• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.68.2-68.2
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• 2009

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.477-485
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• 2018

To control manage environmental load during construction work, it is required to ascertain an accurate quantity for materials those are using during the construction. In construction industrial nowadays, especially on design part, there are lots of mistakes occurred on quantity take-off between plan documents and actual work. That mistakes are caused by omission of design items, overcount because of interference each materials or simple calculate error. Besides, in case of a construction project, engineers are impossible to design perfectly due to a lot of invalid variable in a construction site. Thus, design errors and changes occur frequently in the process of construction work or design due to such unclear elements. And in case of LCA assessment based on 2D design, there is difficult for an engineer who is in charge to calculate the volume of materials manually using drawings and relevant specifications. This study is aimed for examining and verifying a high reliable method of evaluating environmental load which is useful in construction process through comparing LCA analysis. In addition, this study provides the method of calculating the volume of materials and LCA assessment in working on the basis of 2D design, using the specifications which is used for LCA evaluation, and possibility of utilizing the LCA assessment by introducing BIM design technic to improve the former problem through comparing and analyzing the previous method with 3D-based evaluation process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.4
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• pp.364-374
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• 2012

The purpose of this study is to perform the reliability-corrected development cost estimation of the launch vehicle at the conceptual design phase. In order to estimate the launch vehicle development cost, the estimation method based on the independent variable such as the rocket performance and dry mass has been mainly implemented up to now. This approach has made the approximate cost estimation possible, however, the cost variation according to the reliability requirement could not be reflected. In this paper, the cost estimation methodology that introduces the reliability factor in addition to the performance and mass in the TRANSCOST model is presented in order to improve the limitation of current cost estimation method. The development cost of KSLV(Korea Space Launch Vehicle)-II is estimated on the basis of this newly implemented concept with reliability as an added parameter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8128-8139
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• 2015

Recently, the necessity of developing the load and resistance factor design(LRFD) for soft ground improvement method has been raised, since the limit state design is requested as international technical standard for the foundation of structures. In this study, to develop LRFD codes for foundation structures in Korea, target reliability index and resistance factor for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 16 data(in Gwangyang) and the 57 data(Korea Institute of Construction Technology, 2008) sets of static load test and soil property tests conducted in the whole domestic area were collected along with available subsurface investigation results. The resistance bias factors were evaluated for the tow static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods : the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. As a result, when target reliability indices of the driven pipe pile were selected as 2.0, 2.33, 2.5, resistance factor of two design methods for SPT N at pile tip less than 50 were evaluated as 0.611~0.684, 0.537~0.821 respectively, and STP N at pile tip more than 50 were evaluated as 0.545~0.608, 0.643~0.749 respectively. The result from this research will be useful for developing various foundations and soil structures under LRFD.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.5
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• pp.349-357
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• 2022

Since the flight control computer of unmanned aerial vehicle (UAV) is a flight critical equipment, it is necessary to ensure reliability and safety from the development step, and a redundancy-based fault management design is required in order to operate normally even a failure occurs. To reduce cost, weight and power consumption, the dual-redundant flight control system design is considered in UAV. However, there are various restrictions on the fault management design. In this paper, we propose the fault detection and isolation designs for the dual-redundant flight control computer to satisfy the safety requirements of an UAV. In addition, the flight control computer developed by applying the fault management design performed functional tests in the integrated test environment, and after performing FMET in the HILS, its reliability was verified through flight tests.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.1-10
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• 2011

As requirements of embedded system get complicated, the tool for analyzing the reliability of embedded software is being needed. A probabilistic modeling is used as the way of analyzing the reliability of a software and to apply it to embedded software controlling multiple devices. So, it is necessary to specialize that to embedded software. Also, existing reliability analyzers should measure the transition probability of each condition in different ways and doesn't consider reusing the model once used. In this paper, we suggest a reliability analyzer for embedded software using embedded software Markov chin model and a unit testing tool. Embedded software Markov chain model is model specializing Markov chain model which is used for analyzing reliability to an embedded software. And a unit testing tool has host-target structure which is appropriate to development environment of embedded software. This tool can analyze the reliability more easily than existing tool by automatically measuring the transition probability between units for analyzing reliability from the result of unit testing. It can also directly apply the test result updated by unit testing tool by representing software model as a XML oriented document and has the advantage that many developers can access easily using the web oriented interface and SVN store. In this paper, we show reliability analyzing of a example by so doing show usefulness of reliability analyzer.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.123-130
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• 2004

