• Honam Mathematical Journal
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• v.38 no.2
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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.

• Proceedings of the KSME Conference
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• 2003.11a
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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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.

• Fashion & Textile Research Journal
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• v.6 no.3
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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.

• Proceedings of the KSME Conference
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• 2004.04a
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3752-3757
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• 2011

This paper suggests two strategies for the restoration of the Seongbukcheon in Seoul. One is the neighborhood-type development and the other is the construction of the flat open spaces. For the neighborhood-type development, the characteristic of each of the streets which are connected with Seongbukcheon was comprehended and the differentiated approaches for each of them were taken. For the construction of the flat open spaces, the necessity of the flat public open spaces was verified and the strategies for this was suggested.

• Korean Journal of Materials Research
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• v.21 no.10
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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.

• Land and Housing Review
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• v.4 no.4
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• pp.371-382
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• 2013

This study performs an experimental investigation to evaluate the behavior of RC flat plate interior joints specimens. Three 60 percent scale Flat Plate interior specimens assemblies representing a portion of a Flat Plate Apartment Structural System subjected to simulated seismic loading (unbalanced moments) under constant axial load were tested, including one specimens with ordinary shear reinforcement and two specimens with folded bend type shear reinforcement. Test results are shown that (1) the design code KBC 2009 is accurate estimate the behavior of specimens. (2) Two types shear reinforcement have a similar structural behavior, but construction work of rebar with folded bend type shear reinforcement is easier than that of ordinary shear reinforcement. (3) In moderate seismic region, RC Flat Plate interior joint with folded bend type shear reinforcement is apply to structural design of Flat Plate.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.8
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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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.12
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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.