• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.527-538
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• 2021

The purpose of the study is to determine the efficiency, position, and partner selection of securities companies via the negative super-SBM model used in data envelopment analysis (DEA). This model utilizes a variety of inputs, including current assets, non-current assets, fixed assets, liabilities, owner's equity and charter capital, and outputs including net revenue, gross profit, operating profit, and net profit after tax collected from the financial reports (Vietstock, 2020) of 32 securities companies, operating during the period from 2016 to 2019, negative data are collected as well. Empirical results determined both efficient and inefficient terms, and then further determined the position of each securities firm under consideration of every term. The overall score arrived at discovered a large performance change realizing a maximum score able to reach 20.791. In the next stage, alliancing inefficient companies was carried out based on the 2019 scores to seek out optimal partners for the inefficient companies. The tested result indicated that AAS was the best partner selection when its partners received a good result after alliancing, as with FTS (11.04469). The partner selection is deemed as a solution helpful to inefficient securities companies in order to improve their future efficiency scores.

• 한국통신학회논문지
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• 제34권2A호
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• pp.107-112
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• 2009

Spectral efficiency of current two-phase cooperative communications protocols is low since in the second time the relay forwards the same signal received from the source to the destination, the source keeps silent in this time. In this paper, we propose a novel cooperative communications protocol where the signal needed to transmit to the destination is sent in both phases, the source and the relay also transmit different signal to the destination thus no loss of spectral efficiency. This protocol performs signal selection based on log-likelihood ratio (LLR) at relay and maximum likelihood (ML) detection at destination. While existing protocols pay for a worse performance than direct transmission in the low SNR regime which is of special interest in ad hoc networks, ours is better over the whole range of SNR. In addition, the proposal takes advantages of bandwidth efficiency, long delay and interference among many terminals in ad hoc network. Simulation results show that the proposed protocol can significantly save total energy for wireless ad hoc networks.

• Asian-Australasian Journal of Animal Sciences
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• 제20권3호
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• pp.453-460
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• 2007

An overview of developments important in the future of animal breeding is discussed. Examples from the application of quantitative genetic principles to selection in chickens and mice are given. Lessons to be learned from these species are that selection for production traits in livestock must also consider selection for reproduction and other fitness-related traits and inbreeding should be minimized. Short-term selection benefits of best linear unbiased predictor methodology must be weighed against long-term risks of increased rate of inbreeding. Different options have been developed to minimize inbreeding rates while maximizing selection response. Development of molecular genetic methods to search for quantitative trait loci provides the opportunity for incorporating marker-assisted selection and introgression as new tools for increasing efficiency of genetic improvement. Theoretical and computer simulation studies indicate that these methods hold great promise once genotyping costs are reduced to make the technology economically feasible. Cloning and transgenesis are not likely to contribute significantly to genetic improvement of livestock production in the near future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권10호
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• pp.4680-4697
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• 2017

In future, since the user experience plays a more and more important role in the development of today's communication systems, quality of experience (QoE) becomes a widely used metric, which reflects the subjective experience of end users for wireless service. In addition, the energy efficiency is an increasingly important problem with the explosive growth in the amount of wireless terminals and nodes. Hence, a QoE-aware energy efficiency maximization based joint user access selection and power allocation approach is proposed to solve the problem. We transform the joint allocation process to an optimization of energy efficiency by establishing an energy efficiency model, and then the optimization problem is solved by chaotic clone immune algorithm (CCIA). Numerical simulation results indicate that the proposed algorithm can efficiently and reliably improve the QoE and ensure high energy efficiency of networks.

• 한국정보통신학회논문지
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• 제20권7호
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• pp.1249-1254
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• 2016

최근 들어서, Multi-User Massive MIMO 네트워크에서 하드웨어와 알고리즘 측면에서 복잡도를 낮추면서 높은 전송률을 얻을 수 있는 다양한 전송 안테나 선택 기법에 대한 연구가 활발히 진행되고 있다. 또한, 차세대 이동통신 네트워크에서 에너지 소모량을 줄이기 위한 다양한 기술들에 대한 연구가 이루어지고 있다. 그래서, 본 논문에서는 Multi-User Massive MIMO 네트워크에서 낮은 계산 복잡도를 달성하면서 에너지 효율성을 높일 수 있는 전송 안테나 선택 기법을 연구하였다. 먼저, Brute-Force 탐색 기반의 최적 방식을 소개하고 최적 방식 대비 계산 복잡도를 획기적으로 줄일 수 있는 새로운 안테나 선택 기법을 제안하였다. 안테나 수가 증가할수록 최적 방식의 복잡도는 지수적으로 증가하는 반면 제안 방식은 선형적으로 증가한다. 그럼에도 불구하고, 제안 방식과 모든 경우를 고려하는 최적 방식의 에너지 효율 성능 차이는 크지 않다.

