• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.107-110
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• 1994

This paper focuses on the dynamic interaction between travelling vehicle and flexible guideway rail system. From a numerical analysis on the simply supported beam vibration excited by a sequence of magnetic force, we studied the dynamic response of MAGLEV.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.357-359
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• 1995

In this paper, vector control of induction motor drives using space current vector PWM is presented. The scheme gives advantages, besides robustness to inverter arm-shoot, sinusoidal input current and voltage for induction motors. In addition, space vector PWM for CSI produces faster transient response than conventional pattern PWM. Also, a modulation index control is proposed.

• 인터넷정보학회논문지
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• 제17권4호
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• pp.61-68
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• 2016

본 논문에서는 재난대응 현장에서 웹 3.0 정보서비스를 활용한 증강현실 기술의 구현과 적용 방안에 대하여 제안한다. 시맨틱 웹 기반의 웹 3.0 기술의 구조와 특성을 파악하고 증강현실의 재난현장 관련 모바일 비주얼 검색 기술에 대해서 설명한다. 이를 바탕으로 재난 관련 정보에 대한 시맨틱 웹 기반 온톨로지 구성 방안과 재난대응 현장과 재난안전대책본부와의 증강현실 기술을 통한 정보 전달 및 정보제공 방안에 대하여 제안한다. 재난대응 현장에서 신속하고 정확한 정보전달과 재난현장 맞춤형 정보제공을 목적으로 증강현실 기술과 웹 3.0 정보서비스의 상호작용에 대한 활용 방안을 제시한다.

• 한국안전학회지
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• 제5권2호
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• pp.32-39
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• 1990

The ${\gamma}$-Fe$_2$O$_3$ compounds were oxidized in the furance after gas detecting sensor made molding as the Fe$_3$O$_4$ the synthesized Fe$_3$O$_4$, by ferrous sulfate and sodium hydroxide. Their sensities on carbon monoxide, ethyl alcohol and L. P. G. were measured at various temperatures, respectively. And then their electrical resistivities, thermal properties (D.T.A. ＆ T.G.A.), were examined about their having an effet on the gas-sensing in company with the effect of pure ${\gamma}$-Fe$_2$O$_3$ and the detecting sensor ${\gamma}$-Fe$_2$O$_3$, which reacts with $K_2$CO$_3$ in the hydrothermal coundition, and the electrical conductive mechanism was reflected simultaneously. It was observed that the electrical conductivities and response ratios showed highest value at the endothermic temperature part, 300~35$0^{\circ}C$ of D.T.A.―curve. Consequently, the response ratios and response times of the hydrothermal detecting sensor were higher than that of pure detecting sensor, the specific surface areas were the highest at the endothermic range of D.T.A.-curve. These response ratios of detecting sensor for $K_2$CO$_3$, process at hydrothermal condition on carbon monoxide appeared higher than that on ethyl alcohol and in case of L.P.G. last.

• Journal of Korean Neurosurgical Society
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• 제57권1호
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• pp.6-11
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• 2015

Objective : Neuropathic pain causes patients feel indescribable pain. Deep Brain Stimulation (DBS) is one of the treatment methods in neuropathic pain but the action mechanism is still unclear. To study the effect and mechanism of analgesic effects from DBS in neuropathic pain and to enhance the analgesic effect of DBS, we stimulated the ventral posterolateral nucleus (VPL) in rats. Methods : To observe the effect from VPL stimulation, we established 3 groups : normal group (Normal group), neuropathic pain group (Pain group) and neuropathic pain+DBS group (DBS group). Rats in DBS group subjected to electrical stimulation and the target is VPL. Results : We observed the behavioral changes by DBS in VPL (VPL-DBS) on neuropathic pain rats. In our study, the pain score which is by conventional test method was effectively decreased. In specific, the time of showing withdrawal response from painful stimulation which is not used measuring method in our animal model was also decreased by DBS. Conclusion : The VPL is an effective target on pain modulation. Specifically we could demonstrate changes of pain response duration which is not used, and it was also significantly meaningful. We thought that this study would be helpful in understanding the relation between VPL-DBS and neuropathic pain.

• 한국통신학회논문지
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• 제41권7호
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• pp.809-815
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• 2016

본 논문은 줄기세포 재생 치료를 위해 사용되는 배지에 직류전압을 인가하여 배지에 반응되는 전기적인 저항 값, 전류 값 그리고 전압 값의 상태에 대해 분석하였다. 배지에 반응되는 전압은 줄기세포 분화 유도 과정에서 전기적인 자극에 연관되며 반응 전압 상태에 따라 분화의 상태에 대해 확인 할 수 있다. 배지의 반응 전압에서 전압변화 레벨이 적으면 줄기세포 자극 조건이 안정적이며 만일 전압 변화 레벨이 심하면 줄기세포 자극 조건이 불안정하여 줄기세포 분화 과정에서 상당한 손실을 따르게 될 수 있다. 본 연구는 줄기세포 재생 치료의 가능성을 위해 전기적인 자극 조건의 최적화 하는데 도움이 될 것으로 기대한다.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1069-1078
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• 2018

