• 호남수학학술지
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• 제38권2호
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• pp.305-316
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• 2016

In this paper we study general rotational surfaces in the 4-dimensional Euclidean space $\mathbb{E}^4$ and give a characterization of flat general rotational surface with pointwise 1-type Gauss map. Also, we show that a flat general rotational surface with pointwise 1-type Gauss map is a Lie group if and only if it is a Clifford torus.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.37-42
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• 2003

An experiment was performed to study heat transfer characteristics between corrugated heat exchanger and flat plate type one. While heat capacity(13.86kW) was provided constantly and the flow speed was varied from 2.8 to 17.9m/s, The temperature and the pressure drop were measured. Furthermore, Heat transfer coefficient, Colburn factor and Nusselt number were calculated using them. With increase of the flow speed for both exchangers, the coefficient and the pressure drop increased, but Colburn factor decreased. The coefficient, pressure drop and Colburn factor of the corrugated type were all higher than those of the flat one, which is due to the flow interruption with recirculation and reattachment of the corrugated type. The empirical correlations of Nusselt number were suggested for the tested two heat exchangers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.414-417
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• 2001

Recently, developments of device using characteristics of ceramics as a new technical material is in progress. While doing so, Ultrasonic motor which is a part of research & flat-type $L_1-B_8$ mode Ultrasonic motor and measured the operation characteristics of its. The size of USM is 80*20*1.5[$mm{^1}$](length*width*thickness) and is constructed with stator by piezo-ceramics and stainless elastic body and rotator by bearings. As results of experiments, the fastest speed of revolution($\upsilon$), the maximum torque(T) and the efficiency($\eta$) were 37.5[cm/sec], 5.0[mN$\cdot$M] and 1.17[%] respectively when 27.9[kHz], 150[gf], 50[V] were applied. SO, we think this flat-type $L{_1}-B{_8}$ mode Ultrasonic motor is able to be used for applications in forwarding device of a paper or electric card so on. Key Words: Flat=type $L{_1}-B{_8}$ mode Ultrasonic Motors, Piezoelectric ceramics, forwarding device.

• 한국의류산업학회지
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• 제6권3호
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• pp.357-366
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• 2004

The purpose of this study is to classify the types of men's back and chest through the criteria which represent the characteristic of men's back and chest. We have the following conclusions based on our sample size of 291 men's back and chest. The result of factor analysis concerned with men's back indicates that six factors are extracted and they are consist of 80.6% of total variance. We divide the shape of back into three categories: bent, protrusion of the scapula, and breadth. Each category is divided into subcategories. According to the frequency based on our data entries of 291 men's back, we introduce five new types of men's back. 83.8% of examined men's back belong to one of these five types: (i) 15.5% of protrudent and lordotic type; (ii) 6.5% of flat and lordotic type; (iii) 22.7% of protrudent and normal type; (iv) 34.4% of flat and normal type; (v) 4.8% of flat and bent type. The result of factor analysis related to with men's chest shows that six factors are extracted and they are consist of 76.0% of total variance. We divide the shape of chest into three categories: thickness, breadth, and protrusion of the breast. Each category is divided into subcategories. According to the frequency based on our data entries of 291 men's chest, we introduce four new types of men's chest. 65.0% of examined men's chest belong to one of these four types: (i) 7.2% of full and well-developed type; (ii) 24.1% of full and developed type; (iii) 25.8% of flat and developed type; (iv) 7.9% of flat and under-developed type. In order to consider the shape of the upper body as a whole, the back and the chest types should be corresponded.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2135-2140
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• 2004

This study represented experimental research on the flat plate solar collector. For the flat plate Solar system, it is sensitive of the Global radiation. In Actually, it suppose to be dependent on the direct radiation. Also, the existing method's factors are depend upon Global radiation in the flat plate collector system. therefore it needs which is depend upon direct radiation. In this experiment, the flat plate collector is used for obtaining the method's factors of the direct radiation. As a result, the correct $({\tau}{\alpha})_e$ is found out for practical value.

