• 조명전기설비학회논문지
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• 제23권7호
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• pp.57-66
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• 2009

Microturbines system (MTS) are currently being deployed as small scale on-site distributed generators for microgrids and smart grids. In order to fully exploit DG potentialities, advanced integrated controls that include power electronics facilities, communication technologies and advanced modeling are required. Significant expectations are posed on gas microturbines that can be easily installed in large commercial and public buildings. Modeling, control, simulation of microturbine generator based distributed generation system in smart grid application of buildings for both grid-connected and islanding conditions are presented. It also incorporates modeling and simulation of MT with a speed control system of the MT-permanent magnet synchronous generator to keep the speed constant with load variation. Model and simulations are performed using MATLAB, Simulink and SimPowerSystem software package. The model is built from the dynamics of each part with their interconnections. This simplified model is a useful tool for studying the various operational aspects of MT and is also applicable with building cooling, heating and power (BCHP) systems

• 대한인간공학회지
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• 제30권5호
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• pp.683-688
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• 2011

Objective: The aim of this study is to develop a distributed representative human model(DRHM) generation and analysis system. Background: DRHMs are used for a product with multiple-size categories such as clothing and shoes. It is not easy for a product designer to explore an optimal sizing system by applying various distributed methods because of their complexity and time demand. Method: Studies related to DRHM generation were reviewed and the RHM generation interfaces of three digital human model simulation systems(Jack$^{(R)}$, RAMSIS$^{(R)}$, and CATIA Human$^{(R)}$) were reviewed. Results: DRHM generation steps are implemented by providing sophisticated interfaces which offer various statistical techniques and visualization methods with ease. Conclusion: The DRHM system can analyze the multivariate accommodation percentage of a sizing system, provide body sizes of generated DRHMs, and visualize generated grids and DRHMs. Application: The DRHM generation and analysis system can be of great use to determine an optimal sizing system for a multiple-size product by comparing various sizing system candidates.

• 한국컴퓨터정보학회논문지
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• 제21권12호
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• pp.115-124
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• 2016

In this paper, a method to generate the extended model automatically on the critical elements in enterprise system based real time distributed architecture as well as the platform specific model(PSM) for Microsoft(MS) .NET platform is proposed. The key ideas of this method are real time distributed architecture should performed with satisfying strict constraints on life cycle of object and response time such as synchronization, transaction and so on, and .NET platform is able to implement functionalities including before mentioned by only specifying Attribute Code and maximizing advantages of MDA. In order to realize the ideas, functionalities which should be considered enterprise system development are specified and these are to be defined in Meta Model and extended UML profile. In addition, after definition of UML profile for .NET specification, by developing and applying these into plug-in of open source MDA tool, and extended models are generated automatically through this tool. Accordingly, by using proposed specification technology, the profile and tools easily and quickly reusable extended model can be generated even though low level of detailed information for functionalities which is considered in .NET platform and real time distributed architecture. In addition, because proposed profile is MOF which is basis of standard extended and applied, UML and MDA tools which observed MOF is reusable.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.208-209
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• 2011

본 논문에서는, 맵-리듀스 모델 기반에서 나이브 베이스 알고리즘으로 학습과 추론을 수행하는 방안에 대해 소개하고자 한다. 이를 위해 Apache Mahout를 이용하여 분산 나이브 베이스 (Distributed Naive Bayes) 학습 알고리즘을 University of California, Irvine (UCI)의 벤치마크 데이터 집합에 적용하였다. 실험 결과, Apache Mahout의 분산 나이브 베이스 학습 알고리즘은 일반적인 WEKA의 나이브 베이스 학습 알고리즘과 그 성능면에서 큰 차이가 없음을 알 수 있었다. 이러한 결과는, 향후 빅 데이터 환경에서 Apache Mahout와 같은 맵-리듀스 모델 기반 시스템이 기계 학습에 큰 기여를 할 수 있음을 나타내는 것이다.

• KIEE International Transactions on Power Engineering
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• 제4A권4호
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• pp.201-206
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• 2004

With the advent of distributed generation, power systems in general are impacted in regards to stability and power quality. Distributed generation has positive impacts on system restoration following a fault, higher reliability, and mitigation of effect due to voltage sag. However, distributed generation also has negative impacts on the decrease of reliability such as changes of protective device setting and mal-operation. Because bulk power systems consist of various sources and loads, it is complicated to analyze power systems that have distributed generation. The types of distributed generation usually are classified as the rotating machinery system and the inverter-based system. In this paper, distributed generation is designed as a synchronous generator, and the distribution system with its distributed generation model is simulated using EMTP. In addition, this paper shows the simulation results according to the types of distributed generation

• 정보과학회 논문지
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• 제41권11호
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• pp.958-966
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• 2014

무선 센서 네트워크는 분산처리 환경을 제공해준다. 센서 노드들은 계산 능력, 네트워크 대역폭, 전력 등이 제한된 환경에서 배치되고 스스로 네트워크를 구성하여 수집된 데이터들을 싱크노드로 전송한다. 이런 전형적인 무선 센서 네트워크에서는 네트워크 패킷들 간의 충돌이 발생하며 이로 인해 네트워크 수명이 단축된다. 클러스터링과 네트워크 내부처리는 네트워크 내부의 패킷을 줄여 문제점을 해결한다. 제한된 에너지를 가진 센서 노드가 가능한 오랫동안 동작하게 하는 것이 큰 이슈이기 때문에 많은 연구들이 에너지 절약에 중점을 두고 진행되고 있다. 하지만 본 논문에서는 프로세싱 타임라인에 기반을 둔 협력 처리 모델을 제안한다. 이 모델은 처리의 검증, 총 실행시간의 예측, 무선 센서 네트워크에서 분산 처리에 필요한 최적의 노드 개수의 결정 등을 포함한다. 제안된 모델의 정확성을 실험을 통해 나타내고, 사례 연구로 이 모델이 분산처리 어플리케이션에 사용가능함을 보인다.

