• 항공우주시스템공학회지
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• 제9권1호
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• pp.12-18
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• 2015

The inter-conversion between different control laws in flight has a lot of risk. The SWM(Switching Mechanism) including logic and stand-by mode is designed to analyze the transient response of aircraft during inter-conversion between different control laws, based on the in-house software for non-real-time and real-time simulation. The SWM applies the fader logic of TFS(Transient Free Switch) to minimize the transient response of an aircraft during the inter-conversion, and applies the reset '0' type of the stand-by mode to prevent surface saturation due to integrator effect in the disengaged flight control law. The transition time is also important to minimize the objectionable transient response in the inter-conversion, as well as the transition control law design. This paper addresses the results of non-real-time simulation for the characteristics of transient response to different transition time to select the adequate transient time, and the real-time pilot evaluation, using SSWM(Software Switching Mechanism) and HSWM(Hardware Switching Mechanism), which is met for Level 1 flying qualities and assures safety of flight.

• 농촌계획
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• 제21권4호
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• pp.177-186
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• 2015

The main objective of this study was to assess the applicability of IoT (Internet of Things)-based flood management under climate change by developing intelligent water level monitoring platform based on IoT. In this study, Arduino Uno was selected as the development board, which is an open-source electronic platform. Arduino Uno was designed to connect the ultrasonic sensor, temperature sensor, and data logger shield for implementing IoT. Arduino IDE (Integrated Development Environment) was selected as the Arduino software and used to develop the intelligent algorithm to measure and calibrate the real-time water level automatically. The intelligent water level monitoring platform consists of water level measurement, temperature calibration, data calibration, stage-discharge relationship, and data logger algorithms. Water level measurement and temperature calibration algorithm corrected the bias inherent in the ultrasonic sensor. Data calibration algorithm analyzed and corrected the outliers during the measurement process. The verification of the intelligent water level measurement algorithm was performed by comparing water levels using the tape and ultrasonic sensor, which was generated by measuring water levels at regular intervals up to the maximum level. The statistics of the slope of the regression line and $R^2$ were 1.00 and 0.99, respectively which were considered acceptable. The error was 0.0575 cm. The verification of data calibration algorithm was performed by analyzing water levels containing all error codes in a time series graph. The intelligent platform developed in this study may contribute to the public IoT service, which is applicable to intelligent flood management under climate change.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권9호
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• pp.835-846
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• 2005

제품계열(Product Line)은 핵심자산(Core Asset)을 서로 공유하는 제품들의 집합이며, 제품계열 공학(Product Line Engineering, PLE)은 제품계열을 특화(Instantiation) 할 수 있는 원리, 기술, 메커니즘과 프로세스들의 집합이다. PLE는 여러 유사한 제품들간에 공유할 수 있는 핵심자산을 만들고, 그 핵심자산을 특정 제품에 맞게 실체화 시켜서 제품을 만든다. 모델 기반 아키텍처(Model Driven Architecture, MDA)는 자동화 도구를 이용하여 모델로부터 구현으로 구체화하는 접근 방법이다. 그러므로, 핵심자산을 MDA의 플랫폼 독립적인 모델(PIM)로 정의하여 구현까지 자동화한다면, 두 개발 방법의 장점을 극대화 할 수 있다. 하지만, 핵심자산을 표현하는 UML 프로파일은 현재까지 없으며, PLE의 핵심자산 및 제품 조림의 자동화 생산을 위한 PIM 명세 기법의 연구가 부족하다. 본 논문에서는 PLE기술과 MDA 기술을 접목하기 위해 PIM 수준의 핵심자산 명세 기법을 제안한다. 핵심자산을 명세하기 위해 아키텍처 명세, 컴포넌트 명세, 워크플로우 명세, 알고리즘 명세, 결정 모델 명세 기법을 제안한다. 본 논문의 명세 기법은 PLE, MDA 기술을 사용하여 제품의 생산성, 적용성, 유지보수성 및 품질 향상을 지원한다.

