• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2965-2972
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• 2011

The 21th century is carried out a rearing activity of green industries as a part of friendly echo policy for preservation of earth environment. Korean government is spreaded on a whole country to setting up a goal to a sustainable growth power of national for low carbon green growth. The recently rolling stock is received the footlights as a best friendly echo transportation of transport system of automobile, airplane, ship etc., also that is playing a big role to reduction of $CO_2$ greenhouse gas and a discharge of air pollution. This study was carried out the investigation and analysis for technology trend of the system light-weighting of a recently urban railway vehicle on commercial operating in domestic and foreign countries. As the results are proposed a short-term development technology and a long-term development technology of the system light-weighting to be developed for reduction weight of urban railway vehicle.

• Journal of Korean Society for Quality Management
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• v.33 no.4
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• pp.75-87
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• 2005

Generally speaking, weapon system is defined as a combination of primary system and support system which are evaluated by capability and operational availability respectively. Recently comparison of total life cycle cost shows that logistic support system is proved to be more important than primary system. However, until now systematic approach to support system development has not been applied in the area of developing support system. We need to construct a universal metric for effectiveness of logistic support system and to cut out whatever activities or support elements which do not contribute to the metric. This paper describes a new approach based on system engineering approach to logistic support system and also classifies five factors of failure, stock-out frequency, administrative delay time, active repair time and logistic delay time that have influence on operational availability of logistic support system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.127-130
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• 2004

In the recent years, lightweight components fabricated with aluminum alloys have been applied into building the automobiles. Among the several competing fabrication methods, hot forging is taken as the most reliable technique to produce suspension parts such as control arms. Generally, Al forging products have been used widely for the aircraft building with the extruded stock as a starting material. For the economical base, however, the cast stocks turn to be as the forging stocks recently after a continuously casting technique was developed to produce quite a uniform microstructure enough to use for the forging process. Even more, there is a tendency to omit the homogenization step before forging, which is considered to be an indispensable process for all kinds of Al alloy, In the present study, a series of compression test was carried out to find out how the cast structure and the following heat treatments influence the deformation behavior, that is, forging characteristic.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.796-805
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• 2008

Safety Management of Korean railway industry has been rapidly changed into a risk-based approach adopted by developed countries since Railway Safety Act 2004, Rolling Stock Risk Assessment Guidance and its following regulations came into force. The fundamental requirements for the risk-based safety management is to carry out a systematic hazard identification and quantified risk analyses including cost-benefit analyses, but there has been rare a serious discussion over risk acceptance criteria and value of life in order to be able to judge the results of risk analyses and carry out cost-benefit analyses. This study presents the results of a review of risk acceptance criteria and value of life which may be adoped to Korean railway industry through the analyses with comparison of risk accepatnce principles and risk accepatnce criteria which have been already applied to other countries or other railway operators.

• ETRI Journal
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• v.28 no.5
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• pp.638-647
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• 2006

This paper investigates two kinds of strategic combinations carried out by the European telecom operators between 1986 and 2001: acquisitions, on the one hand, and strategic alliances, on the other. The aim of the paper is twofold. First, it analyzes the behavior adopted by these companies to adapt to an environment that, after the processes of globalization and privatization presents a clearly different structure. Second, it focuses on the effect that internationalization and diversification could exert over the returns obtained by the European telecom firms involved in acquisitions and alliances, differentiating when such strategic combinations are more profitable for the shareholders of the firms that carry them out.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.223-230
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• 1999

The seismic damage assessment to the postulated earthquake is attempted for the buildings in the model district of Seoul City. The capacity spectrum method is employed in which the vulnerability functions are expressed as functions of the spectral displacement. the database of the building stock is constructed and managed using Geographic Information System software. The model district is selected to represent the typical structural and residential characteristics of Seoul City The structural properties were collected from the design documents. The field inspections were carried out to find out the current status of the building. They are classified into 11 structural types. The fragility curves in HazUS are employed, The ground motions from the postulated earthquakes are simulated using the Boor's methods, The surface soil in the district is classified into 3 profiles using the depth as the parameter. The one-dimensional wave propagation method is used to calculate he filtered ground motion through surface soil layer. The average spectrum of this sample time histories is used as the demand curves. The calculated results are expressed in maps using GIS software ArcView 3.0a

