공업용수가 61,721원/㎥ ~ 997,092원/㎥, 서비스업용수가 294,923원/㎥ ~ 381,192원/㎥이었다. 특히, 공업부문의 피해 수준이 50% 제약 수준에 서 급격히 증가된다는 점을 확인하였다.

This study set the water input-output model by linking the amount of water use to inter-industry relations table (IRT), and estimated shadow prices of water resources in agricultural, industrial and service sector using linear programming method. The 2014 water data and IRT data were collected and linked for integration of water usage and input-output table, and 30 major categories of IRT were redefined into 12 sub-sectors. Using the data, the shadow prices and their changes in each sector were estimated according to drought scenarios. The main results derived from the water input-output linear programming are as follows. Shadow prices of agriculture water, industrial water and service industry water were 864 won/㎥, 27,545 won/㎥ and 275,449 won/㎥ respectively. The shadow price changes by water shortage (10% to 90% constraint) ranged from 1,518 to 2,369 won/㎥ for agricultural use, 61,721 to 997,092 won/㎥ for industrial use, and 294,923 to 381,192 won/㎥ for service industry. In particular, it was confirmed that the damage level in the industrial sector increased sharply at the 50% restriction level.

퍼지 선형계획법은 불확실성하에서의 문제들을 해결하는데 유용한 의사결정 모형이다. 본 연구에서는 목 적함수 값이 퍼지수이고 우변 상수도 퍼지수인 융합 등식 제약식을 갖는 퍼지 선형계획법 문제를 다룬다. 연구의 목적은 퍼지 해를 정의하고 그것을 구하는 절차를 모색하는 것이다. 목적함수 값에 대한 소속 함수로 부분 선형함수 를, 제약식의 소속 함수로는 사다리꼴 함수를 도입한다. 사다리꼴 함수는 구간별 선형 함수 들로 나누어 나타낼 수 있다. 따라서 모든 소속 함수들을 선형식 들로 대체함으로써 퍼지 선형계획 모형을 Zimmermann의 대칭 선형 모형 으로 바꿀 수 있다. 여기에 최대-최소 기준을 적용하여 일반 선형계획법 문제를 도출해 내고, 이 문제의 최적해로부 터 원 문제의 퍼지 해를 얻게 된다. 본 논문에서는 사다리꼴 소속 함수에 대해 살펴보았는데 앞으로는 오목 부분 선형함수와 같은 좀 더 일반화된 소속 함수에 대한 연구가 필요하다.

The fuzzy linear programming(FLP) is the useful approach to many real world problems under uncertainty. This paper deals with a FLP whose objective value is fuzzy. And the right hand sides of convergent equality constraints are fuzzy numbers. We assume that the membership function of the objective value is piecewise linear and those of the right hand side are trapezoidal. Each of these trapezoidal functions can be algebraically replaced with three linear functions. Then the FLP problem is transformed into the Zimmermann's symmetric model. The fuzzy solution based on the max-min rule can be obtained by solving the crisp linear programming problem derived from the symmetric model. A numerical example has illustrated our approach. The application of our approach to the inconsistent linear system can enable generate us to get define the useful and flexible inexact solutions within acceptable tolerance. Further research is required to generalize the membership function.

Oil, hailed as modern industrial blood, is of greater significance to a state, and is closely related to people's lives. Shadow price of the oil industry is a key evaluation parameter for the business of an economy. In this paper, the application of input-output method and linear programming theory has been sought to establish an optimization model for the oil industry and the shadow price of the oil industry has been calculated according to the 2007 China input-output table. The analysis concludes that among the agriculture, the industry, and the tertiary industry, the prices of oil industry products bear maximum influence on the prices of agricultural products.

The purpose of this research was to make optimal design on capacity and number of multi-objective rainwater detention system that can satisfy irrigation and dimension of flood prevention as well as acquiring water source such as fire water, landscape water, and water for living in the medium and small scale basin where flood occurs frequently during focused raining due to the increase of impermeability layer. The methodology executed in this research was designed so that the construction fee and maintenance/management fee consumed in the rainwater detention system become minimized while various benefits including water and sewage cost, dam construction fee reduction, and flood damage cost reduction fee can be maximized. When considering the installation of rainwater detention system in the already developed cities or new cities, more effective design can be possible when using the same method.

With the growing popularity of cloud computing, more and more data owners are willing to outsource their data to the cloud. However, private data should be encrypted before outsourcing for security requirements, which obsoletes data utilization like content-based image retrieval. In this paper, we propose a secure similarity image search scheme, which allows data owners to outsource their encrypted image database to the cloud server without revealing the real content of images. The proposed scheme supports both global and local feature based image retrieval under various distance metrics, such as earth mover's distance. Firstly, the data owner extracts either global features or local features from images to represent the images. Then, these features are used to generate a searchable index. Finally, both image database and searchable index are encrypted before outsourcing to the cloud server. When a query image coming, the data user extracts feature from the query image and generates the search trapdoor. The trapdoor is then sent to the cloud server and used to compare the similarity with the searchable index. Extensive experiments are conducted to show the efficiency and applicability of our proposed similarity image search system.

