• Earthquakes and Structures
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• 제16권1호
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• pp.69-82
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• 2019

As the residual displacement and/or drift demands are commonly used for seismic assessment of buildings, the estimation of these values play a very critical role through earthquake design philosophy. The residual displacement estimation of fixed base structures has been the topic of numerous researches up to now, but the effect of soil flexibility is almost always omitted. In this study, residual displacement demands are investigated for SDOF systems with period range of 0.1-3.0 s for near-field and far-field ground motions for both fixed and interacting cases. The elastoplastic model is used to represent non-degrading structures. Based on time history analyses, a new simple yet effective equation is proposed for residual displacement demand of any system whether fixed base or interacting as a function of structural period, lateral strength ratio and spectral displacement.

• Structural Engineering and Mechanics
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• 제86권6호
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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.

• 자원환경지질
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• 제54권3호
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• pp.353-364
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• 2021

국내 지질학의 연구 분야는 20세기 중반 이후부터 꾸준하게 발전되어왔다. 학술지 "자원환경지질"은 국내 지질학을 대표하는 역사가 긴 학술지로 지질학을 바탕으로 하는 융복합연구 논문이 게재되고 있다. 본 연구는 학술지 "자원환경지질"에 게재된 논문을 대상으로 문헌 고찰(literature review)을 수행하여 지질학의 역사와 발전에 대해 논의하고자 한다. 1968년부터 2020년까지 총 2,571편의 논문 제목, 주제어, 다국어 초록을 수집하였으며, Latent Dirichlet Allocation (LDA) 기반 토픽모델링을 실시하여 연구 주제를 분류하고 연구 동향과 주제간 연관성을 확인하였다. 학술지 "자원환경지질"은 총 8개의 연구주제('암석학 및 지구화학', '수문학 및 수리지질학', '광상학', '화산학', '토양오염 및 복원학', '기초지질 및 구조지질학', '지구물리 및 물리탐사', '점토광물')로 분류할 수 있었다. 1994년 이전에는 '광상학', '화산학', '기초지질 및 구조지질학'의 연구주제들이 활발하게 연구되었으며, 이후 '수문학 및 수리지질학', '토양오염 및 복원학', '지구물리 및 물리탐사', '점토광물'의 연구주제들이 성행하였다. 연관성분석(network analysis)결과, 학술지 "자원환경지질"은 '광상학'을 기반으로 융복합적 연구 논문들이 게재되었다는 것을 확인하였다. 본 연구의 결과는 지질학을 다루는 연구자들에게 문헌 고찰의 새로운 방법론을 제시하여 지질학의 역사에 대한 이해를 제공했음에 의의가 있다.

• 한국경영정보학회:학술대회논문집
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• 한국경영정보학회 2007년도 International Conference
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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.

• 해양환경안전학회지
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• 제7권2호
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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.

• 유통과학연구
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• 제13권11호
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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.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2004년도 품질경영모델을 통한 가치 창출
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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.

• 디지털융복합연구
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• 제11권3호
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• pp.101-113
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• 2013

기존의 방법론 관련 문헌에서는 반영적 지표를 기반으로 다측정 지표들의 개발과 타당성 검정에 관한 다양한 문헌적 고찰을 수행하였음에도 불구하고 형성적 지표에 대한 관심은 부족하였다. 본 연구의 목적은 형성적 지표를 사용함에 있어서 필요한 접근법에 대한 연구자들의 이해를 돕기 위함이다. 또한 연구자들이 자신의 모델을 위해 필요한 적합한 지표의 선택에 도움을 제공하기 위해 형성적 지표의 본질에 대해서도 살펴보고자 한다. 이를 위해 형성적 지표에 대한 기반이론을 살펴보고 다음으로 실증 분석에서 사용된 사례를 통해 형성적 지표의 접근법과 연구수행 절차에 대해 살펴본다. 마지막으로 실증 연구에서 지표의 사용에 관한 제언을 하고자 한다.

• Earthquakes and Structures
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• 제20권2호
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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.

• 융합경영연구
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• 제11권2호
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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.