• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.103-112
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• 2009

A internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobe with elliptical and involute shapes, while the inner rotor profile is determined as conjugate to the other. And the integrated system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.777-791
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• 1994

For developing the Group Health Care System, health managers' job structure were analysed in the aspects of content, amount, and process. As a trial research, data were collected by a standardized job analysis table to 6 doctors, 40 nurses, and 11 industrial hygienists of Group Health Care System. Health care managers were performing complex and intellectual jobs such as healh education for workers, managing health care, conference as well as more simple jobs like as filling diary. Especially, job was consisted of general job and health care management job in the proportion of 1:2.18. The major general job were data management related with the health statistics, and major health care management jobs were managing health care, health counselling, environmental management of working sites. Each specific jobs were required differentiated intellectual capacity, creativity, autonomy, psychic stress, and physical work; most respondents perceived that health care management jobs should require more inputs than general jobs. Additionally job satisfaction and perceived need on specific Job items were anzlysed. Results of this research, suggested through the field experiences in working sites, should be considered for improving the Group Health Care System.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.36-40
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• 1998

This study was carried out to investigate the collection Efficiency of mass in collector step at the different of physical gas characterization. This work has focused on the dependence of the collection efficiency of mass in the collector zone of a two-stage set up field with gas temperature T and the dew point tmeperature. To identify the dependence of the mass collection efficiency on the Bounded plate of the collector zone MP.k by the spectre electric resistance of dust $p_e$. and the relative humidify ${\varphi}$, 20 at- tempts have been made with three different gas temperature ($50{\circ}C, 80{\circ}C, 110{\circ}C$) at different dew point. At the specific electric resistance of dust $p_e$=$10^6{\Omega}m$ which relative humidity corresponds to $\phi$ > 15%, a easy rise of the sounded plate secluded dust mass share was measured atwain. As the result of the higher cohesion imprisonment power due to the adsorbtion of particle, the rinse of the relative humidity developed on the particle surface. Therefore, the collection efficiency of mass was not predominant the high temperature T in the collector zone, neither was the pecific ellectric resistance of dust dependent.

• Korean Institute of Interior Design Journal
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• v.15 no.5 s.58
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• pp.28-35
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• 2006

During the modern age, various fields have fundamentally changed from the preconceived ideas of the past. The concept of time-space relationship changed also. E. J. Marey was almost the first one to visualize the movement of animals and people through scientific methods. Frank B. Gilbreth used more precise photographic equipments to develop more accurate and specific body movement diagrams. The emergence of visualization of body movement is not the only product from the scientific field. The new concept of time-space can be easily noticed in modem art, music and dance. In space design, Futurism attempted to represent the dynamism and speed in a sculptural form. On the other hand, there were examples to further investigate the specific analysis of body movements such as 'Scientific Management'. Body movement diagrams are widely used in various projects in contemporary space design. The difference is that now the design process is more integrated with the analysis. The representation of speed and the container of movements are interwoven in a complex manner in which fluid relationship between body and space is possible. Three types can now be considered: Object, Container and Interactivity. This study attempts to analyze brief history of body movement studies and their application for contemporary space design.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.15-21
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• 2009

The fiber reinforced composite material is widely used in the multi-industrial field where the weight reduction of the infrastructure is demanded because of their high specific modulus and specific strength. Pressure vessels using this composite material have two main merits which are to cut down energy by reducing weight and to have long-term life due to corrosion resistance. In this paper, we developed optimal design module of laminate for CNG composite pressure vessel winding E-glass/epoxy based on Von-Mises yield criterion, Tsai-Hill theory and stress ratio using finite element method and ANSYS RSM(Response Surface Method).

