• Proceedings of the KSME Conference
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• 2000.04b
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• pp.593-598
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• 2000

Experimental study is conducted to clarify the pneumatic characteristics of brake system for freight train. Empty-load and diaphragm brake systems are mainly installed in the freight trains owned by KNR(Korean National Railroad). Experimental train set is composed of sixteen freight train and one diesel locomotive that are now in use. From the experimental results, in case of commercial brake, empty-load brake system responds to the brake command more slowly than the diaphragm brake system. But, in case of release command, the response time of diaphragm brake system is shorter than that of empty-load one. In the emergency brake test, the decreasing rate of brake pipe pressure of tenth car is almost same that of decreasing rate of commercial brake service.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1739-1747
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• 2001

Experimental study has been conducted to clarify the pneumatic characteristics of brake system for freight train and enhance the performance of diaphragm valve. Empty-load and diaphragm valves are installed in pneumatic brake system for freight trains of KNR (Korean National Railroad). Experiments are conducted by using freight train and diesel locomotive in operation. From the experimental results. new quick release valve shortens release time after brake application. In case of normal brake application, the release time is shortened to 34% of the original diaphragm valve. Reducing the release time of pneumatic brake system will be helpful to assure brake-release application and save maintenance efforts like wheel grinding.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.525-532
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• 2001

Experimental study has been conducted to clarify the pneumatic characteristics of brake system for freight train and enhance the performance of diaphragm valve. Empty-load and diaphragm brake systems are mainly used in the freight trains of KNR (Korean National Railroad). The train set is composed of thirty freight cars and diesel locomotive. From the experimental results, new quick release valve shortens release time after brake application. In case of normal brake application, the release time is short by 34% of that of original diaphragm control valve. It will be expected to assure brake-release application and reduce maintenance efforts.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.742-753
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• 2016

This study aims to reproduce of Anuisamdong's landscape structure and improve the value of Scenic site. It was extract main spot from Geography book published by government in the 19th Century. And analyzed landscape architecture of Dongcheon. Extract main spot from Geography book published by government. Consequently, Hwarim-dong main spot 6 places, Simjin-dong main spot 9 places, and Wonhak-dong main spot 25 places were identified. Hwarim-dong's main spot was divided into 3 places of pavilion and scenery, respectively. Simjin-Dong's main spots was all that natural elements as a scenery. Wonhak-dong's main spot was the most elements of the Anuisamdong in geography book published by government. Hwarim-dong was pavilion-based scenery area complex, Simjin-dong was continues scenery spot along the valley, and Wonhak-dong was hybrid distribution that landscape structure. Each dongcheon in Anuisamdong was created a separate area through isolated geographical, visually for structure of collectively means. Also, a narrow entrance and enclosure topography are areas which arouse atmosphere of paradise. In addition, Aunuisamdong's landscape structure, which was previously divided into individual Dongcheon, was expanded into a single integrated landscape structure of Dongcheon. This is different from the general landscape development of common Dongcheon with the same starting and ending points and sightseeing routes.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.157-163
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• 1996

This paper is concered on the development of low-cost fine blanking die with two fluid chambers of which the pressure can be controlled by a hydraulic unit and its application to producting circular blanks in a conventional hydraulic press, not in a special triple-action press usually adopte in fine blanking operation. Four important working parameters affecting on the precision accuracy of products such as existence and position of Vee-ring, stripping force and counter punching force are primarily considered for experiments. Finite element analysis by suing ABAQUA software is approxi- mately made for blanking of circular specimen with a flat stripper plate and then compared with experimental measurements. The the theoretical prediction of camber height which represents deflection of a dish-shaped specimen after blanking seems to give a qualitatively good agreement. It is shown through experiments the the camber height decreases with decreasing stripping force and also with increasing counter punching force, but particularly depending on the latter much more than the former.

• Journal of The Geomorphological Association of Korea
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• v.19 no.4
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• pp.157-168
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• 2012

The Eonyang section is located at the confluent area of Samdong River to Taehwa River in Sinhwa-ri, Samnam-myeon, Ulju-gun, Ulsan-si, Korea. Physical analyses such as the OSL age dating, magnetic susceptibility and grain size analysis were performed. Coarse grains in the upper section were deposited by the aeolian processes from the local sources and the grains in the lower section by the fluvial processes. The Eonyang section shows the large differences such as the irregularity in the variations of magnetic susceptibility, large deviations in the Y values and very poor sorting values from the loess sediments in Bongdong, Geochang and Daecheon in Korea. These characteristics in the Eonyang section suggest the multi-source areas such as the Chinese Loess Plateau and nearby floodplain or the influences by the other processes. The loess sediments of Eonyang section were formed during the period from the late MIS 3 to MIS 2.

