• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.243-264
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• 2018

Although the worldwide battery market is recently spurring the development of lithium secondary battery, lead acid batteries (rechargeable batteries) which have good-performance and can be reused are consumed in a wide range of industry fields. However, lead-acid batteries have a serious problem in that deterioration of a battery makes progress quickly in the presence of that degradation of only one cell among several cells which is packed in a battery begins. To overcome this problem, previous researches have attempted to identify the mechanism of deterioration of a battery in many ways. However, most of previous researches have used data obtained in a laboratory to analyze the mechanism of deterioration of a battery but not used data obtained in a real world. The usage of real data can increase the feasibility and the applicability of the findings of a research. Therefore, this study aims to develop a model which predicts the battery deterioration using data obtained in real world. To this end, we collected data which presents change of battery state by attaching sensors enabling to monitor the battery condition in real time to dozens of golf carts operated in the real golf field. As a result, total 16,883 samples were obtained. And then, we developed a model which predicts a precursor phenomenon representing deterioration of a battery by analyzing the data collected from the sensors using machine learning techniques. As initial independent variables, we used 1) inbound time of a cart, 2) outbound time of a cart, 3) duration(from outbound time to charge time), 4) charge amount, 5) used amount, 6) charge efficiency, 7) lowest temperature of battery cell 1 to 6, 8) lowest voltage of battery cell 1 to 6, 9) highest voltage of battery cell 1 to 6, 10) voltage of battery cell 1 to 6 at the beginning of operation, 11) voltage of battery cell 1 to 6 at the end of charge, 12) used amount of battery cell 1 to 6 during operation, 13) used amount of battery during operation(Max-Min), 14) duration of battery use, and 15) highest current during operation. Since the values of the independent variables, lowest temperature of battery cell 1 to 6, lowest voltage of battery cell 1 to 6, highest voltage of battery cell 1 to 6, voltage of battery cell 1 to 6 at the beginning of operation, voltage of battery cell 1 to 6 at the end of charge, and used amount of battery cell 1 to 6 during operation are similar to that of each battery cell, we conducted principal component analysis using verimax orthogonal rotation in order to mitigate the multiple collinearity problem. According to the results, we made new variables by averaging the values of independent variables clustered together, and used them as final independent variables instead of origin variables, thereby reducing the dimension. We used decision tree, logistic regression, Bayesian network as algorithms for building prediction models. And also, we built prediction models using the bagging of each of them, the boosting of each of them, and RandomForest. Experimental results show that the prediction model using the bagging of decision tree yields the best accuracy of 89.3923%. This study has some limitations in that the additional variables which affect the deterioration of battery such as weather (temperature, humidity) and driving habits, did not considered, therefore, we would like to consider the them in the future research. However, the battery deterioration prediction model proposed in the present study is expected to enable effective and efficient management of battery used in the real filed by dramatically and to reduce the cost caused by not detecting battery deterioration accordingly.

• Journal of Distribution Science
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• v.13 no.9
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• pp.47-57
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• 2015

Purpose - The aim of this paper is to investigate the explanatory power of the Pecking-order theory (the cost of financing increases with asymmetric information) among Korean retail firms from the perspective of debt capacity. According to the Pecking-order theory, a firm's first preference is to use internal funds for its capital needs, its next preference is the issuance of debt, and its last preference is the issuance of equity; this is due to the information asymmetry problem between existing shareholders and investors. However, prior empirical studies, such as Lemmon and Zender (2010), argue that the entire sample test for the Pecking-order theory could be misleading due to the different levels of debt issuance capability of each of the individual firms; in fact, they confirm that the explanatory power of the Pecking-order theory improves after taking into account the differences in debt capacity of the U.S. firms they examined. This paper implements a case study approach among Korean retail firms to examine the relationship between debt capacity and the explanatory power of the Pecking-order theory in Korea. Research design, data, and methodology - This study uses the sample of public retail firms on the Korea Composite Stock Price Index (KOSPI) from the time period of 1990 to 2013. We gather related financial and accounting statements from the financial information firm WISEfn. Credit rating information is provided by the Korea Investor Service. We employ the models of Lemmon and Zender (2010) and Son and Kim (2013) to measure a firm's debt capacity. Their logit models use the rating dummy variable as a dependent variable and incorporate other firm characteristics as independent variables to estimate debt capacity. To test the Pecking-order theory, we adopt variants of the financing deficit model of Shyam-Sunder and Myers (1999). In the test of the Pecking-order theory, we consider all of the changes in total debt obligations, current debt obligations, and long-term debt obligations. Results - Our main contribution to the literature is our confirmation of the predicted relationship between debt capacity and the explanatory power of the Pecking-order theory among Korean retail firms. The coefficients on financing deficits become greater as a firm's debt capacity improves. This is consistent with the results of Lemmon and Zender (2010). The coefficients on the square of the financing deficits are also negative for the firms in the largest debt capacity group, which is also consistent with the predictions in prior literature. Conclusions - This study takes a case study approach by examining Korean retail firms. We confirm that the Pecking-order theory explains the capital structure of retail firms more appropriately, after taking into account the debt capacity of each firm. This result suggests the importance of debt capacity consideration in the testing of the Pecking-order theory. Our result also implies that there has been a potential underestimation of the explanatory power of the Pecking-order theory in existing studies.

