• 환경영향평가
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• 제14권6호
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• pp.387-402
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• 2005

In this study, we tried to predict the change of future land-cover and relationships between land-cover change and geo-spatial information in the Gongju area by using fuzzy logic operation. Quantitative evaluation of prediction models was carried out using a prediction rate curve using. Based on the analysis of correlations between the geo-spatial information and land-cover change, the class with the highest correlation was extracted. Fuzzy operations were used to predict land-cover change and determine the land-cover prediction maps that were the most suitable. It was predicted that in urban areas, the urban expansion of old and new towns would occur centering on the Gem-river, and that urbanization of areas along the interchange and national roads would also expand. Among agricultural areas, areas adjacent to national roads connected to small tributaries of the Gem-river and neighboring areas would likely experience changes. Most of the forest areas are located in southeast and from this result we can guess why the wide chestnut-tree cultivation complex is located in these areas and the possibility of forest damage is very high. As a result of validation using the prediction rate curve, it was indicated that among fuzzy operators, the maximum fuzzy operator was the most suitable for analyzing land-cover change in urban and agricultural areas. Other fuzzy operators resulted in the similar prediction capabilities. However, in the prediction rate curve of integrated models for land-cover prediction in the forest areas, most fuzzy operators resulted in poorer prediction capabilities. Thus, it is necessary to apply new thematic maps or prediction models in connection with the effective prediction of changes in the forest areas.

• 정보처리학회논문지C
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• 제12C권5호
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• pp.679-686
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• 2005

EPON 가입자 망은 매체를 공유하고, EPON 가입자의 5트래픽을 통합하여 전송하기 때문에 EPON 대역 할당에 대한 제어 방식이 중요하게 다루어지고 있으며, TDMA에 기반한 DBA 방식은 표준에 포함하지 않아서 다양한 알고리즘이 적용될 수 있다. 본 논문은 최선형 서비스와 지연 우선순위 큐 기반으로 높은 우선순위의 트래픽에 대하여 지연 QoS를 보장하는 DBA 방식에 관한 것으로, 제안된 DBA 방식은 전체 트래픽에 대하여 가상 스케줄링 방식을 사용하고 서비스 클래스의 우선순위에 따라 차례로 각 클래스의 트래픽에 적용하는 방식이며, 표준 규격에 명시된 MAC 메시지를 사용하며 DBA 기능 구성이 간단하면서도 각 클래스에 맞게 QoS를 보장할 수 있다. 모사시험을 통하여 폴링시간간격, 상향 및 하향 트래픽 부하 등에 따른 서비스 클래스 별 트래픽의 지연시간으로 성능을 평가하였으며, 가입자의 상향 트래픽 발생에 따른 실제 전달된 통합 트래픽의 양 등을 분석하였다. 제안된 방식과 같이 간단한 우선순위 적용으로도 지연 우선 순위가 높은 트래픽에 대하여 QoS 보장이 충분히 수행되는 것을 확인하였다.

• 한국정보처리학회논문지
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• 제3권1호
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• pp.200-210
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• 1996

소프트웨어 재공학은 시스템 생명주기 전반에 걸쳐 생산성과 품질향상을 가지게 하며 소프트웨어 유지 보수성을 새로운 기법과 유지보수 툴의적용을 통해 기존 시스 템의 성능을 향상시킨다. 또한 기존 시스템의 이해성을 높이고 시스템 전반에 걸쳐 설계 구조나 자료구조와 같은 소프트웨어 컴퍼넌트를 추출하는데도 필요하다. 이들 컴퍼넌트는 시스템 개발 또는 재개발시 재사용된다. 기존의 객체 지향 파라다임은 소 프트웨어 유지 보수성을 향상시키는 방법으로 알려지고 있다. 그러나 객체지향의 개념적 통합을 위한 객체, 속성, 오퍼레이션의 인식과 객체 클래스의 구성과 같은 문제점을 가지고 있다. 따라서, 본 논문에서는 객체지향 시스템의 재공학 기본 방법론과 객체지 향 파라다임의 재공학을 위한 개념 인식에 대해 논하며 또한 기존 절차 중심으로 개발된 프로그램을 객체지향 시스템으로 변경하는 재공학 툴에 대해 논한다. 이툴은 객체지향 인식에서 개념적 무결성 문제를 해결하는 장점을 가진다.

