• 조명전기설비학회논문지
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• 제21권7호
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• pp.84-93
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• 2007

주상변압기는 고객에게 직접 전력을 공급하는 설비로서 전력공급의 안정성확보를 위한 중요한 기자재 중 하나이다. 하지만 제조결함에 의한 3년 이내의 초기고장 또는 13년이 초과 사용한 후의 열화고장이 빈번히 발생하고 있어 변압기 품질분석을 통한 신뢰성이 개선된 주상변압기 개발이 필요하다. 본 논문에서는 열적, 기계적, 전기적으로 성능이 향상된 새로운 모델의 혼합절연 주상변압기를 개발하였다. 변압기의 기계적, 열적특성을 향상시키기 위한 혼합절연 방식에 대한 설계 및 제작방법을 제시하고 과부하시험을 시행하여 순간최대부하에 대응할 수 있도록 과부하내량 160[%] 까지 증가시킬 수 있음을 확인하였다. 또한 본 논문에서는 100[kVA] 1대를 시제품으로 제작하여 단락강도시험과 변압기 관련 절연시험을 시행하여 전자기계력의 분석과 단락강도설계 향상 방안에 대하여 설명하고 이와 관련하여 연구한 결과에 대해 논하였다.

• 한국콘텐츠학회논문지
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• 제18권3호
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• pp.34-40
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• 2018

본 연구에서는 모바일 단말에서 재생되는 동영상 서비스의 끊김 현상을 방지할 수 있는 최적의 버퍼 크기를 산정하고자 한다. 버퍼는 VOD서비스를 위해 수신 단말에 도착한 멀티미디어 패킷의 저장 공간을 의미한다. 만약 버퍼 크기가 너무 크면, 재생 서비스 시작 전의 지연시간이 길어지게 된다. 반대로 버퍼 크기가 너무 작은 경우, 수신 단말에 도착한 패킷의 부족으로 재생 서비스가 중간에 멈출 수 있다. 그러므로 적정 버퍼 크기는 모바일 단말에서의 재생 서비스 품질 척도가 될 수 있다. 본 연구에서는 재생 서비스의 버퍼링 과정을 이산시간 대기행렬로 모델링한다. N정책을 갖는 Geo/G/1 대기행렬에서 바쁜기간의 평균길이와 평균 대기시간을 분석한다. 또한 도출된 성능척도를 이용하여 모바일 단말에서의 최적의 버퍼 크기를 결정하는 수치예제를 제시한다. 본 연구 결과를 이용하여 재생 도중의 끊김 현상 방지와 재생 시작 초기의 지연시간 최소화를 달성하여 이용자 만족도를 높일 수 있을 것이다.

• 응용통계연구
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• 제21권5호
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• pp.717-726
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• 2008

본 연구는 손해보험회사 경영평가를 하기 위하여 국내 및 미국과 일본의 각각 상위 5개 손해보험회사들의 경영실적을 바탕으로 A.M. Best사의 신용평가 기준에 의거하여 각 경영지표 부문별 및 전체점수를 산정 하였다. 경영평가 부문은 성장성, 효율성, 수익성, 안전성, 유동성 부문이며 도출된 결과를 근거로 국내 보험사와 미국 선진회사 및 일본 손해보험사와 비교하여 국내 손해보험 업계에 주는 시사점 및 개선점을 도출하였다. 경영평가 결과를 보면 국내5개 상위 손해보험회사는 성장성 측면에서는 우수하지만 효율성과 수익성면에서는 보통이며 유동성과 안전성면에서 향상을 지속적으로 추진하는 것이 과제라 할 수 있다. 따라서 국내 상위 손해보험회사들은 미국 및 일본 상위사에 비하여 담보력 강화를 통한 안전성 향상과 유동성 지표의 개선이 필요하다. 즉 국내 손해보험회사들은 유동성지표 개선이 필수적이며 글로벌 보험회사로 성장하기 위해서는 수익성 개선을 통해 담보력 확대를 꾀하여 대형물건 및 재보험 보유 확대를 통한 규모 확대가 필요하다 하겠다.