• Journal of Powder Materials
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• v.26 no.5
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• pp.432-436
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• 2019

This study demonstrates the effect of addition of Fe particles of different sizes on the critical properties of the superconductor $MgB_2$. Bulk $MgB_2$ is synthesized by ball milling Mg and B powders with Fe particles at $900^{\circ}C$. When Fe particles with size less than $10{\mu}m$ are added in $MgB_2$, they easily react with B and form the FeB phase, resulting in a reduction in the amount of the $MgB_2$ phase and deterioration of the crystallinity. Accordingly, both the critical temperature and the critical current density are significantly reduced. On the other hand, when larger Fe particles are added, the $Fe_2B$ phase forms instead of FeB due to the lower reactivity of Fe toward B. Accordingly, negligible loss of B occurs, and the critical properties are found to be similar to those of the intact $MgB_2$.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1279-1288
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• 2023

Recently, domestic leisure boats have been actively researching eco-friendly product development to enter the global market. Since the hulls of existing leisure boats are mainly made of fiber reinforced plastic (FRP) or aluminum, design techniques for securing structural safety by applying related materials have been mainly studied. In this study, an initial structural design safety assessment of a trimaran pontoon leisure boat with a modular hull structure and eco-friendly high-density polyethylene (HDPE) material was conducted, and sensitivity evaluation and optimization analysis for lightweight design were performed. The initial structural design safety assessment was carried out by creating a finite element analysis model and applying the loading conditions specified in the ship classification regulation to check whether the specified allowable stresses are satisfied. For the sensitivity evaluation, the influence of stress and weight of each hull structural member was evaluated using the orthogonal array design of experiments method, and an approximate model based on the response surface method was generated using the results of the design of experiments. The optimization analysis set the thickness of the hull structural members as the design variable and considered the optimal design formulation to minimize the weight while satisfying the allowable stress. The algorithm of the optimization analysis applied the Gradient-population Based Optimizer (GBO) to improve the accuracy of the optimal solution convergence while reducing the numerical cost. Through this study, the optimal design of a newly developed eco-friendly trimaran pontoon leisure boat with a weight reduction of 10% was presented.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.2
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• pp.98-108
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• 2006

The vessels, already built and is operating in Korea, have the hull form of catamaran, with LOA(Length Over All) 15 m, LBP(Length Between Perpendiculars) 12 m, GT(Gross Tonnage) 9.77ton, Light Load Displacement 15.1ton. Korean Society of Ship Inspection & Technology, Chungnam National University, Inha University, Seoul National University and Advance Marine Tech co. ltd developed by cooperation it for fishing vessels. And it used FRP(Fiber Reinforced Plastics) for hull material and main engine of diesel $360ps{\times}2800rpm{\times}2sets$ with a water jet system. Based on these results, this paper describe small leisure fishing vessels with multi-hull, in relation to the project of CTYS(Regional Reserch Center for Transportation System of Yellow Sea Inha University) that aimed to development of trimaran hull form(LOA=17m, LBP=14m(Side Hull=6m), GT=9.77ton, Light Weight=11.2 ton).

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.48-63
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• 2015

This study began with the purpose of awakening an interest in Korean Nu-jung and seeking application plan based on Nu-jung of Aneuisamdong. Also it intends to suggest activation plan of Nu-jung while using the culture of taste for the arts and classical scholar of ancestors with the physical place named Nu-jung as the medium. As concrete ways to activate Nu-jung, we suggested plans which use the game of go(Baduk), main material of the culture of taste for the arts and classical scholar, and increase availability by planning a program adding picturesqueness of Nu-jung. By bringing the material named the game of go(Baduk) to the place named Nu-jung, we suggested the plan capable of experiencing the culture of taste for the arts and classical scholar and also expecting local promotion and economical effect. And the plan is to design and conduct night program, 1 night 2 days program, tailored program, and so on by combining the material of the culture of taste for the arts and classical scholar with the medium named 'Dal(the moon)' in the static place named Nu-jung. The plans above are applicable to most of Nu-jung scattered all over the country, which means that we have a lot of Nu-jung in Korea and, at the same time, we have abundant contents to be used as cultural properties. Now it's important how to develop and use these contents through the connection with various academic fields in terms of managing cultural properties. By understanding the value of the original form of culture while emerging from simply using cultural properties, we can use cultural properties in a higher level. For this, preserving cultural properties should be supported by continuous interdisciplinary study.