• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.468-470
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• 2005

본 연구에서는 NSOM(Near-field Scanning Optical Microscope)에서 정밀도의 중요한 요소로 작용하는 100 ~ 200nm Scale의 Optical aperture를 제작하기 위해 Optical Fiber를 이용하여 $CO_2$ Laser Heating Pulling Method에 의하여 제작하고자 한다. Heating Pulling Method 에서 Fiber Tip의 정밀도 및 제작 재현성에 영향을 미치는 중요한 기존의 여러 Fiber Tip 구현방법 중 본 연구에서는 Pulse Width[$PW_{(SEC)}$] 와 Pulling Force 두 요소에 있어서 상호관계를 연구하였으며, 연구 결과 두 변수간의 최적화된 파라미터인 PW 0.07 ~ $0.10_{(SEC)}$ 와 Pulling force 0.2 ~ 0.81b의 구간에서 error율이 최소화되는 범위를 찾을 수 있었고, 그 결과 최적의 상태는 $0.08_{(SEC)}$와 0.21b에서 팁들은 첨예화 되었고 95% 이상의 재현성 및 신뢰성을 얻을 수 있었다.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.795-800
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• 2006

A common approach to achieve better thermal comfort with hydronic radiant floor heating system is supply water temperature control. This is the control method through which supply water temperature is varied with outdoor temperature. In this study, a comprehensive, yet simple calculation method to find optimum supply water temperature is evaluated by combining heat loss from the building and heat emission from the hydronic radiant floor heating system. And then the control performance of suggested calculation method is confirmed through experiment. It is shown that indoor air temperature is stably maintained around the set point.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.66-71
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• 2001

Kinetic parameters for the texture degradation of three varieties of sweet potato during heating were determined using two alternative methods, the biphasic model and the fractional conversion method. The texture degradation of sweet potatoes during heating could be expressed by two simultaneous first order reactions using the biphasic method, whose activation energies were ranged $71.0{\sim}75.1\;kJ/mol\;and\;48.4{\sim}59.6\;kJ/mol$ for the initial fast texture degradation reaction and the slow texture degradation reaction at a prolonged heating period, respectively. However, the whole texture degradation phenomena of sweet potatoes during heating could also be explained by a single first order reaction using the fractional conversion method. The activation energies were $67.5{\sim}75.3\;kJ/mol$, which were comparable with those of the first phase reaction for the texture degradation determined by the biphasic model. A kinetic compensation effect shown between the kinetic parameters determined by both methods indicates that both methods can be conveniently used to determine kinetic parameters for the texture degradation of sweet potatoes by heating.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.2
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• pp.69-80
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• 2002

Sequential process of roll-bending and line heating has been used to deform the curved hull-plates in shipyards. A growing interest for the mechanization or automation of the line heating process has been noted. Relations between heating conditions and residual deformations are important components needed for the mechanization. The residual deformations are investigated by using a thermal elastic-plastic analysis based on the finite element analysis(FEA). Several experiments are also performed to examine the validity of the results of FEA. The input parameters of line heating are suggested by dimensional analysis of line heating. The dimensional analysis can extract the primary input-parameters of line heating. The relations between the heating conditions and the residual deformations are set up by multi-variate analysis and multiple-regression method. This study suggests a method for the relation between the heating conditions and the deformations lying under the line heating.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.1-11
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• 2022

In this study, an electric resistance dual-spot welding process using a copper electrode inserted in a heating electrode is suggested for the spot welding of AZ31 magnesium sheets. This spot-welding process involves two heating methods for welding at the interfacial zone between the magnesium sheets, one of which is the heating method by thermal conduction from the heating electrode heated by the welding current induced to the steel electrode, and the other heating method uses the electric resistance between the contacted surfaces of the two sheets by the welding current induced to the copper electrode. This welding process includes the welding variables, such as the current induced in the heating electrode and the copper electrode, and the outer diameters of the heating electrode. This is because the heat conducted from the heating electrode can be maintained at a higher temperature in the welding zone, which has a slow cooling effect on the nugget of the melted metal after the welding step. The pressure exerted during the pressing of the magnesium sheets by the heating electrode can be increased around the nugget zone at the spot-welding zone. Thus, it not only reduces the warping effect of the elastoplastic deformation of sheets, but also the corona bond can make it less prone to cracking at the welded zone, thereby reducing the number of nuggets expelled out of the corona bond. In conclusion, it was known that an electric resistance dual spot welding process using the copper electrode inserted in the heating electrode can improve the welding properties in the electric resistance spot welding process of AZ31 magnesium sheets.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.05a
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• pp.41-46
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• 2003

