• 한국입자에어로졸학회지
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• 제9권2호
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• pp.103-110
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• 2013

The electrostatic precipitator (ESP) has been used for degrading atmospheric pollutants. These devices induce the electrical forces to facilitate the removal of particulate pollutants. The ions travel from the high voltage electrode to the grounded electrode by Coulomb force induced by the electric field when a high voltage is applied between two electrodes. The ions collide with gas molecules and exchange momentum with each other thus inducing fluid motion, electrohydrodynamic (EHD) flow. In this study, for the simulation of electric field and EHD flow in ESPs, an open source EHD solver, "espFoam", has been developed using open source CFD toolbox, OpenFOAM(R) (Open Field Operation and Manipulation). The electric potential distribution and ionic space charge density distribution were obtained with the developed solver, and validated with experimental results in the literature. The comparison results showed good agreement. Turbulence model is also incorporated to simulate turbulent flow; hence the developed solver can analyze laminar and turbulent flow. In distributions of electric potential and space charge, the distributions become distorted and asymmetric as the flow velocity increases. The effect of electrical drift flow was investigated for different flow velocities and the secondary flow in a flow of low velocity is successfully predicted.

• 정보보호학회논문지
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• 제29권4호
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• pp.919-943
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• 2019

4차 산업 혁명 관련 신흥 기술로 주목받고 있는 분산원장기술은 오픈소스 기반 분산원장기술 시스템(또는 분산원장기술 플랫폼)으로 구현되어 다양한 애플리케이션(또는 서비스) 개발 시 널리 활용되고 있으나, 오픈소스 기반 분산원장기술 시스템에서 제공하는 보안 기능은 매우 미흡한 실정이다. 본 논문에서는 오픈소스 기반 분산원장기술 시스템 운용 시 발생할 수 있는 잠재적인 보안 위협을 식별하고, 국내 법규 및 보안 인증 기준(ISMS-P, Information Security Management System-Privacy)을 분석하여 보안 위협에 대응할 수 있는 보안기능 요구사항을 도출한다. 그리고 국제 표준인 공통평가기준(CC, Common Criteria)의 보안기능 컴포넌트 분석을 통하여 오픈소스 기반 분산원장기술 시스템에 필요한 보안 기능을 구현할 수 있는 방안을 제안함으로서 보안을 강화하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2470-2491
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• 2018

Web-scale open information extraction (Open IE) plays an important role in NLP tasks like acquiring common-sense knowledge, learning selectional preferences and automatic text understanding. A large number of Open IE approaches have been proposed in the last decade, and the majority of these approaches are based on supervised learning or dependency parsing. In this paper, we present a novel method for web scale open information extraction, which employs cosine distance based on Google word vector as the confidence score of the extraction. The proposed method is a purely unsupervised learning algorithm without requiring any hand-labeled training data or dependency parse features. We also present the mathematically rigorous proof for the new method with Bayes Inference and Artificial Neural Network theory. It turns out that the proposed algorithm is equivalent to Maximum Likelihood Estimation of the joint probability distribution over the elements of the candidate extraction. The proof itself also theoretically suggests a typical usage of word vector for other NLP tasks. Experiments show that the distance-based method leads to further improvements over the newly presented Open IE systems on three benchmark datasets, in terms of effectiveness and efficiency.

• Asia pacific journal of information systems
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• 제26권3호
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• pp.339-366
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• 2016

National and local governments around the world have been allowing access to administrative data to increase transparency, motivate civic engagement of citizens, and improve collaboration between the public and the government. This study reviews and classifies existing literature on open government data (OGD). To create a structure to organize the existing studies, the researchers devised a framework based on socio-technical theory and summarized the significance of studies along four major points: (1) readiness, (2) implementation, (3) emerging effects, and (4) actors of open data. Studies in OGD have been growing steadily in the recent years because of the rapid development of adoptable technologies that have enabled easier access to government data. Nonetheless, an examination of existing research not only shows a disparity in research and development of OGD across countries in the Open Government partnership program but also reveals pertinent issues that have arisen in different stages of the OGD initiative. The growing number of studies and expanding body of knowledge show the importance of organizing existing literature. This step is timely and significant to map out the current breadth and depth of OGD research. According to existing research, current open governments fall short in encouraging citizen participation and collaborations among citizens and the government. This study pointed out how studies on OGD actors might be the reason as well as the solution to existing findings. This paper aims to provide a framework for organizing OGD studies, present the status of OGD research, and provide recommendations on current gaps that must be addressed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.188-193
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• 1999

Technology of GIS evolved as a means of assembling and analyzing diverse spatial data. Many systems have been developed, and almost of systems are proprietary. There is a lots of lack of interoperability and reusability between them. This paper describes the development of Open GIS component software. The developing system have an end in view of GIS tool software which is interoperable and reusable. To increase the interoperability and reusability, the system is based on the OGC(Open GIS Consortium)'s Open GIS Simple Features Specification for OLE/COM. The OGC's specification is announced to increasing the full interoperability of various geospatial data and geoprocessing resources. With the Open specification, component based software ensures the reusability. We implement three kinds of component: Geometry component, Spatial Reference System Component, and MapBase Component. The first two components are compatible to the OGC's specification and the third one is designed to GIS tool software for variant GIS applications. The Open GIS component software system is developed on object-oriented computing environment, ATL/COM and Visual C++. As we made application programs using Visual Basic, the advantages of component based Open GIS software was proved.