• Journal of the Korean Institute of Gas
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• v.22 no.5
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• pp.1-17
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• 2018

Related incidents and accidents are frequent after 2000 years, such as the outbreak of the Taian peninsula crude oil spillage and Gumi hydrofluoric acid leakage accident. In the wake of such environmental pollution accidents, Consensus has been formed to enact legislation on liability for the compensation of environmental pollution in 2014 and the rescue, and has been in force since January 2016. Therefore, in the domestic insurance industry, the introduced environmental liability insurance system needs to be managed through the standardization formula of a new insurance model for managing the environmental risk. This study has been carried out by the emergence of a safe insurance model with a risky nature of the risk type, which is one of the services of the knowledge base. The verification of the six assurance media on the occurrence of environmental pollution such as chemical, waste, marine, soil, etc. is expressed through semantic interoperability through this possible ontology. The insurance model was designed and presented by deducing the relationship between the amount of money and the amount of money that was written in the area of existing expertise, In order to exclude the possible consequences, the concept of abstract is conceptualized in the form of a customer, and a plan for the future development of an ontology-based decision support system is proposed to reduce the cost and resources consumed every year. It is expected that standardization of the verification standard of the mass of mass will minimize errors and reduce the time and resources required for verification.

• Journal of Internet Computing and Services
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• v.18 no.3
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• pp.71-83
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• 2017

In recent years, by utilizing the greatest strengths of process mining, the various research activities have been actively progressed to use auditing work of business organization. On the other hand, there is insufficient research on systematic and efficient analysis of massive data generated under big data environment using process mining, and proactive monitoring of risk management from audit side, which is one of important management activities of corporate organization. In this study, we intend to realize Hadoop-based internal audit integrated real-time monitoring system in order to detect the abnormal symptoms in prevent accidents in advance. Through the integrated real-time monitoring system for purchasing audit, we intend to realize strengthen the delivery management of purchasing materials ordered, reduce cost of purchase, manage competitive companies, prevent fraud, comply with regulations, and adhere to internal control accounting system. As a result, we can provide information that can be immediately executed due to enhanced purchase audit integrated real-time monitoring by analyzing data efficiently using process mining via Hadoop-based systems. From an integrated viewpoint, it is possible to manage the business status, by processing a large amount of work at a high speed faster than the continuous monitoring, the effectiveness of the quality improvement of the purchase audit and the innovation of the purchase process appears.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.600-608
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• 2017

This study analyzed the management index, debt ratio, and business performance of livestock agricultural farming corporations since the Korea international financial reporting standards (K-IFRS) was introduced in 2011. In addition, this study was based on credible accounting reports by the financial supervisory service's DART (data analysis, retrieval and transfer) system. First, after analyzing the key management index, the results showed that the current ratio, debt ratio, and current liabilities ratio decreased and the ratio of the owners increased on the safety index. Regarding the profitability index, the ROA (return on total assets), ROE (return on equity), and ROS (return on sales) increased slightly in 2014 compared to 2013. The overall growth and external growth on the growth index have not increased. Second, an analysis of the debt ratio and business performance, the debt ratio has a negative effect on the ROA and ROS. These results show that the use of debt of livestock agricultural farming corporations contributes to the external growth but it has a negative effect on business performance. These results show that management should consider solutions for the increase in sales to achieve cost reductions. In addition, the debt ratio should be reduced and solutions for an increase in revenue are needed to reduce management expenses, such as propagation of technical development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.920-929
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• 2004

Nowadays, wireless packet data services are provided over cdma2000 1x/1xEV-DO mobile communication network and Portable Internet are being standardized for users demanding higher data rate services. Portable Internet can provide high data rate services, but its service coverage is relatively small. If Portable Internet may be integrated with cdma2000 mobile networks, users are able to choose the best service according to service areas and get seamless services while they are moving around. At the same time, it is cost-effective for operators to construct and maintain the integrated network. For the purpose of effectively integrating Portable Internet into cdma2000 networks, we propose an integration scheme including network architecture, protocol architecture, functions in network elements, interfaces between them, and call-flow procedures. The integration scheme proposed in this paper adopts a tightly-coupled architecture for unified authentication/accounting and seamless services. In addition, the scheme can be implemented without modifying the existing cdma2000 mobile communication networks. It is also simple to develop the dual-mode mobile station. Through the simulation results based on the performance model for handoffs between cdma2000 and Portable Internet, it has teen validated that the proposed scheme diminishes packet losses compared with the loosely-coupled architecture.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.4
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• pp.103-133
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• 2007

