• 한국산학기술학회논문지
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• 제2권2호
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• pp.57-63
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• 2001

본 연구는 기존 조적조 주택의 주요 구조부에 컨테이너를 활용한 개발 방식 즉, 컨테이너 하우스의 계획, 설계, 시공 가능한 시스템 개발을 목적으로 하였다. 이를 위해, 스틸하우스의 구조 및 시공 방법 등을 분석하였으며 컨테이너 하우스의 외벽 구성 시스템에 대한 견본품 제작을 완성하였다. 이 컨테이너 하우스 견본품을 토대로 두 개의 컨테이너 하우스 케이스 스터디에 적용하였고, 기존 조적조 주택 공법에 비하여 공사비 절감과 공기단축에 있어 현격한 효과가 있음을 확인하였다. 컨테이너하우스의 제작기술 개발 성공을 통해 스틸하우스 시장의 틈새 공략으로 기업체의 기술개발 및 투자방향을 제공하였다는데 의의가 있다.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1961-1971
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• 2006

A soft recovery system (SRS) is a device that stops a high speed projectile without damaging the projectile. The SRS is necessary to verify the shock resistant requirements of microelectronics and electro-optic sensors in smart munitions, where the projectiles experience over 20,000 g acceleration inside the barrel. In this study, a computer code for the performance evaluation of a SRS based on ballistic compression decelerator concept has been developed. It consists of a time accurate compressible one-dimensional Euler code with use of deforming grid and a projectile motion analysis code. The Euler code employs Roe's approximate Riemann solver with a total variation diminishing (TVD) method. A fully implicit dual time stepping method is used to advance the solution in time. In addition, the geometric conservation law (GCL) is applied to predict the solutions accurately on the deforming mesh. The equation of motion for the projectile is solved with the four-stage Runge-Kutta time integration method. A small scale SRS to catch a 20 mm bullet fired at 500 m/s within 1,600 g-limit has been designed with the proposed method.

• International Journal of Concrete Structures and Materials
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• 제11권2호
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• pp.261-273
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• 2017

The control of the deformative behaviour of pre-stressed concrete roof elements for a satisfactory service performance is a main issue of their structural design. Slender light-weight wing-shaped roof elements, typical of the European heritage, are particularly sensitive to this problem. The paper presents the results of deformation measurements during storage and of both torsional-flexural and purely flexural load tests carried out on a full-scale 40.5 m long innovative wing-shaped roof element. An element-based simplified integral procedure that de-couples the evolution of the deflection profile with the progressive shortening of the beam is adopted to catch the experimental visco-elastic behaviour of the element and the predictions are compared with normative close-form solutions. A linear 3D fem model is developed to investigate the torsional-flexural behaviour of the member. A mechanical non-linear beam model is used to predict the purely flexural behaviour of the roof member in the pre- and post-cracking phases and to validate the loss prediction of the adopted procedure. Both experimental and numerical results highlight that the adopted analysis method is viable and sound for an accurate simulation of the service behaviour of precast roof elements.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권9호
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• pp.439-446
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• 2001

This paper considers the design technique of the real-time control algorithm to implement the electronic interlocking system which is the most important station control system in railway signal field. The proposed technique consists of the structure design and the detail design which are based on the ROOM(Real-Time Object-Oriented Modeling). The structure design is designed with a modeling using the heuristic search technique which, at first, catch and make out the specific requested condition, and then, is designed on the requested condition. The detail design can be implemented if it may get the satisfying values through the repetitive modeling after comparing and examining the data obtained from the structure design in order for the more reliable and accurate system to be implemented. The technique proposed in this paper is implemented with C++ language which is easy to be transferred and compatible with the existing interfaces, and also the operating system is designed and simulated on the VRTX which is a real-time operating system. This proposed technique is applied to the typical station model in order to prove the validity as verifying the performance of the modeled station.

• 정보처리학회논문지A
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• 제12A권6호
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• pp.471-476
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• 2005

자바 언어는 신뢰성 있는 프로그램의 개발을 위해 예외를 처리할 수 있는 명시적인 예외 처리 메커니즘을 제공한다. 따라서 신뢰성 있는 프로그램 개발을 위해서는 실행 시간에 발생 가능한 예외에 대한 적절한 처리가 매우 중요하다 본 논문에서는 신뢰성 있는 프로그램 개발을 위한 동적 예외 모니터링 시스템을 개발하였다. 이 시스템은 프로그래머가 효과적으로 실제 발생된 예외의 처리, 전파과정을 모니터링 할 수 있으며 이러한 기능을 이용하여 좀더 적절한 예외 처리가 가능하도록 하며 결과적으로 개발된 프로그램의 신뢰성을 항상 시킬 수 있다. 본 시스템은 사용자 옵션을 통하여 관심 있는 예외들만을 모니터링 할 수 있으며 또한 시스템의 성능 부하를 줄이기 위해 기존의 코드에 필요한 모니터링 코드만을 삽입하는 방식으로 시스템을 설계하고 구현하였다. 또한 실험을 통해서 그 효과를 보였다.

