• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.855-857
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• 2003

A slotless Permanent Magnet Linear Synchronous Motor (PMLSM) has good control ability but thrust density is low. So, this paper proposes inserted core type of slotless PMLSM to improve its low thrust density. Inserting the core between windings of each phase, detent force is generated by the difference of magnetic resistance in an air gap. To minimize detent force and maxize thrust, this paper applies the neural network to inserted core type of slotless PMLSM.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1104-1107
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• 2005

This paper presents a comparison of core losses for the four cases of Switched Reluctance Motors (SRM) with different winding method and switching sequence. With concentrated winding SRM, two kinds of switching sequence are considered for one-phase exciting and two-phase simultaneously exciting driving. With both distributed winding and toroidal winding, two-phase exciting driving is considered. The ratio of calculated core losses to input power is able to be used a guide or reference for deciding the winding method and switching sequence of in the initial design stage of SRM.

• International Area Studies Review
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• v.14 no.2
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• pp.251-272
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• 2010

This study was done through Panel Gravity Model to analyze the trade pattern of Korean motor industry and empirical analysis was also performed on the effect of regional economies joining to the Korean trade is to draw out some implications. Compared with per capita pattern regarding the income levels of both the countries, the results indicated that trade of Korean motor industry followed GDP pattern in accordance with the overall market. The results of effect on regional economic integration to Korean motor industry reflected 179% and 198% increase in motor trade industry and motor parts trade, respectively. To expand the trade of Korean motor industry at the international competitiveness level, focus should be made on smaller, smarter and greener car with lesser impact on the environment. Hence, the present investigation suggested that government should not delay in retaining the core technology as well as private sector should also aggressively invest in the market.

• Design & Manufacturing
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• v.10 no.2
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• pp.29-33
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• 2016

Production machines have been more important, due to quality level of vehicle motor core is getting higher. That is why, to improve assembly fit of tooling and to be emphasized how much moving down caused of deterioration of high speed press, it is also getting more important parts as solution of problems. To analyze how much move based on condition of movement as tooling and high speed press, and to measure how much impact to embossing height caused of changing movement down. As the result of investigation, in case of material thickness 0.5mm, there is highest pull and force power when emboss height is 0.45mm. If emboss height is less than 0.45mm, pull and force power is getting lower, if emboss height is higher than 0.45mm, it is impossible to make it forming caused of changed press movement, also it has been piercing.

• The Journal of Internal Korean Medicine
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• v.43 no.4
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• pp.656-679
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• 2022

Objectives: The aims of this study were to evaluate the fidelity of stroke stage reporting, the timeliness of the outcome measures, and the use of the core outcome set. Methods: We searched the literature using 6 domestic databases. We selected studies that used Korean medicine interventions and targeted stroke patients with motor sequelae. We examined whether the included studies reported the stroke stage and whether they used the outcome measures in the appropriate period based on the recommendations of the "Stroke Evidence Database to Guide Effectiveness". We also confirmed the use of the essential assessment tools suggested by the core outcome set. Results: Overall, 77 studies were finally selected, with 16 (21%), 55 (71%), and 6 (8%) published on the acute, subacute, and chronic phases, respectively. Only 11 of the studies directly mentioned the stroke stage. The most commonly used assessments were the National Institutes of Health Stroke Scale, Modified Barthel Index, and Manual Muscle Testing. Only 5 studies failed to apply the stage-related outcome measures at the recommended period. The outcome variables used inadequately were the National Institutes of Health Stroke Scale, Functional Ambulation Categories, 36-Item Short Form Health Survey, and Mini-Mental State Examination. Among the core outcome set items, some studies used liver and renal function tests, but no herbal medicine safety reporting was conducted. Conclusions: In future studies, we propose to ensure accurate reporting of the stroke stage with reliable outcome measures to deliver better clinical and research outcomes. Furthermore, in future clinical studies on stroke, a standard protocol that reflects the core outcome set should be developed.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.53-60
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• 2012

