• 한국도로학회논문집
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• 제3권2호
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• pp.141-147
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• 2001

해를 거듭할수록 증가하는 고속도로 연장과 함께 전체 고속도로 유지보수 비용은 급증하는 추세에 있다. 제한된 유지보수 예산으로 전체 고속도로망을 효율적으로 유지관리하기 저해 포장관리시스템 (PMS, Pavement Management System)의 운영은 필수적이라 할 수 있다.본 연구는 PMS의 핵심기능인 보수 우선순위 및 공법결정 논리를 개발하여 실무자들의 PMS 활용도를 높이기 위한 연구로서, 실무자들이 친숙하게 사용할 수 있도록 PMS의 기본기능에 충실하여 쉽게 운영 기능한 시스템을 구성 하는데 역점을 두었다. PMS의 주 논리인 보수우선순위 및 보수공법결정에 관련된 각 항목들의 criteria는 기술자의 판단에 의해서 쉽게 수정할 수 있도록 하여 좀더 유연한 운영을 할 수 있도록 하였고, 보수공법 결정에 있어서도 기계적인 알고리즘께 의한 보수공법결정체계의 경직성을 보완하기 위해, 제시된 보수공법의 적절성을 PMS운영자가 직접 확인하고 필요시 현장실사 또는 정밀조사를 통해 보수공법을 조정할 수 있도록 하였다. 도로 일반현황조회에 있어서는 운영자가 쉽게 포장의 상태를 파악할 수 있도록 HGIS와의 연계를 통해 현황조회 기능을 강화하였다. 고속도로 PMS의 전산화는 각 고속도로 포장과 관련된 모든 정보에 대한 데이터베이스를 기반으로 하여 실무자들이 쉽게 이해하고 편리하게 사용하는데 중점을 두어 개발하였으며 정량화된 객관적인 정보를 실무자에게 제공하여 포장을 효율적으로 관리할 수 있도록 하였다.

• 한국환경과학회지
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• 제25권2호
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• pp.191-216
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• 2016

Since prolonged exposure to elevated ozone ($O_3$) concentrations is known to be harmful to human health, appropriate control strategies for ozone are needed for the non-attainment area such as Seoul, Korea. The goal of this research is to assess factors linked with the 1-hour ozone exceedance through a decision tree model. Since ozone is a secondary pollutant, lag times between ozone and explanatory variables for ozone formation are taken into account in the model to improve the accuracy of the simulation. Results show that while ozone concentrations of the previous day and $NO_2$ concentrations in the morning are major drivers for ozone exceedances in the early afternoon, meteorology plays more important role for ozone exceedances in the late afternoon. Results also show that a selection of lag times between ozone and explanatory variables affect the accuracy of predicting 1-hour ozone exceedances. The result analyzed in this study can be used for developing control strategies of ozone in Seoul, Korea.

• 제어로봇시스템학회논문지
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• 제9권6호
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• pp.448-455
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• 2003

A system design technique of automatic thickness measurement and defect inspection system, which measures the thickness of the ALC(Autoclaved Lightweight Concrete) block and inspects the defect on a realtime basis is proposed. The image processing system was established with a CCD camera, an image grabber, and a personal computer without using assembled measurement equipment. The image obtained by this system was analyzed by a devised algorithm, specially designed for the enhanced measurement accuracy. For the realization of the proposed algorithm, the preprocessing method that can be applied to overcome uneven lighting environment, an enhanced edge decision method using 8 edge-pairs with irregular and rough surface, the unit length decision method in uneven condition with rocking objects, and the curvature calibration method of camera using a constructed grid are developed. The experimental results, show that the required measurement accuracy specification is sufficiently satisfied using our proposed method.

• 전자공학회논문지B
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• 제32B권6호
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• pp.868-875
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• 1995

This paper presents a method of constructing the multiple-valued combinational logic systems(MVCLS) by decision diagram. The switching function truth table of MVCLS is transformed into canonical normal form of sum-of-products(SOP) with literals at first. Next, the canonical normal form of SOP is transfered into multiple-valued logic decision diagram(MVLDD). The selecting of variable ordering is very important in this stage. The MVLDDs are quite different from each other according to the variable ordering. Sometimes the inadequate variable ordering produces a very large size of MVLDD means the large size of circuit implementation. An algorithm for generating the proper variable ordering produce minimal MVLDD and an example shows the verity of the algorithm. The circuits are realized with T-gate acceording to the minimal MVLDD.