• 한국산학기술학회논문지
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• 제12권8호
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• pp.3752-3757
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• 2011

본 논문은 서울시 성북천 복원 계획과 관련하여 '근린형 생태하천복원'을 목적으로 인근 주민들의 공동체적 교류와 편의를 제공하는 근린형 하천복원을 제안하기 위하여 '근린형 개발'과 '평지 조성'이라는 두 개의 계획 전략을 구상하였으며, '근린형 개발' 측면에서는 성북천 일대의 주변 가로들의 특징을 파악하고 그에 따른 차별화된 접근을 시도하였으며, '평지 조성' 측면에서는 성북천 일대의 평지형 공개공지 조성의 필요성을 확인하고 기존의 성북천 복원 계획상에 평지 조성 방안을 제안한다.

• 한국재료학회지
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• 제21권10호
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• pp.532-541
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• 2011

The Xe plasma flat lamp, considered to be a new eco-friendly LCD backlight, requires a further improvement of its luminance and luminous efficiency. To improve the performance of this type of lamp, it is necessary to understand the effects of the discharge variables on the luminous characteristics of the lamp. In this study, the luminous characteristics of a coplanartype Xe plasma flat lamp with a teeth-type electrode pattern were analyzed while varying the gas composition, gas pressure and input voltage. The effects of the phosphor layer on the discharge and the luminous characteristics of the lamp were also studied. The luminous efficiency of the coplanar-type Xe plasma flat lamp improved as the Xe input ratio and gas pressure increased. Higher luminous efficiency was also obtained when helium (He) was used as a buffer gas and when a phosphor layer was fabricated on the electrode region. In contrast, the luminous efficiency was reduced with increasing the input voltage. It was found that the infrared emissions from the lamp were affected by the Xe excitation rate in the plasma, the Xe gas density, the collisional quenching of excited Xe species by gas molecules, and the recombination rate between the Xe ions and electrons.

• 토지주택연구
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• 제4권4호
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• pp.371-382
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• 2013

불균형 모멘트가 작용하는 무량판 슬래브 내부접합부를 대상으로 폐쇄형 전단보강근으로 보강한 1개 실험체와 밴드형 전단보강근으로 전단보강한 2개의 실험체를 제작하여 구조성능을 평가하였다. 구조성능평가 결과, 구조설계기준(KBC 2009)으로 평가한 불균형모멘트는 실험결과의 95%로 매우 잘 일치하나, 개정 구조설계기준(KCI 2012)으로 산정한 불균형모멘트는 실험결과의 약 60%에 불과하여, 내부접합부의 불균형모멘트를 과대평가하는 것으로 나타났다. 밴드형 전단보강근은 기존 전단보강근과 비교하여 유사한 구조성능을 가지며, 시공성이 우수한 것으로 나타나 중진지역의 무량판구조물 설계 시 적용할 수 있는 것으로 평가되었다.

• 한국의류학회지
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• 제36권8호
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• pp.791-801
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• 2012

We performed an assessment of wearing, purchasing, satisfaction, and the fit of brassieres according to body and breast type for college women to provide basic data on the manufacture of an ergonomic brassiere. The classifications of domed and conical breast type or projecting and conical breast type were unclear. Flat breast were dissatisfied with the shape of small and flat, and drooping breast were dissatisfied with the shape of big, projected, and drooping. In purchasing a brassiere, the majority of subjects were ignorant of their brassiere size, and over 80% of the subjects bought a brassiere without trying it on. Over 50% of those surveyed said they found it difficult to buy a well-fitted brassiere, particularly for the flat and drooping breast type. Over 70% of those surveyed wore a brassiere of 3/4 cup size, the slim body type wore a brassiere of 1/2 cup size; however, the obese body type wore a brassiere of full-cup size. The flat-breast or slim-body wore a brassiere of a thick pad type but projecting-breast or drooping breast wore brassiere of a thin pad type. Many of the subjects wore an unfitted brassiere in cup size and under bust size. In the classification of breast type, there were slight differences between the breast type that they recognized and the breast type that they were shown. There were distinctions in function, satisfaction, and fitness based on breast type. Therefore, the development of an ergonomic brassiere should considered the characteristics of breast type for fitness and comfort.

• 한국전기전자재료학회논문지
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• 제21권12호
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• pp.1105-1110
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• 2008

In this study, plasma flat fluorescent lamps (FFLs) having two electrode type structures of surface discharge was fabricated by screen printing and were characterized using spectra-radiometer and square pulse power supply. Two types of FFLs (cross-type and line-type electrode structure) were compared with variation of discharge shape and electrode distance.