• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.59-61
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• 2007

This paper presents the characteristic analysis of the 40-kVA high speed synchronous generator considering the field current. The generator consist of the rotor with the short-circuited field coils connected armature coils of exciter and the stator with three-phase winding. To analyze the characteristics of the generator, the direct finite element method is applied.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.113-115
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• 2007

This paper presents a design notch to reduce cogging torque of interior type permanent magnet motor. As design notch on rotor of IPM motor, magnetic field from between rotor and teeth of state is changed. By reason of variation magnetic field, cogging torque is generated. Through Fourier formulation of magnetic field on rotor, we found position of notch and manufactured armature that is designed by optimizing analysis. The validity of the proposed design is confirmed with experiments.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1049-1055
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• 2013

DC motors are widely used in industries like cement, paper manufacturing, etc., even today. Early fault identification in dc motors significantly improves its life time and reduces power consumption. Many conventional and soft computing techniques for fault identification in DC motors including a recent work using model based analysis with the help of fuzzy logic are available in literature. In this paper fuzzy logic and norm based wavelet analysis of startup transient current are proposed to identify and quantify the armature winding fault and bearing fault in DC motors, respectively. Results obtained by simulation using Matlab and Simulink are presented in this paper to validate the proposed work.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권8호
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• pp.467-474
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• 2002

In this paper, a wind power simulator is designed and implemented. To realize the torque of wind blade, a DC motor is used as a variable torque input device. An induction machine is used as a generator of which speed is controlled to maintain the optimal tip speed ratio during wind speed change. Input torque of system is controlled by armature current of DC motor and speed is controlled by generator control unit using field oriented control algorithm. Various control algorithms such as MPPT, soft start up, the simulator reactive power control, can be developed and tested using the simulator.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권6호
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• pp.255-262
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• 2001

This paper deals with characteristic analysis method of the slotless type Permanent Magnet Linear Synchronous Motor(PMLSM) using the space harmonic method. Analysis models of the PM and the armature current are described by the magnetization configurations taking into account the 2D and 3D distribution. In 3D analysis, the thrust and normal force can be calculated more accurately, because it can consider the z component flux density which is impossible in 2D analysis. In order to verify the validity of the proposed method, the results of the analytic method are compared with not only the experimental ones but ones of Finite Element Method(FEM).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.974-976
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• 2001

This paper presents a method to reduce commutation torque ripples occurred during commutation in brushless do motor drives using a single DC-link current sensor. In brushless dc motor drives with a single dc current sensor instead of 3-phase line current sensors, it is noted that dc-link current sensor cannot give any information corresponding to the motor currents during line current commutation intervals. A new technique to resolve such a problem is dealt with based on a deadbeat current control in which motor armature voltage command is computed from a dc-link current reference, an actual current and counter emf voltage. The simulation results show that the proposed method reduces the torque ripple significantly.

• Animal Systematics, Evolution and Diversity
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• 제32권3호
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• pp.207-218
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• 2016

A harpacticoid copepod, Microarthridion littorale (Poppe, 1881), is newly recorded in Korea. Microarthridion species can be distinguished from each other by a combination of the number of the antennular segment, the number of the seta on the antennary exopod, and the armature of the thoracopod legs. Korean materials examined coincide well with M. littorale on these well-known characteristics. However, there are some minor differences in the ornamentations of the maxilliped and swimming legs. The specimens show additional sexual dimorphisms in the setae on enp-3 of P1 and exp-3 of P2-P4. Morphological diversity of so-called M. littorale is also discussed here with detailed features.

• Animal Systematics, Evolution and Diversity
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• 제32권1호
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• pp.9-20
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• 2016

Two new species of poecilostomatoid copepods associated with echiurans are described from an intertidal mud flat in the Yellow Sea. A new genus Echiuricopus is created to accommodate two new species, E. aprilis and E. tenuipes. Major differences between the two new species are displayed in body length, length of caudal ramus seta I, length/width ratio of leg 5 exopod, and armature of the first antennular segment. Echiuricopus n. gen. is closely related to the genus Goidelia Embleton, 1901, but is distinguished from the latter chiefly by having seven caudal setae, a claw-like process on the first antennular segment, one claw-like process on the maxillary syncoxa, the absence of an inner coxal seta on legs 1-4, different armatures on legs 1-4, and an elongate leg 5 exopod.

• Animal cells and systems
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• 제13권1호
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• pp.25-30
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• 2009

A new marine gastrotrich species, Ptychostomella jejuensis n. sp. belonging to the family Thaumastodermatidae, is described on the basis of the specimens from subtidal sand bottom at about 6-7 m depth of Jeju Island, South Korea. Ptychostomella jejuensis n. sp. is distinguished from its congeneric species with smooth cuticular armature by the character combination: (1) small body up to about 160 ${\mu}m$ in length; (2) presence of knob-like cephalic tentacles; (3) absence of dorsal and ventral adhesive tubes; (4) bifid pedicles; (5) pyriform copulatory organ. Under scanning electron microscopy, numerous epidermal gland openings were observed in the new species, characteristically flanking a bristle. Taxonomic accounts on the affinities, some brief remarks on the epidermal gland openings and the cooccurrence with P. orientalis Lee and Chang, 2003 are also presented with detailed illustrations and scanning electron photomicrographs.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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• pp.65-68
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• 1999

The major deisng parameters that are considered in this paper are: 1) EMF according to width of field coil. 2) EMF according to magnetic shield length. Because of superconducting generator (SG) is actually and air cored machine with its rotor iron and stator iron teeth having been removed. In this case, the desing of the SG must be based on the 3D analysis of the magnetic field. This study presents an effective armature winding type with 3D FEM(Finite Element Method), and compares analyzed and measured results.