• 산업공학
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• 제13권2호
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• pp.188-194
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• 2000

A pattern recognition system is proposed to recognize characters in any type of Giro. The system consist of the character segmentation and the character recognition. Positional features from two round markers at the upper-right part and lower-left part of Giro is used for extracting character strings from images and RLE analysis is used if there are no round markers. A multi step combined method, which use a structural method and a statistical method, is used to improve recognition. The structural method apply rules on each characters, whereas a statistical method gives a different weighting vector to each pixel for improving the classification performance in regard to noises and distortions. The experimental results show that the proposed combined method has higher recognition rate, over than 98% even in cases that images are rotated about 10 degrees as well as have noises.

• Structural Monitoring and Maintenance
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• 제6권3호
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• pp.173-190
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• 2019

Steel-confined reinforced concrete (SCRC) columns feature highly complex and invisible mechanisms that make damage evaluation and pattern recognition difficult. In the present article, the prevailing acoustic emission (AE) technique was applied to monitor and evaluate the damage process of steel-confined RC columns in a quasi-static test. AE energy-based indicators, such as index of damage and relax ratio, were proposed to trace the damage progress and quantitatively evaluate the damage state. The fuzzy C-means algorithm successfully discriminated the AE data of different patterns, validity analysis guaranteed cluster accuracy, and principal component analysis simplified the datasets. A detailed statistical investigation on typical AE features was conducted to relate the clustered AE signals to micro mechanisms and the observed damage patterns, and differences between steel-confined and unconfined RC columns were compared and illustrated.

• Transactions on Control, Automation and Systems Engineering
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• 제2권1호
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• pp.40-46
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• 2000

In this paper, a transient identification based on a Hidden Markov Model (HMM) has been suggested and evaluated experimentally for the classification of transients in the dynamic process. The transient can be identified by its unique time dependent patterns related to the principal variables. The HMM, a double stochastic process, can be applied to transient identification which is a spatial and temporal classification problem under a statistical pattern recognition framework. The HMM is created for each transient from a set of training data by the maximum-likelihood estimation method. The transient identification is determined by calculating which model has the highest probability for the given test data. Several experimental tests have been performed with normalization methods, clustering algorithms, and a number of states in HMM. Several experimental tests have been performed including superimposing random noise, adding systematic error, and untrained transients. The proposed real-time transient identification system has many advantages, however, there are still a lot of problems that should be solved to apply to a real dynamic process. Further efforts are being made to improve the system performance and robustness to demonstrate reliability and accuracy to the required level.

• International Journal of Korean Welding Society
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• 제1권1호
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• pp.7-12
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• 2001

Real time monitoring has become critical as the use of laser welding increases. Plasma and spatter are measured and used as the signal for estimating weld quality. The estimating algorithm was made using the fuzzy pattern recognition with the area of data that is beyond the tolerance boundary. Also, an algorithm that detects the spatter and the localized defect was created in order to kd the partially produced pit and the sudden loss of weld penetration. These algorithms were used in quality monitoring of the $CO_2$ laser tailored blank weld. Statistical program that can display the laser weld quality result and the signal transition was made for the first stage of the remote control system.

• 한국정밀공학회지
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• 제17권7호
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• pp.98-105
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• 2000

In this study, we developed rotating machine vibration condition monitoring system based upon Windows NT and DSP Board. Developed system includes signal analysis module, trend monitoring and simple diagnosis using threshold value. Trend analysis and report generation are offered with database management tool which was developed in MS-ACCESS environment. Post-processor, based upon Matlab, is developed for vibration signal analysis and fault detection using statistical pattern recognition scheme based upon Bayes discrimination rule and neural networks. Concerning to Bayes discrimination rule, the developed system contains the linear discrimination rule with common covariance matrices and the quadratic discrimination rule under different covariance matrices. Also the system contains k-nearest neighbor method to directly estimate a posterior probability of each class. The result of case studies with the data acquired from Pyung-tak LNG pump and experimental setup show that the system developed in this research is very effective and useful.

• 한국대기환경학회지
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• 제6권1호
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• pp.1-10
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• 1990

The purpose of the study was to analyze air quality in underground shopping centers using pattern recognition methods. In order to perform this, the concentraion of air pollutants such as $CO, NO_2, NO_x, SO_2$, and particulate matters was measured at the 11 different shopping centers in Seoul metropolitan area and the total of 47 samples were obtained at random based on the size of shopping centers. To introduce a new concept of the "average concentration" for the indoor air quality analyses, the various multivariate statistical analyses have been studied. Thus, a cluster analysis was applied to separate the samples into pseudo-patterns and a disjoint principal component analysis was used to generate homogeneous patterns after removing outliers from the pseudo-patterns. The 6 homogeneous patterns were then obtained as follows:the first pattern was a group of clean sites;the second a group of sites having high dust concentration;the third a group of sites having high dust and $NO_x$ concentration;the fourth a group of sites having low dust and $SO_2$ concentraion and high CO concentration;the fifth a group of sites having high $NO_2 and SO_2$ concentration;and the final a group of miscellaneous sites. Thus, the average concentration could be estimated for each pattern.h pattern.

