• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3B
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• pp.277-284
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• 2011

The limitations of existing Markov chain model for reproducing extreme rainfalls are a known problem, and the problems have increased the uncertainties in establishing water resources plans. Especially, it is very difficult to secure reliability of water resources structures because the design rainfall through the existing Markov chain model are significantly underestimated. In this regard, aims of this study were to develop a new daily rainfall simulation model which is able to reproduce both mean and high order moments such as variance and skewness using a piecewise Kernel-Pareto distribution. The proposed methods were applied to summer and fall season rainfall at three stations in Han river watershed in Korea. The proposed Kernel-Pareto distribution based Markov chain model has been shown to perform well at reproducing most of statistics such as mean, standard deviation and skewness while the existing Gamma distribution based Markov chain model generally fails to reproduce high order moments. It was also confirmed that the proposed model can more effectively reproduce low order moments such as mean and median as well as underlying distribution of daily rainfall series by modeling extreme rainfall separately.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1261-1265
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• 2003

Axial piston pumps of bent axis have been commonly used in hydraulic systems because of high pressure level. best efficiency, low shear force on pistons and low operating costs. The other side, they have a few demerits like that they have the relatively high number of moving parts and more discharge pressure ripples. Especially, the discharge pressure ripples bring about vibrations and noises in hydraulic system components such as connecting pipes and control valves, so that these deteriorate the stability and accuracy of the systems. Therefore, the hydraulic systems having the axial piston pumps of bent axis require the methods to reduce the discharge pressure ripples. So, the purpose of this paper is to reduce the discharge pressure ripples by the phase interference of pressure wave and to develope the analysis model of the pumps to predict the discharge pressure ripples. In this paper, the analysis model of the axial piston pumps of bent axis was developed using the AMESim software, and the reliability of that was verified by the comparison with the experimental results. The hydraulic pipeline with a parallel line was used as the method to generate the phase interference of pressure wave. the dynamics characteristics of the hydraulic pipeline with a parallel line were analyzed by a transfer matrix method. the usefulness of the phase interference of pressure wave was investigated through the experiment and simulation. The results from the experiment and simulation said that the phase interference of pressure wave by the hydraulic pipeline with a paralle linel could reduce the discharge pressure wave of the pump well. The analysis model of the axial piston pumps of bent axis developed in this paper and the method of the phase interference by the hydraulic pipeline with a parallel line are expected to be helpful to achieve the design of the pump and to reduce the discharge pressure wave of the pump effectively.

• Journal of Distribution Science
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• v.14 no.7
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• pp.101-114
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• 2016

Purpose - The aim of this study is to investigate the benefit-sharing activities. They affect contract renewal intention between franchisers and franchisees that are linked through a contract with the intention of building their relationship from the level based on dynamic trust. This study will show a new approach on qualitative growth and consolidation of competitive power and may well be able to suggest practical ways to strengthen directions in the field of franchise industries. Research design, data, and methodology - In this study, based on literature review, we separated logistical-supporting activities and non-logistical-supporting activities from benefit-sharing activities. We modeled how benefit-sharing activities influence contract renewal intention of franchisees by dynamic trust. In particular, considering the possibility of trading concepts and characteristics of trust between providers opportunistic behaviors was defined as variables, depending on the situation and dynamic characters reveal their relationship trust concept. That is, dynamic trust having the possibility of changing depending on opportunistic risks and interdependencies by Lewis & Weigert(1985, 2012) was classified into transitional-based trust, calculated based trust, relational-based trust and balance-based on trust. The total of 104 samples from domestic franchisees being with franchisees were collected by using a structural composed questionnaire. Results - The results are as following. Benefit-sharing activities in logistical supporting activities appeared to affect the multidimensional concept of transitional trust, calculated based on trust, relationship-based trust and balance based on trust dynamic trust with all-defined impact. Non-logistical supporting activities appeared to affect significantly the positive (+) to the dynamic trust concept except transitional trust. Lewis & Weigert(1985; 2012) have proposed a dynamic confidence calculated from relations within-based trust relationship based on trust appears to affect the significant positive (+) to the balance-based confidence transactions confidence mechanism of the system side in the verified relationship. Finally, a relationship based on trust and confidence in the balance based on the Influence of dynamic renewed confidence showed significantly affect the positive(+). In particular, the balance based trust showed the acts as a mediating factors between relational trust and confidence and renew calculated. Conclusion - From the above these results, the significance from this study is as following. First, the proposed activity is to share and validate the approach by identifying the potential in the relationship from the contract with building dynamic trust, and one of the ways from the franchise headquarters and affiliated merchants mutual growth through win-win cooperation in sharing activities. Next, the dynamic segmentation confidence to suggest the possibility can be broken down over the validity and reliability test for each concept. In addition, by identifying the relationship between the dynamic level of confidence granular multi-dimensional concept, to determine the level of trust with a dynamic relationship between risk and interdependencies can be possible in franchise industries. In order to maintain and develop their mutual relationship, franchise industries should propose confidence-building steps to promote their quality improvement.

