• 제어로봇시스템학회논문지
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• 제17권9호
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• pp.932-940
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• 2011

This paper presents an integrated analysis of supply chain and financing decisions of multi-national corporation. We construct a model in which multiple currency storage units are installed to manage the currency flows associated with multi-national supply chain activities such as raw material procurement, process operation, inventory control, transportation and finished product sales. Core contribution of this study is to quantitatively investigate the influence of macroscopic economic factors such as exchange rates and taxes on operational decisions. The supply chain is modeled by the Process-Storage Network with recycle streams. The objective function of the optimization is minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders interpreted by home currency. The major constraints of the optimization are that the material and currency storage units must not be depleted. A production and inventory analysis formulation, the periodic square wave (PSW) model, provides useful expressions for the upper/lower bounds and average levels of the currency and material inventory holdups. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a subproblem and analytical lot sizing equations. The procurement, production, transportation and financial transaction lot sizes can be determined by analytical expressions after the average flow rates are already known. We show that, when corporate income tax is taken into consideration, the optimal production lot and storage sizes are smaller than is the case when such factors are not considered typically by 20 %.

• 전기학회논문지
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• 제60권4호
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• pp.717-725
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• 2011

In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.

• 한국주거학회논문집
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• 제26권4호
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• pp.45-53
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• 2015

The concept of universal design has become an essential requirement for environmental design, due to the growing population of the aged, and the increasing needs of people with disabilities. This study aims to propose a universal design guideline for apartment housing units that can be adapted to both a general household and a household with elderly or disabled individuals. This design process encompasses literary reviews, and includes the measurements of the dimensions and facilities of currently available apartment housing. The three domestic universal guidelines were reviewed, and a universal design checklist for apartment housing units was developed. Afterward, the individual elements and inclusive factors of universal design, for apartment housing units, were collected and examined according to the each functional space within the home. The results and conclusions are as follows: 1) The factors of universal design are diversified by the division of the functional spaces within the home, such as the private space, the work space and the entertaining space. 2) Due to the lack of space and storage, wheelchairs cannot be used in most currently available apartment types; this problem can be resolved by applying flexibility and optional adaptation. The solutions for the above are additional design factors that will enable more convenient usage and elaborate design.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2007년도 춘계학술대회 논문집
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• pp.49-52
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• 2007

The purpose of this study was to investigate unit care characteristics of large skilled nursing facilities for the elderly, which are located in city areas, and to discuss the way of encouraging home-like atmosphere in perspective of spatial unit. First of all, the analysis of five facilities opened before 2002 was performed, based on previous studies, to compare with them opened in recent 5 years. Most of the previous facilities did not have differentiation between their residential and nursing units, and the number of residents in each unit were excessive in comparison with the standard limit(12-28). On the contrary, the facilities established in recent 5 years had systematic spatial unit structure. The residential units had basically rooms and spaces for small group and the number of elderly residents per unit was appropriate on the basis of standard limit which was suggested by Kwon(2002). The nursing units were consist of nursing station, 2-3 residential units, spaces for large group of residents, hair dressing, nurse, living assistant, bathing, storage and etc. But, there was a problem In space usage even though they have distinct unit care systems. Some spaces for groups were empty without residents, furniture, and other equipments, which were necessary for unit care.

• 전력전자학회논문지
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• 제4권1호
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• pp.66-72
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• 1999

본 논문은 고주파 공진형 PWM 인버터식 X-선 장치의 인버터에 단상과 3상 전파정류방식 및 PSU 전원을 연결시켰을 때 나타나는 단시간 출력특성에 대해 분석하였다. X-선의 선질은 X-선관에 입력되는 DC 전압 파형에 의존한다. DC 출력전압 파형은 DC 전압전원의 고조파 왜곡에 의해 영향을 받는다. 이러한 관전압 파형의 왜곡은 X-선 출력의 직선성, 재현성 및 출력선질을 저하시킨다. 따라서 본 논문에서는 DC 출력전압 파형과 세 가지 형식의 DC 입력전원 형식에 따른 출력선량을 비교하였고 이에 따른 실험결과를 검토하였다.