• 한국인터넷방송통신학회논문지
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• 제16권6호
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• pp.75-81
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• 2016

본 논문에서 제시한 Co-creation 플랫폼 소프트웨어 분석/설계 방법은 제품의 아이디어 단계부터 제품의 디자인 단계, 개발 및 생산, 마케팅 전 과정에 Co-creation 개념을 적용한 Co-creation 플랫폼 구축기술을 제공한다. 그리고 이 방법은 Co-creation 플랫폼 구축을 위한 자체 SNS 기능 및 OPEN API 를 통하여 기업의 클라우드 서비스와 기업 시스템과 연동하도록 설계 및 구현이 가능하도록 한다. 또한 아이디어의 수정 및 완성 단계에서 위키 기술을 적용하고 디자인 제작과정에서 스토리보드 프로토타이핑 협업 도구를 제공함으로써 고객 및 이해관계자가 디자인 작업에 적극적으로 참여하고 의견이 반영이 가능하도록 하는 기능 구현이 가능하다. 따라서 이것들의 설계 과정을 효과적으로 보여주기 위하여 Co-creation 분석/설계를 객체지향 분석방법에 의해 제시하고자 한다.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.950-958
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• 2017

Viaduct increases the height of subway catenary, namely magnifies lightning attraction scope that lead to higher possibility of suffering lightning stroke. Therefore, it is necessary to analyze performance of lightning striking to catenary of subway in viaduct section and propose an improving lightning protection scheme. In this paper, using ATP-EMTP simulation software to establish an associated model to evaluate lightning withstand level of catenary with existing lightning protection schemes including arrester and grounding point, an improving lightning protection scheme is proposed - every pillar ground earth and arresters are installed with some installing spacing between 200m to 400m based on lightning damage degree and reliability requirements - according to analyzing results: while lightning withstand level is lowest for lightning striking to the neutral pillar, lightning withstand level is greatest for lightning striking to the both-ends pillar that arrester and grounding point are both installed; grounding point could obviously improve lightning withstand level for lightning striking to ground wire while arrester could obviously improve the lightning withstand level for lightning striking to catenary; every pillar ground earth could enhance the lowest lightning withstanding level up to 2.5 times than of that pillar ground earth across every 200m.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1915-1920
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• 2015

ISO 26262 is an international standard for the functional safety of electric and electronic systems in vehicles, and this standard has become a major issue in the automotive industry. In this paper, a functional safety compliant electronic control unit (ECU) for an electric power steering (EPS) system and a demonstration purposed EPS system are developed, and a software and hardware structure for a safety critical system is presented. EPS is the most recently introduced power steering technology for vehicles, and it can improve driver’s convenience and fuel efficiency. In conformity with the design process specified in ISO 26262, the Automotive Safety Integrity Level (ASIL) of an EPS system is evaluated, and hardware and software are designed based on an asymmetric dual processing unit architecture and an external watchdog. The developed EPS system effectively demonstrates the fault detection and diagnostic functions of a functional safety compliant ECU as well as the basic EPS functions.

• Steel and Composite Structures
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• 제18권6호
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• pp.1557-1568
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• 2015

The nonlinear static analysis of structure, which is under the effect of lateral loads and provides the capacity curve of the structure, is defined as a push-over analysis. Ordinarily, by using base shear and the lateral displacement of target point, the capacity curve is obtained. The speed and ease of results interpretation in this method is more than that of the NRHA responses. In this study, the nonlinear static analysis is applied on the semi-rigid steel gabled frames. It should be noted that the members of this structure are analyzed as a prismatic beam-column element in two states of semi-rigid connections and supports. The gabled frame is modeled in the OpenSees software and analyzed based on the displacement control at the target point. The lateral displacement results, calculated in the top level of columns, are reported. Furthermore, responses of the structure are obtained for various support conditions and the rigidity of nodal connections. Ultimately, the effect of semi-rigid connections and supports on the capacity and the performance point of the structure are presented in separated graphs.