In recently, Is inhabiting more than 70％ indoors during a day in case of company employee and ordinary people which is looking at usual business. Therefore Thermal comfort of human body about indoor temperature and air flow acting very heftily. When intestine temperature is fallen for external low temperature and air flow in winter in case enter into heated room feel comfort by effect of temperature and feel comfort or discomfort by room heating condition gradually. Therefore it is important that grasp thermal comfort about temperature and air flow in heating to keep continuous comfort in indoor dwelling. Temperature and thermal comfort factor of emotion ＆ sensitivity image exert fair effect since heating middle although thermal comfort change greatly effect on sensation about temperature at actuality heating early. Need much study yet in vantage point of emotion ＆ sensitivity although much study were held about thermal and comfort sensibility and when heat in existing research until now. Therefore this study is targeting that evaluate thermal comfort through introduction of estimation method by emotion ＆ sensibility image real and synthetic sensibility about thermal environment that is becoming winter heating.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.65-72
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• 2011

The use of waste concrete can resolve the environmental pollution and shortage of natural aggregate. However, recycled aggregate includes substantial amount of cement paste. So, these aggregates are more porous, and less resistant to mechanical actions than natural aggregates. So, recently, the new manufacture processes of high quality recycled aggregates were suggested such as heating and solving to acid liquid. But the method of solving to acid liquid is not economical and produces additional environmental pollution. In this paper, for the purpose of manufacture of high quality recycled aggregates, the heating processes was added to the existing process of recycled aggregates. To find the optimum process, the experiment was performed by using the method of statistical experiment design, and the heating temperatures(4 levels : 300, 450, 600 and $750^{\circ}C$) and heating times(4 levels : 5, 20, 40, 60 minute) were main experimental variables. By the test results, the optimum manufacturing condition of coarse recycled aggregate was $600^{\circ}C$ and 40 minute, and for the fine recycled aggregate, a little heating made a satisfaction to the KS standard quality code.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.10
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• pp.654-661
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• 2008

Our government will make a plan regulating the cooling limit temperature of the summer season to 26 degree and the heating limit temperature of the winter season to 20 degree for energy saving. Where, the key point of this politic pursuit can be the charge system on heating and cooling cost. Currently, the heating and cooling cost are charged as much as the volume or heat flow rate regardless of the high and low room temperature. However, we have suggested new cost estimating methodology as a worth method in the precedent study, and preformed the worth evaluation and cost allocation of electricity and heat on various cogenerations. In this study, we applied the suggested worth method to four kind of warm air, and preformed the worth evaluation and cost allocation of each warm air. As a result, the more energy a customer saved, the more heating unit cost decreased, and the more energy a customer consumed, the more heating unit cost increased. From this analysis, we hope that the suggested worth methodology can offer a theoretical basis to the politic pursuit of government, and induce the spontaneous energy saving of consumers.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.304-311
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• 2019

Ohmic heating is a heating method based on the principle when an electrical current passes through food. Since this method is internal, electrical current damage occurred during heating treatment. The results of ohmic heated starch's external structure, X-ray diffraction, DSC analysis and RVA were differed from those of conventional heating at the same temperature. Several starches changed more rigid by structure re-aggregation. This change in starch was caused by change of physical, chemical, rheological property. The rheology of ohmic heated potato and corn starch of different heated methods were compared with chemically modified starch. After gelatinization, sample starch suspension (2%, 3%) measured flow curves by rheometer. Cross-linked chemically modified starch's shear stress was decreased with degree of substitution reversibly. Ohmic heated more dramatic, at $60^{\circ}C$. Potato starch's shear stress was less than commercial high cross-linked modified starch. Flow curves of potato starches measured at $4^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$. Showed that Ohmic heated potato starch's shear stress ranging between $4^{\circ}C$ and $20^{\circ}C$ was narrower than modified starch. According to this study, ohmic heated potato starch can be used by decreasing viscosity agent like cross-linked modified starch.

• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.715-721
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• 2000

Residual stress is one of the causes which makes defects in engineering components and materials. These residual stresses can occur in many engineering structures and can sometimes lead to premature failures. There are commonly used methods by which residual stresses are currently measured. But these methods have a little damage and other problems; therefore, a new experimental technique has been devised to measure residual stress in materials with a combination of electronic laser interferometry, laser heating and finite element method. The electronic laser interferometer measures in-plane deformations while the laser heating and cooling provides for very localized stress relief. FEM is used for determining the heat temperature and other parameters. The residual stresses are determined by the amount of strain that is measured subsequent to the heat-up and cool-down of the region being interrogated. A simple model is presented to provide a description of the method. In this paper, the ambiguity problem for the fringe patterns has solved by a phase shifting method.