• Journal of Powder Materials
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• v.22 no.2
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• pp.116-121
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• 2015

$WS_2$-W-WC embedded carbon nanofiber composites were fabricated by using electrospinning method for use in high-performance supercapacitors. In order to obtain optimum electrochemical properties for supercapacitors, $WS_2$ nanoparticles were used as precursors and the amounts of $WS_2$ precursors were controlled to 4 wt% (sample A) and 8 wt% (sample B). The morphological, structural, and chemical properties of all samples were investigated by means of field emission photoelectron spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. These results demonstrated that the embedded phases of samples A and B were changed from $WS_2$ to $WS_2$-W-WC through carbothermal reaction during carbonization process. In particular, sample B presented high specific capacitance (~119.7 F/g at 5 mV/s), good high-rate capacitance (~60.5%), and superb cycleability. The enhanced electrochemical properties of sample B were explained by the synergistic effect of the using 1-D structure supports, increase of specific surface area, and improved conductivity from formation of W and WC phases.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.140-147
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• 2012

Purpose: This study was conducted to understand the work performance of crank-type rotavators and compare them with those of rotary-type rotavators in Korean farmland conditions. Methods: Tillage operations were carried out using both rotavators with the same nominal rotavating width and rated power. During the operations, PTO speed and torque, actual work speed, and rotavating width and depth were measured. To evaluate work performance, pulverizing ratio, inversion ratio, and specific volumetric tilled soil were calculated and compared for each rotavator. Results: It is found that the crank-type rotavator has better specific volumetric tilled soil performance and deep tillage, while the pulverizing ratio is worse. Conclusions: Crank-type and rotary type rotavator have diffenent properties each other in several work performances. It's important, therefore, to choose a suitable type of rotavator that satisfy the farmer's requirements in accordance with the condition of field and the purpose of tillage operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1715-1720
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• 2011

Studies suggested an increase in the competitiveness and roles of mainline railways like speed and accessibility improvement, as a fundamental direction of the National Transport Network Plan. At this point, topics presented especially for strengthening the role of human and environment centered transportation: as to the greatly improved speed competitiveness, there are an operational speed above 180km/h ~ 200km/h and traveling within 2 ~ 3 hours among big cities. As to accessibility improvement, there are accessibility to main railway stations within 30 minutes, and the improvement of accessibility, safety, eco-friendliness, amenity etc. As a part of these suggestions, field specific plans were proposed for the establishment of expressed mainline railway network in Korea such as train's, civil structures, trolley lines etc. In this paper we analyzed the conventional lines and systems to figure out whether to change details in terms of H/W of signaling system. Additionally, we reviewed the compatibility or difference of signalling system depending on train's speed. With this result, we deduced the number of virtual blocks specific to the speed of 180km/h, 200km/h and 230km/h, which were showed for the speed improvement considering each variable like blocks, braking distance etc. In this way, we suggested the railway signal system establishment plan considering safety operation.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.472-479
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• 2013

The conductive polymer composites recently became increasingly to many fields of industry due to their electrical properties. To understand these properties of composites, electrical properties were measured and were studied relatively. Electrical conductivity measurements showed percolation phenomena. Percolation theories are frequently applied to describe the insulator-to-conductor transitions in composites made of a conductive filler and an insulating matrix. It has been showed both experimentally and theoretically that the percolation threshold strongly depends on the aspect ratio of filler particles. The critical concentration of percolation formed is defined as the percolation threshold. This paper was to study epoxy resin filled with copper. The experiment was made with vehicle such as epoxy resin replenished with copper powder and the study about their practical use was performed in order to apply to electric and electronic industry as well as general field. The volume specific resistance of epoxy resin composites was 3.065~13.325 in using copper powder. The weight loss of conductive composites happened from $350^{\circ}C{\sim}470^{\circ}C$.

• Journal of Information Technology Services
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• v.5 no.2
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• pp.155-168
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• 2006

Software product line is a software product or a set of software system, which has common functions. We can develop a specific software product, which satisfies requirements of a particular market segment and a mission in a specific domain by reusing the core asset such as the developed software architecture through the software product line. Software development methodology based on the software product line can develop a software more easily and fast by reusing the developed software core asset. Developed countries of software technology select software product line as a core field of software production technology, and support technology development. In case of USA, CMU/SEI(Carnegie Mellon University/Software Engineering Institute) developed product-line framework 4.0 together with the industry and the Department of Defense. Europe is supporting the development of product line technology through ITEA(IT for European Advancement) program. However, industries in our country understand the necessity of software production technology based on product line concept for the purpose of increasing productivity, it is not sufficient to invest for this technology development. In this paper, we aim to construct the common architecture of software product line for production of the software product line.