• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.459-459
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• 2000

The purpose of this paper is the application of the techniques for the new estimation of robustness for the aircraft systems having structured uncertainties. The basic ideas to analyze the system which is the originally nonlinear is Lyapunov direct theorems. The nonlinear systems have various forms of terms inside the system equations and this investigation is confined in the form of bounded uncertainties. The number of uncertainties will be the degree of freedoms in the calculation of the robust stability regions called the robustness bounds. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. Using this relaxing stability conditions, in this paper, the quadratic form of Lyapunov function is utilized. In this paper, the practical system of vertical take-off and landing (VTOL) aircraft is analyzed with the proposed stability criteria based upon the Lyapunov direct method. The application of numerical procedures can prove the improvements in estimations of robustness with structured uncertainties. The applicable aircraft system is assumed to be linear with time-varying with nonlinear bounded perturbations.

• KIEAE Journal
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• 제7권5호
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• pp.65-71
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• 2007

The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

• Journal of Power Electronics
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• 제17권6호
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• pp.1454-1468
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• 2017

In this study, a new dual-active soft-switching converter is proposed to improve conversion efficiency and extend the load range for an MTEM electromagnetic transmitter in geological exploration. Unlike a conventional DC/DC converter, the proposed converter can operate in passive soft-switching, single-active soft-switching, or dual-active soft-switching modes depending on the change in load power. The main switches and lagging auxiliary switches of the converter can attain soft-switching over the entire load range. The conduction and switching losses are greatly reduced compared with those of ordinary converters under the action of the cut-off diodes and auxiliary windings coupled to the main transformer in the auxiliary circuits. The conversion efficiency of the proposed converter is significantly improved, especially under light-load conditions. First, the working principle of the proposed converter is analyzed in detail. Second, the relationship between the different operating modes and the load power is given and the design principle of the auxiliary circuit is presented. Finally, the Saber simulation and experimental results verify the feasibility and validity of the converter and a 50 kW prototype is implemented.

• 에너지공학
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• 제11권3호
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• pp.187-193
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• 2002

가스화복합발전기술은 석탄 또는 중질유 등의 기존 발전연료 뿐만 아니라 잔사유 또는 나무와 같은 다양한 연료를 가스터빈에 사용할 수 있어 차세대 발전방식으로 부각되고 있다. 본 논문은 이러한 가스화 복합발전에서 가스화 하여 나온 저열량의 합성가스를 천연가스연료로 설계된 가스터빈에 사용할 때 가스터빈의 성능을 예측하였다. 이를 위해 제한된 설계 데이터로부터 가스터빈의 거동을 예측하는 시스템 적인 방법을 사용하여 발전용 GE 7FA가스터빈에 설계연료인 천연가스와 4가지의 다른 종류의 합성가스를 사용할 때 가스터빈의 설계조건과 탈 설계조건 성능을 예측하였다.

• 한국의상디자인학회지
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• 제22권3호
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• pp.75-87
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• 2020

As the online industry is vitalized by the fashion market, there is a tendency to believe that the recruitment of manpower in the online distribution field is increasing. Thus, this study attempts to analyze the job types and job functions for recruitment in the fashion industry based on job search sites and based on this, suggest an educational direction within the department of fashion design. First, when examining the size (number of employees) of fashion companies that posted jobs, the fashion companies with 30 or fewer employees accounted for 60.7% of the postings, and the location of the fashion companies was most commonly in Seoul with 144 companies located in Gangnam (Seocho-gu, Gangnam-gu). As for the recruitment conditions of the fashion companies, "academic level-irrelevant" was the highest with 42.6%, and in terms of gender and age, 59.3% of the cases were marked as "gender and/or age-irrelevant". Examining the types of jobs for recruitment in the fashion industry, fashion designers were the most popular at 52.6%, followed by on and off-line companies' MD, VMD, and stylist in that order. In the results of examining job function change, it is thought that the fashion design department should have basic educationon in that respect.

• 한국의류산업학회지
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• 제6권4호
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• pp.455-460
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• 2004

This study was performed to analyze the wearing practice and the purchasing characteristics of brassieres in order to offer basic data to produce superior brassiere and to improve the wearing comfort. The questionnaire were 146 Korean college female students. For data analysis, descriptive analysis, crosstabs, factor analysis and one-way ANOVA were used. The results were as follows, first, most subjects didn't know the sizing system of brassiere and their own breast size. So the degree of satisfaction of wearing brassiere was low than subjects who knew their own breast size. And they replied that the most unsatisfaction factor was brassiere size. Second, when subjects decided to purchase a brassiere they considered size, design, color, cost, fabric and brand and so on. Among them size and design were considered the most important. Third, the subjects who wear brassiere all day long, they considered wearing comfort and cost rather than design and collar. Therefore, the markets with brassieres would be able to segmented based on consumers' characteristics. Firth, the subjects were dissatisified at size, the taking off wire and shape modification after washing. And they requested the development of various size, fabric and cost improvement and fittness of brassieres. These results imply that to improve the wearing comfort of brassiere, it is so important to produce and develop various types of size first of all. And consumers should know size system of brassiere and their own breast size.