• Journal of Distribution Science
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• v.14 no.6
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• pp.65-73
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• 2016

Purpose - Recently, the management conditions of small independent retailers are getting worse everyday as large-scale marts and franchised convenience stores are increasing. The objective of this research is to find out the antecedents and consequences of cooperation in voluntary chain in order to enhance small independent retailer's competitiveness. Voluntary chains, also called affiliation or symbol groups, or allied group represent a high market shared in some European countries like Italy, France, and Germany. Nevertheless, there are still limitations in this research from academic fields. Drawing from network theory, the author investigates the relationship between antecedent factors in voluntary chain cooperation, such as participation benefits, justice of compensation, and autonomy in voluntary chain, and relationship specific asset. The author also attempts to examine the relationship between the relationship specific asset and cooperation of voluntary chain member shop and cooperation and consequence factors of voluntary chain cooperation, such as efficiency, group cohesiveness, and long-term relationship. Research design, data, and methodology - The author presented conceptual framework integrating the major antecedents and consequences of voluntary chain cooperation. The data were collected from 174 independent small retailers who joined K-voluntary chain. K-voluntary chain consists of small independent retailers. In accordance with their status, each entrepreneur associated with the voluntary group can own one or more outlets and can be a part of the life and the decision-making process of the group. This participation is not based on company turnover or on the number of outlets, but based on a one member, one vote system. To verify the research model and test hypotheses, the author carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed by using SPSS 18.0 and AMOS structural equation modeling program. Results - The results of this study are as follows. First, as antecedent variables, participation benefits and justice of compensation have positive effect on the relationship specific assets of voluntary chain members. Second, voluntary chain members' relationship specific asset also directly related to the level of its cooperation to chain headquarter. Third, cooperation of voluntary chain member shop facilitates efficiency, group cohesiveness, and long-term relationship. Unexpectedly, there are no effect autonomy in voluntary chain to relationship specific asset. Conclusions - This research shows several theoretical and practical implications to both marketing scholars and marketers. In terms of theoretical implications, this study applies to network theory and network theory variables to explain the antecedent and consequence factors of cooperation in voluntary chain. From the point of view from business management, most of all, this study shows the way how to reinforce competitiveness of voluntary chain. Specifically, it is necessary for voluntary chain headquarter to give higher level of participation benefit and justice of compensation to its members. Second, the results also indicate what the consequence factors of cooperation in voluntary chain. In other words, to increase the level of marketing efficiency, group cohesiveness, long-term orientation in retail voluntary chain, and chain headquarter need to facilitate participants' cooperation.

• Fire Science and Engineering
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• v.31 no.2
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• pp.89-100
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• 2017

This study compared the activities satisfaction factors between volunteer firefighters and general volunteers in Sejong City. For this purpose, 112 volunteer firefighters and 227 general volunteers working in Sejong City were surveyed. In the questionnaire, the independent variable was the motivations, the interpersonal relationships, and the rewards and the dependent variable was the activities satisfaction. The reliability of the survey data in questionnaire design was analyzed by the SPSS 20.0 win program. The factor of the motivations, interpersonal relationships, and rewards had a significant positive influence on the activities satisfaction of volunteer firefighters and general volunteers (<0.05). The activities satisfaction of the volunteer firefighters was influenced in the order of the motivations, rewards, interpersonal relationships, and activities satisfaction of the general volunteers was influenced in order of the motivations, interpersonal relationships, and rewards.

• Journal of Korean Society of Transportation
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• v.29 no.1
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• pp.39-46
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• 2011

Speeding is a major cause of traffic accidents that affects the safety of pedestrians and harms drivers and their families, property and mental health. However, most researches on speeding behavior have been conducted by survey method, so the relationship between cause and effect is not clear. The reliability of the research cannot be carefully examined because most researches involve retrospective methods. It is clear that conducting experimental research is important for overcoming these limitations, but it is impossible to perform tests with real cars in real traffic situations due to the inability to control situational factors (e.g., other vehicles, traffic signal) which affect participants' behavior. A car simulator experiment was designed and the theory of planned behavior was applied to the experiment. Each participant was grouped and assigned to either high speeding intention group or low speeding intention group according to their levels of speeding intention and analyzed the difference of driving behavior indexes between two groups. The results revealed statistically significant differences between two groups on driving speed, speeding frequency, and accelerator pressure deviation. Finally, the limitations and the implications of this study were discussed.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.64-81
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• 2016

The study, based on existing studies, explored influencing relationship, suggesting app service quality and user reviews as previous elements to affect use satisfaction about users' comments based on big data and reuse intention. The study includes a comparative analysis of existing studies. Based on such analysis results, the authors looked into app service quality elements perceived by gourmet restaurant app users and the role of user reviews, and suggested practical implications that can help the development and operation of gourmet restaurant app contents. The study subjects were male and female consumers who over 20 years old throughout Korea who had not a searched smartphone gourmet restaurant app in the three months preceding the survey. The subjects were selected from consumers who search the restaurantsby using restaurant apps like Mango plate, Dining code, Hot place, and selecting restaurants. Among them, consumers with experience using restaurants were finally selected for the survey. According to the results, reliability, informativity, and system capability, among service quality, had positive influences on app use satisfaction, while design and mobility had no effect. App use satisfaction had positive influences on app reuse intention. User comment informativity played a controlling role. The study explored the importance of app service quality and user review informativity as elements that affect continued use of gourmet restaurant apps by dining-out consumers.

