• Journal of Information Processing Systems
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• 제15권1호
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• pp.181-188
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• 2019

A production system is a management system that supports all activities to perform production operations at the manufacturing site. From the point-of-view of a smart factory, smart manufacturing systems redesigned the concept of onsite production systems to fit the entire system and its necessary functional composition. In this study, we select the key functions needed to build a smart factory for a PCB line and propose a new six-step model for the deployment of a smart manufacturing system by integrating essential functions. The smart manufacturing system newly classified the production and operation tasks of PCB manufacturing and selected necessary functions through requirement analysis and benchmarking of advanced companies. The selected production operation tasks are mapped to the functions of the system and configured into seven modules, and the optimal deployment model is presented to allow flexible responses to the characteristics of the tasks. These methodologies are first presented in this study, and the proposed model was applied to the PCB line to confirm that they had significant changes in the work method, qualitative effects, and quantitative effects. Typically, lead time and WIP have reduced by about 50%.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1993년도 추계학술대회발표논문집; 서강대학교, 서울; 25 Sep. 1993
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• pp.12-19
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• 1993

In general, the line balancing problem is defined as of finding an assignment of the given jobs to the workstations under the precedence constraints given to the set of jobs. Usually, the objective is either minimizing the cycle time under the given number of workstations or minimizing the number of workstations under the given cycle time. In this paper, we present a new type of an assembly line balancing problem which occurs in an electronics company manufacturing home appliances. The main difference of the problem compared to the general line balancing problem lies in the structure of the precedence given to the set of jobs. In the problem, the set of jobs is partitioned into two disjoint subjects. One is called the set of fixed jobs and the other, the set of floating jobs. The fixed jobs should be processed in the linear order and some pair of the jobs should not be assigned to the same workstations. Whereas, to each floating job, a set of ranges is given. The range is given in terms of two fixed jobs and it means that the floating job can be processed after the first job is processed and before the second job is processed. There can be more than one range associated to a floating job. We present a procedure to find an approximate solution to the problem. The procedure consists of two major parts. One is to find the assignment of the floating jobs under the given (feasible) assignment of the fixed jobs. The problem can be viewed as a constrained bin packing problem. The other is to find the assignment of the whole jobs under the given linear precedence on the set of the floating jobs. First problem is NP-hard and we devise a heuristic procedure to the problem based on the transportation problem and matching problem. The second problem can be solved in polynomial time by the shortest path method. The algorithm works in iterative manner. One step is composed of two phases. In the first phase, we solve the constrained bin packing problem. In the second phase, the shortest path problem is solved using the phase 1 result. The result of the phase 2 is used as an input to the phase 1 problem at the next step. We test the proposed algorithm on the set of real data found in the washing machine assembly line.

• Industrial Engineering and Management Systems
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• 제13권3호
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• pp.289-296
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• 2014

With society becoming more advanced and complex, the required management engineering makes essential the development of human resources that can propose solutions for problems of new phenomena from a different perspective. As an example of such phenomena, we note a consumer electronics 'Eco-point' system campaign in this study. To mitigate global warming, revitalize the economy, and encourage the adoption of terrestrial digital compatible TVs, the consumer electronics Eco-point system campaign was implemented in May 2009 in Japan. In this study, we note a model which is constant term with exponential curve with notion of the growth phenomenon (Nakagiri and Kurita, Journal of the Operations Research Society of Japan, 2002). In our study, we call this model the 'differential equation model of the growth phenomenon.' This model represents a phenomenon with a hierarchical structure for capturing the properties of n species. In this study, we propose a new model which can represent not only the impact of largescale campaigns but also seasonal factors. Accordingly, we understand the phenomenon of fluctuation of sales of some products caused by large-scale campaigns and predict the fluctuation of sales. The final goal of this study is to develop human resources that can propose provision and solution for pre-consumption and reactionary decline in demand by understanding the impact of large-scale campaigns. As the first step of this goal, our objective is to propose a new regression method with different conventional perspective that can describe the fluctuation of sales caused by large-scale campaigns and show the possibility of new management engineering education.

