• Title/Summary/Keyword: power of discrimination

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A Study on the New Partial Discharge Pattern Analysis System used by PA Map (Pulse Analysis Map) (PA Map(Pulse Analysis Map)을 이용한 새로운 부분방전 패턴인식에 관한 연구)

  • Kim, Ji-Hong;Kim, Jeung-Tae;Kim, Jin-Gi;Koo, Ja-Yoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.6
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    • pp.1092-1098
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    • 2007
  • Since one decade, the detection of HFPD (High frequency Partial Discharge) has been proposed as one of the effective method for the diagnosis of the power component under service in power grids. As a tool for HFPD detection, Metal Foil sensor based on the embedded technology has been commercialized for mainly power cable due to its advantages. Recently, for the on-site noise discrimination, several PA (Pulse analysis) methods have been reported and the related software, such as Neural Network and Fuzzy, have been proposed to separate the PD (Partial Discharge) signals from the noises since their wave shapes are completely different from each other. On the other hand, the relevant fundamental investigation has not yet clearly made while it is reported that the effectiveness of the current methods based on PA is dependant on the types of sensors. Moreover, regarding the identification of the vital defects introducible into the Power Cable, the direct identification of the nature of defects from the PD signals through Metal Foil coupler has not yet been realized. As a trial for solving above shortcomings, different types of software have been proposed and employed without any convincing probability of identification. In this regards, our novel algorithm 'PA Map' based on the pulse analysis is suggested to identify directly the defects inside the power cable from the HFPD signals which is output of the HFCT and metal foil sensors. This method enables to discriminate the noise and then to make the data analysis related to the PD signals. For the purpose, the HFPD detection and PA (Pulse Analysis) system have been developed and then the effect of noise discrimination has been investigated by use of the artificial defects using real scale mockup. Throughout these works, our system is proved to be capable of separating the small void discharges among the very large noises such as big air corona and ground floating discharges at the on-site as well as of identifying the concerned defects.

A Study on the Fault Current Discrimination Using Enhanced Fuzzy C-Means Clustering (개선된 퍼지 C-Means 클러스터링을 이용한 고장전류판별에 관한 연구)

  • Jeong, Jong-Won;Lee, Joon-Tark
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.11
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    • pp.2102-2107
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    • 2008
  • This paper demonstrates a enhanced FCM to identify the causes of ground faults in power distribution systems. The discrimination scheme which can automatically recognize the fault causes is proposed using Fuzzy RBF networks. By using the actual fault data, it is shown that the proposed method provides satisfactory results for identifying the fault causes.

A Study for The Discrimination of Visual Emotions Using Heart Rate Variability (심박변화율(HRV)에 의한 시각감성의 구분에 대한 연구)

  • 오상훈;황민철;임재중
    • Proceedings of the ESK Conference
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    • 1997.10a
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    • pp.473-476
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    • 1997
  • Human visual emotion were investigated by analyzing HRV from ECG signals, which were varied by the visual stimuli. In this paper, twelve university students experienced visual emotion by pictures from IAPS. ECG and subjective rating were obtained for human emotion evaluation. For determination of HRV, ECG was extracted into HF and LF via power spectrum analysis. The results showed that HRV is good for discrimination between positive and negative emotions.

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Performance Evaluation and Forecasting Model for Retail Institutions (유통업체의 부실예측모형 개선에 관한 연구)