• 한국전자통신학회논문지
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• 제6권6호
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• pp.849-854
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• 2011

시스템 이벤트들로부터 그 파급효과를 최소화하기 위해서는 실시간 조건에 기반한 규칙기반 전문가 시스템이 매우 효과적인데, 그 이벤트가 다양하고 부하조건이 매우 가변적이기 때문에 규칙 기반 전문가 시스템을 구축하기가 쉽지 않다. 따라서 본 연구에서는 CART 알고리즘 기반의 의사결정 트리 기법을 적용하여 상정사고 사례들로부터 규칙기반 전문가 시스템을 구축하는 방법론에 대해서 연구하고자 한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 춘계종합학술대회
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• pp.226-230
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• 2000

본 논문에서는 CPLD 칩을 이용하여 QPSK 복조기를 구현하고, 그 결과를 검토하였다. 복조기는 비트 동기를 포착하는 STR(Symbol Timing Recovery) loop와 반송파 동기를 포착하는 CPR(Carrier Phase Recovery) loop로 구성된다 STR loop는 DD-Gardner 방식을, CPR loop는 빠른 반송파 포착을 위하여 Decision-Directed 동기화 방식을 이용하여 구현한 결과를 제시하였다. Altera사의 Design Compiler를 이용하여 FLEX10K 칩에 합성한 QPSK 복조기의 속도는 약 2 (Mbps)의 전송속도를 가지며, ASIC으로 구현시에는 CPLD 속도의 5-6배 이상의 고속화가 가능하다.

• International Journal of Internet, Broadcasting and Communication
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• 제9권1호
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• pp.72-80
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• 2017

In this work, an efficient transmit antenna selection approach for the quadrature spatial modulation (QSM) systems is proposed. The conventional Euclidean distance antenna selection (EDAS)-based schemes in QSM have too high computational complexity for practical use. The proposed antenna selection algorithm is based on approximation of the EDAS decision metric employed for QSM. The elimination of imaginary parts in the decision metric enables decoupling of the approximated decision metric, which enormously reduces the complexity. The proposed method is also evaluated via simulations in terms of symbol error rate (SER) performance and compared with the conventional EDAS methods in QSM systems.

• 제어로봇시스템학회논문지
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• 제10권6호
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• pp.494-500
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• 2004

This paper presents a machine vision system, which inspects the measurement of the ALC block on a real-time basis in the production process. The automatic measurement system was established with a CCD camera, an image grabber, and a personal computer without using assembled measurement equipment. Images obtained by this system was processed by an algorithm, specially designed for an enhanced measurement accuracy. For the realization of the proposed algorithm, a preprocessing method that can be applied to overcome uneven lighting environment, boundary decision method, unit length decision method in uneven condition with rocking objects, and a projection of region using pixel summation are developed. From our experimental results, we could find that the required measurement accuracy specification is sufficiently satisfied by using the proposed method.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1549-1557
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• 2018

Optimizing the design of large-scale electric machines based on nonlinear finite element analysis (FEA) requires longer computation time than other applications of FEA, mainly due to the huge size of the machines. This paper addresses a new region decision method (RDM) with mesh adaptive direct search (MADS) for the optimal design of wind generators in order to reduce the computation time. The validity of the proposed algorithm is evaluated using Rastrigin and Goldstein-Price benchmark function. Moreover, the algorithm is employed for the optimal design of a 5.6MW interior permanent magnet synchronous generator to minimize the torque ripple. Additionally, mechanical stress analysis as well as electromagnetic field analysis have been implemented to prevent breakdown caused by large centrifugal forces of the modified design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5449-5464
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• 2018

Recent works have validated the possibility of reducing the energy consumption in wireless heterogeneous networks, achieved by switching on/off some base stations (BSs) dynamically. In this paper, to realize energy conservation, the discrete time Markov Decision Process (DTMDP) is developed to match up the BS switching operations with the traffic load variations. Then, an asynchronous decision-making algorithm, which is based on the Bellman equation and the on/off priorities of the BSs, is firstly put forward and proved to be optimal in this paper. Through reducing the state and action space during one decision, the proposed asynchronous algorithm can avoid the "curse of dimensionality" occurred in DTMDP frequently. Finally, numerical simulations are conducted to validate the effectiveness and advantages of the proposed asynchronous on/off strategies.