• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.171-178
• /
• 2001

Air spring for railway rolling-stock is a part of secondary suspension system which play the role of supporting load, damping vibration. Recently, air springs are actively applied to railway rolling-stock to substitute coil spring with upgrading the manufacturing skill. This study is started to get the fundamental datum related to air spring for the purpose of developing the test draft for air spring. To analyze the performance of air spring, we conducted the simulation for railway rolling-stock applied air spring and tested train in convention lines. Thus, we have obtained useful datum to develop the test draft for air spring. Here, we describe some results.

• Journal of Korean Institute of Industrial Engineers
• /
• v.3 no.1
• /
• pp.55-59
• /
• 1977

This paper develops a portfolio management game applicable to Korean Stock Market with an emphasis on teaching and training aid. It allows each participant to start out with a certain amount of money and pick his favorable stocks from a list of stocks chosen by instructor. Each participant must make a transaction at each time period and he gets a readout that states his individual performance, i.e., stock lists, cash on hand, net worth, transactions he has made and rank in accordance with his net worth. This game package consists of 10 subprograms and 7 files written with Fortran language for use on the Nova 840 computer and is divided into 3 main categories according to their functions, i.e., book-keeping function, data processing function and information searching function. This package may be used for training portfolio decison makings in the stock market and for comparing various investment methods through hypothetical investments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.134-136
• /
• 2017

The stock price of a companies may be changed according to not only the result of business performance but also the information and trends created by various investors. In this point, this study is to suggest a way to understand the relationship between big-data on each companies and its stock price, and to perform a simulation to examine it.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.11
• /
• pp.151-158
• /
• 2016

This study analyzes the stock market reaction of disclosure of technological information using events which are collected in the Korean stock market for the thirteen-year period between January 2002 and December 2014. We find that abnormal return on the disclosure day of full sample firms is positive and statistically significant. However, abnormal return of high R&D intensity subsample is a larger positive number than that of the low one. Using a longer window, it shows that low R&D intensity negatively decreases the long term performance after the adoption of new technological information. The empirical evidence of the studying is expected to serve as a good judging guide-line for the investors.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.339-344
• /
• 2003

Air spring for railway rolling stock is a part of secondary suspension system, which is supporting load, damping vibration. Recently, air springs are actively applied to railway rolling stock to substitute the coil spring by upgrading the manufacturing skill. This study is started to develop draft for the testing methods of air spring for railway rolling stock. We have tested several items on testing methods to guarantee the performance of air spring. Thus, we have developed the test draft for air spring.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2001.06a
• /
• pp.399-408
• /
• 2001

This paper presents a simultaneous optimization approach of case-based reasoning (CBR) using a genetic algorithm(GA) for the prediction of stock price index. Prior research suggested many hybrid models of CBR and the GA for selecting a relevant feature subset or optimizing feature weights. Most studies, however, used the GA for improving only a part of architectural factors for the CBR system. However, the performance of CBR may be enhanced when these factors are simultaneously considered. In this study, the GA simultaneously optimizes multiple factors of the CBR system. Experimental results show that a GA approach to simultaneous optimization of CBR outperforms other conventional approaches for the prediction of stock price index.

• The Journal of Asian Finance, Economics and Business
• /
• v.6 no.3
• /
• pp.131-140
• /
• 2019

The study aims to examine the impact of productivity in addition to the policy of increasing the foreign investors' ownership rate on the performance of businesses which were listed on Vietnam's stock exchange market from 2010 to 2017. With the database of 3.961 observations, the study employs a statistical method - multiple regression to estimate the relationship between labor productivity, foreign ownership as well as other firm-level characteristics and firm performance. Research findings show that increasing labor productivity and increasing foreign ownership rates help increase firm performance. In addition, except for financial leverage, variables such as liquidity and firm size have positive effects on firm performance measured by Tobin's Q. These findings have theoretical contributions and practical implications for managers, investors and government in Vietnam. Managers should pay attention to improving labor productivity through employing incentive mechanisms, building a good working environment, investing in technology, etc. in order to enhance the firm performance. Investors could utilize the labor productivity and foreign ownership indicators to select stocks of good companies for investment. For Vietnamese government, relaxing the limit of foreign ownership and accelerating the divesting of State capital in State-owned enterprises could help increase the investment scale of foreign investors and resulting in positive effects on the firm performance.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.11 s.188
• /
• pp.85-92
• /
• 2006

For the improvement of a conventional railway speed, tilting train(Tilting Train express) is under the development aiming for a maximum speed 180km/h. Compared to the existing conventional rolling-stock, tilting train could take an advantage of speed improvement about $20{\sim}30%$ on curve sections due to the improvement of cowing performance. However, this speed increasement creates a severe load at wheels, thus it is necessary to study the safety of wheel for tilting train preferentially. On the other hand, it is under consideration that the wheel for conventional railway rolling-stock at speeds of 150km/h will be applied to tilting train at speeds of 180km/h. In this paper, we have studied the strength of wheel structure, the geometrical contact characteristics, and the dynamic performance of wheel to evaluate the safety of wheel for tilting train.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.600-605
• /
• 2003

Battery of rolling stock is a very important device as power supply at starting and emergency control. This paper analyzes the quality of Ni-Cd battery by means of performance test. Ni-Cd battery have suitable and stable properties. That is very stable to discharge on low temperature state and very easy to manage and repair. This paper confirm the performance and property of Ni-Cd battery on low temperature environment by the performance test and estimate the life-cycle of Ni-Cd battery on board at rolling-stock by the life-test and the using-test.

• Journal of Korea Trade
• /
• v.23 no.7
• /
• pp.147-155
• /
• 2019

Purpose - As the U.S.-China trade war has become considerably worse, the Chinese government is considering applying non-tariff barriers to trade, especially local contents rule. The main purpose of this research is to check whether it is suitable for Korean investors to invest in the current Chinese capital market. Design/methodology - In order to check the stability of the recent Chinese capital market, we investigated the behavior of foreign equity investment (including Korean equity investment) in the Chinese capital market after China announced the Shanghai-Hong Kong Stock Connect (SH-HK Connect). In this paper, we researched whether international portfolio investment would or would not contribute to an increase the volatility of an emerging market's stock market (Chinese capital market) when foreign investors make investment decisions based on the objective of short-term gains by rushing into countries whose markets are booming and fleeing from countries whose markets are falling. Findings - The empirical results indicate that foreign investors show strong, negative feedback trading behavior with regard to the stock index of the Shanghai Stock Exchange (SSE), and when the performance of foreign investors in the Chinese stock market was fairly good. Also, we found evidence that the behavior of foreign investors significantly decreased volatility in SSE stock returns. Consequently, the SH-HK Connect brought on a win-win effect for both the Chinese capital market and foreign investors. Originality/value - It appeared that the Chinese capital market was very suitable for Korean investors after the China's declaration of the SH-HK Connect. However, the win-win effect was brought on by the Chinese government's aggressive capital control but the capital controls could possibly cause financial turmoil in the Chinese capital market. Therefore, Chinese reform in industrial structure and the financial sector should keep pace with suitable capital control policies.