• 기술혁신학회지
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• 제14권2호
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• pp.177-204
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• 2011

최근 정부는 기술모방형 R&D 전략의 한계를 극복하기 위해 기초연구에 대한 투자를 대폭 확대하고 있다. 이러한 상황에서 우리나라의 R&D 지원시스템은 창의적 창조적 기초연구를 뒷받침하기에 적절한 지에 대한 평가가 필요한 시점이다. 이에 본 연구는 기초연구에 대한 특성과 필요한 시스템적 요건에 대해 해외사례 및 우리나라의 기초연구 지원시스템에 대한 분석을 통해 접근하였다. 본 연구는 문제점 분석을 통해 새롭게 기초연구의 정책운영체계라는 패러다임 도입이 필요함을 논하였다. 또한 기초연구의 성과는 연구자체의 수월성과 더불어 연구를 지원하는 전주기적 체계의 적절성이 매우 중요한 요소임을 발견하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.429-433
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• 2009

Since the "Low Carbon, Green Growth" as a social requirements is attracted public attention, the policies and investments of the railway which have been less estimated than road is re-considered. Since the starting the commercial service (2004. April), the KTX have been operated successfully while transport passengers over 100million for years. And also the project for development of KHST (Korea High Speed Train ; G7) had been accomplished with a good result, the first trainset of KTX-II which base on G7 project was manufactured and testing now. On the other hand, the world's technology of the high speed train is more faster, and changing to a distributed traction system. To catch up the world's leading technology, the HEMU(High-speed Electric Multiple Unit) project will secure new technology and aims to promote the technology of domestic high-speed train. The authors indicates the result of detail review such as a curve, slope of the track and electrical dead section of the catenary to test at 400kph and also the performance simulation of the developed rolling stock in this paper. As the result, the authors devise the test scenario to perform a maximum speed test (stability at max. speed, acceleration & deceleration etc) with the restricted conditions such as track length, track available time etc by considering above result.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3470-3493
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• 2019

IEEE 802.11s-based infrastructure Wireless Mesh Networks (iWMNs) are envisaged as a promising solution to provide ubiquitous wireless Internet access. The limited network capacity is a problem mainly caused by the medium contention between mesh users and the mesh access points (MAPs), which gets worst when the mesh clients employ the Transmission Control Protocol (TCP). To mitigate this problem, we use wireless network coding (WNC) in the MAPs. The aim of this proposal is to take advantage of the network topology around the MAPs, to alleviate the contention and maximize the use of the network capacity. We evaluate WNC when is used in MAPs. We model the formation of coding opportunities and, using computer simulations, we evaluate the formation of such coding opportunities. The results show that as the users density grows, the coding opportunities increase up to 70%; however, at the same time, the coding delay increments significantly. In order to reduce such delay, we propose to adaptively adjust the time that a packet can wait to catch a coding opportunity in an MAP. We assess the performance of moving-average estimation methods to forecast this adaptive sojourn time. We show that using moving-average estimation methods can significantly decrease the coding delay since they consider the traffic density conditions.

• Fisheries and Aquatic Sciences
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• 제24권4호
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• pp.139-152
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• 2021

The main purpose of this study is to fit catch-per-unit-effort (CPUE) data about Korea chub mackerel (Scomber japonicus) stock with a state-space production (SSP) model, and to provide stock assessment results. We chose a surplus production model for the chub mackerel data, namely annual yield and CPUE. Then we employed a state-space layer for a production model to consider two sources of variability arising from unmodelled factors (process error) and noise in the data (observation error). We implemented the model via script software ADMB-RE because it reduces the computational cost of high-dimensional integration and provides Markov Chain Monte Carlo sampling, which is required for Bayesian approaches. To stabilize the numerical optimization, we considered prior distributions for model parameters. Applying the SSP model to data collected from commercial fisheries from 1999 to 2017, we estimated model parameters and management references, as well as uncertainties for the estimates. We also applied various production models and showed parameter estimates and goodness of fit statistics to compare the model performance. This study presents two significant findings. First, we concluded that the stock has been overexploited in terms of harvest rate from 1999 to 2017. Second, we suggest a SSP model for the smallest goodness of fit statistics among several production models, especially for fitting CPUE data with fluctuations.

• 한국인터넷방송통신학회논문지
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• 제22권4호
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• pp.23-28
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• 2022

최근 스마트폰 또는 타블렛 PC와 같은 스마트기기가 정보의 창구 역할을 하게 되면서 다수의 사용자가 웹포털을 통해 웹 뉴스를 소비하는 것이 더욱 중요해졌다. 하지만 인터넷 상에 생성되는 뉴스의 양을 사용자들이 따라가기 힘들며 중복되고 반복되는 폭발하는 뉴스 기사에 오히려 혼란을 야기 시킬 수도 있다. 본 논문에서는 뉴스 포털에서 사용자의 질의로부터 검색된 뉴스후보들 중 KoBART 기반의 문서요약 기술을 활용한 뉴스 추천 시스템을 제안한다. 실험을 통해서 새롭게 수집된 뉴스 데이터를 기반으로 학습한 KoBART의 성능이 사전훈련보다 더욱 우수한 결과를 보여주었으며 KoBART로부터 생성된 요약문을 환용하여 사용자에게 효과적으로 뉴스를 추천하였다.