• 해양환경안전학회지
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• 제15권4호
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• pp.393-399
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• 2009

해양사고의 대부분은 해상교통량이 많은 연안해역과 해수욕장, 방파제 등 많은 사람들이 찾는 연안지역에서 발생한다. 최근 해양레포츠의 활성화로 연안에서의 안전사고위험은 더욱 증가하고 있다. 그러나 연안의 안전사고에 대한 대책이 안전사고 증가속도에 적절하게 대응하지 못하고 육지와 바다를 연계한 안전관리가 체계적이지 못하다. 최근 5년 동안 발생했던 안전사고를 분석하여 사고발생을 최소화할 수 있는 안전관리 대책방안에 대하여 연구하였다. 연안의 안전사고는 육지와 바다가 접촉되는 연안지역에서 발생하기 때문에 종합적인 안전대책이 필요하며, 종합적인 안전망 구축을 위해서 제도상 법률상으로 주무기관이 일원화되어야 한다. 또한 사고발생시 신속하게 인명과 재산을 구조할 수 있는 사고대응 체제가 체계적이고 효율적으로 작동되도록 구축되어야 한다.

• 융합보안논문지
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• 제13권3호
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• pp.55-62
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• 2013

시스템엔지니어링은 오늘날의 기업에 무척 중요하며 요구공학은 전반적인 과정상 중요한 단계이다. 요구공학은 고객으로부터 요구사항을 도출하고 문서화하는 것으로 시스템 개발의 첫 번째 단계이며, 시스템을 설계 제작하고 시험하고, 운영 유지하는 모든 과정이 요구사항에 관련되어 있어 프로젝트 성공의 매우 중요한 사항으로 평가된다. 프로젝트 성공을 위해 빈약한 요구사항을 최소화하도록 객체 지향 요구공학이 제안되어 졌다. 객체 지향 요구공학은 요구사항 각각에 대하여 기능성은 물론 제품과 프로세스에 대한 정보를 통합하여 관리하는 접근방식이다. 본 논문은 객체 지향적 요구사항 관리의 모범인 OCH(Operations Concept Harbinger)의 개념 적용을 통하여 사용자 요구 수집단계에서 다양한 이해관계자의 의견을 동시에 통합적으로 수렴하여 사용자 요구를 요구사항으로 전환하고 요구사항별로 추적함으로써 무기체계 획득을 위한 정확한 요구사항 개발과 관리를 가능케 하고 사용자 요구누락 및 왜곡을 방지하며 통합적 프로젝트 관리가 가능토록 제안하는 것이다.

• 한국정보과학회논문지:데이타베이스
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• 제30권6호
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• pp.585-592
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• 2003

공간 데이타베이스 시스템에서는 동일한 레이어 상에서 보안등급이 다른 두개 이상의 비공간 정보로 이루어진 공간 객체를 관리할 필요성이 있다. 이러한 공간 객체 관리를 위해 관계 데이터베이스 시스템의 다중인스턴스화(polyinstantiation) 기법을 적용하면 공간 객체의 표현상 문제와 상이한 보안등급을 가지는 주체의 접근으로 인한 서비스 거부(service denial)와 정보 노출(information flow)이라는 문제가 발생한다. 본 논문에서는 이와 같은 문제점을 해결하기 위해 상이한 접근등급을 갖는 공간 객체를 위한 다중인스턴스화 기법을 제안한다. 제안된 기법은 공간 객체에 대해 보안등급 변환검사 단계와 다중인스턴스 생성단계를 통하여 사용자의 등급에 따라 새로운 공간 객체를 생성하고, 이를 보안 정책에 활용한다. 또한 상이한 등급의 사용자가 공간 객체에 대하여 다양한 보안 연산을 요구할 경우 발생하는 서비스 거부와 정보노출의 문제점을 각 등급에 따른 공간 객체 다중인스턴스를 생성하여 해결한다.

• 대한영양사협회학술지
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• 제10권4호
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• pp.452-466
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• 2004

The purpose of this study was to assess the use of food materials at elementary school in Busan area and provide school meal management with basic data to improvement of guideline. A survey was done by e-mail with a set of questionnaires, which was responeded by 122 dietitians in elementary school foodservice. The results were as follows; Sixty percent of the dietitians though to the general imported food materials had to use. Regarding mean score of using the imported food materials; safety was 2.12/5.00, freshness 2.48/5.00, sanitation 2.68/5.00, nutrition 2.73/5.00, preference 2.93/5.00, external form 3.09/5.00, package 3.12/5.00, and price 3.63/5.00. Thirty seven percent of the dietitians had purchase the pro-environment farm products(PEFPs) and 32.0% of them purchased those products for the students' health. But 52.4% could not purchase to the PEFPs because of expensive price. They had negative opinions about deficient supplying of PEFPs 4.51/5.00, too expensive price 4.34/5.00, and the truth or false in source of PEFPs 3.96/5.00. Most of them perceived that using the PEFPs had to apply the step by step. Among of them, 33.9% had the knowledge of PEFPs, but 16.4 of them did not know to the PEPPs. 57.4% of them hoped to purchase the food materials through a center of supporting school meal servcie(it called non-profit-making organizations).

