• Title/Summary/Keyword: partial identification

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Vibration Identification of Gasoline Direct Injection Engine Based on Partial Coherence Function (부분기여도 함수를 이용한 직접분사 가솔린 엔진 부품의 진동원 분석)

  • Chang, Ji-Uk;Lee, Sang-Kwon;Park, Jong-Ho;Kim, Byung-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.11
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    • pp.1371-1379
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    • 2012
  • This paper presents a method for estimating the contribution of vibration sources in gasoline direct injection engine parts with a multiple-input system. A partial coherence function was used to identify the cause of the linear dependence indicated by an ordinary coherence function. To apply the partial coherence function to vibration source identification in the powertrain system of a gasoline direct injection engine, a virtual model of a two-input and single-output system is simulated. For the validation of this model, the vibration of the powertrain parts was measured by using triaxial accelerometers attached to the selected vibration sources-a high-pressure pump, fuel rail, injector, and pressure sensor. After calculating the partial coherence between each source based on the virtual model, the vibration contribution of the powertrain system is calculated. This virtual model based on the partial coherence function is implemented to determine the quantitative vibration contribution of each powertrain part.

Partial Model Matching Control System Design by Considering Pole-Placements (극배치를 고려한 제분 Model Matching 제어계 설계)

  • 이수흠;김수중
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.10
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    • pp.427-437
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    • 1986
  • Identification of the plants is not easy task especially in the fields of process control. From this point of view, Kitamori developed a method of control system design based on partial knowledge about controlled processes. However, it is difficult to control the oscillatory plant by kitamori's method. In this paper, we develope a method of partial model matching control system design, which have desirable pole-placements in order to improve the above defects. Design examples are given to illustrate the effectiveness of the method.

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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.

Adaptive Partial Shading Determinant Algorithm for Solar Array Systems

  • Wellawatta, Thusitha Randima;Choi, Sung-Jin
    • Journal of Power Electronics
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    • v.19 no.6
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    • pp.1566-1574
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    • 2019
  • Maximum power point tracking (MPPT) under the partial shading condition is a challenging research topic for photovoltaic systems. Shaded photo-voltaic module result in complex peak patterns on the power versus voltage curve which can misguide classical MPPT algorithms. Thus, various kinds of global MPPT algorithms have been studied. These have typically consisted of partial shading detection, global peak search and MPPT. The conventional partial shading detection algorithm aims to detect all of the occurrences of partial shading. This results in excessive execution of global peak searches and discontinuous operation of the MPPT. This in turn, reduces the achievable power for the PV module. Based on a theoretical investigation of power verse voltage curve patterns under various partial shading conditions, it is realized that not all the occurrences of partial shadings require a global peak search. Thus, an intelligent partial shading detection algorithm that provides exact identification of global peak search necessity is essential for the efficient utilization of solar energy resources. This paper presents a new partial shading determinant algorithm utilizing adaptive threshold levels. Conventional methods tend to be too sensitive to sharp shading patterns but insensitive to smooth patterns. However, the proposed algorithm always shows superb performance, regardless of the partial shading patterns.

A Perceptual Study on the Temporal Cues of English Intervocalic Plosives for Various Groups Depending on Background Language, English Listening Ability, and Age (언어별, 연령별, 수준별 집단에 의한 모음간 영어 파열음 유/무성 인지 연구)

  • Kang, Seok-Han
    • Speech Sciences
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    • v.13 no.2
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    • pp.133-145
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    • 2006
  • In order to understand the various groups' perceptual pattern in both VCV trochee and iambus, this study examined the identification correctness and cue robustness for the unit intervals in light of background language, age, and English listening ability. The 4 groups of Native Speakers of English, Korean College Students of High Listening Achievement, Korean College Students of Low Listening Achievement, and Korean Elementary Students took part in the experiments. Tokens of $/d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per$ in trochee and of $/{\eth}{\partial}\;p{\ae}d,\;{\eth}{\partial}\;b{\ae}d,\;{\eth}{\partial}\;t{\ae}d,\;{\eth}{\partial}\;d{\ae}d,\;{\eth}{\partial}\;k{\ae}d,\;{\eth}{\partial}\;g{\ae}d/$ in iambus were extracted and modified into experimental signals composed of two digits(voiced-1, voiceless-0) by following the temporal intervals, in which the signals consisted of preceding vowel, closure, VOT, and post-vowel. In the first experiment of identification correctness in VCV iambus environment, all groups showed almost 100% correctness rate, while in trochee environment all groups were different(native speaker 87%, college high 74%, college low 70%, elementary 65%). In the second experiment of cue robustness, all groups showed the similar perceptual pattern in both environments. There was the order of robustness cues in VCV trochee: pre-vowel ${\gg}$ closure ${\gg}$ VOT ${\gg}$ post-vowel, while the order in VCV iambus: VOT ${\gg}$ post-vowel ${\gg}$ closure ${\gg}$ pre-vowel. In some condition, however, we found moderately different perceptual pattern depending on language, age and listening level.

