• Journal of Magnetics
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• 제17권4호
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• pp.280-284
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• 2012

This paper presents a method for evaluating interior permanent magnet synchronous motor (IPMSM) performance over the entire operation region. Using a d-q axis equivalent circuit model consisting of motor parameters such as the permanent magnetic flux, copper resistance, core loss resistance, and d-q axis inductance, a conventional mathematical model of an IPMSM has been developed. It is well understood that in IPMSMs, magnetic operating conditions cause cross saturation and that the iron loss resistance - upon which core losses depend - changes according to the motor speed; for the sake of convenience, however, d-q axis machine models usually neglect the influence of magnetic cross saturation and assume that the iron loss resistance is constant. This paper proposes an analysis method based on considering a magnetic cross saturation and estimating a core loss resistance that changes with the operating conditions and speed. The proposed method is then verified by means of a comparison between the computed and the experimental results.

• 한국신뢰성학회지:신뢰성응용연구
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• 제7권2호
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• pp.89-100
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• 2007

For the certification of aircraft and part, it must be show the compliance with applicable requirements through system safety assessment. The safety assessment process should be planned and managed to provide the necessary assurance that all relevant failure conditions have been identified and that all significant combinations of failures which could cause those failure conditions have been considered. Complex systems, especially aircraft, should take into account any additional complexities and interdependencies which arise due to integration. In all cases involving integrated systems, the safety assessment process is of fundamental importance in establishing appropriate safety objectives for the system and determining that the implementation satisfies these objectives. This study review the safety assessment for the certification process of the aircraft engine system and analyze turbo-fan engine by fault analysis method for compliance with airworthiness requirement of aircraft engine system.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.58-63
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• 1999

Almost all concrete structures have many inevitable cracks for various reasons such as drying shrinkage, heat liberation of cement, fatigues or repeating loads and movements. Conventionally, they are repaired with epoxy materials. The Epoxy resins used by repair materials are different from properties of the base concrete materials such as thermal and mechanical properties - thermal expansion coefficients, bending strength. And the epoxy resin cannot release the water inside the concrete structure and cause corrosion of the steel bars. In this study, before the experiment got launched, we had analyzed cement and slag. Then We blended the two grades of ultra fine cement using high blaine cement and slag. And the cement slurry was produced by water and suprplasticizer to each blended ultra fine cement in various conditions. The slurry produced by each conditions was evaluated with flow properties such as viscosity, dropping time, segregation and observation of dry surface after injection.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.233-236
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• 2006

Chloride attack and carbonation induced corrosion of reinforcement are those of the main factors which cause the deterioration of concrete structures. The objective of this study is to suggest an analytic model for the prediction of chloride penetration into carbonated concrete, in order to make up for the current codes. Carbonation depth model considering the moisture effect is validated by being compared with the test data and the analytic model on chloride penetration into carbonated concrete is developed. Finally, the corrosion-initiation time has been predicted by the present model, being compared with that by the current code equation. The comparison shows that the current code equation can underestimate the chloride penetration into carbonated concrete in marine atmospheric conditions.

• Imaging Science in Dentistry
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• 제41권1호
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• pp.39-42
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• 2011

Facial asymmetry is not an uncommon occurrence in day to day dental practice. It can be caused by various etiologic factors ranging from facial trauma to serious hereditary conditions. Here, we report a rare case of non-syndromic facial asymmetry in a young female, who was born with this condition but was not aware of the progression of asymmetry. No relevant family history was recognized. She was also deficient in both deciduous and permanent teeth in the corresponding region of maxilla. Hence, the cause of this asymmetry was believed to be a segmental odontomaxillary hypoplasia of left maxilla accompanied by agenesis of left maxillary premolars and molars and disuse atrophy of corresponding facial musculature. This report briefly discussed the comparative features of segmental odontomaxillary hypoplasia, hemimaxillofacial dysplasia, and segmental odontomaxillary dysplasia and justified the differences between segmental odontomaxillary hypoplasia and the other two conditions.

• Biomolecules & Therapeutics
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• 제9권3호
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• pp.162-166
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• 2001

Helicobacter pylori is a major cause of gastric-associated diseases. In our previous study, the Adhesin/CTXA2B was expressed as insoluble recombinant chimeric protein derived from the H. pylori adhesin genetically coupled to CTXA2B subunit in Escherichia coli. Since it is very important to optimize IPTG concentration, culture temperature and composition of medium to maximize cell growth and productivity, these conditional growth factors were determined for increasing the productivity of the expressed Adhesin/CTXA2B chimeric protein in Escherichia coli JM101 carrying pTEDhpa/ctxa2b. Our data demonstrate that optimal medium for increased production of chimeric protein was a YCP/Glu medium composed of 2% yeast extract, 1% casamino acid, phosphate solution [0.3% $KH_2P0_4$, 0.4% $Na_2HP0_4$, 0.25% ($NH_4)_2HPO_4$], and 0.5% glucose. In addition, optimal concentration of IPTG was 1 mM and culture temperature, $37^{\circ}C$.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.189-194
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• 2009

In a gas engine based cogeneration system, heat is recovered from two parts, which are jacket water and exhaust gas. The heat from the jacket water is often recovered by a plate type heat exchanger and used for the room heating and/or hot water supply. Depending on the operating conditions of engine and heat recovery system, there should be imbalance in the flow rate and supply pressure between engine and heat recovery side of the heat exchanger. The imbalance cause the deformation of the plate, which affects the pressure drop characteristics. In the present study, the pressure drop inside the heat exchanger has been investigated in a 1/5 scaled test rig and compare with the experimental correlations, which are used for the design.

• Archives of Plastic Surgery
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• 제33권4호
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• pp.503-505
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• 2006

Purpose: Cutis verticis gyrata(CVG) is a morphologic syndrome, typically occurring on the scalp, characterized by varing development of permanent folds and furrows conferring a corrugated or convoluted appearance which resembles the outer surface of the cerebrum. Cutis verticis gyrata can be categorized into primary and secondary types according to various etiologic factors and associated conditions which cause disease process. Methods: We report a case of essential primary cutis verticis gyrata in a 24-year-old male who did not have any other underlying or associated conditions. Results: After we made an incision to the galea aponeurotica of patient's scalp four times under local anesthesia, we dissected along the subapponeurotic layer and adjusted the flaps each other, and then sutured the flap. Conclusion: After the operation, the clear margin disappeared and it did not recur.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.378-382
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• 2004

A study was performed for verification of creation mechanism of turn down mark in thick plate. The roll mark was produced by plate bending when the front of plate was collided with roller table rolls. Various process conditions which are temperatur distribution along the thickness direction of plate, pass line, and reduction ration were investicated. These process conditions affected the amount of plate bending and were a major cause of turn down mark.

• 한국주거학회논문집
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• 제25권3호
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• pp.145-153
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• 2014

This study analyzes the physical environments of studio-housing and suggests alternative solutions for the problems of studio-housing. Based on solving the problems of it through previous research review, the research methods are decided on-site survey and the housing floor plan analysis. The results of this study are follows. First, parking lots make passengers uncomfortable. Narrow spaces between buildings cause problems in terms of light, ventilation, and privacy. Moreover, the short of green space makes living conditions less amenable. Second, the narrow corridors of studio-housing buildings bring about bad effects on walking and privacy. The living conditions becomes worse due to the illegal remodeling. Third, even though a multi-family housing provision for low or middle-income families is a good housing policy, new design policies or interventions are needed to make residents' behavior comfortable.