• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.223-226
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• 2009

Various database and analysis system has been used for the cost effective maintenance of distribution facility but it is not effective because of the lack of interconnection among these systems. In order to overcome this problem this paper proposes reliability centered maintenance system based on the on-line monitoring of distribution system through intelligent distribution equipment. This system is made by the interconnection of distribution automation system, asset management system, failure analysis system and failure mode effect analysis system.

• East Asian Economic Review
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• v.25 no.2
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• pp.125-150
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• 2021

The paper investigates investor sentiment's role in boosting Japanese companies to enhance their environmental, social, and corporate governance (ESG) performance. Using ESG scores of 367 firms between 2005 and 2019 from the ASSET4 database, we find that negative sentiment in the previous year, both firm and market level, can be a stimulation for the company's commitments to its ESG activities next year. Notably, the moderating effect of the business sector and economic cycle on the sentiment-ESG inference are detected in our study differentiating between corporate and market sentiment, which have never been reported before. In detail, we discover that the impact of firm-specific sentiment is less pronounced for high-sensitive ESG firms. On the other hand, the driving force of market sentiment on corporate social behaviors weakens when economic recessions happen. Our results are robust after controlling for potential endogeneity issues and using alternative proxies for market sentiment.

• Journal of information and communication convergence engineering
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• v.21 no.3
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• pp.233-238
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• 2023

This study presents a method for identifying partial discharge defects in an eco-friendly gas insulated system using a backpropagation algorithm. Four partial discharge (PD) electrode systems, namely, a free-moving particle, protrusion on the conductor, protrusion on the enclosure, and voids, were designed to simulate PD defects that can occur during the operation of eco-friendly gas-insulated switchgear. The PD signals were measured using an ultrahigh-frequency sensor as a nonconventional method based on IEC 62478. To identify the types of PD defects, the PD parameters of single PD pulses in the time and frequency domains and the phase-resolved partial discharge patterns were extracted, and a back-propagation algorithm in the artificial neural network was designed using a virtual instrument based on LabVIEW. The backpropagation algorithm proposed in this paper has an accuracy rate of over 90% for identifying the types of PD defects, and the result is expected to be used as a reference database for asset management and maintenance work for eco-friendly gas-insulated power equipment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.591-599
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• 2021

Rail transit agencies in Korea have been struggling to set up a performance-based rail facility maintenance plan because there are no formal definition and decision criteria for aging infrastructure. This study investigates the definition of aging infrastructure through extensive literature review and identifies benchmarking criteria through comparison with rail transit facility management systems in Korea and United States. As results, an aging infrastructure should be defined considering both service age and performance level of a facility. The priority of repair/replacement should be also determined with reasonable criteria based on relationship between service age and performance level. To determine the definition and decision criteria, a practicable classification system for aging rail transit needs to be established in accordance with classification system for performance assessment. Furthermore, a comprehensive database needs to be built including useful life, performance level, and maintenance cost of each component of rail transit. It will allow establishing an efficient budget execution plan for aging infrastructure.

• International Commerce and Information Review
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• v.19 no.1
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• pp.257-278
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• 2017

The paper examines the ownership structure and the firm value of online firms in the world. Data are gathered by using FACTIVA database for firms in the Dow Jones index for the 2014 fiscal year. The Ordinary Least Squares regressions, the Generalized Linear Model, and the model selection criteria are employed to analyze the relationship between the dependent and the independent variables. The paper tests theories such as the convergence of interest theory, the managerial entrenchment theory, and the eclectic theory. The paper finds that the ownership structure has an influence on the firm value depending on the rank of the large shareholders. While the first large shareholders have a negative association with the firm value, the presence of the second and the third large shareholders have a positive influence on the firm value. The paper also finds that the identity of the largest shareholders whether they are insiders or outsiders have an influence on the firm value. The proportion of shareholding by a large shareholder and her identity are variables which predict a firm value.

• The Journal of Industrial Distribution & Business
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• v.8 no.5
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• pp.87-93
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• 2017

Purpose - This paper investigates whether managerial overconfidence is associated with firm-specific crash risk. Overconfidence leads managers to overestimate the returns of their investment projects, and misperceive negative net present value projects as value creating. They even use voluntary disclosures to convey their optimistic beliefs about the firms' long-term prospects to the stock market. Thus, the overconfidence bias can lead to managerial bad news hoarding behavior. When bad news accumulates and crosses some tipping point, it will come out all at once, resulting in a stock price crash. Research design, data and methodology - 7,385 firm-years used for the main analysis are from the KIS Value database between 2006 and 2013. This database covers KOSPI-listed and KOSDAQ-listed firms in Korea. The proxy for overconfidence is based on excess investment in assets. A residual from the regression of total asset growth on sales growth run by industry-year is used as an independent variable. If a firm has at least one crash week during a year, it is referred to as a high crash risk firm. The dependant variable is a dummy variable that equals 1 if a firm is a high crash risk firm, and zero otherwise. After explaining the relationship between managerial overconfidence and crash risk, the total sample was divided into two sub-samples; chaebol firms and non-chaebol firms. The relation between how I overconfidence and crash risk varies with business group affiliation was investigated. Results - The results showed that managerial overconfidence is positively related to crash risk. Specifically, the coefficient of OVERC is significantly positive, supporting the prediction. The results are strong and robust in non-chaebol firms. Conclusions - The results show that firms with overconfident managers are likely to experience stock price crashes. This study is related to past literature that examines the impact of managerial overconfidence on the stock market. This study contributes to the literature by examining whether overconfidence can explain a firm's future crashes.