• 복식
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• 제63권2호
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• pp.68-81
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• 2013

The purpose of this study is the improvement of the senior patients' life quality by providing aesthetic and emotional stability by creating and providing a newly designed patient wear for them. Empirical research and analysis were done for the research. Survey from advanced research and clothing design for the senior citizens in Japan and German are analyzed. The result of this research extracted characteristics, which applied to the production of a severe senior patient wear. And the following characteristics emerged: affordability, comfort, aesthetics, and ease of putting on the clothes. To meet these conditions by the details of the clothing design, using fasteners like zippers and Velcro is useful. It is able to solve the problem of affordability making the vertically integrated overalls to be able being separated by zippers in order to reduce the volume of laundry. It was able to overcome the discomfort due to contamination of the feces through the use of the fasteners even though the importance of choosing the comfort material related closely to the comfort. Using material mixed with multiple colors, plaid or bright pink, instead of using neutral colors fulfilled the aesthetic requirement. In Particular, utilizing detachable function fasteners contributed great services.

• 한국농촌건축학회논문집
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• 제10권3호
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• pp.9-18
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• 2008

The study was intended to suggest the design alternatives of rural village community center based on the design directions which were derived from the previous research, and to evaluate the alternatives by rural residents. The previous research was carried out to grasp the conditions and user's needs of rural village community center. The subjects were 100 residents who lived in rural area in Chonlabukdo. The interview was carried out using a questionnaire with model and isometrics of two alternatives, which showed floor plan and building shape. The subjects evaluated positively both of two alternatives, but slightly more preferred alternative | because of a spacious diningroom and an indoor toilet. The size of a livingroom and entrance, indoor toilet space/location, storage space and deck were significant elements in two alternatives according to t-test. They responded that both of indoor and outdoor toilet should be planned in rural village center. Also, each toilet and room for man and woman should be separated. Entrance space should be enough to take on/off their shoes in a sitting position and deck space was planned to intermediate between indoor and outdoor space.

• 한국추진공학회지
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• 제19권3호
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• pp.89-95
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• 2015

7톤급 로켓엔진용 산화제펌프와 연료펌프에 대하여 물을 매질로 하는 성능시험을 수행하였다. 펌프는 전기모터로 구동되었고 설계 및 탈설계 유량비 조건에서 펌프의 수력성능과 흡입성능이 측정되었다. 양정-유량 곡선, 효율-유량 곡선, 양정-캐비테이션수 곡선을 얻었다. 개발된 펌프는 펌프 양정과 효율의 수력성능에 관한 설계요구조건을 만족시킬 수 있음을 확인하였다. 또한 흡입성능에 관한 설계요구조건을 만족시킨다.

• 한국초전도ㆍ저온공학회논문지
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• 제17권3호
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• pp.13-17
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• 2015

In superconducting coil applications particularly in wet wound coils, coated conductor (CC) tapes are subjected to different type of stresses. These include hoop stress acting along the length of the CC tape and the Lorentz force acting perpendicular to the CC tape's surface. Since the latter is commonly associated with delamination problem of multi-layered CC tapes, more understanding and attention on the delamination phenomena induced in the case of coil applications are needed. Difference on the coefficient of thermal expansion (CTE) of each constituent layer of the CC tape, the bobbin, and the impregnating materials is the main causes of delamination in CC tapes when subjected to thermal cycling. The CC tape might also experience cyclic loading due to the energizing scheme (on - off) during operation. In the design of degradation-free superconducting coils, therefore, characterization of the delamination behaviors including mechanism and strength in REBCO CC tapes becomes critical. In this study, transverse tensile tests were conducted under different loading conditions using different size of upper anvils on the GdBCO CC tapes. The mechanical and electromechanical delamination strength behaviors of the CC tapes under transverse tensile loading were examined and a two-parameter Weibull distribution analysis was conducted in statistical aspects. As a result, the CC tape showed similar range of mechanical delamination strength regardless of cross-head speed adopted. On the other hand, cyclic loading might have affected the CC tape in both upper anvil sizes adopted.