• 전기학회논문지
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• 제61권5호
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• pp.657-663
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• 2012

Recently, by increasing of devices which are sensitive to power quality, the deterioration of power quality has been accelerated. For this reason, the social and economic losses are increased. So not only correct measurement and evaluation, but also countermeasure for improvement of power quality is surely necessary for both electric power supplier and consumer. In this paper, the discrimination algorithm for events and variation occurred in distribution systems using S-transform is proposed. Firstly, we review for events and variations that occur in distribution system. Next, we simulate events and variations on various conditions using ElectroMagnetic Transient Program(EMTP). For the simulation, the IEEE 13 Node Test Feeder and KEPCO's distribution system is modeled. Finally, for the analysis, a modified wavelet transform known as S-transform is adopted to find out the characteristics of each events and variations.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1021-1025
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• 1999

Near-infrared (NIR) spectroscopy has been successfully utilized for the rapid identification of six typical petroleum products such as light straight-run (LSR), naphtha, kerosine, light gas oil (LGO), gasoline, and diesel. The spectral features of each product were reasonably differentiated in the NIR region, and the spectral differences provided enough qualitative spectral information for discrimination. For discrimination, principal component analysis (PCA) combined with Mahalanobis distance was used to identify each petroleum product from NIR spectra. The results showed that each product was accurately identified with an accuracy over 95%. Most noticeably, LSR, kerosine, gasoline, and diesel samples were predicted with identification accuracy of 99%. The overall results ensure that a portable NIR instrument combined with a multivariate qualitative discrimination method can be efficiently utilized for rapid and simple identification of petroleum products. This is especially important when local at-site measurements are necessary, such as accidental petroleum leakage and regulation of illegal product blending.

• 아태비즈니스연구
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• 제11권1호
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• pp.17-26
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• 2020

Purpose - This paper studies the welfare impacts of behavior-based price discrimination (BBPD) when firms are asymmetric in quality improvement costs. Design/methodology/approach - To this end, we consider a differentiated duopoly model with an inherited market share, where firms first make quality decisions and then compete in prices according to the pricing scheme, namely, uniform pricing or BBPD. Findings - We show that BBPD increases social welfare relative to uniform pricing if the firms' cost gap is large enough. This is because BBPD induces more consumers to buy a high-quality product than under uniform pricing, and because a low-cost firm's profit loss from BBPD decreases as the cost difference increases. Research implications or Originality - Our analysis offers policy implications for markets where BBPD raises antitrust concerns, and quality competition prevails.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1998년도 학술발표대회 논문집 제17권 2호
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• pp.57-60
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• 1998

This paper adopts the psychoacoustical methodology to evaluate the acoustical qualities of rooms and describes some of the results of an attempt to develop such a test. In order to investigate the effect of hall response to subjects, a subjective experiment was performed in artificially simulated sound fields. Pairs of sounds having differences in duration/frequency were presented to a subject and the subject's responses were recorded. The stimuli were varied through an auralization system that simulates three different rooms. It was found that duration/frequency discrimination is influenced by the room conditions and that these discrimination procedures may form the basis for assessment of room acoustics.

• 대한의용생체공학회:의공학회지
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• 제10권2호
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• pp.106-108
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• 1989

A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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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.

• 전기학회논문지
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• 제56권6호
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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.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권11호
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• pp.508-514
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• 2005

In this paper, it was investigated the characteristics of PD(partial discharge) pulse shapes in oil and the possibility of TF(Time-Frequency) analysis for the discrimination of air corona in on-site PD measurement of oil transformers. For the purpose, single and multiple discharges combined with oil discharges and air corona were generated and measured by use of artificial models through the HFPD pulse detector and the oscilloscope. PD pulse shapes were different according to the type of defects, especially including air corona- pulses. Also, through the TF analysis, data clusters could be classified each other in the TF Map, even in the case of multiple discharges. Therefore, it is known that TF analysis could be aprlied for the improvement of on-site PD measurement in oil transformers.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권4호
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• pp.183-188
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• 2006

Abstract - In order to investigate the possibility of separating PD(partial discharge) and noises through the pulse analysis by use of a HFCT, pulse shapes measured by a resistive sensor and a HFCT were analyzed and adequate PA(pulse analysis) algorithms were studied. For the purpose, the HFPD detection and PA system has been developed. Also void discharges and air corona were adopted as the artificial defect and noises, respectively. As a result, it is possible to separate partial discharges and noises through the PA method using the $100kHz{\sim}20MHz$ frequency range HFCT. It is expected to apply the developed system to on-site PD measurements for the electric equipments.

• 가족자원경영과 정책
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• 제28권3호
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• pp.17-27
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• 2024

본 연구는 한부모가족 가구주 본인과 자녀가 경험한 차별경험이 가구주의 우울에 어떠한 영향을 미치는지 알아보고자 한다. 연구 표본은 여성가족부의 「2021년도 한부모가족 실태조사를」를 활용하여, 연구에 부합한 1,631명의 데이터를 분석대상으로 하였다. 수집된 자료는 IBM SPSS 25.0을 통해 기술통계, 차이검증, 상관관계, 회귀분석을 실시하였다. 연구 결과는 다음과 같다. 첫째, 일반적 특성을 한부모 및 가족특성 요인, 건강요인, 경제자원 요인으로 구분하고 이에 따른 우울과의 차이를 분석한 결과 건강요인 중 건강상태, 운동빈도, 우울감 해결 방법이 유의미했고, 경제자원 요인은 거주 형태, 월 가구소득이 유의미했다. 둘째, 차별경험이 우울에 미치는 영향 요인을 분석한 결과 건강요인의 건강상태, 경제자원 요인의 월 가구소득, 가구주 차별경험, 자녀 차별경험, 전체 차별경험이 유의미했다. 한부모 및 가족특성 요인은 유의미한 변수가 없었다. 따라서 한부모가족 가구주의 건강요인과 경제자원 요인을 비롯해 차별경험이 우울을 증가시키는 중요한 변수임을 확인하고 이에 따른 대안을 제시하였다.