• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.3
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• pp.92-98
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• 2017

The rapid growth of engineering technology and the emergence of systemized and large-scale engineering systems have resulted in complexity and uncertainty throughout the lifecycle activities of engineering systems. This complex and large-scale engineering system consists of numerous components, but system failure can be caused by failure of any one of a number of components. There is a real difficulty in managing such a complex and large-scale system as a part. In order to efficiently manage the system and have high reliability, it is necessary to structure a system with a complex structure as a sub-system. Also, in the case of a system in which cause of failures exist at the same time, it is required to identify the correlation of the components lifetime and utilize it for the design policy or maintenance activities of the system. Competitive risk theory has been used as a theory based on this concept. In this study, we apply the competitive risk theory to the models with combined structure of series and parallel which is the basic structure of most complex engineering systems. We construct a competing risks model and propose a mathematical model of net lifetime and crude lifetime for each cause of failure, assuming that the components consisting a parallel system are mutually dependent. In addition, based on the constructed model, the correlation of cause of failure is mathematically analyzed and the hazard function is derived by dividing into net lifetime and crude lifetime.

• The KIPS Transactions:PartD
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• v.18D no.4
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• pp.299-308
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• 2011

In the recent years, a variety of projects have been conducted in order to enhance competitiveness of leading businesses and their followers in the market. Accordingly, the importance of project portfolio management has risen in the open market industry. Project portfolio management refers to crucial decision-making processes which aim to maximize benefits by selecting projects most suitable for a strategic objective among multiple projects with limited resources. In this study, the trend of project portfolio management studies is introduced. The study also presents a mathematical model of the problem, which aims at maximizing project values, possibility, and similarity between projects in the limited resources. We use the genetic algorithm to obtain the priority orders of projects. In order to verify this study, we compare the results of this study and the existing schedules of the E-open market in South Korea. This study ultimately reduces project risks, improves efficiency of development and continuity of tasks by properly ordering projects and assigning developers to the projects.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.123-135
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• 2018

The objective of this paper is to investigate the issues related to the supply chain management in plant engineering industry, and propose the framework to improve the project efficiency. The preliminary case study shows that EPC's fragmented nature, lack of coordination and information sharing, and lack of proper risk and change management contribute to project delay and cost overrun. To examine the level of informatization and information sharing in supply chain, survey responses from the suppliers and subcontractors have been collected. The statistical results show that information sharing, early involvement in design process and awareness in SCM have influenced the level of collaboration, but supplier assessment and informatization have no impact on the collaboration. A conceptual model is proposed in order to facilitate the integration of design, procurement and construction functions. Implications from the study are also provided.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.287-297
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• 2019

Responding to the rapid delivery demands and variety of small-volume products through human resource-dependent logistics operations in online markets is difficult. Logistics robots in fulfillment centers are expected to increase due to difficulties in hiring workers and rising labor costs. Amazon operates more than 100,000 robots in its Fulfillment centers. Alibaba, DHL, and UPS are also introducing robot technology to improve the logistics efficiency. Logistics robots are being used actively in the fierce online market competition of the global distribution industry. On the other hand, Korea is relatively sluggish. To revitalize the introduction of logistics robots in Korea, it is necessary to examine the factors that influence acceptance. The description of acceptability was based on an expanded technology acceptance model that has been verified through various studies. Studies have shown that both the ease and usefulness of purchasing have significant effects, and that ease has the greatest effect. The more experience involved, the more innovative, the more positive. The usefulness was shown to be positive as the perceived risks are low, price efficiency is good, and social impact is greater. This study provides theoretical and practical implications for logistics robot development and marketing.

