• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.419-422
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• 2003

The hydraulic excavator has been a popular research object for automation because of its multi-workings and economic efficiency. The objective of this paper is to design each components and to construct boom, arm, bucket circuit. These models modeled with AMESim show us change of variables and behavior of excavator. Simulation model will be used for simulator of excavator.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.373-379
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• 2001

When a train runs into a tunnel at high-speed, aerodynamic drag suddenly increases and the booming noise is generated at the exit of tunnel. The noise shape is very important to reduce the aerodynamic drag in tunnel as well as on open ground, and the micro-pressure wave that is a source of booming noise is dependent on nose shape, especially on area distribution. In this study, the nose shape has been optimized employing the response surface methodology and the axi-symmetric compressible Navier-Stokes equations. The optimal designs have been executed imposing various conditions of the aerodynamic drag and the micro-pressure wave on object functions. The results show that the multi-objective design was successful to decrease micro-pressure wave and aerodynamic drag of trains.

• The Research Journal of the Costume Culture
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• v.6 no.4
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• pp.175-187
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• 1998

Hats are an important part of the fashion accessory business and Their importance is increasing year by year. Their importance is increasing not only as a means of accessory ut also as a means of sportswear due to the leisure-sports boom of the 90's. As hats are becoming more and more popular and ready-made, demand for comfortable and easy-fitting hats are increasing. Being an piece of apparel, fitting is very important factor in hats as well s in other forms of clothing. But many hat-wears complain of dissatisfaction of fitting of their hats. In addition to this, another problem is hat most hat designs have been flown in from the West without inspection of their fits. Designs to fit the Koran face and head have not been developed properly. This study is based on the need for the development of a well-fitting hat pattern design for Korean young women. After taking actual measurements of 170 young womens, a size system was organized for developing patterns for different size groups.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.39-42
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• 2003

A community can have a physical presence or can be formed from a group of people who communicate remotely via a conference call, a fixed Internet chatroom or instant message solution and most recently, a mobile handset. The mobile handset gives community members the advantage over fixed line or physical communities that they are not constricted by time or place as to when they can communicate with any members of their community. Operators, riding on the back of the SMS boom, are deploying community applications to increase both average revenue per user and customer loyalty. The purpose of this study is to find the effects of the characteristics of mobile community on the consumers'satisfaction and loyalty so that operators'participation in mobile community could be enhanced. A general model for the study was proposed with three independent variables. The variables are community usability(dialog and social support, information design, navigation, access), community sociability (purpose, people, policies), and mobile community content(location, personalization, immediacy, availability).

• Journal of Science of Art and Design
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• v.5
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• pp.67-86
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• 2003

In der vorliegenden Arbeit geht es um die Rezeptionsproblem des Bildes im Zeitalter der neuen Median. Heuzutage erleben wir einen Medien-Boom, bzw. digital-Medien. Manche Theoretiker diskutieren deshalb ueber das Problem der digital-Median in den verschiedenen Bereich. Im Bereich der Kunst und Kultur handelt os sich auch urn die Varaenderung des Kunstwerkes, der Rezeption und der Herstellung des Kunstwerkes. In dieser Fragestellung ist es wichtig, das Problem ueber Bild zu erlaeutern, weil das Bild abhaengig von den Medien ist. Durch Medien wird das Bild veraendern koennen. Und auch wird die Rezeption des Bildes veraendern muessen. In Zeitalter der neunen Medien, bzw digital Medien, veraenderten sich die Rezeption des Bildes von der konzentrativen Rezeption zur zerstreuuten und konzentrativen Rezeption. Diese erneuerte Rezeption nenne ich das zerstreuute Kontemplation. Das ist eine Rezeption im Zeitalter der neuen Medien.

