• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.69-72
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• 2004

There are an electronic and a manual type in Bidet. The electronic bidet has some advantages. it supplies multiple functions and is up easily. However, it has frequent defects and a high price. The manual bidet is not need to supply electric and is cheaper than the electronic type. However, it is needed to supply hot water and is hard to set up. In order to solve these defects, this study designed a bidet heating unit using an electric instantaneous water heating method. To get a proper heating elements, experiments were performed about a Ni-Cr heater and a film heater.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.822-826
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• 1994

Effects of concentration(6-9%, db) , heating temperature (80-95$^{\circ}C$), cooking time (10-50min) and heating method (continuous and instantaneous) on the apparent viscosity of cowpea sediment dispersions at 6$0^{\circ}C$ were investigated. The instantaneous heating resulted in higher apparent viscosity than continuous heating regardless concentrations and heating temperatures. The activation energy of the increase rate constant of the apparent viscosity was about 8 kcal/mole. The apparent viscosity of the cowpea sediment dispersion heated to 95$^{\circ}C$ and held for 20 min showed a linear relation with the 20 min height at 92.5$^{\circ}C$ by viscoamylograph.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.776-780
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• 2002

This paper describes the concept and the characteristics of hyper interfacial bonding developed as a new concept joining process for UFG (ultra-fine grained) steel. Hyper interfacial bonding process is characterized by instantaneous surface melting bonding which involves a series of steps, namely, surface heating by high frequency induction, the rapid removing of heating coil and joining by pressing specimens. UFG steels used in this study have the average grain size of 1.25 ${\mu}{\textrm}{m}$. The surface of specimen can be rapidly heated up and melted within 0.2s. Temperature gradient near heated surface is relatively steep, and peak temperature drastically fell down to about 1100K at the depth of 2~3mm away from the heated surface of specimen. Bainite is observed near bond interface, and also M-A (martensite-austenite) islands are observed in HAZ. Grain size increases with increasing heating power, however, the grain size in bonded zone can be restrained under 11 ${\mu}{\textrm}{m}$. Hardened zone is limited to near bond interface, and the maximum hardness is Hv350~Hv390.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.293-296
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• 2002

This paper describes the instantaneous current resultant type load parallel high frequency resonant inverter consisting of three unit half-bridge serial and parallel resonant inverter can be used as power source of induction heating. This proposed inverter can reduce distribution of the switching current because of using the current of serial resonant circuit to the input current of the parallel one. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, the principle of basic operating and the its characteristics are estimated by the parameters such as switching frequency($\mu$), load resistance(λ). Experimental results are presented to verify theoretical discussion. This proposed inverter will can be practically used as a power supply in various fields as induction heating application, DC-DC converter etc.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.2
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• pp.190-199
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• 1998

a new measuring method is suggested to determine the time constant of a thermocouple wire to be applied for the measurement of the true fluid temperatures in varying flow states. Based on the techniques of internal heating which are commonly used to measure mean time constants we extend the existing method to measure instantaneous time constants continuously. A method of measurement and analysis is presented and verified experimentally.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1100-1104
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• 1998

The preference test of cowpea mook(gel prepared with air-dried sediment of cowpea) indicated that the optimum concentration and heating temperature for mook-making were 8% at 95$^{\circ}C$ or 9% at 90$^{\circ}$and 95$^{\circ}C$ with continuous heating method(A), and 8% at 85$^{\circ}C$ or 7% at 9$0^{\circ}C$ with instantaneous heating method(B). Among the samples the mook made from 9% at 95$^{\circ}C$ with the method A was the most preferable. The degree of increase in hardness of mook prepared by the method B stored at 6$^{\circ}C$ for 8hr was much slower than that by the method A. the preference test of the mook stored at 6$^{\circ}C$ for 1 day revealed that the mook by the method A with 8%(95$^{\circ}C$) and by the method B with 7 and 8% (85$^{\circ}C$) were not significantly different.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.659-663
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• 1998

Mook is a traditional Korean food made from the sediment of mungbean, cowpea, buckwheat or acorn. The air-dried sediment of cowpea(6~9%, dry basis) was heated to 80~95$^{\circ}C$ by continuous(method A) or instantaneous(method B) heating method and held at that temperature for 20min and then cooled at 15$^{\circ}C$ for 3hrs. The optimum deformation rate for the measurements of hardness and cohesiveness of cowpea mook by Instron Universal Testing Machine was 55~65% by method A and 60~70% by method B. The hardness of mook made by method A was the highest at heating temperature of 9$0^{\circ}C$, whereas that by method B was linearly decreased as the heating temperature increased at all concentrations. The mook made by method B had higher cohesiveness than that by method A. The ratio of cohesiveness to hardness was also higher in mook made by method B.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.5
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• pp.598-606
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• 1988

The radiation heat-transfer coefficient is generally used to calculate radiant heat exchange of heating space. The coefficient is evenly adopted in most cases, but it is not correct in actual cases. The purpose of this paper is to grasp the changing aspect of radiation heat-transfer coefficient needed for heating load calculation of radiant heating space. Surface temperatures are measured in an Ondol space, and the coefficients are derived and examined. Gebhart's Absorption Factor Method is used for the calculations of the rates of instantaneous radiant exchange in the room. As the result, it is confirmed that the coefficients are variant according to surface temperatures, and proper coefficients are needed for each of conditions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.869-870
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• 2013

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.2
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• pp.153-160
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• 2002

As a way to assess the reliability of programs for building energy analysis, verification experiment and calculation of heating load are simultaneously conducted for a well-defined test space. Experimental conditions are carefully set to minimize uncertainties associated with radiation heating, air change, infiltration, and room-to-room interaction. Dyna- mic load calculations using TRNSYS, which are performed for two different computation domains, rely on the energy rate control that represents inherent load characteristics of a space. The predicted instantaneous heating load favorably simulates the overall behavior the measured one, though the latter fluctuates much more rapidly than the former Comparison of the accumulative load between the experiment and calculations shows a close agreement within an engineering tolerance, regardless of the computation model. It is deduced from such findings that the present experimental results along with weather information can serve as a set of reference data for validating load calculation softwares from the users'standpoint. In order to enhance the completeness of this work, a complementary study on the cooling load for the same test space is highly recommended.