• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.208-216
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• 2020

With the spread of smart manufacturing, one of the key topics of the 4th industrial revolution, manufacturing systems are moving beyond automation to smartization using artificial intelligence. In particular, in the existing automatic machining, a number of machining defects and non-processing occur due to tool damage or severe wear, resulting in a decrease in productivity and an increase in quality defect rates. Therefore, it is important to measure and predict tool life. In this paper, ν-ASVR (ν-Asymmetric Support Vector Regression), which considers the asymmetry of ⲉ-tube and the asymmetry of penalties for data out of ⲉ-tube, was proposed and applied to the tool wear prediction problem. In the case of tool wear, if the predicted value of the tool wear amount is smaller than the actual value (under-estimation), product failure may occur due to tool damage or wear. Therefore, it can be said that ν-ASVR is suitable because it is necessary to overestimate. It is shown that even when adjusting the asymmetry of ⲉ-tube and the asymmetry of penalties for data out of ⲉ-tube, the ratio of the number of data belonging to ⲉ-tube can be adjusted with ν. Experiments are performed to compare the accuracy of various kernel functions such as linear, polynomial. RBF (radialbasis function), sigmoid, The best result isthe use of the RBF kernel in all cases

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.144-151
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• 2002

Future wireless communication systems are expected to provide a broad range of multimedia services in which the asymmetry of traffic load between uplink and downlink is a significant feature. The rode division multiple access system with tune division duplex mode (CDMA/TDD) is a good solution to cope with the traffic asymmetry problem. However. the TDD system is subject to inter-cell interference compared to frequency division duplex (FDD) system. Since both uplink and downlink share the same frequency in TDD. uplink and downlink may interfere each other especially when neighboring cells require different rates of asymmetry. Thus, time slot allocation for tells is an important issue in TDD. In this paper. we propose a genetic algorithm based time slot allocation scheme which maximizes the residual system capacity. The proposed scheme allows that each cell employ different level of uplink/downlink asymmetry and satisfies the interference requirement.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.107-115
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• 2020

Support vector regression (SVR) is devised to solve the regression problem by utilizing the excellent predictive power of Support Vector Machine. In particular, the ⲉ-insensitive loss function, which is a loss function often used in SVR, is a function thatdoes not generate penalties if the difference between the actual value and the estimated regression curve is within ⲉ. In most studies, the ⲉ-insensitive loss function is used symmetrically, and it is of interest to determine the value of ⲉ. In SVQR (Support Vector Quantile Regression), the asymmetry of the width of ⲉ and the slope of the penalty was controlled using the parameter p. However, the slope of the penalty is fixed according to the p value that determines the asymmetry of ⲉ. In this study, a new ε-insensitive loss function with p1 and p2 parameters was proposed. A new asymmetric SVR called GSVQR (Generalized Support Vector Quantile Regression) based on the new ε-insensitive loss function can control the asymmetry of the width of ⲉ and the slope of the penalty using the parameters p1 and p2, respectively. Moreover, the figures show that the asymmetry of the width of ⲉ and the slope of the penalty is controlled. Finally, through an experiment on a function, the accuracy of the existing symmetric Soft Margin, asymmetric SVQR, and asymmetric GSVQR was examined, and the characteristics of each were shown through figures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.2
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• pp.35-48
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• 2011

In this paper, we have studied the impact of adopting XBRL (eXtensible Business Reporting Language) on information asymmetry in capital markets with the additional research on the usefulness of XBRL data how to improve the quality of accounting information. From the Kosdaq XBRL service, the samples are selected including 38 adopted companies and the 30 non-adopted companies for the paired analysis. The daily stock return volatility (VOLA) as independent variable and other several controlling variables have been added for the regression analysis to measure the impact on information asymmetry in capital markets. he analytical result indicated that the asymmetry hypotheses that XBRL data will give a significant impact on the capital market and will reduce the volatility, which are expected in the hypotheses. This is the first analytical research on the capital market and its impacts to the capital market from adopting XBRL based accounting information. Additionally, the analysis showed the impacts on the reporting cycle of accounting information and its usefulness of accounting data itself.

• The Journal of Industrial Distribution & Business
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• v.8 no.1
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• pp.33-39
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• 2017

Purpose - The main purpose of the current study is to examine the impact of accounting information quality and information asymmetry on the underinvestment phenomenon among the listed companies on the Tehran Stock Exchange (TSE). Research design, data, and methodology - The population includes 94 firms selected through systematic sampling. The data is collected from the audited financial statements of the firms provided by TSE's website from 2010 to 2015. Accounting information quality and information asymmetry is considered as independent variables, and their impact is examined on the dependent variable (underinvestment). Results - The statistical results, based on data collected from 94 listed companies on the TSE during 2010-2015, revealed positive impact of accounting information quality and positive impact of information asymmetry on underinvestment. There was a significant relationship between accrual quality (AQ) and underinvestment, and spread and underinvestment. The results also showed that information asymmetry is the main factor in the creation underinvestment. Conclusions - Findings of this article can assist accounting researchers and theoreticians in comparing Real world facts with hypotheses developed with respect to accounting information quality, information asymmetry and underinvestment. However, the results of fuzzy regression analysis indicate significant relationships between the independent variable except underinvestment.

