• Journal of KSNVE
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• v.5 no.1
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• pp.95-106
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• 1995

Flow-induced vibration in heat exchanger (or fuel rod) in nuclar power plant can cause dynamic interactions between tubes and tube supports resulting in fretting-wear. To increase the reliability and design life of heat exchanger components, design criteria that establish acceptable limits of vibration and minimize fretting wear are necessary. The fretting-wear rate is dependent upon material combination, contact configuration, environmental conditions and tube-to tube support dynamic interaction. It is demostrated that the fretting -wear rate correlates well with tube-to-support contact force or work rate. The tube-to-support dynamic interaction, which consists of dynamic contact forces and tube motion, is used to relate single-span wear data to real heat exchanger configurations consisting of multi-span tube bundles. This paper describes the test facility to measure tube-to-support dynamic impact force and reports its dynamic characteristics through the four impact tests - a force transduces independent and external impact tests, central ring inside impact test and additional cylinder impact test. Through the tests the impact parameter change dependent upon the material difference of impacting ball is studied, and the impact parameters of Force Transducer Assembly components are measured. And also the dynamic behavior of Force Transducer Assembly is analyzed. The force measurement technique herein is shown to provide a reasonable measure of dynamic contact forces.

• Nuclear Engineering and Technology
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• v.46 no.4
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• pp.529-540
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• 2014

In this research, a drop impact analysis of a fuel assembly in a research reactor is carried out to determine whether the fuel plate integrity is maintained in a drop accident. A fuel assembly drop accident is classified based on where the accident occurs, i.e., inside or outside the reactor, since each occasion results in a different impact load on the fuel assembly. An analysis procedure suitable for each drop situation is systematically established. For an accident occurring outside the reactor, the direct impact of a fuel assembly on the pool bottom is analyzed using implicit and explicit approaches. The effects of the key parameters, such as the impact velocity and structural damping ratios, are also studied. For an accident occurring inside the reactor, the falling fuel assembly may first hit the fixing bar at the upper part of the standing fuel assembly. To confirm the fuel plate integrity, a fracture of the fixing bar should be investigated, since the fixing bar plays a role in protecting the fuel plate from the external impact force. Through such an analysis, the suitability of an impact analysis procedure associated with the drop situation in the research reactor is shown.

• Korean Management Science Review
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• v.31 no.2
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• pp.15-32
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• 2014

This research empirically investigated the influence factors on the adoption of environmental management systems (EMS) in Korean manufacturing firms. In this study, the external factors (cause factors), the internal factors (facilitating factors) and the firm specific characteristics were integrally considered. In the factor analysis, the third item (regional society) of the external factors and the first item (environmental law) of government regulation were confounded with the items of the other factors. Thus, the confounded items were removed. In the second factor analysis, no items were replicated. The results of a multiple regression analysis showed that the influence factors such as government regulation, normative pressure, top management support, environmental strategy and employees' recognition, and ratio of large shareholders have a significant impact on the construction of EMS. However, the effects of the other firm specific characteristics were not statistically significant. We also examined whether both the number of environmental personnel and the allocation of environmental resources, which are directly related with the adoption of EMS, have a moderating impact on the relationships between other internal factors and the construction of EMS. With a subgroup analysis, the moderating roles of the number of environmental personnel were empirically confirmed. Through a multiple regression analysis, the direct effects of the external factors on the adoption or construction of the internal factors were demonstrated. The effects of government regulation, normative pressure and imitative pressure on the internal factors were significant and positive. Finally, in this study, the fact that the adoption of EMS can improve the environmental performance of a firm was also empirically found.

• Journal of Environmental Impact Assessment
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• v.20 no.5
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• pp.729-745
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• 2011

The purpose of this paper is to estimate the external diseconomies of an unwelcomed facility on the nearby houses. The facility and the area studied are Dangin-Ri power plant in Mapo-Gu, Seoul and the residential district surrounding it respectively. The nearby housing prices have been changed according to the time and circumstances of the public announcements about the reconstruction or removal plans of the plant. These price changes are regarded as the capitalized values of the external diseconomies due to the plant. This study is based on the hedonic price theory in order to estimate the diseconomies in monetary value. The tools for the estimation are four models of multiple regression with the transaction price as the dependant variable and various housing characteristics including the external effects of the plant as the independent variables. The sample analyzed is 833 house transactions for the past 5 years in the research area. The facts found are as follows; First, the most suitable functional form for the estimation is confirmed to be the linear model. Second, there are significant differences in influence on the housing values among the independent variables, that is, locational characteristics, physical features, and environmental changes with time. Third, the external diseconomy is estimated as \80,137,807 in case that the plant would be reconstructed in the underground of the present site, whereon a substitutional public park would be constructed and as \59,142,248 in case that the plant would move away.

