• Annual Conference of KIPS
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• 2016.10a
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• pp.583-586
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• 2016

단백질과 RNA의 상호작용 데이터가 대량으로 늘어남에 따라, 단백질과 RNA의 결합부위를 예측하는 계산학적인 방법들이 많이 개발되고 있다. 하지만, 많은 계산학적인 방법들은 단백질에서 단백질과 RNA 결합부위를 예측한다는 한계점이 있었다. 본 논문에서는 RNA와 단백질의 서열정보를 모두 사용하여, 단백질과 결합하는 RNA 결합부위를 예측하는 기법과 그 결과를 논한다. WEKA random forest(http://www.cs.waikato.ac.nz/ml/weka/)를 이용하여 예측 모델을 개발하였고, RNA 서열의 서열 프로파일, 서열 composition, 결합 상대방의 단백질의 특성 등을 특정으로 표현하였다. Random forest 기법을 사용한 cross validation의 결과로서 1:1 모델에서 제일 높은 성능인 92.4% sensitivity, 92.0% specificity, 92.2% accuracy를 보였고, independent test에서는 72.5% sensitivity, 90.0% specificity, 2.1% accuracy를 보였다.

• Journal of KIISE:Software and Applications
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• v.26 no.5
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• pp.639-646
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• 1999

질의 또는 문서에 대한 상이한 표현 방법 또는 상이한 검색 기법은 서로 다른 집합의 문서들을 검색한다고 알려져왔다. 최근 이러한 특성을 이용하여 다양한 표현 방법 또는 검색 기법을 결합함으로써 보다 높은 검색 효과를 얻을수있음이 입증되었다. 그러나 이러한 다중 증거 결합이 검색 효과를 개선시키는 이유에 대해서는 아직까지 충분한 설명이 이루어지지않은 상태이다. 본 논문에서는 다중 증거 결합이 검색 효과를 개선하는 이유를 분석하고 이에 근거하여 다중 증거들을 효과적으로 결합할수 있는 방법을 조사한다. 또한 다중 증거 결합에 있어서 유사도 대신에 순위의 사용이 검색 효과에 미치는 영향을 조사한다.

• Journal of the Korean Society for information Management
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• v.12 no.2
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• pp.213-223
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• 1995

It has known that different representations of either queries or documents, or different retrieval techniques retrieve different sets of documents. Recent works suggest that significant improvements in retrieval performance can be achieved by combining multiple representations or multiple retrieval techniques. In this paper we propose a simple method for retrieving different documents within a single query representation, a single document representation and a single retrieval technique. We classify the types of documents, and describe the properties of weighting schemes. Then. we explain that different properties of weighting schemes may retrieve different types of documents. Experimental results show that significant improvements can be obtained by combining the retrieval results form different properties of weighting schemes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.815-822
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• 2010

Two-way relaying scheme based on relay selection can not only achieve higher rate but also get the selection diversity gain according to the number of relays. However the scheme can not achieve combining gain because it does not consider the direct link between users. In this paper, we propose, with multiple relays, opportunistic cooperative two-way relaying scheme and incremental cooperative two-way relaying scheme which can achieve both selection diversity gain and combining gain. Simulation results show that proposed scheme outperform the conventional scheme by achieving both combining gain and selection diversity gain according to the number of relays.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.50-52
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• 2000

페이징 기법의 효율성은 어떠한 페이지 교체 기법을 쓰느냐에 따라 결정된다. LRU 기법은 작업 부하의 변화에 잘 적응하여 많은 경우 좋은 성능을 보인다. 그러나 참조의 횟수에 대한 정보를 이용하지 못한다. LFU 기법은 지역성을 가지는 참조 패턴이 발견되면 좋은 성능을 발휘한다. 그러나 작업 부하가 변하는 경우 이에 적응하지 못한다. 여러 응용에 대해 참조 패턴을 분석하여 보면 참조되는 페이지는 최근성과 참조 횟수에 의해 가치가 결정되며, 따라서 LRU나 LFU 기법 한 가지만으로 페이지 교체 정책을 최적화 시킬 수 없다. 본 논문에서는 LRU 기법과 LFU 기법을 결합한 새로운 교체 기법을 제안한다. 이 교체 기법에서는 LRU 리스트와 LFU 리스트를 결합하여 사용함으로써 참조 시간뿐만 아니라 참조 횟수를 이용하여 페이지들을 교체한다. 트레이스 기반 모의 실험에서는 제안 기법의 순수 LRU 기법보다 나은 성능을 보일 때가 있다.

