• 한국학교보건학회지
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• 제23권2호
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• pp.192-199
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• 2010

Purpose: Multi-cultural families are increasing highly in Korea. Health care professionals and students majoring in health and welfare need to develop their cultural competence for quality of life from multi-cultural families. This study was to be conducted by examining the level of culture knowledge, empathy, and cultural sensitivity of university students majoring in health and welfare. Methods: Convenience sampling method was used and 408 students from 3 universities were evaluated for final analysis. Data collection was conducted through the use of questionnaires. Results: The score of cultural knowledge of students was very low. Empathy and cultural sensitivity showed middle range. There was a significant correlation between cultural knowledge and empathy, empathy and cultural sensitivity. However, there was no significant correlations between cultural knowledge and cultural sensitivity. Conclusion: An understanding of multi-cultural enables health and welfare providers to specialize service in cross- cultural situations of multi-cultural families in Korea. Ways to improve cultural competence for students majoring in health care and welfare is needed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.59-64
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• 2003

The parameter modification of the initial FEM model to match it with the experimental results needs the modal information and the modal sensitivity matrix to the parameter change. There are two cases this methodology is ill-equip to deal with; the deficiency of the necessary modal information and the ill-conditioning of the sensitivity matrix. In this research, a novel concept of the feedback exciter that uses the summation of the white noise and the signals from the measurement sensors multiplied with feedback gains as the reference signal is proposed. There are 2 advantages using this external feedback excitation. First, we can use the change of the system response such as modal data by the active energy Path from the sensor to the exciter. This change of the system response can be additional clues to the system dynamics that we want to know. Secondly, the external energy Path alternates the offset of the Parameter change to the system response. That means the modal sensitivity of the parameters becomes different from the original sensitivities by the feedback excitation. Through the feedback loop, we can change the similar modal sensitivities of some updating parameters and consequently discriminate the parameters using the closed-loop modal data. To demonstrate the discrimination performance, the parameter estimation of an indeterminate structure by use of the feedback method is introduced.

• 한국정보기술학회 영문논문지
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• 제10권2호
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• pp.91-101
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• 2020

Recently, the demand for high penetration of variable renewable energy (VRE) penetration in a power system is increased. In consequence, distribution systems including microgrids confront the increased installation of VRE-based distributed generation. Despite of the high demand of VRE-based distributed generation in a distribution system, the installation of photovoltaic (PV) system in a distribution system has been restricted by various problems. In other words, the hosting capacity for high VRE penetration in a distribution system is limited. This paper analyzes the improvements of hosting capacity VRE penetration of stand-alone microgrid (SAMG) with energy storage system (ESS) by considering virtual-slack (VS) control based on power sensitivity. With the pre-defined power sensitivity, the ESS operates as virtual slack in the SAMG by controlling its bus voltage and phase angle indirectly. Therefore, the ESS enables the increase of VRE penetration in the SAMG. The proposed VS control is realized by analyzing the ESS as a virtual slack in power flow analysis based on power sensitivity. Then its validity is demonstrated with the case study on the SAMG in South Korea with practical data.

• 한국정보통신학회논문지
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• 제9권1호
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• pp.204-209
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• 2005

초음파 센서를 이용한 호흡측정방식은 관성 및 압력의 오차의 영향을 거의 받지 않고, 반영구적으로 사용이 가능한 호흡기기이다. 초음파의 특성을 이용한 것으로 송수신시 초음파의 매질인 공기의 흐름에 의한 반송형식인 초음파의 전달속도 차이를 이용하여 호흡량 및 흐름을 detecting하는 기술이다. 본 논문에서는 환자를 중심으로 측정이 이루어져야 하기 때문에 센서의 송수신시 일어나는 신호의 sensitivity를 향상시켜서 약한 호흡에도 dectection이 가능하도록 시스템의 성능을 향상시켰다.

• 동력기계공학회지
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• 제5권4호
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• pp.82-89
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• 2001

To design a structural or a mechanical system with the best performance, the main procedure of a typical design usually consists of repeated modifications of design parameters and the investigation of the system response for each set of these parameters. But this procedure requires much time, effort and experience. Sensitivity analysis can provide systematic information for improving performance of a system. The author has studied on the development of the structural analysis algorithm and suggested recently the transfer stiffness coefficient method(TSCM). This method is very suitable algorithm to a personal computer because the concept of the TSCM is based on the transfer of the nodal stiffness coefficients which are related to force and displacement vectors at each node. In this paper, a new sensitivity analysis algorithm using the concept of the TSCM is formulated for the computation of state variable sensitivity in static problems. The trust of the proposed algorithm is confirmed through the comparison with the computation results using existent sensitivity analysis algorithm and reanalysis for computation models.

