• Journal of Engineering Education Research
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• v.20 no.5
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• pp.34-42
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• 2017

This study aimed to identify the causal relationships among self-regulated learning strategy, problem solving efficacy, task value and learning outcome, and mediation effect of self-regulated learning strategy in engineering capstone design course. The data were collected from 363 university students who enrolled in capstone design courses and analyzed using structural equation modeling method. The results were: first, problem-solving efficacy and task value exerted significant effects on self-regulated learning strategy. Second, self-regulated learning strategy exerted significant effects on learning outcome, but problem-solving efficacy and task value did not. Third, problem-solving efficacy and task value showed significant indirect effects on learning outcome, which confirmed that self-regulated learning strategy fully mediated between two exogenous variables and learning outcome.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.831-836
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• 2004

Vibration of electric-powered hand grinder comes from the parts of motor, gear, bearing, and fan. Excessive vibration can be harmful to workers. To reduce vibration of a hand grinder we analyzed the frequency components from the routing electric-powered grinder and did modal test to find the natural frequencies of the each part. It shows that the vibration is due to the resonance of the case. To remove the resonance, the case structure is modified and the bearing cap is replaced on a basis of the results from the rotor dynamic analysis using SAMCEF. As a result the vibration of the hand grinder is reduced greatly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.346-350
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• 2000

In scroll compressors, there are two major noise sources. Sturctural path: excitation of the compressor housing by unbalance forces and forces generated by compression cycle. Gas cavity path: excitation of top cap by discharge gas pulsation. In this study, in order to analyze the radiated noise generated by the discharge gas pulsation, FEM/BEM model of the top cap is established. Measured pressure of discharge pulsation is introduced in the FEM model as the excitation and vibration response is calculated. Radiated sound pressure is then obtained by BEM method based on this vibration response. Results are compared with the measured data. It is shown that the trend of the noise radiation can be predicted in this approadch.

• Journal of the Korean Society of Visualization
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• v.14 no.2
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• pp.25-30
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• 2016

The wafer temperature and its uniformity inside the LPCVD chamber were analyzed. The temperature uniformity at the end of the wafer load depends on the heat-insulating cap. The finite difference method was used to investigate the radiation and conduction heat transfer mechanisms, and the temperature field and heat diffusion in the LPCVD chamber was visualized. It was found that the temperature uniformity of the wafers could be controlled by the size and distance of the heat-insulating cap.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.12
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• pp.109-119
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• 1995

A driveline incorporating universal joints when driving through an angle can excite various components in a vehicle with second order excitation of torsional and bending vibrations, being transmitted either audibly(noise), or physically(vibration). For a certain range of vehicle dpeed noises can be radiated from the cab wall, in which resonances occur by the excitations transmitted from the driveline as a vibration source. In this paper, the excitation mechanism of cab noises is studied especially for the vehicle speed range of 65 .approx. 75 km/h through the simulation for torsional vibrations of the driveline and for bending vibrations of the cab of an 11 Ton grade Cargo Truck, and verified additionally by vibration and noise measurements. As a result, it is found that the uncomfortable noises in the cab are caused mainly by the abrupt increase of the joint angle of driveline near the axle differential resulted from the excessive clearance alignment of the leaf spring gate.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.363-370
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• 2001

A computationally efficient algorithm to analyze a group pile behavior is proposed by consideration of both soil-pile and pile-cap interactions. Using toad transfer method the nonlinear characteristics of the soil-pile interaction for a single pile is modeled by piecewise linear soil springs (p-y, t-z, and q-z curves). Beam-column method, one of the most practical approaches, is used for numerical modeling of the soil-pile system. In addition to the group effect resulting from the soil-pile-soil interaction, for a more realistic analysis it is essential to consider the effect of pile-cap interaction including geometric configuration of the piles in a group and conectivity conditions between piles and the cap. This paper mainly focuses on the pile-cap interaction and the development of a rational numerical procedure of its incorporation with the beam-column method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.67-72
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• 2004

Generally, the commercial truck has the hydraulic cab tilting system which absorb the vibrations and impacts of the cab. The cab tilting system is equipped for the maintenance and inspection of truck. And it is very important to help user's feeling of driving and convenience. But when the truck cab is tilted, existing model has serious problem of vibration. To satisfy customer's requirements for convenience, it is necessary to improve the hydraulic truck cab tilting system. In this study, the optimization of cab tilting system is carried out by using the G.A to reduce the vibration. The results show that the vibration is reduced and the mean velocity of tilting is improved. In conclusion the improved cab tilting system can be designed and the possibility of optimal design for cab tilting system by using the GA is testified.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06b
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• pp.265-270
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• 2010

소셜 미디어(Social Media)란 사람들이 의견, 생각, 경험, 관점 등을 서로 공유하기 위해 사용하는 온라인 툴과 플랫폼을 뜻한다. 여행에서 가장 중요한 정보는 위치와 경로 정보이다. 하지만 우리가 다른 사람들의 여행정보를 검색하여 보면 위치와 경로 정보를 보여주는 방법으로는 지도를 캡처하여 그 위에 직접 경로를 그린 뒤 그림파일로 저장하여 올려서 사진처럼 보여주는 경우가 대부분이며 지도를 제공하는 여행 블로그 사이트에서는 출발 정보와 목적지 정보를 입력하면 지도 위에 목적지와 그 사이를 선으로 연결하여 같이 보여주는 정도의 서비스를 제공한다. 또한 지도 위의 정보와 실질적인 여행 정보, 즉 사진이나 여행자의 메모나 생각 같은 글이 연결되어 보여주지 못한다. 이에 본 연구에서는 사용자가 자신의 여행기를 정리하고 표현하는데 있어서 지도 위에서 자유롭게 사용자의 의도대로 표현할 수 있는 인터페이스를 생성하는 것을 목표로 한다.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.652-657
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• 2001

Densification behavior of aluminum alloy(A16061) powder was investigated under cold compaction. Experimental data were obtained under triaxial compression with various loading conditions. A special form of the Cap model was proposed from experimental data of A16061 powder under triaxial compression. The proposed yield function and several yield functions in the literature were implemented into a finite element program (ABAQUS) to compare with experimental data for densification behavior of A16061 powder under cold isostatic pressing and die compaction. The agreement between finite element calculations from the proposed yield function and experimental data is very good under cold isostatic pressing and die compaction.

• The KSFM Journal of Fluid Machinery
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• v.19 no.2
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• pp.11-15
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• 2016

In this study, the generation of the propeller hub vortex was analyzed and a PBCF(Propeller Boss Cap Fins) was designed to control the propeller hub vortex. A RANS(Reynolds-averaged Navier-stokes) approach is employed to predict the hub vortex characteristics. The hub profile is an important factor but only a small increase (1.9%) of efficiency was obtained with the hub profile modification. The propeller hub vortex was eliminated by installing the PBCF and as a result, the propeller efficiency was increased by 5.6%.