• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1053-1058
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• 2008

Porous medium was considered in the present study for the heat transfer enhancement. This was attributed to its high surface area to volume ratio as well as intensive flow mixing by tortuous flow passages. But when the air or water flow through in the porous medium, it is occurred the pressure drop between inlet and outlet. So in the present study investigated simulation result about the pressure drop in the porous medium before apply to heat exchanger. In this simulation, the thickness of the solid inside the porous medium region was varied 0.2 mm to 0.4 mm. And then the simulation result were compared the pressure drop in the same unit cell ($0.5\;mm{\times}0.5\;mm{\times}0.5\;mm$). To make the analysis model, it was assumed the 14-sided tetrakaidecahedron cell which has long been considered the optimal packing cell first proposed by the Lord Kelvin in 1887. And then the simulation is carried out using by STAR-CCM+ which is commercial software. The simulation result can be showed quantified pressure drop by solid effect in the porous medium.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.618-623
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• 2008

To enhancement heat transfer performance, the metallic foam as heat exchanger was studied rapidly. This was attributed to its high surface area to volume ratio as well as intensive flow mixing by tortuous flow passages. So the experimental study about the heat transfer characteristic of metallic foam is presented in this paper. The material in this experiment was used as FeCrAl which has density of 10 ppi, 20 ppi and 30 ppi respectively. And the results show the heat transfer is rise with permeability Reynolds number increase and the pressure drop metallic foam was increased with the ppi increase.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.319.2-319.2
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• 2007

• Journal of Engineering Education Research
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• v.14 no.5
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• pp.75-82
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• 2011

The Emergence of german mechanical engineer group is related to the development of polytechnical schools which were founded by the german state governments. Following the model of vienna polytechnical schools, the german polytechnical schools aimed also to educate engineers for private industries. For this purpose, the practices and workshop experiences were more emphasized than the theoretical education. With the further industrialization, the demand for higher educated engineers grew, and the level of theories taught in the polytechnical schools approached to that of university. On the base of mathematicalization of technical and mechanical knowledge, the professors of polytechnical schools succeeded in the establishment of Technische Hochschule which ranked as university. The german mechanical engineers could differentiate themselves from the traditional technicians with the establishment of polytech schools and Technische Hochschule.

• Journal of Engineering Education Research
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• v.14 no.5
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• pp.61-66
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• 2011

The role of the Polytechnician as state engineer in the making of modern engineering science in France has been well known. This article articulates the role of the civilian engineers and the two engineering schools producing those civilian engineers in the making of typically French engineering tradition, particularly in mechanical engineering. The mechanical engineers from Ecoles des Arts et M$\acute{e}$tiers and Ecole Central des Arts et Manufactures played a significant roles in the making of modern engineering sciences through their contributions to the making engineering as a theoretical sciences and to the mediation of the technicians and the managers in mechanical engineering.

• 대한공업교육학회지
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• v.38 no.2
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• pp.1-26
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• 2013

This study inquired following research questions by a narrative research method : What was the job of an engineer in mechanical design field? How did he fulfill his job-related learning in his workplace? What were the context and the characteristic of the job-related learning in the workplace? And some implications of the job-related learning on engineering education were discussed. We identified that the research participant's career as a mechanical engineer has developed through three stages. At first, he engaged on conceptual design of a semi-conductor test machine through self-initiated learning from basic to whole system of the machine. At second stage, he leaded a design group for the concrete design of a ball type semi-conductor test machine. In this stage he learned the meaning of cooperation and cooperative learning. At third stage, he initiated to found an entrepreneur company that was specified to design a semi-conductor test machine. He became CEO of the company. He learned the R & D policy making through contacts with global company, visiting exhibition in abroad. Eventually his main task as a mechanical engineer was the problem solving in the process of machine design. He had experienced and learned through his works : project management, independent fulfilling of tasks, functional analysis and reverse engineering, conceptualizing and test, cohesive cooperation, dialogue and discussion, mediation of conflict, human relationship, leadership. The implication of the narrative analysis on engineering education is, proposed, to give the students more chances to experience and to learn such activities.

• Computers and Concrete
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• v.7 no.2
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• pp.191-202
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• 2010

A laboratory investigation was conducted to characterize the constitutive property behavior of Cor-Tuf, an ultra-high-performance composite concrete. Mechanical property tests (hydrostatic compression, unconfined compression (UC), triaxial compression (TXC), unconfined direct pull (DP), uniaxial strain, and uniaxial-strain-load/constant-volumetric-strain tests) were performed on specimens prepared from concrete mixtures with and without steel fibers. From the UC and TXC test results, compression failure surfaces were developed for both sets of specimens. Both failure surfaces exhibited a continuous increase in maximum principal stress difference with increasing confining stress. The DP tests results determined the unconfined tensile strengths of the two mixtures. The tensile strength of each mixture was less than the generally assumed tensile strength for conventional strength concrete, which is 10 percent of the unconfined compressive strength. Both concretes behaved similarly, but Cor-Tuf with steel fibers exhibited slightly greater strength with increased confining pressure, and Cor-Tuf without steel fibers displayed slightly greater compressibility.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.758-763
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• 1994

The work discusses the problems of modelling of the process of acoustic signal generation in machines. We have pointed out that in the task of minimizing of both moise and vibration, the key problem is identification of sources and paths of propagation, both in terms of their location and of definition of their characteristic features. Properly conducted identification makes possible the use of relatively simple mathematical models and this fact is particularly important for a broad application of the proposed methods in practice.

• Journal of Mechanical Science and Technology
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• v.18 no.3
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• pp.471-480
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• 2004

Statistical simulation approaches are proposed to evaluate the shift feeling for a manual transmission. First, shift force simulator for the manual transmission is developed by considering the dynamic models of the external and internal linkage, synchronizer, and drivetrain. It is found that the shift force by the simulator shows a good correlation with the test results. Using the simulator, two kinds of statistical simulation approaches are proposed and the objective parameters that can be used to evaluate the shift feeling quantitatively are obtained. It is expected that the shift force simulator with the statistical approaches, developed in this study can be used as a useful design tool to evaluate the shift feeling in the initial design stage.

• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.125-131
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• 2002

A low speed wind tunnel test was conducted for a canard airplane model in KARI LSWT. The purpose of the presented paper is to investigate the proper testing approach to correct tare precisely and the interference effects for the canard models which has 21% of canard-to-wing area ratio. Most of tests were performed with image system installation for various elevator deflection conditions at the flexed canard incidence angles. To evaluate the effectiveness of the image system, the obtained correction quantity at an zero elevator setting condition with image system was applied to the rest of elevator deflections and compared with the acquired results for all elevator deflections with image system. Test result showed that the amount of correction quantities were strongly dependent on the elevator deflections, and the difference in aerodynamic coefficients for two approaches was gradually amplified as the elevator deflection angles increased. An adoption of the image system was strongly recommended for the higher canard-to -wing area ratio model, if a proper level of accuracy was required.