• Journal of Advanced Navigation Technology
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• v.17 no.3
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• pp.298-305
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• 2013

In this paper, we propose simple combining schemes for sensing ATSC digital television signals with spectral correlation density (SCD). The detection algorithms exploiting the cyclostationarity exhibited by the pilot of ATSC digital television signals usually use the SCD value at a given particular frequency. However, we found that non-zero SCDs are found to be distributed over a certain range of frequencies in multipath fading environment. To utilize a set of non-zero SCD values computed in the vicinity of the pilot location, we formulate a class of combining methods in analogy with the maximal ratio combining, the square law combining and the equal gain combining. We show that the proposed simple combining schemes improve the detection performance by 0.5~1.0dB under multipath fading environments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.9
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• pp.1-10
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• 2000

This paper proposes symbol decoding schemes combined with channel estimation techniques for coded orthogonal frequency division multiplexing (COFDM) systems in fading channels. sThe proposed symbol decoding schemes are consisted of a symbol decoding technique and channel estimation techniques. The symbol decoding based on Viterbi algorithm is achieved by matching the length of branch word from encoder trellis to the codeword length of symbol candidate on decoder trellis. Three combination schemes are described and their error performances are compared. The first scheme is to combine a symbol decoding technique with a training channel estimation technique. The second scheme joins a decision directed channel estimation technique to the first scheme. The time varying channel transfer functions are tracked by the decision directed channel estimation technique and the channel transfer functions used in the symbol decoder are updated every COFDM symbol. Finally, In order to reduce the effect of additive white Gaussian noise (AWGN) between adjacent subchannels, deinterleaved average channel estimation technique is combined. The error performances of the three schemes are significantly improved being compared with that of zero forcing equalizing schemes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4A
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• pp.307-314
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• 2010

In this paper, a receive diversity combining technique is proposed for single-carrier frequency division multiple access (SC-FDMA)-based cooperative relay systems when discrete Fourier transform (DFT) spreading sizes for mobile station (MS) and relay station (RS) are different. The proposed technique is composed of a DFT spreading size adjustment block, a phase rotation compensation block, a channel phase compensation block, and a receive diversity combining block. The proposed technique is robust to multipath channels and can be operated with a relatively small computational complexity because receive diversity combining is performed with scalar operations in the frequency-domain. It is shown by computer simulation that the proposed receive diversity combining techniques achieve a performance gain over the conventional maximal ratio combining (MRC) techniques for SC-FDMA-based cooperative relay systems.

• Journal of Intelligence and Information Systems
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• v.14 no.3
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• pp.133-154
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• 2008

The data imbalance problem which can be uncounted in data mining classification problems typically means that there are more or less instances in a class than those in other classes. In order to solve the data imbalance problem, there has been proposed a number of techniques based on re-sampling with replacement, adjusting decision thresholds, and adjusting the cost of the different classes. In this paper, we study the feasibility of the combination usage of the techniques previously proposed to deal with the data imbalance problem, and suggest a combination method using genetic algorithm to find the optimal combination ratio of the techniques. To improve the prediction accuracy of a minority class, we determine the combination ratio based on the F-value of the minority class as the fitness function of genetic algorithm. To compare the performance with those of single techniques and the matrix-style combination of random percentage, we performed experiments using four public datasets which has been generally used to compare the performance of methods for the data imbalance problem. From the results of experiments, we can find the usefulness of the proposed method.

• The Korean Journal of Applied Statistics
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• v.14 no.2
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• pp.321-332
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• 2001

본 논문에서는 반응변수가 두 가지의 값을 갖는 회귀분석에 적용할 수 있는 사영추적회귀를 고려하였다. 회귀모형에 필요한 설명변수들의 선형결합이 하나이고 연결함수의 형태를 사전에 알지 못한다는 가정하에서 모의담금질 기법을 이용하여 모형에 필요한 선형결합을 찾는 알고리즘을 제시하였다. 이진 반응변수의 경우에는 평활모수의 값에 따라 잔차이탈도함수의 반응표면이 단봉의 형태를 갖지 않는 경우가 있어 비동질적 마코프체인을 이용한 모의담금질 기법을 적용하면 효율적으로 선형결합을 탐색할 수 있다.