• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.405-410
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• 2021

In this study, a finite element analysis was performed applying a nonlinear material model and fatigue load conditions to evaluate the service life and spring stiffness of the resilient pad for rail fastening system. As a result of the fatigue analysis, the rate of change in spring stiffness compared to the initial condition was about 16%, indicating that fatigue hardening occurred. As for the stress generated in the longitudinal direction of the resilient pad, the difference between the stress generated at the center and the edge was about 10 times or more. In addition, it was analyzed that the equivalent stress of the outer boundary was more than twice as large as that of the central part. Therefore, it was analyzed that the damage and deformation of the resilient pad are the corners of the resilient pad under actual service conditions. The fatigue life diagram of the resilient pad (S-N curve) was derived using the equivalent stress of the resilient pad according to the fatigue cycles. Using the fatigue life diagram of the resilient pad derived in this study, it is considered that it can be used to predict the fatigue life under the relevant conditions by calculating the equivalent stress of the resilient pad under various load conditions.

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.27-41
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• 2010

This study developed a settlement environment diagnostic indices (SEDI) of rural villages which can apply to analyze variable conditions of villages having development projects. The index consists of 5 diagnostic areas (first level) with 13 items (second level), including detail indices of 40 criteria (third level) defined by specialists' brainstorming process. In order to develop the index system, object-oriented approach was used to extract the 5 diagnostic areas (infra-basic settlement facility, life condition & environmental resources, industry & economic infrastructure, community, and residents) from rural villages. For the 40 criteria, it was introduced a quantification method that all villages have absolute values in national level, not relative value between villages within an unit area. The diagnostic diagram and table were developed to evaluate the villages compositively. The developed SEDI was applied to study areas, 56 villages in 2 subdivision areas of county, located on county of Keumsan. Applicability of the index system, database system should be developed with the surveying method of data in village level.

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.117-129
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• 2010

The purpose of this paper is to develop a web-based information system for rural settlement environment diagnosis which is useful to apply the village based evaluation for new rural development projects. To achieve this purpose, this study performed : 1) analyzing the business process in the field of rural settlement environment diagnosis, 2) designing the data flow diagram and the database based on settlement environment diagnostic indices(SEDI), and 3) developing the system using APM (Apache, PHP, and MySQL) of web-system development environment. The developed system was applied to the study rural villages for testing of efficient and logical working. Users of the system, such as, researchers, decision makers, and rural residents, can input directly the village data to diagnose through a file format of Excel in MS Office. Futhermore, they can analyze the visual results with graphic and graph types, simultaneously. From the results of this study, it showed that the developed system enables decision-makers not only to assist the planning process of the rural village development project, but also to improve the level of information technology in the research and planning field concerning with rural development.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.57-62
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• 2008

The aim of this investigation was to extract the fatigue properties at the designated fatigue life of copper foil and observe the mean stress and stress amplitude effects on both the fatigue life and the corresponding surface morphology. Tensile tests were performed to determine the baseline monotonic material properties of the proportional limit and ultimate tensile strength. Constant amplitude fatigue tests were carried out using a feedback-controlled fatigue testing machine. The mean stress and the stress amplitude were changed to obtain the complete nominal stress-life curves. An atomic force microscope was utilized to observe the relationship between the fatigue damage and the corresponding changes in surface morphology. A Basquin's exponent of-0.071 was obtained through the fatigue tests. An endurance limit of 122 MPa was inferred from a Haigh diagram. The specimen surface became rougher as the number of fatigue cycles increased, and there was a close relationship between the fatigue damage and the surface roughness evolution.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.75-80
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• 2015

The rebar factory production process involves the repetitive bending of rebars. Therefore, the fatigue failure of the rebar bending machine needs to be considered. In this paper, fatigue analysis of the rebar machine was performed using the commercial software DAFUL, which is based on MFBD (Multi Flexible Body Dynamics). The rotating roller, fixing roller and rebar were modeled by the finite element method. The rebar bending process is simulated and the mechanical stresses on the rollers are calculated. Structural analysis of the rebar bending roller was performed using the maximum bending angle of $180^{\circ}$ and maximum processing rebar diameter of ${\Phi}19mm$. Then, for fatigue analysis, the S-N curve of STD-11 was. The fatigue life of rollers is estimated by modified Goodman diagram. The fatigue life range of the rotating roller is $2.99961{\times}10^5{\sim}1{\times}10^8$ while that of the fixed roller is $2.53142{\times}10^5{\sim}1{\times}10^8$. STD-11 has an infinite life cycle after $1{\times}10^8$. Therefore, the rollers of the rebar bending machine may be expected to suffer fatigue failure. Thus, we performed a parameter study of fatigue life according to various axial radii of the fixed roller and rotating roller, and redesign of the rebar bending machine. Consequently, the axial radius of the fixed roller and rotating roller was found to be 35~37.5mm and 30~35mm, respectively, and an infinite life cycle was confirmed at these.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.123-130
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• 2006

