• Title/Summary/Keyword: Distribution Department

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Back EMF Design of an AFPM Motor using PCB Winding by Quasi 3D Space Harmonic Analysis Method

  • Jang, Dae-Kyu;Chang, Jung-Hwan;Jang, Gun-Hee
    • Journal of Electrical Engineering and Technology
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    • v.7 no.5
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    • pp.730-735
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    • 2012
  • This paper presents a method to design the waveform of a back electromotive force (back EMF) of an axial flux permanent magnet (AFPM) motor using printed circuit board (PCB) windings. When the magnetization distribution of permanent magnet (PM) is given, the magnetic field in the air gap region is calculated by the quasi three dimensional (3D) space harmonic analysis (SHA) method. Once the flux density distribution in the winding region is determined, the required shape of the back EMF can be obtained by adjusting the winding distribution. This can be done by modifying the distance between patterns of PCB to control the harmonics in the winding distribution. The proposed method is verified by finite element analysis (FEA) results and it shows the usefulness of the method in eliminating a specific harmonic component in the back EMF waveform of a motor.

Distribution and Abundance of Planktonic Shrimps in the Southern Sea of Korea during 1987-1991

  • Park, Won-Gyu;Ma, Chae-Woo;Hong, Sung-Yun;Lee, Ki-Won
    • Fisheries and Aquatic Sciences
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    • v.12 no.3
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    • pp.240-248
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    • 2009
  • Distribution and abundance of planktonic shrimps were studied in the southern sea of Korea from 1987 to 1991. Nine species of five genera belonging to three families were identified. Of these, Leptochela sydniensis and Lucifer intermedius were predominant species and Lucifer penicilifer and Lucifer typus were common species. Remaining five species, Acetes chinensis, Leptochela gracilis, Lucifer chacei, Process wheeleri and Sergestes similis occurred sporadically and rarely. The distribution pattern of planktonic shrimps varied with species and sampling periods. L. intermedius occurred abundantly along inshore waters. L. penicilifer and L. typus appeared in both inshore and offshore waters, but more abundantly in offshore waters under influence of the Tsushima Current. In conclusion, the distribution patterns of planktonic shrimps may be related with hydrographic characteristics and seasonality in the southern sea of Korea.

System Size and Service Size Distributions of a Batch Service Queue

  • Lee, Soon-Seok;Lee, Ho-Woo;Yoon, Seung-Hyun;Nadrajan, R.
    • Journal of the Korean Operations Research and Management Science Society
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    • v.18 no.3
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    • pp.179-186
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    • 1993
  • We derive the arbitrary time point system size distribution of M/ $G^{B}$1 queue in which late arrivals are not allowed to join the on-going service. The distribution is given by P(z) = $P_{4}$(z) $S^{*}$ (.lambda.-.lambda.z) where $P_{4}$ (z) is the probability generating function of the queue size and $S^{*}$(.theta.) is the Laplace-Stieltjes transform of the service time distribution function. We also derive the distribution of the service siez at arbitrary point of time. time.

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Development of a Islanding Protection Algorithm for Distributed Resources (분산 전원의 고립 운전 진단 알고리즘 개발)

  • Jang, S.I.;Park, J.Y.;Kim, K.H.
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1287-1289
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    • 2001
  • This paper presents the logic based islanding protection algorithm for distributed resources(DR) which are interconnected with distribution network. Due to the negative impacts from islanding operations of DR on protection, operation and management of distribution system, it is necessary to effectively detect the islanding operations of DR and disconnect it from distribution network rapidly. Generally, it is difficult to detect islanding operation by monitoring only one system parameter. The proposed islanding protection algorithm utilizes multi-criteria, voltage variation, phase displacement frequency variation, the variation of total harmonic distortion(THD) of current; therefore it effectively detects island operation of DR unit. We also verified the efficiency of the proposed algorithm using the radial distribution network of IEEE 34 bus model.

