• 한국컴퓨터정보학회논문지
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• 제21권6호
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• pp.107-115
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• 2016

In this paper, we propose a Bicycle sharing has grown popular around the cities in the world due to its convenience. However, the bicycle sharing system is not problem-free, and there remains many managerial problems to be solved. In this study, we analyzed pricing strategy of a bicycle sharing system by minimizing the number of bicycles relocated by trucks, the act of which incurs penalty. The objective function is constructed by applying mixed integer programming and is presented as a stochastic model by using Markov chain so that arrival and departure rates of bicycle stations can be utilized in the analysis. The efficiency of the presented model is verified upon the analysis of bicycle sharing data gathered in Daejeon in 2014.

• ETRI Journal
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• 제44권2호
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• pp.220-231
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• 2022

Building smart transportation services in urban cities has become a worldwide problem owing to the rapidly increasing global population and the development of Internet-of-Things applications. Traffic congestion and environmental concerns can be alleviated by sharing mobility, which reduces the number of vehicles on the road network. The taxi-parcel sharing problem has been considered as an efficient planning model for people and goods flows. In this paper, we enhance the functionality of a current people-parcel taxi sharing model. The adapted model analyzes the historical request data and predicts the current service demands. We then propose two novel online routing algorithms that construct optimal routes in real-time. The objectives are to maximize (as far as possible) both the parcel delivery requests and ride requests while minimizing the idle time and travel distance of the taxis. The proposed online routing algorithms are evaluated on instances adapted from real Cabspotting datasets. After implementing our routing algorithms, the total idle travel distance per day was 9.64% to 12.76% lower than that of the existing taxi-parcel sharing method. Our online routing algorithms can be incorporated into an efficient smart shared taxi system.

• Steel and Composite Structures
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• 제12권6호
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• pp.523-540
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• 2012

It was clear from the former researches on reinforced concrete filled tubular steel (RCFT) structures that RCFT structures have different performance than concrete filled steel tubular (CFT) structures. However, despite of that, load-sharing ratio of RCFT is evaluating by the formula and range of CFT given by JSCE. Therefore, the aim of this investigation is to study the load-sharing ratio of RCFT columns subjected to axial compressive load by performing numerical simulations of RCFT columns with the nonlinear finite element analysis (FEA) program - ADINA. To achieve this goal, firstly proper material constitutive models for concrete, steel tube and reinforcement are proposed. Then axial compression tests of concrete, RC, CFT, and RCFT columns are carried out to verify proposed material constitutive models. Finally, by the plenty of numerical analysis with small-sized and big-sized columns, load-sharing ratio of RCFT columns was studied, the evaluation formulas and range were proposed, application of the formula was demonstrated, and following conclusions were drawn: The FEA model introduced in this paper can be applied to nonlinear analysis of RCFT columns with reliable results; the load-sharing ratio evaluation formula and range of CFT should not be applied to RCFT; The lower limit for the range of load-sharing ratio of RCFT can be smaller than that of CFT; the proposed formulas for load-sharing ratio of RCFT have practical mean in design of RCFT columns.

• 한국IT서비스학회지
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• 제19권5호
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• pp.65-81
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• 2020

This study aims to examine the effects of users' perceptions of COVID-19 risk on their seeking and processing of relevant information as COVID-19 emerges and spreads worldwide in 2019. We apply the risk information seeking and processing model (RISP Model) to verify whether users' COVID-19 related information seeking and processing behaviors have a positive effect on their preventive and information sharing behaviors. To achieve this research goal, an online survey was conducted with about 400 of social media users. The users' perceptions of risk for COVID-19 increased their perceived insufficiency of COVID-19 information. In addition, the perceived insufficiency of users' information formed a positive relationship with seeking and searching of information behaviors. The processing of COVID-19 related information has increased related preventive behaviors and sharing of information through social media. While searching for information related to COVID-19 prompted personal information sharing behaviors, it did not significantly affect preventive behaviors. Accordingly, in order to promote COVID-19 preventive behaviors as well as overall user health-related behaviors it can be inferred that additional measures are needed in addition to pursuing relevant information.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.263-272
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• 2018

