• Landscaping Tree
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• v.78 no.1_2
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• pp.24-26
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• 2004

우리 산야에 자생하는 것 중 이른 봄 가장 먼저 피는 것을 들라하면 단연 복수초이다. 추위에 강해 겨울의 한복판인 2월에도 설악산에서 눈과 얼음을 뚫고 나올 정도이다. 반면에 여름 고온에는 무척 약해 햇볕이 많이 드는 곳에서는 6월 하순부터 지상부가 거의 말라죽는다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.334-335
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• 2000

우리나라 연근해 어업자원은 어종 수는 많으나 양적으로 뚜렷한 우세종이 없는 것이 특징이며, 어업형태도 복수어종을 대상으로 하거나 단일어종을 복수어업으로 어획하는 것이 대부분이다. 이러한 다종어업에 대하여 단일어종에 대한 자원평가모델을 적용하는 것은 효과적인 방법이 될 수 없다. 따라서, 본 연구에서는 다종자원평가 방법과 관리방안을 모색해 보았다. (중략)

• Journal of Radiation Protection and Research
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• v.33 no.4
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• pp.151-160
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• 2008

In Korean nuclear power plants (NPPs), two thermoluminescent dosimeters (TLD) were provided to workers who work in an inhomogeneous radiation field; one on the chest and the other on the head. In this way, the effective dose for radiation workers at NPPs was determined by the high deep dose between two radiation dose from these TLDs. This represented a conservative method of evaluating the degree of exposure to radiation. In this study, to prevent the overestimation of the effective dose, field application experiments were implemented using two-dosimeter algorithms developed by several international institutes for the selection of an optimal algorithm. The algorithms used by the Canadian Ontario Power Generation (OPG) and American ANSI HPS N13.41, NCRP (55/50), NCRP (70/30), EPRI (NRC), Lakslumanan, and Kim (Texas A&M University) were extensively analyzed as two-dosimeter algorithms. In particular, three additional TLDs were provided to radiation workers who wore them on the head, chest, and back during maintenance periods, and the measured value were analyzed. The results found no significant differences among the calculated effective doses, apart from Lakshmanan's algorithm. Thus, this paper recommends the NCRP(55/50) algorithm as an optimal two-dosimeter algorithm in consideration of the solid technical background of NCRP and the convenience of radiation works. In addition, it was determined that a two-dosimeter is provided to a single task which is expected to produce a dose rate of more than 1 mSv/hr, a difference of dose rates depending on specific parts of the body of more than 30%, and an exposure dose of more than 2 mSv.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.89-97
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• 2015

In bidding processes conducted by government agencies, local governments or public agencies, budget prices are critical to both ordering bodies and bidders since budget prices are bases for selecting a successful bidder. Since a high budget price goes against ordering bodies and a low one goes against bidders, most ordering bodies adopt a system using multiple preliminary prices for determining a budget price to ensure fair and transparent manners. Discussed are how budget prices change depending on the methods of sampling 15 preliminary prices and the methods of sampling 4 out of 15 prices. Computer simulation is conducted to analyze budget prices for various methods to determine multiple preliminary prices. It is more likely for budget prices to be close to base prices when splitting a range of generating preliminary prices into 15 intervals and taking 4 preliminary prices from 15 intervals than when taking 4 preliminary prices from a whole range. In cases when splitting a range of generating preliminary prices, if we take 2 preliminary prices out of intervals above 100% and take 2 out of intervals below 100%, the expected budget prices are equal to a base price and the standard deviations are about half in comparison with those when taking 4 out of 15 intervals.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.141-152
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• 2009

The simultaneous operation of multiple UAV's makes it possible for us to raise the mission accomplishment and cost efficiency. For this we need an easily scalable control algorithm, and swarm intelligence having the characteristics such as flexibility, robustness, decentralized control and self-organization comes into the spotlight as a practical substitute. In this paper the features of swarm intelligence are described, and various research results are introduced which show that the application of swarm intelligence to the control of multiple UAV's enables the missions of surveillance, path planning, target tracking and attack to be accomplished efficiently by simulations and tests.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2935-2944
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• 2009

This paper proposes Dual DBR(Drum-Buffer-Rope) system for a small-to-medium-sized PCB(Printed Circuit Board) manufacturing line. DBR method of TOC(Theory of Constraints) is an effective system for a small-to-medium-sized company to build production scheduling system. But to apply it to PCB line, it needs more technical consideration because of multiple constraints, looping process line and complex buffer management. This paper proposes an answer of these problems using Dual DBR to build production scheduling system more successfully. And it was confirmed that lead time was reduced more than 20% applying Dual DBR system to a domestic PCB manufacturing line actually.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.290-293
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• 2011

현재 전국적으로 도시 철도의 각 호선별 열차 운행은 차량기지에서 출고된 열차가 기점과 종점의 두 지점 사이를 여러 차례 왕복한 후 정해진 차량기지로 입고방식을 취하는 것이 대부분이다. 그리고 매일 열차 운행이 개시되기 전 각 차량기지의 보유 열차 수는 전날과 동일해야 하는데 차량 기지가 복수로 존재할 경우 열차 운행계획 수립 시 어느 기지에서 출고한 어떤 차량이 어느 기지로 입고해야 하는지를 결정하는 문제가 더욱 어려워진다. 승객 수송을 위한 여러 가지 요구조건 또한 모두 만족시키면서 이 입출고 제약도 만족시키는 것은 쉬운 문제가 아니다. 하지만 열차 운행 계획 수립을 자동으로 생성하는 방법에 대한 연구는 매우 부족한 실정이다. 따라서 본 논문에서는 차량기지가 복수로 존재하는 상황에서의 현실 제약을 모두 만족하는 도시철도 운행 계획을 자동으로 생성하는 방법을 제시한다. 본 논문에서 제시하는 방법으로 실험 한 결과 기존의 방법으로 해결이 어려운 차량기지가 복수로 존재하는 상황에서의 현실제약을 모두 만족하는 계획을 빠른 시간 내에 수립 할 수 있음을 확인 하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.254-262
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• 2014

Radar task scheduling deals with the assignment of task to efficiently enhance the radar performance on the limited resource environment. In this paper, total weighted tardiness is adopted as the objective function of task scheduling in operation of multiple multi-function radars. To take into account real-time implementability, heuristic index-based methods are presented and investigated. Numerical simulations for generic search and track scenarios are performed to evaluate the proposed methods, in particular investigating the effectiveness of multi-radar operation concepts.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.61-67
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• 2004

The next generation cellular wireless communication systems require high data rate transmissions and large system capacities. In order to meet these requirements, multiple antennas can be used at the base and mobile stations, forming MIMO(Multiple Input Multiple Output) channels. This paper proposes a MIMO SDMA(Space Division Multiple Access) technique with dynamic slot allocation which allows the transmitter to efficiently transmit parallel data streams to each of multiple receivers. The proposed technique can increase system capacities significantly by transmitting a larger number of data streams than conventional MIMO techniques while minimizing the performance degradation due to the beamforming dimension reduction.

• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.23-43
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• 2010

This article compares two different auction designs for $CO_2$ emission allowances, namely uniform pricing and multiple pricing, in view of market efficiency. Experimental economic method of Buckley et al. (2004) is applied in this analysis. As a result of this analysis as expected, multiple pricing method brings out Winner's curse. It means that uniform pricing method is more efficient than multiple pricing method.