• 한국컴퓨터정보학회논문지
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• 제3권2호
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• pp.217-227
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• 1998

정보화 사회에서 지역주민을 위한 진보적 인간자원개발의 방향성 연구는 정보화사회와 IMF 시기에 중요한 연구다. 인간자원개발은 지역사회에서 적시적소에 훌륭하게 대처할 수 있도록 하는 지역사회의 삶의 질을 높이는 사회보장의 한 과정이라고 할 수 있다. IMF 시절에 이 프로그램에 참여폭이 높아지고 있으며 특히 자신의 분신상승과 재취업과 기술 제고 등은 인간자원의 진보적이며 확고한 능력을 제고하는 것이라 할 수 있다. 이러한 분야는 정보화 사회에서 생산의 효율과 유익성에 중요한 전략적인 요소로 작용하고 있다. 역시 인간자원 개발은 국제적인 경영의 한 장으로 다이나믹한 요소로 작용한다. 과거 산업사회의 조직의 세 가지 요소는 바로 자본과 기술 노동이라고 하였지만 정보화 사회에서는 지식과 정보 및 창의력이데 이는 인간적인 능력이라 할 수 있다. 인간자원개발의 요소를 개인적인 개발, 경력개발, 동기유발, 이미지메이킹, 창의력개발, 교육 및 시간관리로 구성하였다.

• 대한기계학회논문집B
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• 제26권4호
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• pp.524-530
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• 2002

Micro electric spark discharge device was fabricated on a FOTURAN glass wafer using MEMS processing technique and its performance of electron discharge and subsequent formation of ignition kernel were tested. Micro electric spark device is an essential subsystem of a power MEMS that has been under development in this laboratories. In a combustion chamber of sub millimeter scale depth, spark electrodes are formed by electroplating Ni on a base plate of FOTURAN glass wafer. Optimization of spark voltage and spark gap is crucial for stable ignition and endurance of the electrodes. Namely, wider spark gaps insures stable ignition but requires higher ignition voltage to overcome the spark barrier. Also, electron discharge across larger voltage tends to erode the electrodes limiting the endurance of the overall system. In the present study, the discharge characteristics of the proptotype ignition device was measured in terms of electric quantities such as voltage and currant with spark gap and end shape as parameters. Discharge voltage shows a little decrease in width of less than 50㎛ and increases with electrode gap size. Reliability test shows no severe damage over 10$\^$6/ times of discharge test resulting in satisfactory performance for application to proposed power MEMS devices.

• Journal of Power Electronics
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• 제16권5호
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• pp.1884-1893
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• 2016

The ride-through control of a doubly-fed induction generator (DFIG) for the voltage sags on wind farms utilizing crowbar circuits by which the rotor side converter (RSC) is disabled has being reported in many literatures. An analysis and calculation of the transient current when the RSC is switched off are of significance for carrying out the low voltage ride through (LVRT) of a DFIG. The mathematical derivation is highlighted in this paper. The zero-state and zero-input responses of the transient current in the frequency domain through a Laplace transformation are investigated, and the transient components in the time domain are achieved. With the characteristics worked out from the linear resolving without modeling simplification, the selection of the resistance in the linear crowbar circuit and the value conversion from a linear circuit to a nonlinear one is proposed to setup the attenuation rate. In terms of grid code requirements, the theoretical analysis for the time constant of the transient components attenuation insures the controllability when the excitation of the RSC is resumed and it guarantees the reserved time for the response of the reactive power compensation. Simulations are executed in MATLAB/SIMPOWER and experiments are carried out to validate the theoretical analysis. They indicate that the calculation method is effective for selection of the resistance in a crowbar circuit for LVRT operations.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권5호
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• pp.315-323
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• 2005

The recent development of embodiment technology of the medical images makes most medical institutions introduce PACS in haste. However, while many older HIS and PACS systems are not yet capable of some of the integration, several new systems are moving rapidly in that direction. Typical PACS system architecture begins with the HIS since this is where the correct patient demographic information and in many cases the orders originate. So, PACS developed convenience of users and to satisfy user's demand because of financial limitations and administrator-oriented considerations in the process of development. Therefore, we have developed a CDA (Clinical Document Architecture) based PACS with HIS, by which we can search and refer to the patient's medical images and information with few restrictions of time and space for diagnosis and treatment. Target model of this research limited to 135 of hospital have 200 beds. We'll make more effort to develop the application which insures the better quality and information of medical images. Medical Image History manages the patient's image files and various medical informations like film chart in connection with time. This trial will contribute to the reduction of the financial loss caused by unnecessary devices and improve the quality in the medical services. The demand on the development of the program which refers to the medical data quickly and keeps them stable will be continued by the medical institute. This will satisfy the client's demand and improve the service to the patients in that the program will be modified from the standpoint of the users.

