• Structural Engineering and Mechanics
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• v.86 no.6
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• pp.715-730
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• 2023

Broad studies have addressed the issue of structural element damage identification, however, rubber bearing, as a key component of load transmission between the superstructure and substructure, is essential to the operational safety of a bridge, which should be paid more attention to its health condition. However, regarding the limitations of the traditional bearing damage detection methods as well as few studies have been conducted on this topic, in this paper, inspired by the model updating-based structural damage identification, a two-stage bearing damage identification method has been proposed. In the first stage, we deduce a novel bearing damage localization indicator, called element relative MSE, to accurately determine the bearing damage location. In the second one, the prior knowledge of bearing damage localization is combined with sailfish optimization (SFO) to perform the bearing damage estimation. In order to validate the feasibility, a numerical example of a 5-span continuous beam is introduced, also the noise robustness has been investigated. Meanwhile, the effectiveness and engineering applicability are further verified based on an experimental simply supported beam and actual engineering of the I-40 Bridge. The obtained results are good, which indicate that the proposed method is not only suitable for simple structures but also can accurately locate the bearing damage site and identify its severity for complex structure. To summarize, the proposed method provides a good guideline for the issue of bridge bearing detection, which could be used to reduce the difficulty of the traditional bearing failure detection approach, further saving labor costs and economic expenses.

• Economic and Environmental Geology
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• v.54 no.3
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• pp.353-364
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• 2021

Since the mid-twentieth century, geology has gradually evolved as an interdisciplinary context in South Korea. The journal of Economic and Environmental Geology (EEG) has a long history of over 52 years and published interdisciplinary articles based on geology. In this study, we performed a literature review using topic modeling based on Latent Dirichlet Allocation (LDA), an unsupervised machine learning model, to identify geological topics, historical trends (classic topics and emerging topics), and association by analyzing titles, keywords, and abstracts of 2,571 publications in EEG during 1968-2020. The results showed that 8 topics ('petrology and geochemistry', 'hydrology and hydrogeology', 'economic geology', 'volcanology', 'soil contaminant and remediation', 'general and structural geology', 'geophysics and geophysical exploration', and 'clay mineral') were identified in the EEG. Before 1994, classic topics ('economic geology', 'volcanology', and 'general and structure geology') were dominant research trends. After 1994, emerging topics ('hydrology and hydrogeology', 'soil contaminant and remediation', 'clay mineral') have arisen, and its portion has gradually increased. The result of association analysis showed that EEG tends to be more comprehensive based on 'economic geology'. Our results provide understanding of how geological research topics branch out and merge with other fields using a useful literature review tool for geological research in South Korea.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.608-613
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• 2007

Prediction of corporate bankruptcies has long been an important topic and has been studied extensively in the finance and management literature because it is an essential basis for the risk management of financial institutions. Recently, support vector machines (SVMs) are becoming popular as a tool for bankruptcy prediction because they use a risk function consisting of the empirical error and a regularized term which is derived from the structural risk minimization principle. In addition, they don't require huge training samples and have little possibility of overfitting. However. in order to Use SVM, a user should determine several factors such as the parameters ofa kernel function, appropriate feature subset, and proper instance subset by heuristics, which hinders accurate prediction results when using SVM In this study, we propose a novel hybrid SVM classifier with simultaneous optimization of feature subsets, instance subsets, and kernel parameters. This study introduces genetic algorithms (GAs) to optimize the feature selection, instance selection, and kernel parameters simultaneously. Our study applies the proposed model to the real-world case for bankruptcy prediction. Experimental results show that the prediction accuracy of conventional SVM may be improved significantly by using our model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.2
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• pp.39-48
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• 2001

In recent years, the marine traffic congestion has increased due to the expansion of vessel traffic volume in Korean coastal waterway. Heavy traffic could bring serious marine casualties which cause the loss of human lives, properties and marine pollution in coastal area. The prevention of marine accidents has been a major topic in marin society and various policies and countermeasures have been developed, applied to the industries. VTS(Vessel Traffic Services) is considered as one of effective method to promote marine safety but it needs relatively huge amount of budgets to build and also number of personnels for the operation. Thus prior to establishing the VTS. It should be surveyed the marine traffics, general conditions of waterway including geographical, meteorological characteristics and assessed to find the most reasonable area and places for the system. Therefore this paper aims to develop the method for this evaluation through the hierarchical evaluation structure model in connection with ISM(interpretive structural modeling) and AHP(analytic hierarchy process) methods. The model in this paper is applied to 4 coastal area in Korean waterway as candidates and found that the priority for the needs of VTS should be in order such as Yosu, Wando, Mokpo, Geoje coastal area.

