• 한국유체기계학회 논문집
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• 제15권2호
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• pp.5-11
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• 2012

In this paper, the heat transfer coefficient measurement techniques using TSP(temperature sensitive paint) were introduced and the results of a comparative study on the heat transfer coefficient measurement by steady state and transient TSP techniques were discussed. The distributions of heat transfer coefficient by a single $60^{\circ}$ inclined impingement jet on a flat surface were measured by both techniques. Tested Reynolds number based on the jet diameter (d) was 30,000 and the distance between jet exit and target plate (L) was fixed at 10d. Results showed that the measured Nusselt number by both techniques indicated significant difference except near the center of impingement jet. Also, the heat transfer coefficients measured by the transient TSP technique were affected by the reference temperature of the jet. Based on the measured data, characteristics of both TSP techniques were analyzed and suggestions for applying them were also given.

• 한국레이저가공학회지
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• 제16권3호
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• pp.11-21
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• 2013

As parts are becoming more complex and smaller with the development of new materials, high-quality laser precision processing is getting the limelight. Laser enables quick processing and less deformation of materials. It also enables welding with diverse materials. In this study, the pole rod and tap for the secondary battery were laser-welded using cross and coaxial nozzles. The results of the comparative analysis of cross and coaxial nozzles according to the processing parameters showed that the coaxial nozzle had more sensitive welding characteristic to the nozzle position or pressure than the cross nozzle. This indicated that the processing parameters should be carefully determined for the welding with the coaxial nozzle. The pole rod and tap were welded together in a form of T joint to improve the output of the secondary battery, and the cross nozzle had a better welding characteristic than the coaxial nozzle.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.634-637
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• 2005

A subjective index of sound quality when it hit him is required since human listening is very sensitive and complex. Sound quality evaluation it leads consequently rightly in each situation and it composes a sound quality factor. But one of the levels in interest frequency range is substitute we cannot see the tendency of frequency substitute at whole that is executes a clear voice evaluation. Design of experiment is used and dividing 12 equally in frequency domain, the sound quality using sharpness and annoyance is performed by modifying each of frequency domains. Design of experiment method reduces much number experiment very effectively and each main effect of domain solution analysis, such as a case of sharpness and annoyance, the change of domain (increase and decrease of sound pressure level, or change nil) can grasp a type of effect should have influenced to a sound quality, and it will be able to select the objective frequency domain which hits to the sound quality. Through these obtained results the physical changes of level at arbitrary frequency domain sensitivity can be adapted.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.303-310
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• 2007

The vehicle noise is classified into interior and radiated exterior noise. And it influences on consumer‘s vehicle decision and traffic noise environment very much. In case of the vehicle exterior noise, it is related with traffic noise and in case of the interior noise, it is related with driver’s and passenger‘s sensitivity quality. Because these influenced on drivers and traffic environment, so standards are restricted by the laws and regulated for the measurement. But, the existence standards measuring the only sound pressure level are limit to reflect consumer’s sensitive aspects. Therefore in this study, the recent standards and laws were searched about domestic and abroad papers and the testing mode for the sound quality (SQ) evaluation was constructed about the vehicle interior noise. Finally, we aimed at the standard establishment to evaluate the vehicle interior SQ using statistics method.

• 한국소음진동공학회논문집
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• 제23권4호
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• pp.332-337
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• 2013

This paper presents a subsequent research work on the roller design of IRB(isolation roller bearing) seismic isolation device presented in Part 1 by focusing on heat treatment. The hardness and friction factor are very important factors of material and after-treatment process selection. Normally, roller bearing consists of roller and retainer. The roller gets high pressure constantly, while the retainer gets tensile and compressive stress. Therefore, sensitive material selection and heat treatment of each part is quite important. In this experimental evaluation, carbon steel, chrome special steel and others are employed and their characteristics after heat treatment are identified. Each material is prepared by refining high frequency heat treatment. The friction factor and static load capacity of manufactured material are experimentally identified and destructive test of material is processed. Optimal material and heat treatment conditions for IRB roller bearing are determined based on experiment results.