• Asia pacific journal of information systems
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• v.18 no.4
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• pp.57-81
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• 2008

Knowledge is an essential strategic weapon for sustaining competitive advantage and is the key determinant for organizational growth. When knowledge is shared and disseminated throughout the organization, it increases an organization's value by providing the ability to respond to new and unusual situations. The growing importance of knowledge as a critical resource has forced executives to pay attention to their organizational knowledge. Organizations are increasingly undertaking knowledge management initiatives and making significant investments. Knowledge sourcing is considered as the first important step in effective knowledge management. Most firms continue to make an effort to realize the benefits of knowledge management by using various knowledge sources effectively. Appropriate knowledge sourcing strategies enable organizations to create, acquire, and access knowledge in a timely manner by reducing search and transfer costs, which result in better firm performance. In response, the knowledge management literature has devoted substantial attention to the analysis of knowledge sourcing strategies. Many studies have categorized knowledge sourcing strategies into intemal- and external-oriented. Internal-oriented sourcing strategy attempts to increase firm performance by integrating knowledge within the boundary of the firm. On the contrary, external-oriented strategy attempts to bring knowledge in from outside sources via either acquisition or imitation, and then to transfer that knowledge across to the organization. However, the extant literature on knowledge sourcing strategies focuses primarily on large organizations. Although many studies have clearly highlighted major differences between large and small firms and the need to adopt different strategies for different firm sizes, scant attention has been given to analyzing how knowledge sourcing strategies affect firm performance in small firms and what are the differences between small and large firms in the patterns of knowledge sourcing strategies adoption. This study attempts to advance the current literature by examining the impact of knowledge sourcing strategies on small firm performance from a holistic perspective. By drawing on knowledge based theory from organization science and complementarity theory from the economics literature, this paper is motivated by the following questions: (1) what are the adoption patterns of different knowledge sourcing strategies in small firms (i,e., what sourcing strategies should be adopted and which sourcing strategies work well together in small firms)?; and (2) what are the performance implications of these adoption patterns? In order to answer the questions, this study developed three hypotheses. First hypothesis based on knowledge based theory is that internal-oriented knowledge sourcing is positively associated with small firm performance. Second hypothesis developed on the basis of knowledge based theory is that external-oriented knowledge sourcing is positively associated with small firm performance. The third one based on complementarity theory is that pursuing both internal- and external-oriented knowledge sourcing simultaneously is negatively or less positively associated with small firm performance. As a sampling frame, 700 firms were identified from the Annual Corporation Report in Korea. Survey questionnaires were mailed to owners or executives who were most erudite about the firm s knowledge sourcing strategies and performance. A total of 188 companies replied, yielding a response rate of 26.8%. Due to incomplete data, 12 responses were eliminated, leaving 176 responses for the final analysis. Since all independent variables were measured using continuous variables, supermodularity function was used to test the hypotheses based on the cross partial derivative of payoff function. The results indicated no significant impact of internal-oriented sourcing strategies while positive impact of external-oriented sourcing strategy on small firm performance. This intriguing result could be explained on the basis of various resource and capital constraints of small firms. Small firms typically have restricted financial and human resources. They do not have enough assets to always develop knowledge internally. Another possible explanation is competency traps or core rigidities. Building up a knowledge base based on internal knowledge creates core competences, but at the same time, excessive internal focused knowledge exploration leads to behaviors blind to other knowledge. Interestingly, this study found that Internal- and external-oriented knowledge sourcing strategies had a substitutive relationship, which was inconsistent with previous studies that suggested complementary relationship between them. This result might be explained using organizational identification theory. Internal organizational members may perceive external knowledge as a threat, and tend to ignore knowledge from external sources because they prefer to maintain their own knowledge, legitimacy, and homogeneous attitudes. Therefore, integrating knowledge from internal and external sources might not be effective, resulting in failure of improvements of firm performance. Another possible explanation is small firms resource and capital constraints and lack of management expertise and absorptive capacity. Although the integration of different knowledge sources is critical, high levels of knowledge sourcing in many areas are quite expensive and so are often unrealistic for small enterprises. This study provides several implications for research as well as practice. First this study extends the existing knowledge by examining the substitutability (and complementarity) of knowledge sourcing strategies. Most prior studies have tended to investigate the independent effects of these strategies on performance without considering their combined impacts. Furthermore, this study tests complementarity based on the productivity approach that has been considered as a definitive test method for complementarity. Second, this study sheds new light on knowledge management research by identifying the relationship between knowledge sourcing strategies and small firm performance. Most current literature has insisted complementary relationship between knowledge sourcing strategies on the basis of data from large firms. Contrary to the conventional wisdom, this study identifies substitutive relationship between knowledge sourcing strategies using data from small firms. Third, implications for practice highlight that managers of small firms should focus on knowledge sourcing from external-oriented strategies. Moreover, adoption of both sourcing strategies simultaneousiy impedes small firm performance.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.99-108
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• 2013