• Journal of Distribution Science
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• v.13 no.11
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• pp.15-22
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• 2015

Purpose - This study aims to propose and validate a research model that describes the relationships between customer socialization, customer participation, and customer loyalty in the online service industry. Although customer loyalty is frequently discussed topic in marketing and strategy research, this study takes a novel approach in adopting customer socialization and participation as the antecedents to customer loyalty. Research design, data, and methodology - Based on adopting and modifying measurement items of the constructs from previous studies, this study develops survey regarding the constructs within the proposed research model. Among current registered members of Facebook and DaumKakao, 522 college students and other regular users are selected as the samples for conducting the survey. The collected data is analyzed by structural equation modeling method using SPSS and AMOS. Results Proposed hypotheses of the positive relationships - between customer socialization and customer participation, and between customer participation and customer loyalty are all supported. Conclusions - The results of this study suggest customer participation as an important precursor to customer loyalty in the online service industry. Also, customer socialization is validated as a new strategy to increase customer participation. These results validate the practical importance of communicating mission, purpose, value, and other customer socialization activities that firms undertake.

• Proceedings of the Korean Society for Quality Management Conference
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• 2004.04a
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• pp.38-43
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• 2004

Customer satisfaction is becoming an increasingly salient topic in many firms and in academic research. One main rationale behind this interest is that customer satisfaction is believed to be associated with fruitful customer re-visit from the firm's point of view. Some country already had index models which can measure the degree of customer satisfaction. But, such models are ordinary models which used generally the scope of nation-wide industry. Therefore, we needs some modifications to measure customer satisfaction for specific product & service and to provide the valuable feedback to specific firms. In this perspectives, this study will evaluate the customer satisfaction index about automobile company and analyze it's result for valuable feedback. This study will present a model for an integrated customer satisfaction evaluation system which used structural equation modeling. Through this study, we anticipate that it will offer the measuring method about customer satisfaction and some guideline for product design process.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.101-113
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• 2013

Although the methodological literature is replete with advice regarding the development and validation of multi-item scales based on reflective measures, the issue of index construction using formative measures has received little attention. The aim of this paper is to enhance researchers' understanding of formative measures of high-order factor and assist them in their index construction efforts. This article is also to provide some insights into the nature of formative indicators for researchers to reach an informed choice as to the appropriate high order formative measurement model for their needs. We first provide a brief background on formative indicators, drawing from the limited and fragmented literature on the topic. Next we give an example of constructing an index based on actual survey data and highlight the procedures used to assess its quality. We conclude the article with some thoughts about the use of indexes in empirical studies.

• Earthquakes and Structures
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• v.20 no.2
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• pp.201-213
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• 2021

Contrast to the conventional jointed bridge design, integral abutment bridges (IABs) offer some marked advantages like reduced maintenance and enhanced service life of the structure due to elimination of joints in the deck and monolithic construction practices. However, the force transfer mechanism during seismic and thermal movements is a topic of interest owing to rigid connection between superstructure and substructure (piers and abutments). This study attempts to model an existing IAB by including the abutment backfill interaction and soil-foundation interaction effects using Winkler foundation assumption to determine its seismic response. Keeping in view the significance of abutment behavior in an IAB, the probability of damage to the abutment is evaluated using fragility function. Incremental Dynamic Analysis (IDA) approach is used in this regard, wherein, nonlinear time history analyses are conducted on the numerical model using a selected suite of ground motions with increasing intensities until damage to abutment. It is concluded from the fragility analysis results that for a MCE level earthquake in the location of integral bridge, the probability of complete damage to the abutment is minimal.

• The Journal of Economics, Marketing and Management
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• v.11 no.2
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• pp.1-11
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• 2023

Purpose: With the rapid development of e-commerce, logistics services, as an important part of e-commerce shopping, have gradually attracted people's attention. Customer engagement behavior is a new topic in marketing, and its connotation is still being explored. The purpose of this paper is to study the relationship between logistics service quality and customer engagement behavior. Research design, data and methodology: This study employed the method of online questionnaire survey, with Chinese e-commerce platform users as the survey objects, 248 valid survey sample data were collected, and the method of factor analysis and structural equation model analysis was used to verify the research hypothesis model constructed in this paper. Results: The four dimensions of e-commerce logistics service quality have different influences on customer satisfaction, and the influence of availability on customer satisfaction is not significant. Convenience, assurance, and security have a significant positive impact on customer satisfaction; Customer satisfaction has a significant positive impact on the three dimensions of customer engagement behavior: customer repeat purchase behavior, online word-of-mouth, and customer referrals. Conclusion: The results of this study will provide useful reference for the managers of e-commerce companies to improve customer engagement behavior by improving the logistics service quality.

• The Journal of Information Systems
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• v.32 no.3
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• pp.63-83
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• 2023

Purpose With the continuous growth of the OTT services market, trust issues are becoming increasingly important, but research on this topic is still in its infancy. The purpose of this study is to identify the structural relationship between information system quality and reuse intention of OTT services and to analyze the impact of trust and user satisfaction. Design/methodology/approach This study proposed a research model based on the information system success model. In this study, a survey was conducted among 236 Korean users who have used OTT services within the last six months. Findings The results of the analysis showed that text quality and visual quality had a significant impact on trust in OTT services, with text quality having the largest impact. System quality and text quality also had a significant impact on trust in OTT service providers. However, visual quality did not have a statistically significant effect on trust in the service provider. Trust in the OTT service and the service provider was analyzed to have a significant impact on user satisfaction. However, it did not have a statistically significant impact on reuse intention. These findings have important implications for improving trust in OTT services to increase users' reuse intentions. It is also expected to contribute to further expanding the field of OTT service research.