The purpose of this study is to investigate whether customer satisfaction is affected by the expenditure for the customer satisfaction such as advertising, promotion, and training. This study also investigate whether the financial performance of the firm is affected by the customer satisfaction. The major findings are summarized as following. First, the customer satisfaction is affected by the expenditure for the customer satisfaction such as promotion, training. But customer satisfaction is not affected by advertising cost. Second, considering the time-lag and incremental valiables, the relationship between customer satisfaction and expenditure for the customer satisfaction is not founded. Third, the customer satisfaction affects positively on the corporate financial performance, such as ratio of operating income to sales, ratio of net income to sales, return on total assets, and return on equity. Finally, considering the time-lag the relationship between customer satisfaction and financial performance is not founded. Considering the incremental valiables, the relationship between customer satisfaction and financial performance is founded when ratio of operating income to sales and return on total assets are used financial performance. These findings imply that the expenditure for promotiom and training is needed to increase the customer satisfaction. Also improvement customer satisfaction is needed to increase the financial performance. The limitations of this study are as following. First, this study could not consider the other variables that would affect on the relationship among expenditure for customer satisfaction, level of customer satisfaction, and financial performance. Second, the results of this study are difficult to generalize because this study is focused on the service industry.

• Management & Information Systems Review
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• v.34 no.2
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• pp.113-130
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• 2015

This study considers the relation between firms' earnings management and credit rating. Unlike preceding papers only focusing earnings management by accrual(thereafter, AM), this paper examines the effect of accrual earnings management(AMs) and real earning management(thereafter, RM) on credit rating. RMs have more negative effects on firms' forward cash flow generation abilities and long term operating performances than AMs. So, RMs are more negative signals for credit analysts than AMs. But credit analysts have much difficulty in seeing through RM, because if credit analysts want to find out RMs, they have to understand firms' internal operating activities, cost structures, receivables collection practices, and review whether profit distortions are due to abnormal change of them. Sample of this study consists of 2,150firm-year data listed companies from 2002 to 2010. Empirical evidence shows that AMs and RMs are negatively related to credit rating. This result implies that credit analysts see through AMs and RMs in interpreting financial informations, that is to say, they discount credit rating in considering level of earnings management that consist of real activity and accrual earning management. This paper also finds that RMs are more negatively related to credit ratings than AMs. This result suggests that credit analysts don't take RMs into account in credit rating process as much as AMs.

• Convergence Security Journal
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• v.7 no.3
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• pp.87-93
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• 2007

We propose a mobile point-of-sale system, which consists of only mobile information terminals and personal computers. The proposed system provides most of functionalities related with resource planning, adminstration and management, provided by medium-scale or large-scale POS systems, with additional functionalities, such as automatic information gathering and management through mobile interconnection, while eliminating the necessity of additional special-purpose devices, such as bar-code systems. The proposed system transmits order information through wireless and wired communication lines, thus allowing real-time sharing of order information among diverse information devices, such as mobile order receiving terminals, main server within stores, monitors and printers located in production lines. Also, the system is able to transfer such detail information produced within stores in real-time to the enterprise-level accounting, sales, logistics, personnel management system, which facilitate enterprise-wide management and administrative decision-making. No additional programs are required for mobile terminals. Order information received by such terminals are entered into databases through web server of main server and that information is again transferred to main server and production line printers. The proposed system can handle all the point-of-sale information and can provide almost of the POS functionalities by simply utilizing wireless internet, personal computers, and mobile terminals without installing specific-purpose peripheral devices. The proposed system can be widely applied to the small-scale stores and will contribute in reducing construction and maintenance cost required for point-of-sale management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5B
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• pp.456-477
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• 2006

Due to advances in wireless communication technology and increasing demand for various types of wireless access, cellular, WLAN, and portable internet(such as WiBro and IEEE 802.16) systems are likely to be integrated into a unified wireless access system. This expectation premises the availability of multi-mode handsets and cooperative interworking of heterogenous wireless access networks allied by roaming contracts. Under such environments, a user may lie in the situation where more than one wireless accesses are available at his/her location, and he/she will want to choose the 'best' access among them. In this paper, we define the 'best' access(es) as the access(es) that charges minimum cost while fulfilling the required QoS of wireless access, and address the problem of choosing the optimal set of accesses theoretically by introducing a graph representation of service environment. Two optimal selection algorithms are proposed, which individually consider cases where single or multiple wireless access can be supported by multi-mode handsets.