• 한국산림과학회지
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• 제84권3호
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• pp.356-360
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• 1995

잣나무림에 있어서 목재 및 종자 생산이 중요 경영 목적이므로 이러한 형질을 개량하기 위한 선발육종이 진행중에 있다. 본 연구는 잣나무의 유전모수 및 조기선발 효율 등을 추정하여 1세대 채종원을 전진세대 채종원으로 유도하는데 필요한 자료와 정보를 얻기 위하여 수행하였다. 1986년 50가계로 된 풍매 차대검정림을 3곳에 조성하여 6년간(5~10년생) 수고 생장을 조사하여 분석한 결과, LAR에 대한 수령간 유전 및 표현형 상관의 단순직선회귀는 유의차가 있었으며($r^2=0.7862$, 0.8256), 성숙기를 20년으로 가정하였을 때 조림 후 3년생이 1.96으로 조기선발 효율이 가장 높은 수령으로 추정되어 조기선발이 가능하였다.

• 정보보호학회논문지
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• 제30권4호
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• pp.537-544
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• 2020

악성코드 기술 발전으로 변이, 난독화 등의 탐지 회피 방법이 고도화되고 있다. 이에 악성코드 탐지 기술에 있어 알려지지 않은 악성코드 탐지 기술이 중요하며, 배포된 악성코드를 통해 저자를 식별하여 알려지지 않은 악성코드를 탐지하는 악성코드 저자 식별 방법이 연구되고 있다. 본 논문에서는 바이너리 기반 저자 식별 방법에 대해 중요 정보인 컴파일러 정보를 추출하고자 하였으며, 연구 간에 특징 선택, 확률 및 비확률 모델, 최적화가 분류 효율성에 미치는 민감성(Sensitive)을 확인하고자 하였다. 실험에서 정보 이득을 통한 특징 선택 방법과 비확률 모델인 서포트 벡터 머신이 높은 효율성을 보였다. 최적화 연구 간에 제안하는 프레임워크를 통한 특징 선택 및 모델 최적화를 통해 높은 분류 정확도를 얻었으며, 최대 48%의 특징 감소 및 51배가량의 빠른 실행 속도라는 결과를 보였다. 본 연구를 통해 특징 선택 및 모델 최적화 방법이 분류 효율성에 미치는 민감성에 대해 확인할 수 있었다.

• 한국위성정보통신학회논문지
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• 제11권3호
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• pp.58-64
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• 2016

본 논문에서는 다중사용자 Massive MIMO 시스템 환경에서 계산 복잡도와 성능의 균형을 고려한 효율적인 송신 안테나 선택 기법을 제안한다. Massive MIMO 시스템은 차세대 5G 이동 통신의 목표 성능을 달성하기 위한 핵심 기술 중 하나로, 높은 주파수 효율과 신뢰성, 다중화 이득 등을 얻을 수 있다. 하지만 기지국에 장착되는 대규모 송신 안테나들과 RF chain은 높은 하드웨어 비용과 복잡도, 높은 소비 전력 등의 문제를 야기한다. 따라서 본 논문에서는 기지국의 RF chain의 수를 줄이는데 효과적인 송신 안테나 선택기법을 연구하고, 기존의 기법에서 성능과 복잡도의 균형을 고려한 새로운 송신 안테나 선택 기법을 제안한다. 또한 주파수 효율분석과 함께 최적의 안테나를 찾는데 필요한 탐색 수 분석을 통해 각 송신 안테나 기법 별 성능과 복잡도를 나타낸다.

• 지식경영연구
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• 제13권3호
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• pp.55-77
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• 2012

Selecting promising technology is becoming more and more difficult due to the increased number and complexity. In this study, we propose hybrid AHP/DEA-AR method and hybrid AHP/DEA-AR-G method to evaluate efficiency of technology alternatives based on ordinal rating data collected through survey to technology experts in a certain field and select efficient technology alternative as promising technology. The proposed method normalizes rating data and uses AHP to derive weights to improve the credibility of analysis, then in order to avoid basic DEA models' problems, use DEA-AR and DEA-AR-G to evaluate efficiency of technology alternatives. In this study, we applied the proposed methods to clean technology and compared with the basic DEA models. According to the result of the comparison, we can find that the both proposed methods are excellent in confirming most efficient technology, and hybrid AHP/DEA-AR method is much easier to use in the process of technology selection.

• 한국건축시공학회지
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• 제3권2호
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• pp.149-156
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• 2003

The purpose of this study was to find out the most reasonable design in the superstructure of an underground parking lot which needs to be considered with the economic efficiency being influenced on the subdivision price, construction duration, workability and the maintenance of crack and leakage status of apartment house. In this research, we've evaluated the fitness for the superstructure of an underground parking lot by examination of construction constraint, which was based on the calculated data of structural design and quantity survey. The results of this study are summarized as follows. 1. The system of the absent structure of beam is proper structure for economic efficiency, construction duration and workability, but it is disadvantageous at the side of maintenance efficiency because of the many part of large slab. In the opposite direction, the establishing structure of beam has the advantages of structural stability except economic efficiency, construction duration and workability 2. It's required a proper selection for the views being contrary to each other which the owners considers good quality, on the other hand, the contractors consider construction duration and workability. 3. In making a selection for the superstructure of an underground parking lot, we have concluded that it is the most important to choose the proper structure for the demanded performance by contrasting with two system. (2Bay or 3Bay)