• 센서학회지
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• 제15권6호
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• pp.433-441
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• 2006

Because of the low power and low rate of a sensor network, outlier is frequently occurred in the time series data of sensor network. In this paper, we suggest periodic pattern analysis that is applied to the time series data of sensor network and predict outlier that exist in the time series data of sensor network. A periodic pattern is minimum period of time in which trend of values in data is appeared continuous and repeated. In this paper, a quantization and smoothing is applied to the time series data in order to analyze the periodic pattern and the fluctuation of each adjacent value in the smoothed data is measured to be modified to a simple data. Then, the periodic pattern is abstracted from the modified simple data, and the time series data is restructured according to the periods to produce periodic pattern data. In the experiment, the machine learning is applied to the periodic pattern data to predict outlier to see the results. The characteristics of analysis of the periodic pattern in this paper is not analyzing the periods according to the size of value of data but to analyze time periods according to the fluctuation of the value of data. Therefore analysis of periodic pattern is robust to outlier. Also it is possible to express values of time attribute as values in time period by restructuring the time series data into periodic pattern. Thus, it is possible to use time attribute even in the general machine learning algorithm in which the time series data is not possible to be learned.

• 디지털산업정보학회논문지
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• 제15권4호
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• pp.63-70
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• 2019

The subject of the simultaneous measuring system of base pattern and deposition pattern is a new research topic on a defect inspection of OLED. In this paper, we propose a new OLED inspection method that simultaneously measures standard and deposition pattern images. This method reduces unnecessary processes and tac time during OLED inspection. For an additional reduction of the tac time during pattern measurement, the ROI was configured to measure only in the designated ROI area instead of measuring the entire area of an image. During the ROI set-up, the value of effective deposition pattern area is included so that if the deposition pattern is out of the ROI zone, it would be treated as a defect before measuring the size and center point of the pattern. As a result, the tac time and inspection process could be shortened. The proposed method also could be applied to the OLED manufacturing process. Production of OLED could be increased by reducing tac time and inspection process.

• 대한가정학회지
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• 제35권1호
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• pp.319-338
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• 1997

This study examined the time allocation pattern of husbands and wives. This study investigated i)the pattern of time allocation in the light of the extent of time spent in housework child care and leisure among husbands and wives living in urban area ii) the differences in extent of time spent in such activities between wives and husbands and iii) the determinants of time spent in such activities. A system of time allocation equations based on household production theory and several hypotheses explaining the distribution of domestic work among couples were employed. According to the results the pattern of time allocation was different between wives and husbands. Regardless of women's employment status wives were more likely to have dual responsibilities than were husbands. The time equation employed in this study had more explanatory power in the pattern of time allocation of wives than of husbands and of employed wives than of non-employed wives. The sex-role ideology hypothesis was supported for non-employed wives but not for employed wives. The time availability hypothesis was supported for the time allocation of employed wives and husbands. The economic efficiency hypothesis was supported for employed wives' time allocation.

• 한국소음진동공학회논문집
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• 제16권6호
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• pp.627-633
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• 2006

The tire is considered as one of the important noise sources having an influence on vehicle's performance. The Pattern noise of a tire is the transmission sound of airborne noise. On smooth asphalt road, Pattern noise is amplified with the velocity. In recent, the study on the reduction of Pattern noise is energetically processed. Pattern noise is strongly related with pitch sequence. To reduce the pattern noise, tire's designer has to randomize the sequence of pitch. The FFT is a traditional method to evaluate the level of the randomization of the pitch sequence, but gives no information on time-varying, instantaneous frequency. In the study, we found that Time-Frequency transform is a useful method to non-stationary signal such as tire noise.

• 한국농촌생활과학회지
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• 제9권1호
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• pp.67-78
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• 1998

This study compared the pattern of couples' time-use in rural areas. Wives' and husbands' time spent in household work, leisure, and agricultural labor were compared. In addition, this study examined what factors determine the amount of time of couples spent in such activities. According to the results, in general, the pattern of couple's time-use in rural area was different. Regarding the pattern of time-use, three major results could be mentioned. First of all, husband in rural area spent most agricultural labour time in busy farming season. And then husband spent much time in leisure activities and wife spent in household work. Second, wife spent more time in inactive leisure and husband spent more time in active leisure. Third, husband in rural area spent less time in household work. In particular. they spent less time in female-typed work than male-typed work. To examine what factors determine the extent of time spent in such activities, three theories were employed and tested. According to the results, the models employed in this study were realistic in explaining the amount of time of couple in rural area, and more adjustable wife than husband. In conclusion, a combination of the multidimensional theoretical perspectives used in this study helpfully explains the variation in the amount of time-use of couple in rural area.

• 한국멀티미디어학회논문지
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• 제9권9호
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• pp.1118-1130
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• 2006