The automobile suspension system is composed of parts that affect performances of a vehicle such as ride quality, handling characteristics, straight performance and steering effort, etc. Moreover, by using the finite element analysis the cost for the initial design step can be decreased. In the design of a suspension system, usually system vibration and structural rigidity must be considered simultaneously to satisfy dynamic and static requirements simultaneously. In this paper, we consider the weight reduction and the increase of the first eigen-frequency of a suspension part, the upper control arm, especially using topology optimization and size optimization. Firstly, we obtain the initial design to maximize the first eigen-frequency using topology optimization. Then, we apply the multi-objective parameter optimization method to satisfy both the weight reduction and the increase of the first eigen-frequency. The design variables are varying during the optimization process for the multi-objective. Therefore, we can obtain the deterministic values of the design variables not only to satisfy the terms of variation limits but also to optimize the two design objectives at the same time. Finally, we have executed reliability based optimal design on the upper control arm using the Monte-Carlo method with importance sampling method for the optimal design result with 98％ reliability.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1037-1040
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• 2001

생체인식 기술이 차세대 보안 기술로서 주목을 받고 있으나 대부분의 생체 시스템이 독립적으로 존재하고 있어, 표준화 노력의 일환으로 세계적인 생체인식협회인 BioAPI Consortium에서 표준 BioAPI version 1.1이 제정되었다. 본 논문에서는 BioAPI에서 제안한 명세서를 토대로 하여 클라이언트-서버구조로서 웹기반 사용자 인증시스템을 설계한다. 클라이언트는 입력 장치 및 BSP에 따른 Hybrid기법을 적용함으로서 신뢰성을 부여하여 웹 상에서 사용자의 취득 가능한 여러 생체 정보를 검증 자료로 사용하고, 실 시간성을 부여하기 위하여 ActiveX를 사용하여 객체의 크기를 작게 한다. 서버는 생체검증의 기본기능인 등록, 인증, 검증을 할 수 있도록 BioAPI 인터페이스를 사용하여 BSP에 따른 기 입력된 사용자의 생체 정보를 검증하게 되며, 본 논문에서는 구조적 접근 방법을 사용한 서명과 ID 및 password 의 조합을 검증기로서 사용하게 된다. 개방형 네트워크인 웹 상에서 생체 정보를 이용한 사용자 검증시스템은 전자 상거래 등의 신원확인이 필요한 분야에 신뢰성을 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.615-618
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• 2005

기업 내의 정보 시스템은 기업 내 모든 정보를 저장하여 관리하여 의사 결정 지원 및 고객 맞춤 서비스를 제공하는 등 기업의 이익은 물론 기업의 이미지, 신뢰도 등에 매우 중요한 역할을 한다. 대학의 정보 시스템은 대학 행정, 학사 업무, 연구 지원 등을 한다. 특히 학사 정보 시스템의 경우 대학의 개교 이래 학생들의 모든 수강 기록, 성적 등의 기록이 저장되고 관리되어지는 매우 중요한 시스템이다. 그러나 열악한 대학 재정의 한계로 학사 정보 시스템의 중요성에 비해 백업 시스템을 전혀 운용하지 않고 있거나, DAT 복사 등의 매우 초보적인 수준으로 백업 시스템을 구성 및 운용하고 있다. 본 논문에서는 대학 내 학사 정보 시스템의 안정적인 운용을 위하여 2년여 동안의 시스템을 분석한 후, 대학의 열악한 재정 상황을 고려하여 E-IDE 디스크 기반의 스토리지를 이용한 네트워크 기반의 백업 시스템을 설계, 구현한다. 또한 설계, 구현한 백업 시스템을 사용하는 경우 일, 주, 월 등으로 학사 정보 시스템의 정보를 안정적으로 백업하고 운영할 수 있다. 특히 천재지변, 화재 등 예상치 못한 장애에 대하여서도 효과적인 대처가 가능하다.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.129-131
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• 2012

세계 스마트폰 OS 시장의 절반 이상을 차지한 안드로이드는 향후 태블릿, 스마트 TV, 자동차 등으로 시장의 확대가 전망된다. 현재 안드로이드 OS를 기반으로 수많은 애플리케이션이 개발되고 있지만 애플리케이션의 신뢰성을 보장하기 위한 연구들은 부족한 상태이다. 이는 안드로이드 애플리케이션이 GUI를 기반으로 동작하기 때문에 기존의 테스트 방법을 적용하기 어렵기 때문이다. 구글에서 애플리케이션 테스트를 위한 환경을 제공하지만 개발자가 이를 활용하여 효율적인 테스트 코드를 작성하는 것은 쉽지 않다. 이 논문에서는 안드로이드 앱 개발에서 GUI 구현의 기본 단위인 액티비티에 대한 단위 테스트 방법을 제시한다. 이를 위해 테스트 케이스 설계 방법과 테스트 수행 코드를 자동으로 생성하는 프로그램을 구현한다. 이 방법을 통해 개발자는 쉽게 테스트 코드를 생성할 수 있으며 신뢰성있는 앱을 개발할 수 있다.