• 펄프종이기술
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• 제37권3호
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• pp.1-8
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• 2005

Increase in the utilization rate of recycled paper and closing level of papermaking system increased the problem associated with stickies that include decrease in process runnability and product quality. It is required to establish a process for removing the micro stickies to solve the problems associated with stickies. In this study, the application of flotation process as a method to remove micro stickies was examined. Model micro stickies (MMS) were prepared using microcrystalline cellulose (MCC) and pressure sensitive adhesives (PSA), and the influence of three nonionic surfactants on the removal efficiency of MMS from flotation process was examined. Also the effect of surfactants on the deposition of micro stickies that remaining in the papermaking wet end onto wire was examined. Removal efficiency of MMS by flotation was increased when the proportion of nonionic surfactant with propylene oxide (PO) type hydrophilic tail was increased and stock pH was 7. It was suggested that this nonionic surfactant minimized the increase of surface energy of hydrophobic MMS. The MMS with high hydrophobicity remaining in the papermaking system, however, would cause more serious deposition problems on papermaking wet end. Therefore, it is of great importance to increase the removal efficiency of MMS in flotation process for the prevention of papermaking system contamination caused by stickies deposition.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.241-252
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• 2010

This study investigates the application of dilatometer test for evaluating the deformation characteristics of granular soil. $K_D$ is the most sensitive to the stress history among CPT and DMT measurements, and $E_D$ and $q_c$ are observed to be similarly affected by the stress history. The coefficient of at-rest earth pressure($K_0$) is an indirect measure evaluating the stress history of granular soil. A relation using only DMT indices provides appropriate prediction of $K_0$ values. Although penetration of dilatometer inevitably induces the failure of cementation bonds, $E_D$ reflects the deformation characteristics of undamaged cementation relatively well. Therefore, a slightly better prediction of M value for cemented sand is achieved by using $E_D$ rather than $q_c$. Because of the weaker particle strength of calcareous sand compared than quartz sand, the majority of sand particles adjacent to dilatometer probe will be crushed during penetration. The particle crushing will induce the less contraction of the dilatometer membrane during penetration, consequently, the smaller $K_D$ and $E_D$ of calcareous sand.

• Transactions on Electrical and Electronic Materials
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• 제14권1호
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• pp.20-23
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• 2013

When applying superconducting wire to power machines, an investigation needs to be carried out on the characteristics of wire phase changes in connection with the insulating layer. This study examined trends in the increase of the wire's resistance and the characteristics of its recovery from quenching by a current-applied cycle at temperatures of 90 K, 180 K, and 250 K. The procedure was conducted based on the thickness and presence (or absence) of the insulating wire layers. To achieve this, YBCO thin-film wires with the same critical temperatures were prepared with copper and stainless steel stabilizing layers. At levels (-one, three, and five-), with superior performance, polyimide pressure-sensitive adhesive tape was attached to the wires at a very low temperature. The eight prepared test samples were wound around the linear frames. The wire's voltage and current created from the phase change characteristics were measured at the wire's prescribed temperature, using the four-point probe method. The wire's resistance and recovery characteristics were examined for each cycle at temperatures of 90 K, 180 K, and 250 K.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.551-564
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• 2016

High-speed flight vehicles (HSFVs) such as space launch vehicles and missiles undergo severe dynamic loads which are generated during the launch and in in-flight environments. A typical vehicle is composed of thin plate skin structures with high-performance electronic units sensitive to such vibratory loads. Such lightweight structures are then exposed to external dynamic loads which consist of random vibration, shock, and acoustic loads created under the operating environment. Three types of dynamic loads (acoustic loads, rocket motor self-induced excitation loads and aerodynamic fluctuating pressure loads) are considered as major components in this study. The estimation results are compared to the design specification (MIL-STD-810) to check the appropriateness. The objective of this paper is to study an estimation methodology which helps to establish design specification for the dynamic loads acting on both vehicle and electronic units at arbitrary locations inside the vehicle.

• Journal of Chest Surgery
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• 제29권4호
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• pp.449-453
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• 1996

20개월 전에 신장이식을 시행한 환자에 있어서 해리성 흥복부 대동맥류를 성공적으로 절제하였다. 이 식된 신장은 정상 신장에 비하여 허혈에 보다 민감하므로 동맥혈 차단후 이식된 신장의 관류를 위하 여 대퇴 동-정맥으로 심페기를 연결하였다. 138분간의 대동맥 교차 차단중에 신장으로의 관류는 관류압이 (19-)1) 27 minHg이고 관류량은 0.53에서 0.83 Limin 였고, 32mm 크기의 헤마쉴드(길이 22cm)가 동맥류 부위 에 대용되 었다. 수술후 특별한 합병증은 없었으며 심폐기를 이용한 대퇴동-정맥 우회술은 이와같은 수술시 척수와 신 장을 보호하는 간단하고 효율적 인 방법으로 사료된다.