• 한국실내디자인학회논문집
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• 제17권6호
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• pp.197-206
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• 2008

This study aimed to suggest practical and useful design directions for furniture for the rapidly-increasing university dormitory population. The process of the study took four steps; theoretical research, in-depth interview based on questionnaire, analysis, and development of design directions. Interviews were conducted with 25 university students living in dormitories in Seoul to find out problems with the existing furniture, students' satisfaction with the furniture, and their needs for other options. From these interviews, we found a few problems with dorm units, such as insufficient storage space, spaces too small for privacy, monotonous & standardized furniture design, and lack of multi-purpose furniture, etc. To support college students' complex lifestyles, five design directions were suggested from the analysis, such as a furniture design with highly multiple uses, modular furniture design, sufficient storage space, an application of various colors & materials, and practical use of dead space. Among these, two items were selected to be manufactured by the furniture design company. We expect that our suggested design directions for dorm furniture will support students' complex lifestyles, and satisfy students' needs with highly enhanced and better designed environments.

• 한국항공우주학회지
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• 제45권8호
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• pp.678-685
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• 2017

지구관측위성에 탑재되는 자료처리/저장장치 방열판은 장비의 주기적인 고발열, 배치, 장착성 등 설계 특성으로 인해 쉴드가 장착된 홈 형태를 갖는다. 홈 형태 방열판의 영향성과 쉴드 방열판의 열성능을 확인하기 위해, 평판 방열판을 기준으로 홈 형태의 방열판과 쉴드 방열판을 비교하여 열진공 시험을 실시하였다. 시험결과를 바탕으로 view factor에 의한 열교환과 방열판의 온도를 이론해석적으로 분석하여 열 설계 성능비교의 타당성을 입증하였다.

• 한국주거학회논문집
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• 제20권5호
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• pp.41-50
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• 2009

This case study is an effort to provide new knowledge on the U.S. elderly public housing focusing on the residents' perceptions of the environmental conditions. For this study, we conducted a survey using written questionnaires and interviews with 20 residents who rent in Columbia, MO. The recorded interview data was used for final analysis; primary findings are as follows: The residents reported relatively high satisfaction on their overall environmental conditions in the two target public housing, built in 1950s. As the most significant problem, residents perceive the lack of storage space for individual units, Partially attributed to space limitations. In addition, bathroom needs varied dramatically among residents based on their health and whether wheelchairs are used. Therefore, it was found that instead of standardized bathrooms, a customizable configuration for the resident's unique physical condition and accessibility must be considered. The residents also addressed their concerns about security for entrance and foyer areas. Due to the small living areas, they wanted to have available outdoor public space for various social activities. Furthermore, they reported the need for small social gathering areas while friends and family members are visiting them, in addition to their small living units, which average 49.8 sq. ft. each.

• Macromolecular Research
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• 제12권4호
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• pp.384-390
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• 2004

Single-walled carbon nanotubes (SWNTs) have been chemically modified through the formation of carboxylic acid functionalities or by grafting octadecylamine and polystyrene onto them. We purified SWNTs with nitric acid to remove some remaining catalysts and amorphous carbon materials. After purification, we broke the carbon nanotubes and shortened their lengths by using a 3:1 mixture of concentrated sulfuric acid and nitric acid. During these purification and cutting processes, carboxylic acid units formed at the open ends of the SWNTs. Octa-decylamine and amino-terminated polystyrene were grafted onto the cut SWNTs by condensation reactions between the amine and carboxylic acid units. The cut SWNTs did not disperse in organic solvents, but the octadecylamine-grafted and polystyrene-grafted SWNTs dispersed well in dichloromethane and aromatic solvents (e.g., benzene, toluene). Composites were prepared by mixing polystyrene with the octadecylamine-grafted or polystyrene-grafted SWNTs. Each composite had a higher dynamic storage modulus than that of a pristine polystyrene. The composites exhibited enhanced storage moduli, complex viscosities, and unusual non-terminal behavior when compared with a monodisperse polystyrene matrix because of the good dispersion of carbon nanotubes in the polystyrene matrix.

• 항공우주기술
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• 제2권2호
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• pp.58-65
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• 2003

소형위성인 다목적실용위성 아리랑1호(KOMPSAT-1)의 PFM (Proto-Flight Model)에 대한 시스템/서브시스템 기능시험 및 열주기시험을 Storage Plan에 의거하여 한국항공우주연구원 우주시험동 하이베이에서 기능시험팀에 의해 수행하여 장기간 저장에 의한 위성 부분품들의 성능이 감쇠됨 없이 양호함을 확인하였다. 본 서에서는 시험항목, 시험방법, 시험절차 및 시험결과를 정리하였다.