• Structural Engineering and Mechanics
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• v.47 no.2
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• pp.287-305
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• 2013

Economic performances of consecutive multi-span suspension bridges are studied. The material amount and cost estimation formulas of the bridges have been derived in the part 1 of the study. A parametric study is carried out based on the formulas for investigating the different factors' effect on the bridge cost. The factors include the bridge sag, the bridge span, the bridge foundation and the environment condition, etc. Then, an economical layout of the bridges is proposed for different conditions. Lastly, a selection of suspension bridge types is discussed based on the economy of bridges.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.03a
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• pp.9-14
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• 1993

Practical solutions that are available today for assessing stability of tunnel working face are largely based on the concept of critical stability ratio. The accuracy of a prediction of the soil behavior in the working face, thus, depends on the ability of the solution to completely and accurately describe the stress fields or kinematics generated by the excavation and the accuracy of the undrained shear strength of the soil introduced in the computation. This paper reviews the selected solutions describing stability of the tunnel heading in squeezing ground, and suggests a reference solution which is established based on comparison of the solutions and field data on stability of tunnel headings in clays. Although dealing with the shear strength determination is an important companion part of the geotechnical prediction for stability of the tunnel heading in clays, this part is beyond the scope of this paper at this time.

• Journal of Korean Association for Spatial Structures
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• v.15 no.1
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• pp.111-118
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• 2015

In Part I, we disccussed of joint between PHC pile and steel column in foundation of large space structures, one prototype of a joint of PHC pile to steel pipe column was suggested on the basis of analytical studies. In this paper, I explain the Joint of PHC pile to steel tube column and more detail of analysis.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.5
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• pp.380-387
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• 2014

Piper Alpha disaster drew attention to the damage likely to arise from explosions and fires on an offshore platform. And great concerns have been increased to prevent these hazards. Blast wall is one of the passive safety systems; it plays a key part of minimizing the consequences. However, a buckling due to explosion loads is a factor which can reduce the strength of blast wall. The buckling often occurs between web and flange at the center of blast wall. This study aims to find a solution for reinforcing its strength by installing a flat plate at the spot where the buckling occurs. First of all, ANSYS finite element method is adopted to numerically compute the structural resistance characteristic of blast wall by using a quasi-static approach. Sequentially, the impact response characteristics of blast wall are investigated the effect on thickness of flat plate by using ANSYS/LS-DYNA. Finally, pressure-impulse diagrams (P-I diagram) are presented to permit easy assessment of structural response characteristics of stiffened blast wall. In this study, effective use is made to increase structural intensity. of blast wall and acquired important insights have been documented.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.4 s.111
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• pp.79-96
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• 2005

This study is to suggest the technique of ecological park to compatible mountain ecosystem near the urban in Woomyeonsan Urban Nature Park. It was proposed to differential technique from established ecological park focused on changing the cognition of nature, wetland ecosystem protection and restoration, and studying by served sound leisure program(nature observation and experience, etc.), in compatible mountain and urban forest near the Urban. Firstly, to achieve this aim, it was carried out delicated research and analysis that were the angle of inclination, trail, fauna, actual vegetation, bird and insect, and then to selected nature trail course and analysis capability through it.. In the basic concept and plan, firstly to make park aid mark and foundation mark, and then to establish the detail programs, nature observation program, management and organization program. This site where valley and mountain coexist was highly capable but whole site was very steep, so usable area is very narrow. To make Woomyeonsan nature ecological park escape from the established wetland type, ecological park and the park of event have to use nature material and introduce visitor. To establish it as the Nature Culture observation park and reflect on forest, valley of Woomyeonsan was divided into three display places; Nature ecosystem Zone, Meditation Zone, Nature Culture experience Zone and Nature Culture observation Center. For satisfying with ecological park aid mark and foundation mark, it was proposed to settle management plan for volunteer control and organization composition.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.79-88
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• 2009