• The KIPS Transactions:PartD
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• v.16D no.5
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• pp.701-714
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• 2009

In the enterprises the data integration based on service requires integrated data management as the change in the environment of enterprises accelerates. Cooperation among enterprises is accomplished through accessing distributed database using business process. As this approach is performed based on the global query, problems such as data heterogeneity, schema heterogeneity, and verification of validity have to be solved in advance for the interoperability among the heterogeneous system. Thus, cooperation requires dynamic and reliable construction. In this paper, we propose XMDR-DSM (eXtended MetaData Registry-Data Service Mediator) system for cooperation. XMDR-DSM, which is comprised of XMDR-DS, XMDR-DQP, and XMDR-DAI, supports the mapping between global schema and local schema and provides data access and integration service. Therefore, XMDR-DSM enables the mutual support of business operations among heterogeneous database. In addition, it can secure information as reusable asset and the standardization of interchange. Also it can manage unified information since it provides business process based on workflow; therefore, it will be able to increase the life span of information and reduce the cost.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.941-948
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• 2024

BIM (Building Information Modeling) is touted for efficient building maintenance and operation. However, transitioning from construction to maintenance poses challenges in information transfer and definitive data before completion. Existing structures often lack BIM, demanding more modeling. Additionally, few maintenance staff are skilled in BIM tools.On the other hand, there are studies utilizing point clouds for maintenance. Since point cloud data can record the current situation in 3D, it has advantages such as easily representing valve positions of equipment compared to deformed BIM data.Attribute information uses the international standard COBie, which can record and manage data necessary for building asset management.Point cloud data is broken down into groups of objects necessary for maintenance management by referencing the Common Specification for Building Preservation. Each decomposed object is assigned a corresponding Uniclass number.In this system, the point cloud data, which represents the shape information of the building, is decomposed into objects based on the Common Specification. Using COBie, the building database is created and tasks related to the objects are organized. Each database and system is then connected using Uniclass.By implementing this system, even buildings completed can easily create BIM data from point clouds. Furthermore, since it complies with the international standard COBie, maintenance tasks can be performed in a standardized format, serving as a bridge to the maintenance management system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.1
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• pp.1-5
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• 2020

In this study, the objective is to improve the criteria used for statistical comparison of the VLF tanδ (TD) database and failure rate according to water-tree degradation in underground distribution power cables. The aging condition of the KEPCO criteria is divided into 6 levels using the Weibull distribution, and the "failure imminent" condition is quantified by using the statistical end-point of the lifetime parameter of the VLF big-data group obtained from KEPCO. Moreover, new criteria with a 2-dimensional combination of TD, DTD, and a statistical normalized factor are suggested. These criteria exhibit high reproducibility for the detection of cables in an imminent failure state. Consequently, it is expected that the adoption of the extended VLF-2019 criteria will reduce the asset management cost of cable replacement compared to the VLF-2012 criteria of KEPCO.

• The Journal of Asian Finance, Economics and Business
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• v.4 no.1
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• pp.5-18
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• 2017

Total debt in the People's Republic of China surged to nearly 290% as a ratio to GDP by the second quarter of 2016, mostly on account of non-financial corporate debt. The outpouring of credit to stem the impact of the global financial crisis accentuated industrial overcapacity in traditional sectors, such as steel, cement, and energy, while feeding asset bubbles in the property, equity and bond markets. At the Chinese corporate level, this has translated into weakened fundamentals and a fall in industrial profits, particularly of SOEs. As debtors struggle to service interest payments, non-performing loans (NPLs) have been on the rise. This paper assesses the financial fragility of the Chinese economy by looking at risk factors in the non-financial sector. We apply quantile regressions to a dataset containing all Chinese listed companies in Standard & Poor's IQ Capital database. We find higher sensitivity over time of corporate leverage to some of its key determinants, particularly for firms at the upper margin of the distribution. In particular, profitability increasingly acts as a curb on corporate leverage. At a time of falling profitability across the Chinese non-financial corporate sector, this eases the brake on leverage and may contribute to its continuing increase.