• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.2
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• pp.315-320
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• 2008

Nowadays, a lot of related data obtained from these research could be given a new present meaning to accomplish the original purpose of the whole research as a human genome project. In such a thread, construction of gene expression analysis system and a basis rank analysis system is being watched newly. Recently, being identified fact that particular sub-class of tumor be related with particular chromosome, microarray started to be used in diagnosis field by doing cancer classification and predication based on gene expression information. In this thesis, we used cDNA microarrays of 3840 genes obtained from neuronal differentiation experiment of cortical stem cells on white mouse with cancer, created system that can extract informative gene list through normalization separately and proposed combination method for selecting more significant genes. And possibility of proposed system and method is verified through experiment. That result is that PC-ED combination represent 98.74% accurate and 0.04% MSE, which show that it improve classification performance than case to experiment after generating gene list using single similarity scale.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2004.11a
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• pp.286-295
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• 2004

생물학적으로 의미 있는 결과를 도출하기 위해서는 많은 실험 데이터가 필요하다. 최근에는 마이크로 어레이 실험 기술이 발달함에 따라 대량의 데이터를 얻을 수 있게 되었고, 이로 인해서 데이터를 체계적으로 관리하고 필요한 정보를 습득할 수 있는 시스템이 필요하게 되었다. LIMS(Laboratory Information Management System) 는 이러한 요구 조건을 충족시키기 위한 시스템으로 기존의 파일 시스템에 의존해서 비효율적으로 실험 데이터를 관리해 오던 것을 체계적이고 효율적으로 관리해 주기 위한 시스템이다. 대량의 유전자 발현 데이터의 생산은 유전자의 조절 네트워크 예측을 가능하게 하였다. 유전자간의 상호 작용을 분석하는 것은 세포의 활동을 이해하는데 매우 중요한 요소라고 할 수 있다. 본 논문에서는 기존의 LIMS 기능과 유전자 조절 네트워크 분석 시스템을 통합하여 사용자가 쉽게 데이터를 공유 및 습득할 수 있으며 편리한 사용자 인터페이스를 이용하여 컴퓨터에 익숙하지 않은 실험들도 쉽게 사용할 수 있는 GELIM(an Integrated system with GEnetic network analyzer and LIMs) 을 소개한다.

• Journal of Intelligence and Information Systems
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• v.10 no.1
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• pp.109-123
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• 2004

Corporate financial distress and bankruptcy prediction is one of the major application areas of artificial neural networks (ANNs) in finance and management. ANNs have showed high prediction performance in this area, but sometimes are confronted with inconsistent and unpredictable performance for noisy data. In addition, it may not be possible to train ANN or the training task cannot be effectively carried out without data reduction when the amount of data is so large because training the large data set needs much processing time and additional costs of collecting data. Instance selection is one of popular methods for dimensionality reduction and is directly related to data reduction. Although some researchers have addressed the need for instance selection in instance-based learning algorithms, there is little research on instance selection for ANN. This study proposes a genetic algorithm (GA) approach to instance selection in ANN for bankruptcy prediction. In this study, we use ANN supported by the GA to optimize the connection weights between layers and select relevant instances. It is expected that the globally evolved weights mitigate the well-known limitations of gradient descent algorithm of backpropagation algorithm. In addition, genetically selected instances will shorten the learning time and enhance prediction performance. This study will compare the proposed model with other major data mining techniques. Experimental results show that the GA approach is a promising method for instance selection in ANN.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.263-272
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• 2016

In this study, we aimed to identify the nonsynonymous single nucleotide polymorphisms (nsSNPs) located in lipid metabolism-related genes because lipids are an important factor affecting the taste and flavor of meat, and they predict the functional consequences. The results showed that we identified 139 common nsSNPs in all five Korean native chicken (KNC) lines from the 81 genes related to lipid metabolism. Furthermore, sorting intolerant from tolerant (SIFT) and polymorphism phenotyping v2 (Polyphen-2) analyses predicted that among the genes, 14 nsSNPs of nine genes might be deleterious. Protein domain prediction of the nine genes revealed that all deleterious nsSNPs identified in this study were located outside the functional domain. This observation suggests that the common deleterious nsSNPs might be dispensable and have a minor effect on the traits of the KNCs.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.5
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• pp.17-24
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• 2010