Recently, Korean government promotes BTL(Build-Transfer-Lease) for their public construction project to apply private sector's experience and finance initiatives. Many of public buildings and civil infrastructure projects were planned to be delivered by BTL and it helps to continue public projects under tight budget conditions. Since the characteristics of BTL projects, creative ideas for the project function, performance and its LCC (Life Cycle Cost) become more important than usual public work project. This paper introduces the systematic "VE job Plan" application techniques for BTL project and shows the process. This study shows the application of "VE job Plan" for BTL project to help decision making and value improvement. Also, Project cost was estimated by LCC (Life Cycle Cost) analysis. Technical "FAST diagram"was developed and used to find major functions of the project. So, it helps to improve performance of functions and make creative ideas. FAST diagram also help to find relationships between functions and cost. A case study (Daegu Art Gallery BTL Project) was conducted using proposed "VE job Plan. Study demonstrates how value management helps save money and increase functional performance. Researcher found that project can save cost and improve performance of functions significantly by using appropriate VE analysis process at appropriate time.

• The Journal of Korean Medical History
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• v.31 no.1
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• pp.23-42
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• 2018

This study examines the variation in diagrams of the kidney, and the effects on location of the Life Gate as a result. My study analyzes diagrams of kidney form and location, such as appearance, the vertebral spine, ShenXi, and "Life Gate", and also explores the causes for such variations. The kidney is commonly described as having the shape of a bean, which throughout medical history has showed almost no variation. The spine was initially described with a total of 21 vertebrae, and later with a range of 19-25 vertebrae. Regarding the height of kidney in relationship to the spine, it was initially described as beginning at the 14th vertebrae, and later changed to the 15th or 17th vertebrae. However, there have been no changes in the perception of the height of kidney. Initially, the location of the Life Gate could not be identified. Three different suggestions of its location were found throughout historical literature, including: (1) at or within the right kidney; (2) between two kidneys; and (3) between 14th-15th spine. There were also variations noted in the process of copying diagrams of kidney in many books not only because the work of copying was not precise, but also because each medical practitioner had a different interpretation of the kidney's form and function in Traditional Korean and Chinese Medicine. It appears that some practitioners may have been influenced by their understandings of theory of Life Gate.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.26-32
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• 2010

SM45C steel rods using generally for machine components were selected and welded by butt-GMA welding method for this study. And then they were studied about characteristics of fatigue behavior and fracture surfaces by rotary bending test. Fatigue strength in weld zone present highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. The region of infinite life by Haigh diagram present highly in order of the boundary between deposited metal zone and heat affected zone, deposited metal zone, heat affected zone. Fatigue cracks in unnotched specimens of base metal and weld zone introduce simultaneously from extensive out-side of circumferential cross-section and propagate to the other side indicating beach markings and dimples according to consolidation of fatigue cracks. Fatigue cracks in all of notched specimens introduce simultaneously in out-side of circumferential cross-section by high stresses and propagate to center of it indicating beach markings.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1660-1664
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• 2008

Extra-corporeal Life Support System (ECLS) is the device used in emergency cases to substitute a extracorporeal circulation in open heart surgery, cardiac arrest or in acute cardiopulmonary failure. To obtain the effect of counter-pulsation on hemodynamic response in the ECLS quantitatively, we developed cardiovascular model which consists of 12 compartment model of heldt et al. and 3 compartment model of Schreiner et al. based on windkessel approximation. We compared coronary perfusion, arterial pulse pressure, cardiac output, and left ventricular pressure-volume diagram according to flow configuration such as counter-pulsation, copulsation, and continous flow. When counter-pulsation was applied, 5% higher coronary perfusion, 26% lower pulse pressure, and 2% higher cardiac output than copulsation condition were calculated. We conclude that counter-pulsation configuration in the ECLS is hemodynamically more stable than copulsation and influences the positive effect to recover ventricles.

• Journal of Life Science
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• v.7 no.1
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• pp.24-29
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• 1997

The actual vegetation map, community composition and vegetation structure of an isolated Evodia daniellii community due to the urbanization were investigated. At the habitat of Evodia daniellii, east cliff of Mt. Sudo, I made 30 plots of 100m$^{2}$ and adjusted 15 times the aspect of vegetation in whole growing season. On the base of these data, synoptic vegetation table was constructed. The constellation diagram by the calculation of ${\chi}$$^{2}$-value based on the vegetation data shown three vegetation groups pf Albizzia julibrissin with 10 species, Zanthoxylum shinifolium with 12 species and Ulmus parvifolia with 6 species. Through the DBH measurement of 5 major tress, we found that Ailanthus altissima, Paulownia tomentosa and Zelkova serrata are dominant in present, but it will be change by Evodia daniellii.