• 산업융합연구
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• 제18권6호
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• pp.147-154
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• 2020

상이한 특성을 가진 퍼블릭 블록체인과 프라이빗 블록체인에 대한 전체적인 동작을 통합적으로 교육하는 것은 용이하지 않다. 현재 블록체인의 개념과 동작을 위한 교육은 대부분 비트코인, 이더리움과 같은 퍼블릭 블록체인을 대상으로 하고 있다. 그러나 실제 기업환경에서는 사용자에 대한 인증을 통하여 기업 데이터에 접근통제를 하기 때문에 하이퍼레저패블릭(HLF)과 같은 프라이빗 블록체인이 활용되고 있다. HLF 기반으로 교육하는 경우에는 피어, 오더러, 채널 등 퍼블릭 블록체인에 없는 다양한 구성요소에 대한 이해가 필요하다. 본 논문에서는 이와 같은 구성요소의 기능과 동작에 대한 효율적이고 체계적인 이해를 위하여 실습프레임워크를 설계하였다. 설계된 프레임워크은 HLF 네트워크제어 체인코드제어 탈중앙화소프트웨어(Decentralized Application, dApp) 제어기능으로 구성되어 있다. 프레임워크을 통하여 네트워크을 구성하고 체인코드의 배포 및 활성화 후 dApp 실행과정을 단계적으로 확인하였고 블록체인 서비스를 위한 전체 흐름을 이해하는 것이 매우 용이하였다. 또한 향후 네트워크의 확장 등에도 전체 흐름에 대한 체계적인 이해가 가능할 것으로 기대한다.

• Agribusiness and Information Management
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• 제11권2호
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• pp.5-15
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• 2019

The world of smart agribusiness is still far from being fully and effectively applied by the Italian entrepreneurial fabric. In part, this is due to the fact that its potential and important connections with the technological world of reference are not fully known. The imperative is therefore: to learn how to manage all the processes that characterize the agricultural chain in a synergistic way, from production to the sale of the product to the final consumer. It is therefore essential to know every minimum aspect of the supply chain considering the current strengths on which to leverage but especially the weaknesses on which to intervene thanks to the use of technology available on the market. Today, the supply chain is still considered as a set of phases, one consecutive to the other, as if they were detached from each other. However, in order to operate efficiently, each step should be interconnected: from the farmer's decision to produce an agricultural good to the choice of production factors, from the implementation of harvesting and post-harvest operations to processing, from the selection of goods suitable for sale to the logic of distribution on the target territory. This work investigates the potential strategy using digital technologies in order to make dynamic the agribusiness supply chain, especially because in Italy the agri-food is one of the most important economic sectors but it is far from the most innovative trends available on the market.

• Nuclear Engineering and Technology
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• 제42권5호
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• pp.590-599
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• 2010

Recently, efficient operation and practical management of power plants have become important issues in the nuclear industry. In particular, typical aging parameters such as stress and cumulative usage factor should be determined accurately for continued operation of a nuclear power plant beyond design life. However, most of the major components have been designed via conservative codes based on a 2-D concept, which do not take into account exact boundary conditions and asymmetric geometries. The present paper aims to suggest an effective fatigue evaluation methodology that uses a prototype of the integrated model and its transfer functions. The validity of the integrated 3-D Finite Element (FE) model was proven by comparing the analysis results of individual FE models. Also, mechanical and thermal transfer functions, known as Green's functions, were developed for the integrated model with the standard step input. Finally, the stresses estimated from the transfer functions were compared with those obtained from detailed 3-D FE analyses results at critical locations of the major components. The usefulness of the proposed fatigue evaluation methodology can be maximized by combining it with an on-line monitoring system, and this combination, will enhance the continued operations of old nuclear power plants.