데이터 스트림에 대한 기존의 패턴 분석 알고리즘은 대부분 속도 향상과 효율적인 메모리 사용에 대하여 연구되어 왔다. 그러나 기존의 연구들은 새로운 패턴을 가진 데이터 스트림이 입력되었을 경우, 이 전에 분석된 패턴을 버리고 다시 패턴을 분석하여야 한다. 이러한 방법은 데이터의 실시간적인 패턴 분석을 필요로 하는 실제 환경에서는 많은 속도와 계산 비용이 소모된다. 본 논문에서는 끊임없이 입력되는 데이터 스트림의 패턴을 실시간으로 분석하는 방법을 제안한다. 이 것은 먼저 빠르게 패턴을 분석하고 그 다음부터는 이전에 분석된 패턴을 효율적으로 갱신하여 실시간적인 패턴을 얻어내는 방법이다. 데이터 스트림이 입력되면 시간 기반 윈도우로 나누어 여러 개의 순차들을 생성한다. 그리고 생성된 순차들의 정보는 해시 테이블에 입력되어 정해진 개수의 순차가 해시 테이블에 채워질 때마다 해시 테이블에서 패턴을 분석해 낸다. 이렇게 분석된 패턴은 패턴 트리를 형성하게 되고, 이 후에 새로 분석된 패턴들은 이 패턴 트리 안의 패턴 별로 갱신하여 현재 패턴을 유지하게 된다. 새로운 패턴 추가를 위해 패턴을 분석할 때 이전에 이미 발견된 패턴이 Suffix로 나올 수 있다. 그러면 패턴 트리에서 이 전 패턴으로의 포인터를 생성하여 중복되는 패턴 분석으로 인한 계산 시간의 낭비를 방지한다. 그리고 FIFO방법을 사용하여 오랫동안 입력이 안 된 패턴을 손쉽게 제거한다. 패턴이 조금씩 바뀌는 데이터 스트림 환경에서 RSP-DS가 기존의 알고리즘보다 우수하다는 것을 성능 평가를 통하여 증명하였다. 또한 패턴 분석을 수행할 데이터 순차의 개수와 자주 등장하는 데이터를 판별하는 기준을 조절하여 성능의 변화를 살펴보았다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.144-147
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• 2005

The tire is considered as one of the Important noise sources having an influence on vehicle's performance. The Pattern noise of a tire is the transmission sound of airborne noise. On smooth asphalt road, Pattern noise is amplified with the velocity. In recent, the study on the reduction of Pattern noise is energetically processed. Pattern noise is strongly related with pitch sequence. To reduce the pattern noise, tire's designer has to randomize the sequence of pitch. The FFT is a traditional method to evaluate the level of the randomization of the pitch sequence, but gives no information on time-varying, instantaneous frequency. In the study, we found that Time-Frequency transform is a useful method to non-stationary signal such as tire noise.

• 대한전기학회논문지:전력기술부문A
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• 제53권11호
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• pp.596-603
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• 2004

This paper proposes an expert system based on the pattern recognition method which can enhance the accuracy and effectiveness of real-time bus reconfiguration strategy for the transfer of faulted load when a main transformer fault occurs in the automated substation. The minimum distance classification method is adopted as the pattern recognition method of expert system. The training pattern set is designed MTr by MTr to minimize the searching time for target load pattern which is similar to the real-time load pattern. But the control pattern set, which is required to determine the corresponding bus reconfiguration strategy to these trained load pattern set is designed as one table by considering the efficiency of knowledge base design because its size is small. The training load pattern generator based on load level and the training load pattern generator based on load profile are designed, which are can reduce the size of each training pattern set from max L/sup (m+f)/ to the size of effective level. Here, L is the number of load level, m and f are the number of main transformers and the number of feeders. The one reduces the number of trained load pattern by setting the sawmiller patterns to a same pattern, the other reduces by considering only load pattern while the given period. And control pattern generator based on exhaustive search method with breadth-limit is designed, which generates the corresponding bus reconfiguration strategy to these trained load pattern set. The inference engine of the expert system and the substation database and knowledge base is implemented in MFC function of Visual C++ Finally, the performance and effectiveness of the proposed expert system is verified by comparing the best-first search solution and pattern recognition solution based on diversity event simulations for typical distribution substation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.842-847
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• 2005

This paper proposes a novel real-time EMG pattern recognition for the control of a multifunction myoelectric hand from four channel EMG signals. To cope with the nonstationary signal property of the EMG, features are extracted by wavelet packet transform. For dimensionality reduction and nonlinear mapping of the features, we also propose a linear-nonlinear feature projection composed of PCA and SOFM. The dimensionality reduction by PCA simplifies the structure of the classifier, and reduces processing time for the pattern recognition. The nonlinear mapping by SOFM transforms the PCA-reduced features to a new feature space with high class separability. Finally a multilayer neural network is employed as the pattern classifier. We implement a real-time control system for a multifunction virtual hand. From experimental results, we show that all processes, including virtual hand control, are completed within 125 msec, and the proposed method is applicable to real-time myoelectric hand control without an operation time delay.

• 융합정보논문지
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• 제10권7호
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• pp.147-152
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• 2020

본 연구는 발파 설계에 있어서 발파공의 직경과 발파 패턴을 중심으로 비용 효과를 분석하기 위하여 수행되었다. 발파 패턴을 단일 직경 발파공으로 설계한 경우와 직경의 다른 2개의 발파공을 혼합하여 설계한 경우에 대하여 천공 시간, 장약 시간과 화약과 화공품 소모량을 비교 분석하였다. 소요 발파공 수는 단일 직경 발파공으로 설계할 경우와 직경이 다른 두 개의 발파공으로 설계할 경우 각각 138개와 93개로 나타났다. 직경이 다른 두 개의 발파공을 이용하여 설계한 경우, 단일 직경 발파공으로 설계한 경우보다 천공 시간은 139분이 단축되고 천공 효율은 25% 증가되었다. 규격이 다른 두 개의 발파공을 적용하여 설계한 경우, 작업 인원당 장약 단축 시간과 작업 효율 증가는 각각 22.5분과 33%로 분석되었다. 화약 소요량과 뇌관 소요량은 단일 규격 배열시 300개와 138개였으며, 혼합 규격 배열시 242개와 93개로 후자의 경우 각각 58개와 45개 적게 소요되는 것으로 나타났다. 직경이 다른 두 개의 발파공 혼합 설계 패턴은 발파 비용 절감의 잠재성을 가지고 있는 것으로 나타났다.