• 한국시뮬레이션학회논문지
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• 제19권4호
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• pp.235-247
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• 2010

군사훈련을 지원하는 워게임 모델은 환경요소가 매우 중요하다. 한국군의 대부분 워게임 모델들은 동일한 기상을 모든 작전지역에 적용하고 있다. 이에 따라 충실도가 높은 모의결과를 도출하지 못하고 있다. 이러한 실정에 비추어 본 연구는 분포형 합성환경 모델링 자료를 군사시뮬레이션에 적용할 수 있는 충실도 높은 워게임을 위한 요소기술을 개발 하는 것이다. 그것은 본 연구를 위해 개발한 2D GIS기반의 "단순 탐지확률 모델"과 이 모델에 지역별로 상이한 분포형 강수량 자료의 적용 기술이다. 이로써 군사시뮬레이션 수행 시 모델 해상도(전구급~공학급), 용도(훈련용, 분석용), 묘사 수준(군단급~대대급)에 따라 다양하게 작전지역별 상이한 국지기상을 반영하는 분포형 합성환경의 제공과 사용이 가능해졌다.

• 기술혁신학회지
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• 제19권4호
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• pp.687-710
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• 2016

본 연구의 목적은 국가연구개발사업을 대상으로 각 연구단계별 연구개발 지출과 논문 성과 간의 시차구조를 분석하는 것이다. 이에 본 연구는 6T(IT, BT, NT, ST, ET, CT) 기술로 범주화 된 104개 기술의 횡단면 자료와 2007년부터 2014년까지의 시계열로 구성된 패널자료를 분석 자료로서 활용하였으며, 일반적인 시차분포모형을 통해 회귀분석을 실시할 경우 다중공선성이 내포된 분석결과가 도출될 가능성이 크기 때문에 다항시차분포모형을 통해 시차효과를 분석하였다. 그 결과 기초연구의 경우 4년 간 비교적 고른 분포를 보이는 것으로 나타났고, 응용연구와 개발연구의 경우 각각 3년, 2년간 투자효과가 유효한 것으로 확인되었다. 이러한 결과로 보건대, 국가연구개발사업의 논문 성과를 진단함에 있어 각 연구개발단계별 시차적 특성을 감안한 분석 및 평가가 신중하게 고려될 필요가 있을 것이다.

• 농업과학연구
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• 제45권3호
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• pp.521-532
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• 2018

In recent decades, the dry stream phenomena of small and medium sized rivers have been attracting much attention as an important social problem. To prevent dry stream phenomena, it is necessary to build an infrastructure that manages rivers. To accurately determine the progress of dry stream phenomena, it is necessary to continuously measure the discharge and other hydrological factors for small and medium sized rivers. However, until now, the flow data for small and medium rivers in Korea has been insufficient. To overcome the lack of supporting data for supporting rational decision-making in policy and project implementation, a short- and long-term hydrological model was developed that takes into consideration hydrological changes such as the increase of the impervious area due to urban development and groundwater pumping, the construction of a large-scale sewage treatment plant, the maintenance of stream-oriented rivers, etc. In the developed model, the distributed grid is represented by three layers: Surface flow, interflow, and groundwater flow. The surface flow and intermediate flow flowed along the flow direction, and the groundwater flow was calculated by a two-dimensional groundwater analysis model such that the outflow occurred in all directions without a specific flow direction. The effects of land use and cover on evapotranspiration and infiltration and the effects of multiple landscapes can be simulated in the developed model.

• Computers and Concrete
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• 제20권1호
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• pp.11-22
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• 2017

There are two methods to model the plastification of members comprising lumped and distributed plasticity. When a reinforced concrete member experiences inelastic deformations, cracks tend to spread from the joint interface resulting in a curvature distribution; therefore, the lumped plasticity methods assuming plasticity is concentrated at a zero-length plastic hinge section at the ends of the elements, cannot model the actual behavior of reinforced concrete members. Some spread plasticity models including uniform, linear and recently power have been developed to take extended inelastic zone into account. In the aforementioned models, the extended inelastic zones in proximity of critical sections assumed close to connections are considered. Although the mentioned assumption is proper for the buildings simply imposed lateral loads, it is not appropriate for the gravity load effects. The gravity load effects can influence the inelastic zones in structural elements; therefore, the plasticity models presenting the flexibility distribution along the member merely based on lateral loads apart from the gravity load effects can bring about incorrect stiffness matrix for structure. In this study, the linear flexibility distribution model is improved to account for the distributed plasticity of members subjected to both gravity and lateral load effects. To do so, a new model in which, each member is taken as one structural element into account is proposed. Some numerical examples from previous studies are assessed and outcomes confirm the accuracy of proposed model. Also comparing the results of the proposed model with other spread plasticity models illustrates glaring error produced due to neglecting the gravity load effects.