Purpose: The load on the planet gear of a planetary gear set is uniformly distributed. However, manufacturing and assembly errors cause uneven load sharing in the planetary gear set. To solve this problem, most studies have suggested applying a floating sun gear to the planetary gear set. However, the effect of the floating ring gear and floating carrier has not been extensively studied. This study aimed to investigate the effect of the floating ring gear. Methods: Two models were developed; one was the fixed ring gear model, and the other was the floating ring gear model. In the fixed ring gear model, the clearance between the ring gear and the housing was $0{\mu}m$, and in the floating ring gear model, the clearance was from $10{\mu}m$ to $100{\mu}m$. The load sharing of the planetary gear set was evaluated by the load sharing factor. Results: Our study showed that with increase in clearance, the load sharing factor of the planetary gear set approached unity. In addition, when the clearance increased above a certain level by which a fully floating ring gear was achieved, the load sharing factor was not affected by the clearance. Conclusions: This indicates that the fully floating ring gear increased the power density of the planetary gearbox by uniformly dividing the load of the planetary gear set. For this reason, the size of the gearbox could be decreased by using a fully floating ring gear.

• 지식경영연구
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• 제21권1호
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• pp.151-173
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• 2020

The purpose of this study is to identify the antecedents that impact on the individual knowledge sharing based on motivational perspectives. Specifically, the authors investigate the roles of general self-efficacy and popularity on knowledge sharing drawn on costly signaling theory and trait activation theory. Data from 227 pairs of employees and coworkers working in companies located in South Korea supported the model. General self-efficacy was positively related to knowledge sharing and popularity was positively associated to knowledge sharing. Also, by taking an interactional approach, our study demonstrated the moderating effect of popularity on the relationship between general self-efficacy and knowledge sharing. The positive relationship between general self-efficacy and knowledge sharing is significant when popularity is low, but not significant when popularity is high. Our findings suggest that the various motivation types including intrinsic and extrinsic motivations for knowledge sharing of individuals exist simultaneously and these motivations have an interactive effect on knowledge sharing.

• 한국전자거래학회지
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• 제7권3호
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• pp.121-137
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• 2002

SCM(Supply Chain Management) have been introduced in many companies for integrated management and improvement of business process. Recently, as internet and e-business concept are spread globally, the SCM concept is expanded from one internal company process to inter-company process, it makes a Global SCM concept. In this paper, we discuss the implementation of the Global SCM concept using e-business infrastructure, and propose SCM portal models. Four types of the SCM portal model are discussed, which are forecasting information sharing model, e-Marketplace-typed model, collaboration model and logistics information sharing model. The major concept of the SCM portal is to share information of supply chain process, it provide merits of scale to company. The result of this paper can be summarized as follows : First, the information sharing is very useful in the Global SCM. Second, the e-business infrastructure, especially e-Marketplace can be usefully used for implementation of SCM portal. Third, the M2M(Market to Market) function of e-Marketplace is a major function for implementing SCM portal.

• 한국경영과학회지
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• 제36권1호
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• pp.69-84
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• 2011

In this study, based on the principal-agent paradigm, we investigate a joint cost reduction activity in a buyer-supplier supply chain where a buyer motivates its operations department and a supplier to reduce the supply chain's production cost. We construct a benefit-sharing model based on the target cost scheme, a basic philosophy in practice which has not been explored in previous studies. The model also incorporates various supply chain issues such as the cooperation of multiple agents, the opportunity loss, and the degree of strategic relationship between the buyer and the supplier. Based on the analysis of the principal-agent model, we investigate the benefit-sharing rule to control agents' actions, and we also provide important managerial implications into supply chain practices via extensive comparative static analyses.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.564-568
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• 2005

Recently, Knowledge Management (KM) has been applied to construction industry. Surprising, there is few studies that address the most fundamental problem in KM: people may prefer not to share their knowledge so as to preserve their intellectual or unique values in the organization. Without the premise of each individual's willingness to share knowledge, there will be no valuable input for the IT system and, thus, no knowledge management at all. This paper aims to model the behavioral dynamics of knowledge sharing and to design an incentive system that may facilitate knowledge sharing for construction companies. In this paper, a game-theory based model will be developed, and the framework for designing an incentive system will be proposed according to the model.

• 정보보호학회논문지
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• 제34권3호
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• pp.463-478
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• 2024

발전제어시스템의 보안 취약점 개선을 위한 선행 연구의 한계점을 분석하고 그 대안으로 사이버 보안 정보공유모델을 제안하였다. 발전제어시스템의 운영 특성을 파악하고 사이버 보안 정보공유 개념과 정책, 실제 구현사례들을 분석하여 발전제어시스템에 효과적으로 적용할 수 있는 정책과 기술방안을 제시하고 모델평가를 시행하였다.