• Geomechanics and Engineering
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• v.15 no.3
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• pp.811-822
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• 2018

Chip size distribution can be used to evaluate the cutting efficiency and to characterize the cutting behavior of rock during cutting and fragmentation process. In this study, a series of linear cutting tests was performed to investigate the effect of cutting conditions (specifically cut spacing and penetration depth) on the production and size distribution of rock chips. Linyi sandstone from China was used in the linear cutting tests. After each run of linear cutting machine test, the rock chips were collected and their size distribution was analyzed using a sieving test and image processing. Image processing can rapidly and cost-effectively provide useful information of size distribution. Rosin-Rammer distribution pamameters, the coarseness index and the coefficients of uniformity and curvature were determined by image processing for different cutting conditions. The size of the rock chips was greatest at the optimum cut spacing, and the size distribution parameters were highly correlated with cutter forces and specific energy.

• Advances in Computational Design
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• v.5 no.3
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• pp.261-276
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• 2020

The reasonable layout of vacuum cleaner can effectively improve the collection efficiency of iron filings generated in the process of steel production. Therefore, in this study, the CFD-DEM coupling model and two-fluid model are used to calculate the iron filings collection efficiency of vacuum cleaner with different inclination/cross-sectional area, pressure drop and inlet angle. The results are as follows: The CFD-DEM coupling method can truly reflect the motion mode of iron filings in pneumatic conveying. Considering the instability and the decline of the growth rate of iron filings collection efficiency caused by high pressure drop, the layout of 75° inclination is suggested, and the optimal pressure drop is 100Pa. The optimal simulation results based on two-fluid model show that when the inlet angle and pressure drop are in the range of 45°~65° and 70Pa~100Pa, larger mass flow rate of iron filings can be obtained. It is hoped that the simulation results can offer some suggestion to the layout of vacuum cleaner in the rolling mill.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.263-268
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• 1999

The most important things to the tube the of the heat exchanger are the precision of t hole position and the quality of the drill face. Nowadays, 6 and 12 spindle multi-drilling machine controlled by CNC or used to drill holes of the tube sheet. The drilling of 12 axes can offer high speover three times as fast as the drilling of axis. However, the drilling of 12 axes h difficulty in controlling many motors to d spindles and assigning a corresponded numbe accurately to each axis. In the past, conventional method to inspect the code the drilling was machining holes on a thin plate previously which resulted in the productivity because it required a h production cost by machining and weldin time. In this thesis, there are two drilling codes different from CNC code. M code is used to control many motors and S code is used to assign a correspondent number for each axis. For increasing the productivity by removing process, this paper is intended to take simulation of the drill machining c including 6 and 12 axis on the persona computer.

• Journal of the Korean Society of Visualization
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• v.4 no.2
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• pp.81-87
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• 2006

In this paper, we present flow patterns around and performance of an air-flow separator by using the numerical analysis. With this separator, particles of different density are to be separated by using the drag force from the air flow. The low-density particles are designed to be separated by using inhalation through holes on a rotating drum. To obtain the flow informations needed for determining the proper design parameters, we have performed numerical simulations by using a commercial code, ANSYS CFX. Various parameter set was tested and it was found that depending on the design of drums there exist critical parameter set regarding the attachment of light particles on the drum, which is prerequisite for the separation of materials. We present here the possibility of using the present design in separation of particles mixed in the clod for use in recycling.

• Journal of Powder Materials
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• v.1 no.2
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• pp.208-216
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• 1994

A radically new approach to the in situ synthesis of the consituent phases of a composite structure has enabled the production of a new WC/Co materials with an ultrafine microstructure. The process for synthesizing nanophase WC/Co powders consists of spray drying from solution to form a homogeneous precursor powder, and thermochemical conversion of the precursor powder to the nanophase WC/Co powder. Near theoretical density of pure nanophase WC-10 wt%Co has been obtained in only 30 sec at 140$0^{\circ}C$. But WC particles were grown up very rapidly with longer sintering time to get full density. To overcome coarsening of WC particle during sintering, VC, TaC and VC/TaC were used as the grain growth inhibitor with different amount respectively. VC/TaC doped WC-10 wt%Co was shown superior hardness and TRS and microstructure was maintained ultrafine scale (average WC size is less than 0.1 ${\mu}{\textrm}{m}$).

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.405-416
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• 2014

The importance of Human Resource Management is big issue in business management recently. However, employ's job satisfaction is appeared as low. In this study, surveys were conducted among those long-term employs. The importance of job satisfaction is prioritized by AHP analysis based on results of survey to compare to the results of previously studied research. And this study will contribute to improvement of job satisfaction by comparing the facts in two different groups of occupation.

• The Research Journal of the Costume Culture
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• v.13 no.2 s.55
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• pp.189-199
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• 2005

The purposes of this study are to see a manufacturing process on knit by comparison, and to present whole garment knitting machine different from the traditional method of the production by using the whole garment system. The characteristics of each stage were examined through SDS-one, Shimaseiki Design CAD System and the whole garment knitting machine. The whole garment knitting machine as a method of composing a suit of knitting product is a way of making creative knitting fashion, which also can be used as a basic material for the further study on the whole garment knitting machine. Eventually, it is expected that this machine can satisfy the knit wearers' various needs by showing more useful method to knit designers.

• Journal of The Korean Digital Architecture Interior Association
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• v.7 no.2
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• pp.33-41
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• 2007

This thesis aims at understanding Le Corbusier's architecture through study of proportion. Based on the analysis of these texts, four elements - geometry in the outline, diagonal regulation lines in the facade, arithmetic rhythm in the structure, composition in the inner space - were listed. Through these four proportional systems. ten houses of 1920's, designed by Le Corbusier were analysed. The Le Corbusier's proportional system can be classified by two different purposes ; aesthetics and utility standardization for the mass production was reflected. In the later period, the proportion system of 1920's has changed through the process of self-contradiction. But the concept of the golden section and the human scale was reflected on Modulor, which Le Corbusier created in 1940's. Therefore, Le Corbuiser's notion of proportion for harmony of architecture has consistent meaning throughout all of his works from the 1920's.

• Korean Institute of Interior Design Journal
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• no.27
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• pp.12-19
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• 2001

The purpose of this study is to develope instructional strategies and assessment model for distance learning in interior design education in Korea. Literature from various sources were examined to provide guidelines for instructional and technical strategies, communication system, and administrative process. Strategies and assessment model for transition to distance learning from goal setting to program evaluation were introduced. The results of this study indicated that distance learning in interior design education is optimized when applied in studio critique, portfolio production, and professional practice and with other traditional programs depending on the characteristics of the instructional materials. It is suggested for further studies that various distance learning programs based on instructional theories to be conducted and evaluated in different areas of interior design education for their maximum application as instructional tool.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1150-1152
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• 1998

Recently, our electric industry confronts a structural change and high competiveness environment in the course of deregulation. Rapid growth in electricity demand, financial need for new power plant construction, and envionmental problems have led to search for more efficient energy production and energy conservation techmologies. Especially, residential and commercial buildings consumes 40% of electricity demands and building energies are increasing more and more in Korea. The purpose of this paper is to analyze the electricity use of commercial buildings by end-use. Also, we will use it as a basic informations of DSM potential evaluation and evaluation process based on different approach by sector and type of potential.