• 한국정보처리학회논문지
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• 제7권9호
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• pp.2940-2947
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• 2000

무선 ATM 환경에서 다양한 멀티미디어 트래픽을 지원하기 위해서는 매체 접RMS 제어(MAC) 프로토콜이 필요하다. MAC 프로토콜은 다양한 트래픽 클래스에 대한 QoS를 보장하면서 제한된 무선 대역폭을 효율적으로 활용할 수 있도록 설계되어야 한다. 본 논문에서는 서로 다른 종류의 트래픽이 혼재된 무선 ATM 환경에서 각 서비스 클래스의 QoS를 만족할 수 있는 동적 자원 할당 방식 기반의 MAC 프로토콜을 제안하였다. CBR이나 VBR에 비해 낮은 우선 순위를 가지는 ABR 트래픽에 대해서는 최소 대역폭을 확보함으로써 지연을 크게 개선하였으며, 실시간 VBR 트래픽의 경우에는 대역폭이 초기에 경쟁을 통해 할당되고 이후로는 경쟁 없이 대역폭을 할달함으로써 처리율을 증가시켰다.

• 품질경영학회지
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• 제31권3호
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• pp.62-84
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• 2003

The typical reason of the private sector's increasing share in standardization is that the procedures of official standardization organizations are out of step with the rate of technical development. At today's so fast pace that the success of a technology is decided in the market even before it is standardized, several industry leaders jointly make their draft standard at the early stage of development, which becomes 'De fecto Standard.' To respond effectively to current trends of standardization where the market's decision is thought much of than official standardization procedures, it is necessary to shift from our current public sector-driven to private sector-driven standardization. Therefore, to vitalize the private sector-driven standardization in Korea, there is a need to: Run a standard foundation to secure stable resources for standardization Make information exchange between the govertment and private sector active and policy-making on standards consistent by designating a private organization to cover the roles, policies on standards, and support of the national standardization organization Establish a system to make private sector-driven standards approved as international standards Offer a training program to forster standard experts Publicize the importance of standards Promote standardization forums driven by private businesses, like the Integrated Forum. Maximize the benefits of linking standards and patents Now, Korea is on the threshold of developing into a world-class standard leader, and the private sector-driven standardization should be a stepping-stone for crossing over the threshold. This study is designed to suggest a method of promoting private sector-driven standardization to effectively cope with fast-changing international standards, based on the cases in developed countries.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.491-494
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• 2009

This paper introduces the design concepts and characteristics of WinDS3000$^{TM}$ which is a trade mark of Doosan's 3MW offshore/onshore wind turbine. WinDS3000$^{TM}$ has been designed in consideration of high RAMS (Reliability, Availability, Maintainability and Serviceability) and cost effectiveness for the TC Ia condition in GL guideline. An integrated drive train design with an innovative three-stage gearbox has been introduced to minimize nacelle weight of the wind turbine and to enhance a high reliability for transmission. A permanent magnet generator with full converter system has been introduced to get higher efficiency in part load operation, and grid friendliness use of 50 Hz and 60 Hz grid. A pitch regulated variable speed power control with individual pitch system has been introduced to regulate rotor torque while generator reaction torque can be adjusted almost instantaneously by the associated power electronics. An individual pitch control system has been introduced to reduce fatigue loads of blade and system. The wind turbine has been also equipped with condition monitoring and diagnostic systems in order to meet maintainability requirements. And internal maintenance crane in nacelle has been developed. As a result, the maintenance cost was dramatically reduced and maintenance convenience also enhanced in offshore condition.

• Structural Engineering and Mechanics
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• 제38권1호
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• pp.39-63
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• 2011

Referring to the formulation of physical stochastic optimal control of structures and the scheme of optimal polynomial control, a nonlinear stochastic optimal control strategy is developed for a class of structural systems with hysteretic behaviors in the present paper. This control strategy provides an amenable approach to the classical stochastic optimal control strategies, bypasses the dilemma involved in It$\hat{o}$-type stochastic differential equations and is applicable to the dynamical systems driven by practical non-stationary and non-white random excitations, such as earthquake ground motions, strong winds and sea waves. The newly developed generalized optimal control policy is integrated in the nonlinear stochastic optimal control scheme so as to logically distribute the controllers and design their parameters associated with control gains. For illustrative purposes, the stochastic optimal controls of two base-excited multi-degree-of-freedom structural systems with hysteretic behavior in Clough bilinear model and Bouc-Wen differential model, respectively, are investigated. Numerical results reveal that a linear control with the 1st-order controller suffices even for the hysteretic structural systems when a control criterion in exceedance probability performance function for designing the weighting matrices is employed. This is practically meaningful due to the nonlinear controllers which may be associated with dynamical instabilities being saved. It is also noted that using the generalized optimal control policy, the maximum control effectiveness with the few number of control devices can be achieved, allowing for a desirable structural performance. It is remarked, meanwhile, that the response process and energy-dissipation behavior of the hysteretic structures are controlled to a certain extent.