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The Effects of Servant Leadership on Organizational Identification and Innovative Behavior (서번트 리더십이 조직동일시와 혁신행동에 미치는 영향)

  • Hwang, Sang-Kyu
    • Journal of the Korea Safety Management & Science
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    • v.18 no.1
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    • pp.191-201
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    • 2016
  • The paper examines how servant leadership and organizational identification contributed to explaining innovative behavior. In order to verify the relationships and mediating effect, data were collected from 298 individuals in employees working in small and medium-sized firms at Jinju, Changwon, Gimhae, Busan City to test theoretical model and its hypotheses. All data collected from the survey were analyzed using with SPSS 18.0. This study reports findings as follows: first, the relationship between the servant leadership and the organizational identification is positively related. Second, there was also a positive correlation between the organizational identification and the innovative behavior. Third, the relationship between the servant leadership and the innovative behavior is positively related. Finally, the organizational identification played as a partial mediator on the relationship between servant leadership and innovative behavior. Based on these findings, the implications and the limitations of the study were presented including some directions for future studies.

The Effects of Ethical Leadership on Organizational Identification and Organizational Commitment (윤리적 리더십이 조직동일시와 조직몰입에 미치는 영향)

  • Hwang, Sang-Kyu
    • Journal of the Korea Safety Management & Science
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    • v.16 no.4
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    • pp.285-294
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    • 2014
  • The paper examines how ethical leadership and organizational identification contributed to explaining organizational commitment. In order to verify the relationships and mediating effect, data were collected from 256 individuals in employees working in small and medium-sized firms at Jinju, Changwon, Gimhae City to test theoretical model and its hypotheses. All data collected from the survey were analyzed using with SPSS 18.0. This study reports findings as follows: first, the relationship between the ethical leadership and the organizational identification is positively related. Second, there was also a positive correlation between the organizational identification and the organizational commitment. Third, the relationship between the ethical leadership and the organizational commitment is positively related. Finally, the organizational identification played as a partial mediator on the relationship between ethical leadership and organizational commitment. Based on these findings, the implications and the limitations of the study were presented including some directions for future studies.

Noise Source Identification of a Car A/V System (차량탑재용 A/Y 시스템의 소음원 규명)

  • 홍종호;이상호;강연준
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.10
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    • pp.930-938
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    • 2004
  • This paper presents the noise source identification of a car A/V system. There are two different kinds of noise sources noise generated by loading mechanism and rattle noise by externally forced vibration. A dynamometer has been made to produce stationary inertia to the loading mechanism of A/V system. Sound pressure spectra and sound intensity were measured by operating the dynamometer setup as various motor speeds, and the results were analyzed. A dominant rattle noise source about A/V system's components has been found by multi-dimensional spectral analysis. Residual spectrum method was applied for eliminating coherence between the vibration sources. In result, the dominant rattle noise source was identified by partial coherent output spectrum of individual vibration component.

Satellite Fault Detection and Isolation Scheme with Modified Adaptive Fading EKF

  • Lim, Jun Kyu;Park, Chan Gook
    • Journal of Electrical Engineering and Technology
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    • v.9 no.4
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    • pp.1401-1410
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    • 2014
  • This paper presents a modified adaptive fading EKF (AFEKF) for sensor fault detection and isolation in the satellite. Also, the fault detection and isolation (FDI) scheme is developed in three phases. In the first phase, the AFEKF is modified to increase sensor fault detection performance. The sensor fault detection and sensor selection method are proposed. In the second phase, the IMM filer with scalar penalty is designed to detect wherever actuator faults occur. In the third phase of the FDI scheme, the sub-IMM filter is designed to identify the fault type which is either the total or partial fault. An important feature of the proposed FDI scheme can decrease the number of filters for detecting sensor fault. Also, the proposed scheme can classify fault detection and isolation as well as fault type identification.

Identification of partial discharge sources in GIS using AEsensor (초음파센서를 이용한 GIS내 부분방전원의 식별)

  • Lee, Y.H.;Lee, K.W.;Lee, Y.H.;Shin, Y.S.;Seo, J.M.;Kang, S.H.;Lim, K.J.
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.200-202
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    • 2002
  • The use of ultrasound is proposed as the most economic and practical nondestructive test method for the detectin of electrical degradation in insulating materials. This paper has studied identification and characterization of partial discharge signals according to defects in GIS using AE(acoustic emission)sensor. Analysis of PD signals use $\psi-v-n$, skewness and kurtosis.

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