• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.378-384
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• 2008

This Paper presents dynamic analysis of HVAC(Heating Ventilation & Air Condition) Heater Case which consists of heater and evaporator unit for passenger car. To analyze the dynamic characteristics of HVAC Heater Case. finite element model which consists of shell elements is constructed for modal analysis and experimental Modal analysis has been conducted. Finite element analysis results are compared with experimental results to evaluate of validity of finite element model After identifying node shape and natural frequency of HVAC Heater Case, local stiffness of HVAC Case is evaluated through point mobility using finite element analysis and experiment.

• Journal of Welding and Joining
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• v.6 no.3
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• pp.21-26
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• 1988

The behavior of angular distortion in butt joint wleding of thin plate structure is investigated with an experimental model and partially with a computational model. The experimental model studying the effects of specimene size and degree of restraint on the angular distorion offers a good method for analyzing the behavior of the distrotion. In addition, the distrotion during welding was demonstrated by both experimental measurement and numericla prediciton. The facts evealed in this study are as follows : 1) distrotion angles were changed with variations of specimene wldth. 2) With the restraint, angular distrotion was reduced to 20% to that of free joint. 3) After the restraint being removed, the effect of restraint was also remained. 4) Same heat input per unit thickness caused same amount of distortion. 5) The mode of angular distortion was expected to be changed with expected to be changed with time, i.e. convex movement during heating and concave one during cooling.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1108-1113
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• 1992

In this paper, the high frequency twin resonant inverter using MOSFET is presented. The output control is excellent and the EMI noise is reduced, because the output appear as the vector sum of current in each unit inverter. The output voltage and the output current of the inverter are controlled by PLL. In this paper, the principle of the twin resonant method is described. And computer simulations and experimental results are shown.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.2
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• pp.93-96
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• 2012

We have designed high performance prism light-guide plate (LGP) in 17 inch TFT-LCD. In test result to embody high brightness BLU in case of LGP of base and upper surface with 17 inch, thickness 8mm adding prism construct. Using optical simulation, we forecast the brightness and uniformity in LGP with prism structure. And we adopted novel injection mold method and Nickel stamper to make actual evolution sample. Novel injection mold process has steady heating time zone in heat cycle time of injection mold process. For this novel heat cycle control, we achieved above 90[%] height prism structure as our design. It is superior brightness improvement than previous that of printing form about some 20[%] and in this course to embody actual material it succeeded prism LGP production by 17 inch injection form process.

• Environmental Engineering Research
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• v.14 no.1
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• pp.48-52
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• 2009

Solubilization of sewage sludge creates favorable conditions for anaerobic microorganisms to produce biogas. In this paper, we quantify the effect of heating pretreatment on the degree of solubilization of sewage sludge. The pretreatment process was carried out using a lab-scale industrial microwave unit (2450 MHz frequency). Response surface analysis was applied to determine the combination of temperature-increase rate (ramp rate) (2.9 to 17.1 ${^{\circ}C}$/min) and terminal temperature (52 to 108${^{\circ}C}$). Both ramp rate and temperature significantly affected the solubilization degree of sludge. Within the design boundaries, the conditions predicted to maximize the solubilization degree of 15.8% were determined to be 2.9 ${^{\circ}C}$/min and 104${^{\circ}C}$.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.32-41
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• 1999

Natural gas is an attractive fuel in view of environment benefits due to its flow carbon-to-hydrogen ratio. However, its compositions and properties are varied depending upon production regional groups. Therefore, study on the combustion characteristics of natural gas engines with a variety of compositions has been demanded for the efficient application of gas engines. This study aims to investigate the effects of gas composition on engine combustion characteristics. It was found that , by controlling an engine with fixed fuel nozzle area, power and heat release were subject to Wobbe Index. And at fixed excess air ratios, power and heat release were subject to low heating value of unit mixture . In addition, in case of constant nozzle area, combustion duration was found to be inversely proportional to CP(Combustion Potential), and the condition of fixed excess air ratios showed no change in combustion duration, regardless of CP.

• KIEAE Journal
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• v.10 no.3
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• pp.17-26
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• 2010

This study aims at exploring the characteristics of the Usonian houses of Frank Lloyd Wright from an ecological viewpoint. After considering the definition and application of ecological architecture through literature review, 28 Usonian houses were selected and analyzed for the study. Also, nine Usonian houses, which clearly have ecological and historical importance, were visited and more thoroughly analyzed. The result shows that Usonian houses are ecological in terms of 1) the relationship among nature, landscape and house, 2) the orientation, natural light and natural ventilation, 3) the use of natural local materials including wood, stones and bricks, 4) the use of floor heating (the On-dol system inKorea), 5) the human scale, 6) the use of the board and batten unit (an early system of prefabrication), and 7) the openness and flexibility of floor plans.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.223-225
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• 2005

This paper will be introduce a new paradigm and prospects for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power units. Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use as like in district heating, electric power generation, seawater desalination or hydrogen generation. This paper presents a new way and prospects for power source in distribution system by using the distributed & remote cogeneration system using small reactor.

• Journal of Plant Biology
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• v.32 no.4
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• pp.275-283
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• 1989

$\beta$-1, 4-endoglucanase (EC 3, 2, 1, 4) was isolated and purified from Nicotiana tabaccum L. Var. Virginia 115 suspensin cultured cells. The molecular weight as estimated by Sephadex G-100 was about 14, 000. The optimum pH for activity was 5.4. The Km value for carboxymethyl cellulose was 0.18 mg/unit and the enzyme was quite resistant to heating. Polyamine did not affect the activity of $\beta$-1, 4-endoglucanase in vitro but the activity increased drastically when polyamines were added in the suspension culture medium. It is suggested that increase in $\beta$-1, 4-endoglucenase activity due to polyamine might be related to growth of the plant.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.187-190
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• 1999

This study is intended to present the properites of planting concrete using the light-weight aggregate and crushed aggregate. According to the result of experiment, the concrete using orchid stone shows a better performance in voids volume, unit weight, absorbtion, thermal conductivity and pH, which are helpful for planting and heat isolation. Therefore, if planting concrete used with orchid stone are utilized to be the planting base on the building's roof, it will be effective to reduced the cost of construction and heating due to the redution of building's self weight and heat isolation effection.