• Ocean and Polar Research
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• 제26권2호
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• pp.113-120
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• 2004

The abundance, biomass and distribution of phytoplankton, bacterioplankton and heterotrophic protists in the Bering Sea were investigated from July to August 1999. Chlorophyll a concentrations in the surface waters ranged from 0.16 to $3.79{\mu}g\;l^{-1}$ Nano-phytoplankton were found to constitute from 63 to 98% of the total phytoplankton biomass, and were clearly the dominant primary producers. The biomass of bacterioplankton in the surface layers varied from 1.46 to $20.2{\mu}g\;C\;l^{-1}$ and accounted for 30% of the total phytoplankton biomass. The biomass of bacterioplankton integrated over a depth of 0 to 100m averaged 65.4% of the total phytoplankton biomass. The surface biomass of heterotrophic protists ranged from 1.2 to $27.4{\mu}g\;C\;l^{-1}$, and was within the same order of magnitude as that of bacterioplankton. Of the total biomass of heterotrophic protists in the upper 100m of the water column, 65% was attributed to protists in the nano-size class. The results of this study suggest that bacteria and nano-protists are important components of the planktonic community in the Bering Sea during the summer season. The abundance of bacterioplankton and planktonic protists decreased from the western to northeastern and eastern regions of the Bering Sea. The abundance of these organisms also decreased with depth. The available evidence suggests that variation in the abundance and distribution of these organisms may be affected by water currents and vertical temperature variation in the Bering Sea.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
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• pp.231-234
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• 2006

시맨틱웹 분야의 온톨로지는, 분산 이종 스키마를 갖는 정보에 대한 의미적 통합, 에이전트에 의한 자동화된 유통, 그리고 명시적으로 표현되지 않은 암묵적 지식의 추론을 가능케 하는, 논리에 기반하여 잘 정의된 도메인 의존적인 콘텐츠로 볼 수 있다. 이 논문에서는 과학기술 연구분야 도메인에서 정의된 하나의 시맨틱웹 온톨로지인 '국가과학기술 R&D 기반정보' 온톨로지를 소개한다. 이 온톨로지는, 논문, 과제, 특허 등과 같은 연구성과물을 바탕으로 특정 분야 전문가들이나 연구자 네트워크를 추론해 냄으로써 실제 연구자나 연구과제 기획/평가자들에게 도움을 주기 위한 목적으로, 현재 한국과학기술정보연구원에서 개발되고 있다. 이 논문에서는 온톨로지의 스키마 구성 요소로써 클래스와 속성을 기술하고, 온톨로지에서의 인스턴스 표현의 예를 보인다. 상기 온톨로지는 인력, 기관 등과 같은 실세계 인스턴스의 고유한 신원을 온톨로지 내에 대응시키기 위해, 실세계 신원의 중의성 해소 기법과 함께 개별 클래스에 종속적인 URI할당지침을 사용하여 온톨로지 내에 인스턴스를 표현하고 있다.

• 산업경영시스템학회지
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• 제40권1호
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• pp.87-94
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• 2017

Many industrial accidents have occurred continuously in the manufacturing industries, construction industries, and service industries of Korea. Fatal accidents have occurred most frequently in the construction industries of Korea. Especially, the trend analysis of the accident rate and fatal accident rate is very important in order to prevent industrial accidents in the construction industries systematically. This paper considers forecasting of the accident rate and fatal accident rate with static and dynamic time series analysis methods in the construction industries. Therefore, this paper describes the optimal accident rate and fatal accident rate by minimization of the sum of square errors (SSE) among regression analysis method (RAM), exponential smoothing method (ESM), double exponential smoothing method (DESM), auto-regressive integrated moving average (ARIMA) model, proposed analytic function model (PAFM), and kalman filtering model (KFM) with existing accident data in construction industries. In this paper, microsoft foundation class (MFC) soft of Visual Studio 2008 was used to predict the accident rate and fatal accident rate. Zero Accident Program developed in this paper is defined as the predicted accident rate and fatal accident rate, the zero accident target time, and the zero accident time based on the achievement probability calculated rationally and practically. The minimum value for minimizing SSE in the construction industries was found in 0.1666 and 1.4579 in the accident rate and fatal accident rate, respectively. Accordingly, RAM and ARIMA model are ideally applied in the accident rate and fatal accident rate, respectively. Finally, the trend analysis of this paper provides decisive information in order to prevent industrial accidents in construction industries very systematically.