• 한국군사과학기술학회지
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• 제20권3호
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• pp.337-344
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• 2017

In this paper, the optical axis alignment(OAA) of an infrared sensor(IRS) using a microwave sensor(MWS) was presented as a method of an axis alignment to minimize the problems that could be caused by the misalignment of the two sensors in the missile including the dual-mode sensor. The azimuth(AZ) and elevation(EL) angles of the two targets used for each sensor test were calculated by using the transformation equation and the test results of the MWS and IRS, and then the proposed OAA was verified by comparing the angles. Furthermore, the validity of the proposed OAA was demonstrated by confirming the abnormality of the OAA through the test results of the electro optical head(EOH) of the IRS which was equipped with a tilt on the missile fuselage.

• 대한전기학회논문지:전력기술부문A
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• 제49권7호
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• pp.359-364
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• 2000

This paper is introducing a newly developed spark-gap switch with dual trigger system, into which the current from the voltage source is injected along with the test sequence during the synthetic testing of high voltage circuit-breaker. The currently-used spark gap switch is narrow in operating range due to the use of the method of triggering energy being injected by single way. As a result, the frequent happening of misoperation has greatly reduced the test quality and test efficiency and has required the cost of maintenance excessively. In this study, accordingly, in order to basically remove these problems, another triggering system is installed to the opposite direction on the existing triggering system; attaching the same time and the same rising time of pulse wave as on the existing system, so that at a comparatively trigger gap distance from the main electrode(the gap can be operated at 60% of self-break voltage, while at 80% in the current system), the main electrode has been enabled to be closed by the development of spark gap switch with dual trigger system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.392-395
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• 2003

For the first time, the new dual trench gate Emitter Switched Thyristor is proposed for eliminating snap-back effect which leads to a lot of serious problems of device applications. Also, the parasitic thyristor that is inherent in the conventional EST is completely eliminated in the proposed EST structure, allowing higher maximum controllable current densities for ESTs. Moreover, the new dual trench gate allows homogenous current distribution throughout device and preserves the unique feature of the gate controlled current saturation of the thyristor current. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and $354/{\S}^2$, respectively. But the proposed EST exhibits snap-back with the anode voltage and current density 0.93V and $58A/{\S}^2$, respectively. Saturation current density of the proposed EST at anode voltage 6.11V is $3797A/{\S}^2$. The characteristics of 700V forward blocking of the proposed EST obtained from two dimensional numerical simulations (MEDICI) is described and compared with that of the conventional EST.

• 대한가정학회지
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• 제30권3호
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• pp.285-305
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• 1992

The purpose of this study was to describe the current status of dual-earner families in Seoul. The specific aims of this study were to examine the dynamics of marital relationship, parent-child relationship and old mother-daughter/daughter in law relationship in the same family. The sample consised of 265 dual-earner families was selected based on wives' jobs, primarily non-professional. The information was gathered from working couples and their school-aged children. The findings of this study were as follows: 1. Sex role attitude of husbands was more traditional than their wives. Therefore, housework sharing of husbands was very low and wives' perception of inequity was high. Wives' marital satisfaction was affected by the wives' perception of inequity, joint leisure activity, sexual satisfaction, and wives' job satisfaction. Husbands' marital satisfaction was affected by sexual satisfaction, perceived difficulties and problems of the husbands caused by wives' employment, and the degree of their housework participation. 2. The emotional uneasiness of children during mothers' absence was reported. The communication about mothers' job was helpful to gain children's understanding toward mothers' job. Mothers suffered from guilty feeling of neglecting their children in spite of their good performance of mothering role. 3. The employed daughters/daughters in law perceived high rewards and low cost in relationships with their mothers/mothers in law. The perceived quality of daughter-mother relationship was higher with low cost and high rewards than that of daughter in law/mother in law. Finally practical and policy implications were suggested.