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Influence of Electron and Hole Distribution on 2T SONOS Embedded NVM

  • Choi, Woo Young;Kim, Da Som;Lee, Tae Ho;Kwon, Young Jun;Park, Sung-Kun;Yoon, Gyuhan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.5
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    • pp.624-629
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    • 2016
  • The influence of electron and hole (EH) distribution on two-transistor (2T) silicon-oxide-nitride-oxide-silicon (SONOS) embedded nonvolatile memory (eNVM) is investigated in terms of reliability. As PE (program/erase) cycles are repeated, it is observed that the electron distribution in the nitride layer becomes wider. It leads to the EH distribution mismatch, which degrades the reliability of 2T SONOS eNVM.

Bayesian estimation in the generalized half logistic distribution under progressively type-II censoring

  • Kim, Yong-Ku;Kang, Suk-Bok;Se, Jung-In
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.5
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    • pp.977-989
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    • 2011
  • The half logistic distribution has been used intensively in reliability and survival analysis especially when the data is censored. In this paper, we provide Bayesian estimation of the shape parameter and reliability function in the generalized half logistic distribution based on progressively Type-II censored data under various loss functions. We here consider conjugate prior and noninformative prior and corresponding posterior distributions are obtained. As an illustration, we examine the validity of our estimation using real data and simulated data.

Neural-Tabu algorithm in optimal routing considering reliability indices (신뢰도 지수를 고려한 계통의 Neural-Tabu 알고리즘을 이용한 최적 전송 경로 결정)

  • Shin, Dong-Joon;Jung, Hyun-Soo;Kim, Jin-O
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1245-1247
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    • 1999
  • This paper describes the optimal reconfiguration of distribution network. The optimal routing of distribution network should provide electricity to customers with quality, and this paper shows that optimal routing of distribution network can be obtained by Neural-Tabu algorithm while keeping constraints such as line power capacity, voltage drop and reliability indices. The Neural-Tabu algorithm is a Tabu algorithm combined with Neural network to find neighborhood solutions. This paper shows that not only the loss cost but also the reliability cost should be considered in distribution network reconfiguration to achieve the optimal routing.

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Bayesian estimations on the exponentiated half triangle distribution under Type-I hybrid censoring

  • Kim, Yong-Ku;Kang, Suk-Bok;Seo, Jung-In
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.3
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    • pp.565-574
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    • 2011
  • The exponenetiated distribution has been used in reliability and survival analysis especially when the data is censored. In this paper, we derive Bayesian estimation of shape parameter and reliability function in the exponenetiated half triangle distribution based on Type-I hybrid censored data. Here we consider conjugate prior and noninformative prior and obtained corresponding posterior distributions. As an illustration, the mean square errors of the estimates are computed. Comparisons are made between these estimators using Monte Carlo simulation study.

N(2D) Product Velocity Mapped Imaging in the VUV Photolysis of Nitrous Oxide at 118.2 nm

  • Cosofret, Bogdan R.;Lambert, H. Mark;Houston, Paul L.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.179-183
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    • 2002
  • Resonance-enhanced multiphoton ionization with time-of-flight product imaging of the $N(^2D)$ atoms has been used to study the $N_2O$ photodissociation at 118.2 nm and the two-photon dissociation at 268.9 nm. These imaging experiments allowed the determination of the total kinetic energy distribution of the $NO(X^2{\prod})$ and $N(^2D_{5/2})$ products. The $NO(X^2{\prod})$ fragments resulting from the photodissociation processes are produced in highly vibrationally excited states. The two-photon photodissociation process yields a broad $NO(X^2{\prod})$ vibrational energy distribution, while the 118.2 nm dissociation appears to produce a vibrational distribution sharply peaked at $NO(X^2{\prod},\;{\nu}=14)$.

Bayesian Estimations on the Exponentiated Distribution Family with Type-II Right Censoring

  • Kim, Yong-Ku;Kang, Suk-Bok;Seo, Jung-In
    • Communications for Statistical Applications and Methods
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    • v.18 no.5
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    • pp.603-613
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    • 2011
  • Exponentiated distribution has been used in reliability and survival analysis especially when the data is censored. In this paper, we derive Bayesian estimation of the shape parameter, reliability function and failure rate function in the exponentiated distribution family based on Type-II right censored data. We here consider conjugate prior and noninformative prior and corresponding posterior distributions are obtained. As an illustration, the mean square errors of the estimates are computed. Comparisons are made between these estimators using Monte Carlo simulation study.