Demand response (DR) programs give opportunity to consumers to manage their electricity bills. Besides, distribution system operator (DSO) is interested in using DR programs to obtain technical and economic benefits for distribution network. Since small consumers have difficulties to individually take part in the electricity market, an entity named demand response provider (DRP) has been recently defined to aggregate the DR of small consumers. However, implementing DR programs face challenges to fairly allocate benefits and payments between DRP and DSO. This paper presents a procedure for modeling the interaction between DRP and DSO based on a bilevel programming model. Both DSO and DRP behave from their own viewpoint with different objective functions. On the one hand, DRP bids the potential of DR programs, which are load shifting and load curtailment, to maximize its expected profit and on the other hand, DSO purchases electric power from either the electricity market or DRP to supply its consumers by minimizing its overall cost. In the proposed bilevel programming approach, the upper level problem represents the DRP decisions, while the lower level problem represents the DSO behavior. The obtained bilevel programming problem (BPP) is converted into a single level optimizing problem using its Karush-Kuhn-Tucker (KKT) optimality conditions. Furthermore, point estimate method (PEM) is employed to model the uncertainties of the power demands and the electricity market prices. The efficiency of the presented model is verified through the case studies and analysis of the obtained results.

• Smart Structures and Systems
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• 제23권3호
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• pp.307-318
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• 2019

The frequently excessive vibrations presented in civil structures during seismic events or service conditions may result in users' discomfort, or worst, in structures failure, producing economic and even human casualties. This work contributes in proposing the synthesis of a nonlinear optimal control strategy for semiactive structural control, with the main characteristic that the synthesis considers both the structure model and the semiactive actuator nonlinear dynamics, which produces a nonlinear system that requires a nonlinear controller design. The aim is to reduce the unwanted vibrations in the response of civil structures, by means of intelligent fluid semiactive actuator such as the Magnetorheological Damper (MRD), which is a device with a low level of power consumption. The civil structures for which the proposed control methodology can be applied are those admitting a state-dependent coefficient factorized representation model, such as buildings, bridges, among others. A scaled model of a three storey building is analyzed as a case study, whose dynamical response involves displacement, velocity and acceleration of each one of the storeys, subjected to the North-South component of the September 19th., 2017, Puebla-Morelos (7.1M), Mexico earthquake. The investigation rests on comparing the structural response over time for two different conditions: with no control device installed and with one MRD installed between the first floor and the ground, where a nonlinear optimal signal for the MRD input voltage is determined. Simulation results are presented to show the effectiveness of the proposed controller for reducing the building's dynamical response.

• 한국화재소방학회논문지
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• 제23권3호
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• pp.40-47
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• 2009

오늘날 전기제품의 다양화, 대용량화와 더불어 전기화재의 발생이 점차 증가하고 있다. 반면 저압 배전계통에서 사용되고 있는 기존의 과부하겸용 누전차단기 즉, RCD의 저조한 응답특성으로 인한 전기화재 원인의 대부분을 차지하는 단락사고 및 과부하사고에 대한 대응이 매우 미흡한 실정이다. 이에 본 논문에서는 기존 RCD에 대한 모의 사고실험을 통하여 그 비신뢰성을 확인하고, 이러한 RCD의 단점을 개선하고자 고정밀 전류센서를 이용한 전기화재 방재장치를 제안하여 저압 배전계통에서의 단락 및 과부하사고로 인한 전기재해를 방지하고자 한다. 제안한 장치의 고정밀 전류센서로 사용된 리드스위치는 각종 전기사고에서 수반되는 단락전류 및 과전류에 의한 배전선로의 상승된 자속을 정밀 감지한 후, 자체 차단장치를 동작시키거나 또는 기 설치된 RCD를 신속히 차단시키는 이중 보호용 제어 동작원리를 가진다. 다양한 동작특성 분석을 통해 기존의 차단기와 비교하여 차단동작 응답속도와 신뢰성이 입증된다. 이로써 제안한 전기화재 방재장치는 기존 RCD들의 빈번한 오동작과 비신뢰성, 저조한 응답특성으로 인한 각종 전기사고 및 전기화재의 발생을 방지하고자 한다.

• 한국음향학회지
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• 제39권3호
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• pp.200-206
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• 2020

본 논문은 공간 응답 변화량(Spatial Response Variation, SRV)을 사용한 광대역 빔 형성 방법을 제안한다. SRV를 정규화 항으로 적용하여 목표하는 주파수 대역에서 주 빔 폭의 변동이 약 1도 이내로 적은 양질의 광대역 빔패턴을 얻도록 하였다. 설계 실험에서 제안 된 방법이 기존 방법보다 낫다는 것을 입증하였다.