• 대한가정학회지
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• 제36권10호
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• pp.35-48
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• 1998

The Korean family is changing. The growth in dual-earner households has been the 'revolution' of the century, implying inevitable modification of the role division in marriage toward greater symmetry of responsibility for breadwinning and homemaking. So, the purpose of this study is to understand husbands' housework and to investigate the change of the husbands' housework. This means to investigate how the husband is related to housework. For these research purpose, 60 dual-earner couples were deeply interviewed. The major discussions of this study can be summarized as follows: There are four types of housework in men's work, the type of refusal, the type of avoidance, the type of inevitability, and the type of participation. These types are taken order to understand change in housework is women's work. Men in the type of avoidance in household work is 25%, they have a tendency to avoid housework with making any excuses. People in the type of inevitability is 20%. These men are compelled to work in household owing to circumstances beyond control. 13% of couples is type of participation. These have a new idea of housework. They don't get the gender role division. They can become a good husband. and eventually solve conflicts and problems in couples.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.219-224
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• 2002

This paper aims to derive a mathematical model of the dynamics of handling tasks in robot finger which stable grasping and manipulates a rigid object with some dexterity. Firstly, a set of differential equation describing dynamics of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange's equation. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of area-contacts of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for overall system of differential-algebraic equations is presented. Thirdly, simulation results are shown and the effects of geometric constraints of area-contact is discussed. Finally, it is shown that even in the simplest case of dual single D.O.F manipulators there exists a sensory feedback from sensing data of the rotational angle of the object to command inputs to joint actuators and this feedback connection from sensing to action eventually realizes secure grasping of the object, provided that the object is of rectangular shape and motion is confined to a horizontal plane.

• 한국공작기계학회논문집
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• 제18권1호
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• pp.50-58
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• 2009

For precise tracking control of a servo system with nonlinear friction, a robust friction compensation scheme is presented in this paper. The nonlinear friction is difficult to identify the friction parameters exactly through experiments. Friction parameters can be also varied according to contact conditions such as the variation of temperature and lubrication. Thus, in order to overcome these problems and obtain the desired position tracking performance, a robust adaptive back-stepping control scheme with a dual friction observer is developed. In addition, to estimate lumped friction uncertainty due to modeling errors, a DEKF recurrent neural network and adaptive reconstructed error estimator are also developed. The feasibility of the proposed control scheme is verified through the experiment fur a ball-screw system.

• Journal of Information Display
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• 제5권2호
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• pp.6-9
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• 2004

We have developed the Scan-backlight Stereoscopic LCD that is a kind of field-sequential -Stereoscopic LCD combining the Dual- Directional- Backlight and the fast-response OCB panel. The Dual-Directional-Backlight using a double-sided prism sheet can change the direction of light by switching the LED light sources. The OCB panel using Feed-Forward Drive can realize frame rate of 120 Hz. As a result, the Scan-backlight Stereoscopic display works at its original resolving power, and produces flicker-free stereoscopic images. This auto- stereoscopic display can resolved the problems of the double images and the pseudoscopic images in case of watching at oblique angles.

• 전력전자학회논문지
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• 제2권4호
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• pp.1-10
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• 1997

공진형 듀얼 컨버터는 스위칭손실이 낮은 고주파 스위칭으로 전력변환을 실현할 수 있는 회로방식으로서 주목받고 있다. 본 논문에서는 유도전동기를 부하로 하여 구동과 회생운전이 가능한 쌍방향 공진형 전력변환 시스템을 구축하고, 이 시스템의 실제적인 적용을 위하여 일련의 실험을 통해 제작시스템의 운전특성을 검증한다. 고찰부분으로서는 입출력특성, 공진부특성, 주소자와 클램프소자에서의 턴 오프특성 및 영전압특성에 대한 실험결과를 대상으로 한다. 본 연구에서는 관측된 파형들을 검증함으로서 제작시스템에 있어서의 문제점을 고찰하고 금후의 연구를 위한 제안을 제시하고자 한다.

• 한국추진공학회지
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• 제25권1호
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• pp.58-67
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• 2021

본 논문에서는 연소특성이 다른 이종추진제를 갖는 이중추력 추진기관 개발을 기술하였다. 적용된 이종추진제의 조성 개발과 이종추진제간 접착방법과 접착력 개선을 위해 free-grain형식으로 추진제 충전 제작 공정을 개발하였다. 추가해서, 소형 추진기관으로 점화 현상을 충족시키기 위해 고밀도 foam으로 개발한 노즐 마개를 적용함으로써 점화지연을 개선시켰다. 이런 설계와 개선된 제작공정을 반영하여 개발된 추진기관은 지상성능시험으로 그 성능을 평가하였다.