• The Journal of Information Technology
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• v.7 no.4
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• pp.119-127
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• 2004

As increasing trade through the world, especially in food, asymmetry of information can make the trade shrink. With the industrial development, Korea's agriculture had shrunk dramatically. By the result of the nation's industrial restructuring, over than 3/4 of Korea food consumption comes from abroad. And China is an important source of agricultural product to Korea. Increasing family income and increasing importing food consumption, Korean consumers have been interested in food safety. Especially. after experiencing several cases like struggle for safety of GMO food, poultry influenza, lead contained Chinese fish import, mad cow disease, cheating origin, etc. Obviously, those unreliable cases will hinder the increase of world free trade as well as the trust of two countries. Furthermore, distrust will be a cause of adverse selection. So, it need to find a way to solve the distrust which caused by asymmetry of information. And automatic identification procedures can help mitigate asymmetry of information in trade. And it will make Korean consumers can avoid adverse selection. This paper suggests adoption of Auto ID to encourage agricultural trade between Korea and China.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2588-2597
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• 2011

The EEG asymmetry of prefrontal lobe has been researched to analyze the affect such as depression or anxiety and the behavioral characteristics such as BIS(Behavioral Inhibition System)/BAS(Behavioral Activational System) on the basiss of alpha band. However there has been several proposals about the importance of beta asymmetry pointing out the limitation of alpha asymmetry. Here, for 44 numbers of 4-year-old children, by comparing alpha asymmetry and beta asymmetry with BIS/BAS results respectively, we propose the way to classify the characteristics of affect and behavioral trend. We also found that BIS is related with beta-asymmetry, while BAS is related with alpha-asymmetry. As for the affective trait, we use the alpha asymmetry following the other results. Our results seem to be consistent with the other results that the synapse formation of young children is more active at the hemisphere than the right hemisphere.

• Physical Therapy Korea
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• v.27 no.4
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• pp.241-249
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• 2020

Background: Prolonged standing during work causes a lower extremity pain and disorders. Patellofemoral pain syndrome (PFPS) is one of the common diagnoses of the knee pain. Although the etiology of PFPS is not completely understood, it is considered to be multifactorial. Objects: The purpose of this study was to investigate difference in strength of knee muscles, quadriceps:hamstring muscles strength ratio (Q:H ratio), asymmetry ratio of knee muscles strength and dorsiflexion range of motion (ROM) between standing workers with and without PFPS. Methods: Twenty-eight standing workers with PFPS and 26 age-, height-, and weight-matched standing workers without PFPS participated in this study. A tension sensor measured knee muscle strength, and motion sensor measured dorsiflexion ROM. The asymmetry ratio of knee muscles was calculated by a specific formula using the knee muscles strength of the dominant side and the sound side. An independent t-test was used to identify significant differences in the strength, ROM, Q:H ratio, and asymmetry ratio between the PFPS and normal groups. Results: The standing worker with PFPS have significantly lower dorsiflexion ROM (p < 0.000) and higher asymmetry ratio of the hamstring muscles strength (p < 0.000) compare to the standing worker without PFPS. No significant differences were seen in the strength of quadriceps muscle and hamstring muscles, Q:H ratio, and asymmetry ratio of quadriceps muscle strength. Conclusion: There was a significant difference in the asymmetry ratio of the isometric hamstring muscle strength. This finding suggests that the asymmetry ratio of isometric hamstring muscle strength may be more important than measuring only the hamstring muscle strength of the PFPS side. Furthermore, the results of this study showed a significant difference in dorsiflexion ROM between the standing industrial workers with and without PFPS. Dorsiflexion ROM and isometric hamstring muscle strength should be considered when evaluating the subjects with PFPS.

• Korean Business Review
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• v.10
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• pp.23-33
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• 1997

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.3827-3833
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• 2011

This paper performed empirical tests of the validity of the pecking order theory which explains financing behavior of firms under information asymmetry. The results of regression analyses using the data of listed manufacturing companies in the Korean Stock Market from 1981 to 2010 have shown strong evidences supporting the pecking order theory. Especially regression coefficients of change of debt on funds deficit and control variables were found to be almost (+1) with statistically significance, which is interpreted as being consistent with the pecking order theory. Same results were found when I performed regression analyses by dividing the sample period into pre-currency crisis period, currency crisis period and post-currency crisis period and using 2 regression models. Change of tangible asset were found to function as collateral rather than reducing information asymmetry and as the firm size decreased, use of debt increased and as profitability increased use of debt decreased, which are consistent with the pecking order theory.