• 한국전기전자재료학회논문지
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• 제20권10호
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• pp.901-906
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• 2007

In this study, we measured the partial discharge phenomenon of inside the closed switchgear, using ultra wide band antenna. The characteristics of $\Phi-q-n$ in the normal state are stable, and confirmed at less than 0.01, but in proceeding states, about 2 times larger. And in the abnormal state, it grew hundreds of times larger compared with normal state. According to K-means analysis, if slant of discharge characteristics is a straight line close to "0" and standard deviation is small, it is in a normal state. However if we can find a peak from K-means clusters and standard deviation to be large, it is in an abnormal state.

• 한국통신학회논문지
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• 제29권5C호
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• pp.700-705
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• 2004

Autoencoder와 Fuzzy c-Means 알고리즘을 이용하여, 불완전한 데이터의 군집화를 위한 알고리즘이 본 논문에서 제안되었다. 본 논문에서 제안된 Optimal Completion Autoencoder Fuzzy c-Means (OCAEFCM)은 손상되어 불완전한 데이터의 최적 복원과 데이터의 군집화를 위해 Autoencoder Neural Network (AENN) 과 Gradient-based FCM (GBFCM)을 이용하였다. OCAEFCM 의 성능평가를 위해 IRIS 데이터와 금융기관에서 취득한 실제 데이터를 사용하였다 기존의 Optimal Completion Strategy FCM (OCSFCM)과 비교했을 때, 제안된 OCAEFCM 이 OCSFCM 보다 18％-20％의 성능 향상을 보여준다.

• 디지털융복합연구
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• 제12권11호
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• pp.281-288
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• 2014

본 논문에서는 복잡한 영상에서의 윤곽선 검출을 기존의 방법보다 더 명확하고 효율적으로 나타내기 위해서 K-means 군집화를 이용하였다. 제안하는 방법에는 세 가지 단계를 거친다. 첫 번째는 명암분포를 균일하게 하기 위하여 히스토그램 평활화를 사용한다. 두 번째는 거리에 기반을 둔 클러스터링 기법으로 기준점에서 가까운 곳의 데이터들을 하나의 군집으로 묶는 K-means 군집화를 사용하고 마지막으로 에지검출의 가장 대표적인 1차 미분 연산자인 소벨 마스크를 사용하여 윤곽선을 검출한다. 따라서 기존에 있던 윤곽선 검출보다 더 나은 결과로 명확하게 윤곽선을 검출 할 수 있음을 보인다.

• 대한기계학회논문집
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• 제17권7호
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• pp.1783-1793
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• 1993

Pattern recognition technique using fuzzy c-means algorithm and multilayer perceptron was applied to classify tool wear states in turning. The tool wear states were categorized into the three regions 'Initial', 'Normal', 'Severe' wear. The root mean square(RMS) value of acoustic emission(AE) and current signal was used for the classification of tool wear states. The simulation results showed that a fuzzy c-means algorithm was better than the conventional pattern recognition techniques for classifying ambiguous informations. And normalized RMS signal can provide good results for classifying tool wear. In addition, a fuzzy c-means algorithm(success rate for tool wear classification : 87%) is more efficient than the multilayer perceptron(success rate for tool wear classification : 70%).

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2003년도 추계학술대회
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• pp.249-258
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• 2003

K-means clustering has been widely used in many applications, such that pattern analysis or recognition, data analysis, image processing, market research and so on. It can identify dense and sparse regions among data attributes or object attributes. But k-means algorithm requires many hours to get k clusters that we want, because it is more primitive, explorative. In this paper we propose a new method of k-means clustering using the grid-based sample. It is more fast than any traditional clustering method and maintains its accuracy.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2003년도 추계학술대회
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• pp.229-238
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• 2003

K-means clustering has been widely used in many applications, such that pattern analysis, data analysis, market research and so on. It can identify dense and sparse regions among data attributes or object attributes. But k-means algorithm requires many hours to get k clusters, because it is more primitive and explorative. In this paper we propose a new method of k-means clustering using the grid-based representative value(arithmetic and trimmed mean) for sample. It is more fast than any traditional clustering method and maintains its accuracy.

• 한국농공학회지
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• 제45권3호
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• pp.73-83
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• 2003

Methods of fuzzy C-means have been used to characterize geotechnical information from static cone penetration data. As contrary with traditional classification methods such as Robertson classification chart, the FCM expresses classes not conclusiveness but fuzzy. The results show that the FCM is useful to characterize ground information that can not be easily found by using normal classification chart. But optimal number of classes may not be easily defined. So, the optimal number of classes should be determined considering not only technical measures but engineering aspects.

• Journal of the Korean Data and Information Science Society
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• 제17권4호
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• pp.1413-1425
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• 2006

When X and Y have independent gamma distributions, we develop a Bayesian procedure for testing the equality of two gamma means. The reference prior is derived. Using the derived reference prior, we propose a Bayesian test procedure for the equality of two gamma means using fractional Bayes factor and intrinsic Bayes factor. Simulation study and a real data example are provided.

• 한국컴퓨터정보학회논문지
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• 제20권12호
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• pp.9-14
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• 2015

In this paper, we present an color quantization method by complementing the disadvantage of K-means color quantization that is one of the well-known color quantization. We named the proposed method "octree-means" color quantization. K-means color quantization does not use all of the clusters because it initializes the centroid of clusters with random value. The proposed method complements this disadvantage by using the octree color quantization which is fast and uses the distribution of colors in image. We compare the proposed method to six well-known color quantization methods on ten test images to evaluate the performance. The experimental results show 68.29 percent of mean square error(MSE) and processing time increased by 14.34 percent compared with K-means color quantization. Therefore, the proposed method improved the K-means color quantization and perform an effective color quantization.

• 디지털산업정보학회논문지
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• 제8권3호
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• pp.65-74
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• 2012

A barcode is a representative means of cognition. It is either printed on the package of a product or attached to it as a sticker. It is used for the fast cognition of a product at a store. It is considerably cheap to make a barcode. Also, it is possible to read it fast by using a barcode reader. Because of such convenience provided by the barcode, a new system using the barcode as a means of settling payments like a currency or a credit card has been developed. However, due to its characteristics, it is easy to reduplicate, forge or falsify a barcode easily. Therefore, this study focuses on the case of applying the system using barcodes as a means of settling payments without providing solutions for the potential weaknesses. Also, this study suggests various points to consider regarding the creation of safe barcodes as one of the related measures, while providing various methods using additional means of certification other than the one of using barcodes in addition to the way of applying complexity with barcode numbers. Throughout this study, it will be possible to safely establish and operate the payment-settlement system using barcodes.