• Korean System Dynamics Review
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• v.12 no.4
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• pp.157-175
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• 2011

The purpose of this paper is to find out the effects of the gambler's fallacy bias on the supply chain. For this study, the simulation was based on a casual structure of the Beer Distribution Game from Sterman(2000)'s Business Dynamics and designed into 2 different models : the first model carries the exact same structure as the reference mentioned above and for the second model, the comparison model is used reflecting gambler's fallacy bias. Each model has 2 different demand patterns. The 4 cases of models was tested with 1,000 different random number seeds. The results for the simulation are following : In the aspect of the inventory and out of stock, the basic model resulted better than the comparison. However, in the bullwhip effect, the comparison model has less than the basic in terms of the level demand pattern. But there was no significant difference in the cycle demand.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.21-29
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• 2017

Stock investment becomes one of the most popular investments in these days, and the ultimate goal of investors in the stock market is to maximize profits and minimize losses, in order to achieve this, investors will select based on investment information. namely, the information about the company which we interest is essential to stock investors. Also, investors are affected by their propensity to invest according to their attitude toward risk. With these situations, this research tried to show the private investors' actual performance of Investment by studying individual investors' propensity and Information explore. The purpose of this study is to analyze the effect of investors' propensity and information search on investment satisfaction. The questionary method required some sample surveys. The data of the practical analysis was carried out with the on-line researching method. The researching time was from the 1st of Dec. 2016 to the 15th of Dec. 2016. Of the 357 questionnaires submitted, 7 were deemed inappropriate or incomplete; thus, 350 questionnaires were used in the final analysis of the study. For analysis methodology, this research is using SPSS 21.0 along with analytic techniques, such as implementation of basic statistical analysis, reliability, and regression analysis. The practical analysis results are as follows; Among the investment propensities, profit propensity, analytical propensity, and investment propensity has a significant effect on investment performance. On the other hand, brokerage firm information, firm accounting information, private information has a statistically significant effect on investment performance. Finally, we confirmed the mediating role of investment sentiment.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.304-311
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• 2010

Korea National Forest Inventory System has been adopting different cluster plot design and new equations to estimate growing stock volumes since 2006. These changes have resulted in volume estimations which show some difference from previous ones. This study is to find out the source of such difference. For this, relevant data was collected from 80 plots of 20 cluster samples according to the cluster plot design applied to 4th and 5th National Forest Inventory. Then growing stock volumes were estimated by using current and previous individual tree volume equations respectively. An investigation was made to detect whether such difference in volume estimates was originated from the changes in cluster plot design or from using different volume equations. T-test results showed that the difference from changes in cluster plot design was negligible. Instead, changes in volume equations had statistically significant effects in volume estimation. Since the volume estimation by the 5th National Forest Inventory would bring overestimation by applying different volume equations, all the volume estimations made prior to 2006 would require necessary modifications for international reporting.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.89-99
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• 2014

Correlation of KOSPI from stock market and Apartment Prices in Seoul HPPCI from real estate market has been found from this research. Furthermore, from the comparison of those indicators' flows, certain precedence was found as well. The purpose of this research is to analyze correlation and precedence among KOSPI, Apartment price in Seoul, HPPCI and CLI. As for predicting KOSPI of stock market and real estate market, it is necessary to find out preceding indices and analyzing their progresses first. For 27 years from the January 1987 to December 2013, KOSPI has been grown by 687%, while CLI showed 443%, Apartment of Seoul showed 391%, HPPCI showed 263% of growth rate in order. As the result of correlation analysis among Apartment of Seoul, CLI, KOSPI and HPPCI, KOSPI and HPPCI showed high correlation coefficient of 0.877, and Apartment of Seoul and CLI showed that of 0.956 which is even higher. Result from the analysis, CLI shows high correlation with stock and real estate market, it is a good option to watch how CLI flows to predict stock and real estate market.