• Journal of Communications and Networks
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• 제7권3호
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• pp.377-384
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• 2005

The purpose of this research is to develop and evaluate a traffic engineering architecture that uses local state information. This architecture is applied to an Internet protocol radio access network (RAN) that uses multi-protocol label switching (MPLS) and differentiated services to support mobile hosts. We assume mobility support is provided by a protocol such as the hierarchical mobile Internet protocol. The traffic engineering architecture is router based-meaning that routers on the edges of the network make the decisions onto which paths to place admitted traffic. We propose an algorithm that supports the architecture and uses local network state in order to function. The goal of the architecture is to provide an inexpensive and fast method to reduce network congestion while increasing the quality of service (QoS) level when compared to traditional routing and traffic engineering techniques. We use a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm. We use the network simulator ns-2 as the core of our simulation environment. Around this core we built a system of pre-simulation, during simulation, and post-processing software that enabled us to simulate our traffic engineering architecture with only very minimal changes to the core ns-2 software. Our simulation environment supports a number of different mobility scenarios and a mix of different types of traffic to evaluate our architecture and algorithm.

• 인터넷정보학회논문지
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• 제14권1호
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• pp.23-30
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• 2013

지금까지는 FP, UCP, COCOMO 모델에 의하여 시험노력을 추정하거나, 또는 개발한 수많은 프로젝트 데이터 측정을 통하여 각 단계별 노력 투입 비율에 의거 시험단계에 투입된 시험노력을 추정하였다. 본 연구에서는 소프트웨어 시험노력 추정을 소프트웨어 개발노력 추정과 독립적으로 이루어질 수 있도록 시험노력 추정 모델을 만들고 또 시험노력 추정절차를 제시한다. 모델은 시험노력이 테스트 케이스의 수와 복잡도에 비례하는 특성을 반영하고, 통합시험, 시스템시험, 인수시험 등 시험 태스크를 수행하는 시험 조직의 역량에 영향을 받는 점을 고려하였다. 제시한 시험노력 추정 모델과 절차에 의해 기존의 프로젝트 데이터에 시험에 관련된 추정 데이터를 이용하여 시험노력을 추정한 결과와, 개발계획 수립을 위하여 추정한 개발노력 상에서 배분된 시험노력과 비교하였을 때 4.7% 정도의 오차를 보였다. 시험 조직이 갖는 기술적인 경험, 구축된 시험환경의 정도, 프로젝트의 복잡성과 개발조직의 환경 등을 측정하여 주어진 모델의 조정 계수 값에 반영한다면, 보다 정교한 독자적인 시험노력 추정이 가능하다.

• 한국시뮬레이션학회논문지
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• 제17권4호
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• pp.209-218
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• 2008

UML(Unified Modeling Language)은 소프트웨어 설계 단계에서 디자인을 구체화하고, 가시화하여 구성하고, 문서화하는데 일반적으로 사용되고 있다. UML 대부분의 설계는 소프트웨어 시스템 구조의 설계에 초점을 맞추고 있다. 최근에는 aspect-oriented 설계와 같이 복잡한 소프트웨어 시스템을 설계하기 위한 부가적인 설계의 요구 사항들이 등장하고 있다. 본 논문에서 는 policy-driven 아키텍처의 동적인 양상을 연구한다. 다양한 어플리케이션 도메인에서 적용할 수 있는 policy-driven 관리 어플리케이션의 상단계에서의 모델링을 제안한다. 어플리케이션들의 많은 활동들을 관리하기 위해서, 같은 상황에서의 다른 자원들에게 정책(policies)과 함께 활동성과 유연성이 지원되어야 확장이 가능하다. 이러한 흐름에서, policy-driven 아키텍처의 동적인 양상을 보여주기 위해 메타 모델링 방법론을 연구하였다. 본 방법론에 기반으로 하여 본 논문에서는 policy-driven 관리 어플리케이션 영역에서의 메타모델링을 설립하였다.