• Asia Marketing Journal
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• v.8 no.1
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• pp.49-76
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• 2006

This study investigates the effect of market orientation of knowledge-based service suppliers on the sourcing process of service recipients. Focusing on a dyadic relationship between a supplier and a buyer, this study proposed a conceptual model of market orientation incorporating the antecedents and consequences of market orientation. This study empirically tested research hypotheses delineated from the conceptual framework. The present study revealed that the impact on the buyer's performance of the supplier's customer and competitor orientation turned out to be more influential than that of inter-departmental cooperation. Also these two dimensions of customer and competitor orientation played a positive role in reducing buyer's perceived risk and uncertainty related to the evaluation of services out-sourced. Interestingly enough, the supplier's perceived importance on the distance between the buyer and supplier remains important especially when the degree of buyer's market orientation is high. This finding is somewhat contrary to the fact that the geographic location of the buyer becomes less important for the internet-based B2B service providers. Based on the findings, this study suggested managerial implications and broadened the scope of academic research in the field of business services. Future research directions and the limitations of this study are also discussed.

• Korean Journal of Social Welfare Studies
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• v.42 no.1
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• pp.219-242
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• 2011

This study examined the factors associated with exit from and reentry into the rehabilitation center among homeless persons with mental illness. Shelter use of a total of 203 study population was monitored between 2004 and 2008. Cox's proportional hazard model was employed to analyze the factors influencing the rate of the first exit from and the first reentry into the rehabilitation center. Also, competing risk analysis was conducted to examine the factors differently associated with the type of the first exit from the rehabilitation center: a positive exit and a negative exit. This study found that homeless persons with mental illness were less likely to experience the negative exit while their resident registration status not being abolished on the first entry into the rehabilitation center, having more frequent hospitalizations during the rehabilitation center stay, being connected to the family members, having more participations into the basic rehabilitation, mental rehabilitation, and vocational rehabilitation programs during the rehabilitation center stay. Age, the number of hospitalization and of the participations into the mental rehabilitation programs during the rehabilitation center stay were associated with the rate of the first reentry into the rehabilitation center.

• Journal of Korea Technology Innovation Society
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• v.10 no.2
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• pp.255-283
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• 2007

As of April 2006, Korea had successfully invited twelve global IT R&D centers to help implement the u-IT839 strategy, but there have also been some worries about their research and collaboration performance in Korea. Although it is too early to judge the invitation outcome only after two years or less of their working, the Korean government is being advised to employ a more customized invitation strategy. In this paper, an analytic framework for the attraction of global R&D centers is developed based on the attractiveness-competitiveness matrix, and is applied empirically to the IT industry. Fourteen major IT technology categories and their sub-technological areas are classified into four strategic groups (priority group, wish group, consideration group, and hold group) along the framework via expert surveys and the Analytic Hierarchy Process (AHP) technique. This study is expected to help the government to implement the 'select and focus' strategy in inviting global R&D centers and creating synergy effects between them by providing basic data on global R&D partnership priorities. The implications and limitations of the research and future research directions are discussed at the final section.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.153-168
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• 2019

Augmented Reality(AR) has been one of the important technologies of the 4th industrial revolution. Consumer acceptance of new technologies is substantial issue for market expansion, but there have been few empirical studies on factors that affect the acceptance or use intention of AR. In this study, we have explored and analyzed the factors influencing technology acceptance based on the extended unified theory of acceptance and use of technology(UTAUT2) model in the AR business and have discussed it with comparison with existing research based on this analysis. The results of this study suggest that the main variables of the existing UTAUT1 model had significant positive effect on the intention to use, such as performance expectancy, effort expectancy, facilitating conditions and hedonic motivation, habits of UTAUT2. In addition, perceived risk introduced in this study had a negative effect on intention to use. Furthermore, the impact between these two factors have been effort expectancy(${\beta}=.294$)>habits(${\beta}=.268$)>hedonic motivation(${\beta}=.266$)>performance expectancy,(${\beta}=.263$)>facilitating conditions(${\beta}=.233$)>perceived risk(${\beta}=-.094$). The impact of social influence did not have a significant effect on intention to use. The intention to use was analyzed to have a significant positive effect on the actual use and recommendation intention. On the other hand, the hypothesis that the age and gender has played a moderating role between independent variables and the intention of use were investigated. Age was found out to play a role as a moderator between social influence, facilitating conditions, hedonic motivation, habits and intention to use. In the same way, gender has been shown to play a moderating role between facilitating conditions, perceived risk and intention to use. Academic and practical implications are suggested based on the results of this study.