• Journal of Distribution Science
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• v.12 no.6
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• pp.41-48
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• 2014

Purpose - This study aims to investigate a solution to reduce the negative reactions arising from the performance of duties or the job distress of workers in the service industry, because human resource statistics regarding workers in the service sector have been unreported, while concerns regarding exposure to emotional exertion and poor working conditions have been continuously increasing. Research design, data, and methodology - This study specifically focused on workers in highway service areas. It differs from previous studies because it involves the perspective of the person-organization fit and regards workers' cognition of leaders through the psychological distance toward the leader and the contact frequency between workers and leaders within the framework of the leader-individual fit. Moreover, this study highlights the role of the self-leadership of workers as an important factor that becomes manifested in the individual-level fit to the organization. Hence, this study investigates whether the positive role of the above factors, in turn, could reduce job distress. Workers from highway service areas in Gyeonggi-do province provided data; 141 valid questionnaires are collected. SPSS 19.0 and AMOS 19.0 were used to test the reliability and validity of constructs. Simple regression, multiple regression, and 3 step mediation tests were used to test the hypotheses after the correlation tests. Results - Results indicated that leader-member contact frequency and psychological distance have negative effects on job distress but positive effects on self-leadership. A mediation test revealed that self-leadership, in the relationships between contact frequency and job distress and between psychological distance and job distress, resulted in partial mediation and full mediation, respectively. Conclusions - The result can be understood through two different possible explanations. First, service area workers generally possess a positive perspective toward their leaders. This can be interpreted to mean that increased contact frequency and psychological distance would be considered as supports from the leader, rather than intrusive controls or management schemes. Therefore, the management in highway service areas should invest efforts in increasing contact frequency as well as maximizing psychological similarities by adopting the viewpoints of workers in terms of moral and ethical management, to reduce the workers' job distress. The results relating to self-leadership also indicate that increased contact frequency must be accompanied by intentions for the effective promotion of workers' self-leadership. It also signifies the necessity of a strategic approach by leaders to induce workers to perceive "in-group"ness as suggested both by the similarity-attraction theory and by the social identity theory. In addition, the results of the mediation test of self-leadership indicate that because workers' self-leadership activates upon increased contact frequency by the leader, it should not be a means of control and should not be utilized only from the perspective of management. It is also suggested that strategies such as transfer of authority could have a positive effect in promoting the expansion of self-influence from workers.

• Korean Journal of Childcare and Education
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• v.3 no.2
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• pp.68-85
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• 2007

The purpose of this study is to investigate the changes of mothers' condition including the level of knowledge and parenting stress that mothers have on infant development. The subjects of this study are 270 mothers whose infants range in age from birth to 36 months. The instruments used are: 1)KCDI(Knowledge of Child Development Inventory, Larsen & Juhasz, 1985) 2)Parenting Stress Scale(Kim & Kang, 1997), and a demographic questionnaire. The data analyses use SPSS 12.0 which employs basic statistics, reliability test, and t-test. This study is time-lag design covering five years. Therefore, the data collected originates from 2002 and 2007 to constitute input from two times. The results of this study indicate that the average pregnancy from the 2007 statistics occurred 0.46 months earlier, after marriage, as compared to pregnancies in 2002. Mothers who gave birth by natural birth increased from 59.9 % to 75.3 % over the five year period. Regarding knowledge of infant development, the level of mothers' knowledge was lower in 2007 than in 2002 according to study results. The level of parenting stress of mothers increased for the 2007 statistics as compared to the 2002 survey.

• Journal of the Korean Geotechnical Society
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• v.27 no.1
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• pp.77-86
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• 2011

The advanced geotechnical information has been required to determine the accurate design parameters for complex construction. However, the Standard Penetration Test (SPT), which has low reliability, has been used to estimate the subsurface condition in the field. The objective of this paper is development and application of the Static-Dynamic penetrometer, which detects the resistances in soft clay, sand and rock. The energy losses according to the rod connection methods (perfect or non-perfect connection, and number rods) are experimentally evaluated. The reflection and transmission ratios are used to investigate the energy loss by a simulation. The static-dynamic cone penetrometer, in which the accelerometers and strain gauges are installed on the cone tip and the rod head, is used to estimate the energy loss during penetration by impacts. The experimental and simulation studies show that the transferred energy through rods with non-perfect connection dramatically decreases. Furthermore, the transferred energy on the rod head is not the same as that on the cone tip. This study demonstrates that the energy loss should be evaluated on the cone tip.