As enforced by the regulation on the improving fuel efficiency and increased the demand on green technology, many interests are focused on electric vehicles and hybrid vehicles. Thus the technology development in electrification of vehicle operation system, including steering and braking field, is actively progressive. Especially electric power steering substitutes for hydraulic power steering rapidly in the market, which is more complex and bigger in packaging volume compared with electric power steering system. The core component in electric power steering system is a motor, which is required to be silent and powerful to guarantee required system performance. Brushless synchronous motors are widely used and many variations of the motors are introduced in the market, while the performance of each type is not well defined or studied for electric power steering system. In this paper, recent developments in brushless synchronous motor are reviewed and compared applying finite element analysis in electromagnetic field. As results, each characteristic of different types of brushless synchronous motors is compared and summarized for optimized selection in electric power steering system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.105-111
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• 2012

High speed machining is the core technology that influences the performance of machine tools, and the high speed motor spindle is widely used for the high speed machine tools. The important problem in high speed spindle is to minimize the thermal effect by motor and bearing and frequency effect. This paper presents the thermal characteristic analysis and frequency experiment for a high speed spindle considering the flow rate of cooling oil. A high speed spindle is composed of angular contact ceramic ball bearings, high speed built-in motor, oil cooling jacket and so on. The thermal analyses of high speed spindle need to minimize the thermal effect and maximize the cooling effect and they are carried out under the various cooling conditions. Heat generations of the bearing and the high speed motor are estimated from the theoretical and experimental data. To find out the characteristic of vibration, the high speed spindle is excited in operational range. This result can be applied to the design and manufacture of a high speed tapping spindle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.11
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• pp.1067-1071
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• 2006

Prior to destructive testing, diagnostic tests were performed in ten high voltage motors. Diagnostic tests included polarization infer, ac current, dissipation factor$(tan{\delta})$ and partial discharge magnitude. The rewind of motet slater insulation at rated voltage is assessed by the results of these tests. After completing the diagnostic tests, the stator windings of motors were subjected to gradually increasing ac voltage, until the insulation punctured. No. 8 motor failed near rated voltage of 19.0 kV. The breakdown voltage of No. 4 motet was 7.0 kV which is lower that expected for good quality coils in 6.6 kV class motors. The failure was located in a line-end coil at the exit from the core slot. These two motors began operation in 1994. While testing No. 7 motor, flashover occurred between the stator winding and the stator frame at 15 kV. The relationship between the diagnostic test and the drop in insulation breakdown voltage was analyzed.

• Journal of Power Electronics
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• v.14 no.5
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• pp.866-873
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• 2014

In this paper, a novel 12/8 segmental rotor type switched reluctance motor (SRM) is proposed for cooling fan applications. Unlike conventional structures, the rotor of the proposed structure is constructed from a series of discrete segments, and the stator is constructed from two types of stator poles: exciting and auxiliary poles. Moreover, in this structure, short flux paths are taken and no flux reversion exists in the stator. While the auxiliary poles are not wound by the windings, which only provide the flux return path. When compared with the conventional SRM, the proposed structure increases the electrical utilization of the machine and decreases the core losses, which may lead to a higher efficiency. To verify the proposed structure, the finite element method (FEM) and Matlab-Simulink are employed to get the static and dynamic characteristics of the proposed SRM. Finally, a prototype of the proposed motor was tested for characteristic comparisons.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1695-1702
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• 2015

This paper presents the characteristic analysis and experiment of force characteristics in permanent magnet linear synchronous motor for accuracy prediction of linear motion machine tools. In particular, the pitching moment resulting from attraction force ripple has been analysed and tested. Firstly, we analysed the characteristics of detent force, attraction force, and pitching moment in permanent magnet linear synchronous motor according to the design techniques such as auxiliary teeth, chamfering, and permanent magnet skewing. In addition, we suggested the experimental set for measurement of pitching moment. Finally, the results from measurement shows the good agreement with those obtained from finite element analysis results.