This study was conducted to evaluate the non-timber forest functions of the Research Forest area of Kangwon National University. In this study, forest recreation function was investigated through survey method answered by forest management experts. The evaluation factors for forest recreation function were separated into external and internal factors. Each factor was classified into intermediate element and detailed element. Therefore in this study, the evaluation factors of forest recreation function were divided into two groups which are the potential of external factors and the suitability of internal factors. Potential of the external factors were divided into accessibility, location, landscape and induction factors while the suitability of internal factor was divided into stand structure, forest structure and human impact. The priority of the potential of external factors was in order that location, accessibility, induction factors and landscape. The most important factors for the location, accessibility, induction and landscape factors are based on regional characteristics.

• Knowledge Management Research
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• v.20 no.4
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• pp.75-97
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• 2019

In the rapidly changing business environment, knowledge has been recognized as a core asset for sustaining an organization's competitive advantage. In addition, knowledge sharing is one of the key elements of knowledge management, emphasizing external knowledge sharing beyond initial internal knowledge sharing. However, while knowledge management research emphasizes knowledge sharing, which is a positive aspect, research on preventing knowledge leakage that can have negative consequences is relatively lacking. Companies have tried to minimize the negative effects of knowledge management but many knowledge leakage accidents are still occurring. Therefore, this study aims to examine the effects of external factors based on deterrence theory and internal factors based on self-determination theory on knowledge leakage intention focusing on tacit knowledge. The results of the empirical analysis of 100 data sets collected through a scenario-based survey show that certainty of sanctions, social disapproval, and competence are found to have a significant effect on reducing tacit knowledge leakage intention. Furthermore, informal sanctions have a greater impact on tacit knowledge leakage intention than formal sanctions and external factors have a greater effect on tacit knowledge leakage intention than internal factors.

• Journal of Information Technology Applications and Management
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• v.14 no.4
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• pp.97-120
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• 2007

Development of information technology and Internet brought big changes in information society. Quantity of information increased rapidly and various types of information were presented through diverse channels. This change brought an impact in electronic commerce environment. A large number of products are transacted in online market. And various search functions and product information are presented for supporting customer's decision making. This study examined the effect of external information on purchase decision-making in electronic commerce environment. An experiment was conducted to see the customer product review, unit sales, etc. on purchase decision-making process in online shopping mall based electronic commerce. As a result of study, external information referring to number of purchasing, positive product review, and reliability of information has a positive effect on purchase-decision. The significance of the study can be found in that it defined 1) external information has an effect on decision-making, 2) positiveness and reliability of product information showed that they have an influence on customer, and 3) when self opinion and other person's opinion are different, one is not satisfied with decision making process. The results of the study can be of practical use in the design and implementation of online shopping mall in electronic commerce.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.115-120
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• 2005

Impact seismic wave method is a method for non-destructive testing of concrete structure using of stress wave which is propagate and reflected from internal flaws within concrete structure and external surface. In this study, we performed frequency domain method using impact seismic wave test for safety diagnosis of civil engineering structure. And reflection method which is used for one-dimensional target such as tunnel lining and transmission method are compared with each other.

• Journal of KSNVE
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• v.6 no.6
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• pp.735-747
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• 1996

In this paper, buckling reliability analyses of stiffened cylinder with random initial geometric imperfection under axial impact load are performed by the combined response surface method. The effect of random geometric imperfection on the failure probability and reliability is recognized quantitatively. Buckling reliability decreases with the increase of mean value, cov of initial geometric imperfection under the same external load. Buckling probability under impact load is greater than those under static load with the same condition. From the probabilistic characteristics of imapct buckling load, relation between reliability index and safety parameter can be obtained in addition to the relation between load and reliability index. And those results can be used to determine the range of required safety parameter and acceptable imperfaction.