In this study, it was studied on arching characteristics of a grand section tunnel with pre-steel-rib nail reinforcement. In this study, we examine the adaptation of tunnel plan and the case which is based on the strengthening method for preexistence tunnel and other pre-steel-rib nail while the upper part of cover depth is low or soil condition is bad. When the pre-steel-rib nail as new technology and method reinforces the foundation placed of grand section tunnel, it is much better in strengthening effect, safety and effectiveness than the conventional one. After investigation about the plan pre-steel-rib nail method, construction case and calibration data, it was confirmed and examined about the upper part of tunnel for strengthening the pre-steel-rib nail thereby arching characteristics of grand section tunnel using MIDAS/GTS finite element program. Moreover we present the method that could upgrade the accurate installation interval and adaptation method for strengthening effect to adapt the pre-steel-rib nail method in a foundation placed over a tunnel.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.324-330
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• 2004

To integration the field device as a control system correctly in fielders systems. We have to offer the DD(Device Description) with the function and internal parameter into the configuration software. The DD which is written in the DDL(Device Description Lansuage) is made as IEC 61804-PART 2 and it is used in Profibus, Foundation Field bus, HART. However, the DD is dependent to the fieldbus and it doesn't have a suitable form in the industrial Ethernet. Therefore, in this paper, we described the internal function and parameter of the Field device as XDD(XML for Device Description) by using XML (extensible Markup Language) which isn't dependent to fieldbus and has a suitable form for industrial ethernet. Futhermore, we present the possibility of XDD's application in the distributed control system by examining the possibility of ethernet's development in the industrial area.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.135-143
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• 2000

The vision system is easy to use the exclusive use as a independent computer system but it is not much popularization by reason of expensive and difficult to adapt to the various fields, because it is easy to the existed computer system, the price is cheap and also it can use to the various measurement purpose which user wanted and programed. The measurement method of the vehicle axle casing nut welding part is that measure the value of the welding part to adapt the actual operation program from using the ratio between the actual length of the standard specimen and the length of image, to measure the ratio between the actual product and the camera image. A defect is found by the assembled visual inspection system. The inspection algorithm which estimates the quality of welded product is developed and also, the software program which processes the automatic test function of the inspection system. We make the foundation of the inspection automatic system and we will help to apply other welding machine.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.2
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• pp.146-173
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• 1998

It is one of the most important factors Seafarers Education Quality Assurance and management in Higher Maritime Education Institution. The educational process and result of Higher Maritime Educational Institution. The educational process and result of Higher Maritime Educational Institution should be evaluated according to the 1995 Amendments to the International Convention on Standards of Training Certification and Watchkddping for Seafares(STCW) 1978. Actuall above-mentioned evaluation is deemed to make foundation in order to enhance the efficiency of shipboard education by surveying the satisfaction of shipboard training for Marine Engineering part cadets by the group. In this paper we carried out the questionnaire survey to study stisfactory value and the reason of dissatisfaction of 89 cadets being trained on board the Training Ship in Maritime College of Korea Maritime University The results were calculated by frequency and percentage; the significance of difference among Department groups like Marine Engineering Maritime polic and Ship Operating Systems Engineering Engineering was analysed by $x^2$ inspection.

• Tribology and Lubricants
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• v.30 no.2
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• pp.116-123
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• 2014

The objective of this study is to model and simulate the nonlinear lubrication performance of the sliding part between the piston and cylinder wall in a hydrostatic swash-plate-type axial piston pump. A numerical algorithm is developed that facilitates simultaneous calculation of the rotating body motion and fluid film pressure to observe the fluid film geometry and power loss. It is assumed that solid asperity contact, so-called mixed lubrication in this study, invariably occurs in the swash-plate-type axial piston pump, which produces a higher lateral moment on the pistons than other types of hydrostatic machines. Two comparative mixed lubrication models, rigid and elastic, are used to determine the reaction force and sliding friction. The rigid model does not allow any elastic deformation in the partial lubrication area. The patch shapes, reactive forces, and virtual local elastic deformation in the partial lubrication area are obtained in the elastic contact model using a simple Hertz contact theory. The calculation results show that a higher reaction force and friction loss are obtained in the rigid model, indicating that solid deformation is a significant factor on the lubrication characteristics of the reciprocating piston part.