• Corrosion Science and Technology
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• 제8권6호
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• pp.217-222
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• 2009

The production of advanced high strength steels requires the improvement of cooling technology. The use of high cooling rates allows relatively low levels of expensive alloying additions to ensure sufficient hardenability. In classical annealing and hot-dip galvanizing lines a mixing station is used to provide atmosphere gas containing 3-5% hydrogen and 97-95% nitrogen in the various sections of the furnace, including the rapid cooling section. Heat exchange enhancement in this cooling section can be insured by the increased hydrogen concentration. Drever International developed a patented improvement of cooling technology based on the following features: pure hydrogen gas is injected only in the rapid cooling section whereas the different sections of the furnace are supplied with pure nitrogen gas; the control of flows through atmosphere gas management allows to get high hydrogen concentration in cooling section and low hydrogen content in the other furnace zones. This cooling technology development insures higher cooling rates without additional expensive hydrogen gas consumption and without the use of complex sealing equipments between zones. In addition reduction in electrical energy consumption is obtained. This atmosphere control development can be combined with geometrical design improvements in order to get optimised cooling technology providing high cooling rates as well as reduced strip vibration amplitudes. Extensive validation of theoretical research has been conducted on industrial lines. New lines as well as existing lines, with limited modifications, can be equipped with this new development. Up to now this technology has successfully been implemented on 6 existing and 7 new lines in Europe and Asia.

• 한국재료학회지
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• 제15권11호
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• pp.705-710
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• 2005

NIL (nanoimprint lithography) technique has demonstrated a high potential for wafer size definition of nanometer as well as micrometer size patterns. During the replication process by NIL, the stiction between the stamp and the polymer is one of major problems. This stiction problem is moi·e important in small sized patterns. An antistiction layer prevents this stiction ana insures a clean demolding process. In this paper, we were using a TCP (transfer coupled plasma) equipment and $C_4F_8$ as a precursor to make a Teflon-like antistiction layer. This antistiction layer was deposited on a 6 inch silicon wafer to have nanometer scale thicknesses. The thickness of deposited antistiction layer was measured by ellipsometry. To optimize the process factor such as table height (TH), substrate temperature (ST), working pressure (WP) and plasma power (PP), we were using a design of experimental (DOE) method. The table of full factorial arrays was set by the 4 factors and 2 levels. Using this table, experiments were organized to achieve 2 responses such as deposition rate and non-uniformity. It was investigated that the main effects and interaction effects between parameters. Deposition rate was in proportion to table height, working pressure and plasma power. Non-uniformity was in proportion to substrate temperature and working pressure. Using a response optimization, we were able to get the optimized deposition condition at desired deposition rate and an experimental deposition rate showed similar results.

• 영어영문학
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• 제55권6호
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• pp.1013-1034
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• 2009

The space of the Other assumes the space of Barthes's multiplicity and Foucault's transdiscursive position, and, therefore, aims at becoming the locus in which the speaking subject and the hearing subjects are supposed to communicate and constitute as if they were situated in the pscychoanalytic session. However, the wall of untranslatibility across language and cultures still exist there in the space of the Other in the form of trauma and aggressivity, as Lacan demonstrate perceptively through the reading of Kant avec Sade. In short, Lacan regards the moral commandment (to love one's neighbor as oneself) as the obstacle in the Freud's myth of transgression, and interprets this in terms of the emergence of the Other. Freud understands that the aggressivity in the subject's own heart was inherent in all humans, and that one's neighbor would be evil. Lacan goes beyond Freud and articulates that the aggressivity in the imaginary relation with the Other in the mirror stage insures that an evil inheres in the very being of humanity. A global phenomenon of the diasporic identities and hybridity, the phenomenon which has been represented by the complicated intermixture of terms which span from diaspora, postcolonialism, postnationalism. and transnationalism can be clarified, if they are put in the context of the ethics of Othering or becoming the Other. The ethics of Othering presupposes the situation in which the diasporic subjects encounter the lack of the cross-cultural negotiation and communication. The purpose of this paper is to demonstrate how the poetics of Other and the logic of the ethics of Othering can explain the postmodern or transmodern world which has become deterritorialized, diasporic, and transnational as well as how one can encounter the results of diasporic and postcolonial double consciousness, a consciousness which is a discursive category for multicultural or cross-cultural, focusing on the concept of liminality/interstitiality