• Structural Monitoring and Maintenance
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• 제5권2호
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• pp.231-242
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• 2018

Subway tunnel structure has been rapidly developed in many cities for its strong transport capacity. The model-based damage detection of subway tunnel structure is usually difficult due to the complex modeling of soil-structure interaction, the indetermination of boundary and so on. This paper proposes a new data-based method for the damage detection of subway tunnel structure. The root mean square acceleration and cross correlation function are used to derive a statistical pattern recognition algorithm for damage detection. A damage sensitive feature is proposed based on the root mean square deviations of the cross correlation functions. X-bar control charts are utilized to monitor the variation of the damage sensitive features before and after damage. The proposed algorithm is validated by the experiment of a full-scale two-rings subway tunnel lining, and damages are simulated by loosening the connection bolts of the rings. The results verify that root mean square deviation is sensitive to bolt loosening in the tunnel lining and X-bar control charts are feasible to be used in damage detection. The proposed data-based damage detection method is applicable to the online structural health monitoring system of subway tunnel lining.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.287-289
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• 2009

The conventional computing is a centralizing system, but it has been gradually going to develop ubiquitous computing which moves roles away from the main. The Community Computing, a new paradigm, is proposed to implement environment of ubiquitous computing. In this environment, it is important to accept the user demand. Hence in this paper recognizes pattern of user's activity statistically and proposes a method of pattern estimation in community computing. In addition, user's activity varies with time and the activity has the priority We reflect these. Also, we improve accuracy of the method through Knowledge Base organization and the feedback system. We make program using Microsoft Visual C++ for evaluating performance of proposed method, then simulate it. We can confirm it from the experiment result that using proposal method is better in environment of community computing.

• 대한전자공학회논문지SP
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• 제46권2호
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• pp.99-107
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• 2009

본 논문에서는 자동차 번호판 숫자의 특징을 추출하기 위해 강화된 독립성분분석(independent component analysis)의 혼합모델을 제안한다 독립성분분석은 고차 통계적 특성만을 이용하기 때문에 고차 통계적 특성과 숫자 종류별 상관관계에 대한 특성을 고려하지 못한다. 이러한 독립성분분석의 한계를 극복하기 위해, 본 논문에서는 주성분분석(principle component analysis)과 선형판별분석(linear discriminant analysis)을 조합한 혼합 모델 형태의 독립성분분석을 제안한다. 실험 결과, 제안된 혼합 모델은 독립성분분석이나 다른 혼합 모델들보다 특징 추출과 인식에서 우수한 성능을 보임을 확인하였다.

• 대한가정학회지
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• 제30권4호
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• pp.231-247
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• 1992

A Study on Maternal Verbal Control Patterns and Children's Recognition against those. The primary objective of the material presented in this dissertation is the analysis of the maternal verbal control patterns. The major focus is given to the differences between maternal verbal control patterns and children's recognition against those. The purspoe of this study were; 1) to investigate the maternal verbal control patterns recognized by children according to their family and personal surroundings; 2) to investigate the verbal control patterns in mother's response according to the differences of family and personal surroundings; 3) to find the differences between children's recognition and maternal verbal control patterns; 4) How the maternal verbal control patterns recognized by children are? The materials of this study were 81(37; boys, 44; girl)) from kindergarten in Seou. The sample of age used in this study was 5 to 7 years old. The test about maternal verbal environment used the question sheet for reaction between mother and children by Gumperz. The kids got interviews with same questions as mothers with question sheet. The statistical tools used is the analysis of the data were frequency, crosstab, and t-test. The result of the study were summarized as follows; 1) The maternal verbal control patterns recognized by children had differences according to whether living with grand-parent or not. Living with grand-parent are more person-oriented than without grand-parent group. 2) The maternal verbal control patterns of mother response show the differences within mother's academic background, present situation of child, and parent's expection to child. The imperative verbal control pattern was more frequently used of low academic background who just fraduate the middle or high school. The personal verbal control pattern was more frequently used of high educational background's like university graduate or more educated group. 3) The differences between maternal verbal control patterns with children's recognition and with mother response is that mother responseis more person-oriented than children's. 4) The imperative verbal control pattern used command, verbal purnishment, and physical purnishment. the status-oriented verbal control pattern used univesal positional appeals and limited positional appeals. The person-oriented verbal control pattern used child-oriented cognitive affective appeals.