Recently the study of identifying bio-markers for disease diagnosis and prognosis has been actively performed. In particular, lots of attentions have been paid to the finding of pathway gene-sets differentially expressed in disease patients rather than the finding of individual gene markers. In this paper we propose a novel method to identify disease-related pathway gene-sets based on time-series microarray data. For this purpose, we firstly compute individual gene scores by the using maSigPro (microarray Significant Profiles) and then arrange all the genes in the decreasing order of the corresponding gene scores. The rank of each gene in the entire list is used to evaluate the statistical significance of candidate gene-sets with Wilcoxson rank sum test. For the generation of candidate gene-sets, MSigDB (Molecular Signatures Database) pathway information has been employed. The experiment was conducted with prostate cancer time-series microarray data and the results showed the usefulness of the proposed method by correctly identifying 6 out of 7 biological pathways already known as being actually related to prostate cancer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.206-206
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• 2010

본 연구에서는 신경망을 이용하여 SiN 박막의 특성을 예측하는 모델을 개발하였다. 신경망으로는 일반화된 회귀 신경망 (generalized regression neural network-GRNN)을 이용하였고, GRNN 모델의 예측수행은 유전자 알고리즘 (genetic algorithm-GA)을 이용하여 최적화 하였다. 개발된 모델을 이용하여 증착률과 굴절률 및 균일도를 공정변수의 함수로 예측하였다.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.177-178
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• 2007

플라즈마 공정은 집적회로 제작을 위한 미세 박막의 증착과 패턴닝에 핵심적으로 이용되고 있다. 본 연구에서는 플라즈마공정감시와 제어에 응용될 수 있는 모델을 제안한다. 본 모델은 광방사분광기 (Optical emission spectroscopy-OES)정보와 역전파 신경망을 이용해서 개발하였다. 제안된 기법은 Oxide 식각공정에서 수집한 데이터에 적용하였으며, 체계적인 모델링을 위해 공정데이터는 통계적 실험계획법을 적용하여 수집되었다. Raw OES 정보대신, Actinometric OES 정보를 이용하였으며, 신경망의 예측성능은 유전자 알고리즘을 이용해서 증진시켰다. OES의 차수를 줄이기 위해 주인자 분석 (Principal Component Analysis-PCA)을 세 종류의 분산(100, 99, 98%)에 대해서 적용하였다. 최적화한 모델의 예측에러는 323 $\AA/min$이었다. 이전에 PCA를 적용하고 은닉층 뉴런의 함수로 최적화한 모델의 예측에러는 570 $\AA/min$이었으며, 개발된 모델은 이에 비해 43% 증진된 예측 성능을 보이고 있다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.165-166
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• 2007

신경망을 이용하여 반구형 유도결합형 플라즈마 장비에 대한 전자온도의 예측모델을 개발하였다. 신경망으로는 Radial Basis Function Network을 이용하였고, 신경망의 예측성능은 유전자 알고리즘을 이용하여 최적화하였다. 체계적인 모델링을 위해 $2^4$ 전 인자 (Full Factorial) 실험획법을 이용하여 $Cl_2$ 플라즈마에서의 데이터를 수집하였다. 최적화된 전자온도 모델의 예측성능은 0.143 eV이었다. 개발된 모델을 이용하여 공정변수에 따른 예측온도의 영향을 고찰하였다. 소스전력과 압력의 변화에 따른 전자온도의 변화는 작았다. 그러나 $Cl_2$ 유량과 특히 척위치의 증가에 따른 전자온도의 증가는 현저하였으며, 이는 고이온밀도의 형성에 기인하는 것으로 해석되었다.

• The KIPS Transactions:PartB
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• v.15B no.4
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• pp.323-330
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• 2008

Since complex diseases are caused by interactions of multiple genes, traditional statistical methods are limited in its power to predict the onset of a complex disease. Recently new approaches using machine learning techniques are introduced. Neural nets are a suitable model to find patterns in complex data. When large amount of data are fed into a neural net, however, it takes a long time for learning and finding patterns. In this study we suggest a new model that combines the set association, which is a statistical technique to find important SNPs associated with complex diseases, and neural network. We experiment with SNP data related to asthma to test the effectiveness of our model. Our model shows higher prediction accuracy and shorter execution time than neural net only. We expect our model can be used effectively to predict the onset of other complex diseases.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.423-432
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• 2017

This study used SSARR model to predict the flood hydrograph for the Miho stream in the Geum river basin. First, we performed the sensitivity analysis on the parameters of SSARR model to know the characteristics of the parameters and set the range. For the parameter calibration, optimization methods such as genetic algorithm, pattern search and SCE-UA were used. WSSR and SSR were applied as objective functions, and the results of optimization method and objective function were compared and analyzed. As a result of this study, flood prediction was most accurate when using pattern search as an optimization method and WSSR as an objective function. If the parameters are optimized based on the results of this study, it can be helpful for decision making such as flood prediction and flood warning.