• 한국재료학회지
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• 제17권8호
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• pp.433-436
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• 2007

Nano-structured polyaniline have been synthesized by interfacial polymerization method at room temperature. An aqueous solution of aniline in chloroform and another solution of ammonium peroxydisulfate in doping acid were prepared at different times terminated with methanol at room temperature. SEM, UV-vis were used to characterize the polyaniline with regard to their morphology and structure. The diameter and length of polyaniline can be controlled by the reaction time. Nano-structured polyaniline were found to have superior sensitivity for volatile organic compounds(VOCs). As the reaction time to increase from 30minute to 2hours the sensitivity were decreased to VOCs vapors. The sensitivity of Nano-structured polyaniline sensor appeared to VOCs better than the sensitivity of chemical synthesis sensors. The sensitivity of Nano-structured polyaniline sensor improved benzene vapors.

• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.147-153
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• 2011

This paper proposes a methodology using a tool based on the branch-parameter continuation power flow (BCPF) in order to restore the power flow solvability in unsolvable contingencies. A specified contingency from a set of transmission line contingencies is modeled, considering the transient analysis and practice in the Korean power system. This tool traces a solution path that satisfies the power flow equations with respect to the variation of the branch parameter. At a critical point, in which the branch parameter can move on to a maximum value, a sensitivity analysis with a normal vector is performed to identify the most effective compensation. With the sensitivity information, the location of the reactive power compensation is determined and the effectiveness of the sensitivity information is verified to restore the solvability. In the simulation, the proposed framework is then applied to the Korean power system.

• 정보저장시스템학회논문집
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• 제3권4호
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• pp.191-195
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• 2007

The optical disc drive has used a high NA objective lens and a shorter wavelength laser diode for high recording density. But high NA and shorter wavelength cause several margins to become short. Focusing and tracking servo has to be more accurate and active tilt compensation mechanism is also needed for coma aberration compensation. In this paper, we proposed 3-axis moving magnet type actuator. For 3-DOF motion, moving coil actuator has to be equipped with 6 wires for supplying 3 independent signals. However, moving magnet type actuator doesn't need to change the configuration of wires because coils are in stator. So, we added a tilt mechanism to the 2-axis moving magnet actuator which is designed in previous research. Addition of the tilt mechanism cuts down the focus sensitivity. So, maximization the tilting sensitivity and securing the focusing sensitivity are objectivities of this research. DOE (design of experiments) procedures of electromagnetic circuit are performed for parameter study and the optimization is also performed to maximize the tilt sensitivity. And then the final design is suggested and its performance is verified by FE simulation.

• 대한기계학회논문집A
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• 제25권2호
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• pp.182-191
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• 2001

The paper describes the improvement on concurrent subspace optimization(CSSO) via automatic differentiation. CSSO is an efficient strategy to coupled multidisciplinary design optimization(MDO), wherein the original design problem is non-hierarchically decomposed into a set of smaller, more tractable subspaces. Key elements in CSSO are consisted of global sensitivity equation, subspace optimization, optimum sensitivity analysis, and coordination optimization problem that require frequent use of 1st order derivatives to obtain design sensitivity information. The current version of CSSO adopts automatic differentiation scheme to provide a robust sensitivity solution. Automatic differentiation has numerical effectiveness over finite difference schemes tat require the perturbed finite step size in design variable. ADIFOR(Automatic Differentiation In FORtran) is employed to evaluate sensitivities in the present work. The use of exact function derivatives facilitates to enhance the numerical accuracy during the iterative design process. The paper discusses how much the automatic differentiation based approach contributes design performance, compared with traditional all-in-one(non-decomposed) and finite difference based approaches.

• 한국정보통신학회논문지
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• 제16권4호
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• pp.721-729
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• 2012

본 논문에서는 인간의 감성을 멀티모달 환경에 기반하여 인식하여 감성지수에 따라 조명의 색을 조절하는 감성조명 시스템을 구현하였다. 감성조명을 위하여 사용된 LED 조명은 친 환경적이며 고효율 및 긴 수명을 가지고 있다. 특히 LED 조명은 단일 조명구로도 다양한 색 표현이 가능한 장점을 가지고 있다. 인간의 감성을 보다 정확하게 판별하기 위하여 사용자의 얼굴 영상 정보와 및 각성 상태 정보를 동시에 사용하여 멀티모달에 기반된 감성지수를 산출하였다. 실험을 통하여 LED 조명 색감이 사용자의 감성지수에 따라 변화 되므로 기존의 조명들에 비하여 인간 친화적인 조명시스템을 구축함을 보인다.