• 대한임베디드공학회논문지
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• 제11권6호
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• pp.325-334
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• 2016

Recently, Open Computing Language (OpenCL) has been proposed to provide a framework that supports heterogeneous computing platforms. By using an OpenCL framework, digital communication systems can support various protocols in a unified computing environment to achieve both high portability and high performance. This article introduces a parallel software decoder of Low Density Parity Check (LDPC) codes for China Multimedia Mobile Broadcasting (CMMB) on a heterogeneous platform. Each step of LDPC decoding has different parallelization characteristics. In this paper, steps suitable for task-level parallelization are executed on the CPU, and steps suitable for data-level parallelization are processed by the GPU. To improve the performance of the proposed OpenCL kernels for LDPC decoding operations, explicit thread scheduling, loop-unrolling, and effective data transfer techniques are applied. The proposed LDPC decoder achieves high performance by using heterogeneous multi-core processors on a unified computing framework.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.779-782
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• 2017

OpenBR은 안면인식 관련 새로운 방식의 연구, 기존 알고리즘 개선, 상용 시스템과 상호 작용, 인식 성능 측정, 자동화 된 생체 인식 시스템을 배치하기 위한 프레임 워크입니다. 신속한 알고리즘 프로토타이핑을 용이하게 하기 위해 고안되었으며 성숙한 핵심 프레임 워크, 유연한 플러그인 시스템 및 개방형 및 폐쇄형 소스 개발 지원을 특징으로 한다. 기성의 알고리즘은 얼굴 인식, 연령 산정 및 성별 추정과 같은 특정 양식에 대해서도 사용할 수 있다. 본 논문에서는 OpenBR의 프레임 워크의 구성방법에 대해서 기술하고 지원되는 프로그램을 통해서 이용한 안면인식, 성별추정, 나이추정 구현하고 기술하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권5호
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• pp.23-29
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• 2017

This study was conducted to evaluate performance of geothermal heat exchanger (GHE) in the combined well and open-closed loops geothermal (CWG) systems. The CWG systems were designed to combine open loop geothermal heat pumps and closed loop geothermal heat pumps for high energy efficiency. GHE of the CWG systems could be installed at pumping wells for agricultural usage. To get optimal heat exchange capacity of GHE of the CWG systems, 4 GHEs with various materials and apertures were tested at laboratory scale. Polyethylene (PE) and stainless steel (STS) were selected as GHE materials. The maximum heat exchange capacity of GHEs were estimated to be in the range of 33.0~104 kcal/min. The heat exchange capacity of STS GHEs was 2.4~3.2 times higher than that of PE GHE. The optimal cross section area of GHE and flow rate of circulating water of GHE were estimated to be $2,500mm^2$ and 113 L/min, respectively. For more complicated GHE of the CWG systems, it is necessary to evaluate GHEs at various scales.

• 한국위성정보통신학회논문지
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• 제11권2호
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• pp.36-41
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• 2016

건물을 에너지 수요관리 자원으로 활용하기 위해서는 수요 반응에 대응할 수 있는 자동화된 시스템을 필요로 한다. 에너지 수요관리 사업자의 출현으로 이를 뒷받침할 수 있는 건물 에너지 관리 시스템과 수요반응 시스템에 대한 연구 개발이 활발히 이루어지고 있다. 하지만 아직까지 자동화된 실시간 수요 반응 시스템 도입은 미흡하고 비용도 높다. 본 연구에서는 이를 해소하기 위해 건물을 대상으로 수요 반응 시스템 구축을 위한 OpenADR 프로토콜과 수요 반응에 참여할 수 있는 건물 에너지 관리 시스템을 개발하고 실환경에 적용하여 실증을 수행하였다. OpenADR은 표준 프로토콜로 사업자와 수요자원간의 이벤트 발생과 리포팅을 통해 자동화된 시스템이다. 또한 다양한 제어 시스템이 이용되고 있는 건물을 대상으로 단일화된 제어 시스템 구축을 위해 웹 기반 건물 자동제어 시스템을 개발하여 수요 반응 이벤트 발생 시 부하를 줄일 수 있도록 한다. 개발된 결과물을 건물에 적용하여 동작하는 것을 검증하고 감축량을 측정하여 수요반응 효과를 확인하였다.

• Structural Engineering and Mechanics
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• 제40권1호
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• pp.85-103
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• 2011

Integration of finite element analysis (FEA) software into various software platforms is commonly used in coupling systems such as systems involving structural control, fluid-structure, wind-structure, soil-structure interactions and substructure method in which FEA is used for simulating the structural responses. Integrating an FEA program into various other software platforms in an efficient and simple way is crucial for the development and performance of the entire coupling system. The lack of simplicity of the existing integration methods makes this integration difficult and therefore entails the motivation of this study. In this paper, a novel practical technique, namely CS technique, is presented for integrating a general FEA software framework OpenSees into other software platforms, e.g., Matlab-$Simulink^{(R)}$ and a soil-structure interaction (SSI) system. The advantage of this integration technique is that it is efficient and relatively easy to implement. Instead of OpenSees, a cheap client handling TCL is integrated into the other software. The integration is achieved by extending the concept of internet based client-server concept, taking advantage of the parameterization framework of OpenSees, and using a command-driven scripting language called tool command language (TCL) on which the OpenSees' interface is based. There is no need for any programming inside OpenSees. The presented CS technique proves as an excellent solution for the coupling problems mentioned above (for both linear and nonlinear problems). Application examples are provided to validate the integration method and illustrate the various uses of the method in the civil engineering.