  • Kim, Jung-Uk
    • Journal of Distribution Science
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    • v.12 no.11
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    • pp.77-83
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    • 2014
  • Purpose - The National Agricultural Cooperative Federation of Korea and National Fisheries Cooperative Federation of Korea have prosecuted both financial and retail businesses. As cooperatives are public institutions and receive government support, their sound management is required by the Financial Supervisory Service in Korea. This is mainly managed by CAEL, which is changed by CAMEL. However, NFFC's business section, managing the finance and retail businesses, is unified and evaluated; the CAEL model has an insufficient classification to evaluate the retail industry. First, there is discrimination power as regards CAEL. Although the retail business sector union can receive a higher rating on a CAEL model, defaults have often been reported. Therefore, a default prediction model is needed to support a CAEL model. As we have the default prediction model using a subdivision of indexes and statistical methods, it can be useful to have a prevention function through the estimation of the retail sector's default probability. Second, separating the difference between the finance and retail business sectors is necessary. Their businesses have different characteristics. Based on various management indexes that have been systematically managed by the National Fisheries Cooperative Federation of Korea, our model predicts retail default, and is better than the CAEL model in its failure prediction because it has various discriminative financial ratios reflecting the retail industry situation. Research design, data, and methodology - The model to predict retail default was presented using logistic analysis. To develop the predictive model, we use the retail financial statements of the NFCF. We consider 93 unions each year from 2006 to 2012 to select confident management indexes. We also adapted the statistical power analysis that is a t-test, logit analysis, AR (accuracy ratio), and AUROC (Area Under Receiver Operating Characteristic) analysis. Finally, through the multivariate logistic model, we show that it is excellent in its discrimination power and higher in its hit ratio for default prediction. We also evaluate its usefulness. Results - The statistical power analysis using the AR (AUROC) method on the short term model shows that the logistic model has excellent discrimination power, with 84.6%. Further, it is higher in its hit ratio for failure (prediction) of total model, at 94%, indicating that it is temporally stable and useful for evaluating the management status of retail institutions. Conclusions - This model is useful for evaluating the management status of retail union institutions. First, subdividing CAEL evaluation is required. The existing CAEL evaluation is underdeveloped, and discrimination power falls. Second, efforts to develop a varied and rational management index are continuously required. An index reflecting retail industry characteristics needs to be developed. However, extending this study will need the following. First, it will require a complementary default model reflecting size differences. Second, in the case of small and medium retail, it will need non-financial information. Therefore, it will be a hybrid default model reflecting financial and non-financial information.

An Analysis of Reliability and Discrimination Power on Evaluation Criteria of Dream Start Services (드림스타트 사업 평가지표의 신뢰도와 변별력 측정)

  • Song, Mi-Ryoung;Kim, Jeong-Wha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.2
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    • pp.210-217
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    • 2019
  • This research examines whether the evaluation index used Dream Start services operation evaluation has 'reliability in evaluation field and area' and 'whether there is discrimination according to evaluation index'. To do this, we conducted an empirical analysis based on the evaluation data of 126 municipal and provincial governments that received the 2018 Dream Start services operation evaluation. First, as a result of examining whether there is trust in each evaluation area, it was found that the reliability of the basic construction, integrated case management, and service operation field is higher than .6 and the lower evaluation indexes are the same Standards were met. However, the field of resource exploit and connectivity was not so reliable as the concept of sub-domains. Second, 'Are there discriminatory power according to the evaluation indexes?' The results showed that 18 of the 28 indicators were highly discriminative. On the other hand, 10 indicators showed low discrimination power.

Evaluation of the performance of the ranking DEA model (순위결정 DEA모형의 변별력 평가)

  • Park, Man-Hee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.298-299
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    • 2018
  • In this study, the discriminant power of the DEA models which do not require the prior information of decision makers was evaluated. Entropy model, Bootstrap model, Benevolent Cross Efficiency model, Aggressive Cross Efficiency model and Game Cross Efficiency model were selected as the DEA model for discriminant power evaluation. The discriminant power of five DEA models was evaluated using coefficient of variation and degree of importance. According to the evaluation results, the rank of discrimination power was evaluated in the order of Entropy model, Aggressive CE model, Benevolent CE model, Game CE model, and Bootstrap model in both evaluation indexes.