• Journal of the Korea Furniture Society
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• v.12 no.1
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• pp.125-130
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• 2001

The sofa industry, which is now one of the major furniture industries in Korea, has developed since 1970s as the apartment building boom and the rise of living standards triggered its demand. Among others, durable and high-quality leather sofa had been most favored and excelled other sofas since mid-1980s along with the growth of national economy before IMF control tightened money market in late 1990s. Leather sofa is still favored and its industry has great possibilities to increase as people tend to seek higher and more personalized living conditions with the stabilization of economy. However, there are several problems in the sofa industry due to the current economic difficult conditions, i.e.; 1. It is hard to cut down the cost of raw material as the supply mostly depend on import. 2. It is hard to keep product quality due to technical difficulties. 3. There are still illegal duplicates of foreign or domestic competitors'design. The aim of this study is to examine the reality of the leather sofa industry in Korea and to suggest new vision for its progress.

• Journal of Drive and Control
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• v.16 no.2
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• pp.30-35
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• 2019

EPPR (Electro-hydraulic Proportional Pressure Reducing) valves are pressure control valves. In this study, an independent metering valve (IMV), which is a combination of a spool valve opened and closed with the help of an EPPR valve, was discussed. The overall performance of the valve (IMV) was obtained by the respective modeling and simulation of the system. The valve investigated in this study is to be used for independent metering of hydraulic excavator actuator e.g. boom, arm, bucket etc. To design the model, continuity equations and force balance equations were used. The set of differential equations were then simulated in Simulink using ODE45 option in the configuration toolbox. The valve has to be able to control the flow rate going in and out of the cylinder separately, which is why the particular configuration was needed and selected.

• Advances in nano research
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• v.14 no.5
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• pp.451-461
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• 2023

Two-dimensional (2D) materials have been attracting attention since graphene monolayer was firstly separated. However, after an explosive boom, there is always quandary and stagnancy following and soon will come the refractory period of capital market. To avoid that undesired future, a paradigm of quasi 2D monolayer has been contemplated and devised in this article, with examples studied theoretically. The results show the general dynamic nonlinearity, and the expected tunability of bandgap without extra doping or substitution. These together suggest its intriguing both electronical and mechanical properties, which will enrich the arsenal of potential 2D materials.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.43-53
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• 2015

As part of alternative of elderly problems in the future super-aging society, this study aims to extract an improvement plan of interior environment design of Seoul-type day care centers to expand in future by observing day care centers as medical and healing environments, from the perspective of user experience. For this study, after selecting major activity areas of representative cases of Seoul-type day care centers, user behaviors in the space were observed and 4 seniors of baby-boom generation who are potential uses were chosen as personas by reflecting characteristics of healthy elderly, physical aging, mental aging and infirm elderly, from the perspective of user experience. Based on previous studies on healing environments, these characteristics and demands of personas were classified into environmental aspects, physical aspects and mental aspects to extract an improvement plan. The study results are as follows. First, interior environment design reflecting persona characteristics helps the elderly adapt to the environment and provides a comfortable environment like home for stability, treatment and recovery of memory. Second, interior environment design reflecting persona characteristics helps psychological healing through light entering the large windows and natural environment elements. Third, for interior environment design reflecting persona characteristics, finish materials with bright and soft colors should be used to change the images of facilities positively. Fourth, spatial composition should be remedied through division of space and built-in furniture depending on the needs of users for loitering of extra time and programs.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.349-353
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• 2007

The main functions of excavator are mainly carried out by excavator attachments such as arm and boom. These components should be designed to be light as well as durable enough because their effects on the whole structure are significant. In this paper, an optimization procedure for lightweight design considering fatigue strength for excavator attachments is presented. The weight of attachments and allowable fatigue stresses at critical areas are used as objective function and constraints, respectively, in which design variables are the thickness of the plates of attachments. The simulated annealing search method is adopted for a global optimization solution. Besides, the response surface method using the artificial neural network is used to simulate constraint function for the sake of practical fast calculation. Some example case of optimization is presented here for a sample excavator. This weight optimization is expected to contribute to a considerable improvement of fuel efficiency of excavator.