In this paper, an energy efficient temperature control algorithm for peak power reduction in cooling systems of a large glass-covered building is proposed using control horizon method. A control horizon switching method and linear programming algorithm is used for optimal control, and a time-of-use (TOU) electricity rate is included to calculate the energy costs. Simulation results show that the reductions of energy cost and peak power can be obtained using proposed algorithms.

Distance function introduced by Shephard (1953) can be used to describe multi-inputs multi-outputs production technologies without price information. Estimated distance functions have been used for analyzing the economies of scale, the substitutability of inputs and outputs, the shadow prices of inputs and outputs, the tehcnical and allocative efficiencies of production organizations. Distance functions can be estimated using several techniques which include corrected ordinary least squares (COLS), stochastic frontier analysis (SFA), linear programming model (LPM), and quadratic programming model (QPM). In this paper we compared the merits and demerits of the four distance function estimation methods from a theoretical standpoint. Also we applied the estimation methods to the real data set used in some previous studies and we observed a guideline which allow researchers to select an appropriate distance function estimation method.

How to schedule multiple sensing units of a sensor to cover multiple targets becomes a new challenging problem. This problem is formulated as an integer linear programming problem for maximizing the network lifetime. We propose a novel energy-efficient target coverage algorithm to solve this problem based on clustering architecture. First of all, the network probability model is established and the subordinate relation between sensor nodes and the target nodes is presented. Secondly, a series of probability is computed and the related theorems and reasoning are also proven. Thirdly, effective coverage for the monitoring region is achieved through scheduling mechanism of nodes themselves, thus the purpose of increasing network lifetime can be realized. Finally, experimental results show that the proposed algorithm could achieve complete coverage for networks of different scale, and increase the network lifetime. It possesses the good quality of effectiveness and stability.

Based on data mining of outliers of time series, current studies have developed many methods, but there exist certain disadvantages for each method. This paper developed the method of mining outliers of time series based on linear programming model, verified high efficiency through an actual case and make up for the shortcoming of other methods.

In recent year, multi-layered semiconductor package is one of the most important technologies to enhance its performance. To bond between each layer of multi-chip package, die-bonding film is known as an effective material. We had developed a novel low-modulus die-bonding adhesive film. Properties of the films are widely changed by the ratio of epoxy resin and acrylic polymer contents. To satisfy the target properties, the influence of various parameters on material properties was examined. However, it is not easy for researchers to find out the formulation which satisfy the targets. To solve the problem, this paper proposes the weak conditioned combinatorial linear programming method (WCCLP). By defining solution area as a function of combination index, the optimum formulations are acquired. This optimization can be done by newly developed user-friendly software. The software is applicable not only to semiconductor related materials but also to any such formulation as paint, medicine and food.

Currently, issues related to freight at Vietnamese logistics companies are becoming more and more urgent because of typical problems in Vietnam such as traffic, infrastructure, and application of information technology. This problem has been studied by applying many different approaches such as Integer Programming (LP), Mixed Integer Programming (MIP), hybrid, meta search, … In this paper, we applied the ILP model in order to deal with the VRP problem in a small size logistics company which is very popular in Vietnam. The experiments showed promising results with some optimal solutions with some small extra costs.

Renewable sources integration is gaining importance in electrical utilities all over the world. The liberization of power sector in competitive regime, the share of renewable energy sources is increasing and it is essential to carry out the impact of clean energy on the system performance In this paper, analysis has been carried out with the PV-based distribution generation in the power system network. A Mixed Integer Nonlinear Programming (MINLP) approach has been utilized for determining optimal location and number of distributed generators considering minimization of fuel cost of conventional and solar PV power. The pattern of nodal real and reactive power prices have been obtained with and without PV integration. The results are also obtained for, loss reduction, fuel cost saving and voltage profile. The impact of different load models as PQ load and Zip load model has been studied. The proposed MINLP based optimization approach has been applied for IEEE24 bus reliability test system.

This paper presents a multi objective approach to solve a Capacitated Vehicle Routing Problem ith Time Windows (CVRPTW). The proposed model was implemented and tested in a real life roblem of a distribution company “Just in Time Delivery S.A” in Portugal. In this paper we ave considered an objective function with two main goals: the first is to minimize the total number f vehicles used in the distribution of the commodities to the several clients and the second is to inimize the travelling time of the used vehicles. The proposed model has been solved numerically sing the GLPK software and the optimal solution is presented.

Clostridium acetobutylicum is an attention-grabbing bacterium in that it produces several solvents, especially butan-1-ol. We reconstructed a genome-scale metabolic network of C. acetobutylicum ATCC 824 which comprises 502 reactions and 479 metabolites. Then, we carried out flux balance analysis using both linear and non-linear approach which is a modification of previous studies.1,2) Here, we present metabolic features and feasibilities of C. acetobutylicum, and hypothetical annotations derived during the reconstruction of the network. [This work was supported by the Korea–Australia Collaborative Research Project on the Development of Sucrose-Based Bioprocess Platform (N02071165) from the Korean Ministry of Knowledge Economy. Further support by LG Chem Chair Professorship and Microsoft are appreciated.]