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Design and Fabrication of Wideband DFD Phase Correlator for 6.0~18.0 GHz Frequency (6.0~18.0 GHz 주파수용 광대역 DFD 위상 상관기 설계 및 제작)

  • Choi, Won;Koo, Kyung-Heon
    • Journal of Advanced Navigation Technology
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    • v.18 no.4
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    • pp.341-346
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    • 2014
  • This paper has presented the design and fabrication of phase correlator for wideband digital frequency discriminator (DFD) operating over the 6.0 to 18.0 GHz frequency range. Fabricated DFD phase correlator has been measured I or Q output signal, and analyzed frequency discrimination error. The operation of the proposed mixer type correlator has been analyzed by deriving some analytic equations. To design the phase correlator, this paper has modeled and simulated IQ mixer and 8-way power divider by using RF simulation tool. Designed phase correlator has fabricated and measured. The phase error and frequency discrimination error have been presented using by measured I and Q output signal. Over the 6.0~18.0 GHz range, the root mean square(RMS) phase error is $4.81^{\circ}$, RMS and frequency discrimination error is 1.49 MHz, RMS.

The Study for Advancing the Performance of Speaker Verification Algorithm Using Individual Voice Information (개별 음향 정보를 이용한 화자 확인 알고리즘 성능향상 연구)

  • Lee, Je-Young;Kang, Sun-Mee
    • Speech Sciences
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    • v.9 no.4
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    • pp.253-263
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    • 2002
  • In this paper, we propose new algorithm of speaker recognition which identifies the speaker using the information obtained by the intensive speech feature analysis such as pitch, intensity, duration, and formant, which are crucial parameters of individual voice, for candidates of high percentage of wrong recognition in the existing speaker recognition algorithm. For testing the power of discrimination of individual parameter, DTW (Dynamic Time Warping) is used. We newly set the range of threshold which affects the power of discrimination in speech verification such that the candidates in the new range of threshold are finally discriminated in the next stage of sound parameter analysis. In the speaker verification test by using voice DB which consists of secret words of 25 males and 25 females of 8 kHz 16 bit, the algorithm we propose shows about 1% of performance improvement to the existing algorithm.

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A Study on the Fault Discrimination and Location Algorithm in Underground Transmission Systems Using Wavelet Transform and Fuzzy Inference (지중송전계통에서 Wavelet 변환과 퍼지추론을 이용한 고장종류판별 및 고장점 추정에 관한 연구)

  • Park, Jae-Hong;Lee, Jong-Beom
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.3
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    • pp.116-122
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    • 2006
  • The underground transmission lines is continuously expanded in power systems. Therefore the fault of underground transmission lines are increased every year because of the complication of systems. However the studies dealing with fault location in the case of the underground transmission lines are rarely reported except for few papers using traveling wave method and calculating underground cable impedance. This paper describes the algorithm using fuzzy system and travelling wave method in the underground transmission line. Fuzzy inference is used for fault discrimination. To organize fuzzy algorithm, it is important to select target data reflecting various underground transmission line transient states. These data are made of voltage and average of RMS value on zero sequence current within one cycle after fault occurrence. Travelling wave based on wavelet transform is used for fault location. In this paper, a variety of underground transmission line transient states are simulated by EMTP/ATPDraw and Matlab. The input which is used to fault location algorithm are Detail 1(D1) coefficients of differential current. D1 coefficients are obtained by wavelet transform. As a result of applying the fuzzy inference and travelling wave based on wavelet transform, fault discrimination is correctly distinguished within 1/2 cycle after fault occurrence and fault location is comparatively correct.

A Study on School Facilities Build Transfer Lease Project - Centering on the improvement of the assessment - (학교시설 임대형민자사업의 평가기준 개선연구)

  • Kwon, Byoung-Koo;Lee, Jae-Rim;Jo, Jin-Il
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.7 no.2
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    • pp.30-46
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    • 2008
  • In this study, were prepared after statistical analysis was conducted of assessment items and marks distribution for the selection of executors of the BTL project. When tests of the degree of dispersion and degree of appropriateness for each assessment item were analyzed, it was found that the degree of dispersion among assessment points has the power of discrimination since it is highly marked in the design field and operation management field. In contrast, 'business management plan' and 'investment composition for economic quality assessment' have a low level of the power of discrimination since points given to them have smaller difference between business projects.

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