• Asia Marketing Journal
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• v.13 no.3
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• pp.25-53
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• 2011

This study probes the effect of loyalty program on the customer retention based on the real transaction data(n=2,892) acquired from education service industry. We try to figure out the outcomes of reward program through more than 1 year-long data gathered and analyzed according to quasi-experimental design(i.e., before and after design). We adopt this kinds of research scheme in regard that previous studies measured the effect of loyalty program by dividing the customers into two group(i.e., members vs. non-members) after the firms or stores had started the program. We believe that it might not avoid the self-selection bias. The research questions of this study could be explained such as: First, most research said that the loyalty programs could increase the customer loyalty and contribute to the sustainable growth of company. But there are little confirmation that this promotional tool could be justified in terms of financial perspective. Thus, we are interested in both the retention rate and financial outcomes caused by the introduction of loyalty programs. Second, reward programs target mainly current customer. Especially CRM(customer relationship management) said that it is more profitable for company to build positive relationship with current customer instead of pursuing new customer. And it claims that reward program is excellent means to achieve this goal. For this purpose, we check in this study whether there is a interaction effect between loyalty program and customer type in retaining customer. Third, it is said that dis-satisfied customers are more likely to leave the company than satisfied customers. While, Bolton, Kannan and Bramlett(2000) claimed that reward program could contribute to minimize the effect of negative service by building emotional link with customer, it is not empirically confirmed. This point of view explained that the loyalty programs might work as exit barrier to current customer. Thus, this study tries to identify whether there is a interaction effect between loyalty program and service experience in keeping customer. To achieve this purpose, this study adopt both Kaplan-Meier survival analysis and Cox proportional hazard model. The research outcomes show that the average retention period is 179 days before introducing loyalty program but it is increased to 227 days after reward is given to the customers. Since this difference is statistically significant, it could be said that H1 is supported. In addition, the contribution margin coming from increased transaction period is bigger than the cost for administering loyalty programs. To address other research questions, we probe the interaction effect between loyalty program and other factors(i.e., customer type and service experience) affecting it. The analysis of Cox proportional hazard model said that the current customer is more likely to engage in building relationship with company compared to new customer. In addition, retention rate of satisfied customer is significantly increased in relation to dis-satisfied customer. Interestingly, the transaction period of dis-satisfied customer is notably increased after introducing loyalty programs. Thus, it could be said that H2, H3, and H4 are also supported. In summary, we found that the loyalty programs have values as a promotional tool in forming positive relationship with customer and building exit barrier.

• Journal of Korea Port Economic Association
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• v.36 no.2
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• pp.19-36
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• 2020

The bidding phase for logistics outsourcing services is critical for both shippers and logistics companies. According to the logistics bidding phase, the shipper should provide logistics operation information to logistics companies to resolve uncertainty. In addition, the logistics company can win the contract volume that was placed in the bid by expressing their experience and know-how, and proposing to share the risks and benefits of the shipper's logistics operation. Therefore, it is necessary to examine the factors that can be identified during the bidding phase for logistics outsourcing and how these factors affect the satisfaction of logistics outsourcing services. Based on the factors identified in the preceding studies on logistics outsourcing partnership factors and those on logistics outsourcing determinants, a survey was conducted on experts engaged in logistics companies, performing logistics for domestic shippers and analyzed using Smart-PLS. This study presents the following implications. First, in the logistics bidding phase, the shipper should provide its logistics operation information to logistics firms to resolve uncertainties. Details An in-depth explanation of the operation details will be presented via the bidding presentation, and on-site tours of manufacturing plants and logistics centers should also be carried out if necessary. Second, in the bidding phase, logistics companies should appeal through proposals to their competitiveness, such as experience and knowledge of the logistics of the shipper, and also consider alliances with other logistics companies to supplement their insufficient logistics services. Third, logistics companies should make proposals to share profits and risks through logistics outsourcing during the bidding phase, propose accepting risks from environmental uncertainties of the shipper within its capacity to an acceptable extent, and share the benefits of carrying out the shipper's logistics.