• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.839-845
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• 2009

The Vehicular Ad-hoc Network (VANET) has two main problems to be overcome due to high mobility and frequently changing density: one is short link duration time and the other is high packet loss ratio. To solve the problems, there have been many studies to predict vehicular mobility. Most of the studies try to enhance link expire time and link reliability, however the distance between two relay nodes becomes too short to have high network throughput. In this paper, we propose a new routing algorithm that considers both link expire time and network throughput in the VANET. The proposed algorithm aims to find path with long link expire time and high throughput. Our simulation results show that the proposed algorithm outperforms the legacy greedy algorithm and its variants.

• East Asian Journal of Business Economics (EAJBE)
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• v.5 no.3
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• pp.48-63
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• 2017

Purpose - The objective of this research is to investigate not only the effect of a company creating shared value (CSV) influencing consumers' emotions that lead to prosocial consumer behavior but also the moderating effect of Companies' authenticity in the causal relationship between economic or social value of CSV and either gratitude or pride of consumers. Research design, data, methodology - The 9 hypotheses presenting the relationship among CSV, consumer's emotion and prosocial consumer behavior were proposed and tested in this study. Research data were collected from the surveying of 350 respondents over 20 years and the 340 samples were used to test the proposed hypotheses. SPSS 20.0 and AMOS 20.0 were used for statistical analysis such as reliability test, validity test and path analysis. Results - The results show that the economic or social value of corporate CSV activities affects positively consumer's gratitude or pride except for the relationship between social value of CSV and consumer's pride. The results also show that gratitude or pride of consumers affects positively consumers' prosocial behavior. We also found that there is a moderating effect of Companies' authenticity in the causal relationship between economic or social value of CSV and either gratitude or pride of consumers. Conclusions - Company's activities in creating shared value influences consumer emotions and pride, and although these activities induce gratitude, this does not apply to pride. In addition, when these shared value activities influence consumer emotions, the authenticity of the company has shown to have a moderating effect.

• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.91-110
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• 2012

In the modern management literature, knowledge has been recognized as a new strategic resource enabling a firm to create its competitiveness. Shipping companies under fierce competitive structure need to pay attentions to the utility of knowledge management. A shipping firm may develop its unique service capability by classifying, sharing, and transferring the data, information and knowledge obtained from both inside and outside its global service network. The current study attempts to analyze influential relationships between liner shipping firms' knowledge management and service capabilities. In order to achieve this goal, this study designed a knowledge chain model measuring shipping companies' knowledge management levels and tested its validity and reliability based on a total of 80 replied questionnaires from national and foreign liners. The empirical result presents that supportive and primary activities composing a knowledge chain could exert significant positive influences on the enforcement of shipping service capabilities. This research shows that the utility of knowledge management is adoptable in the maritime industry, and recommends that shipping firms should recognize strategic importance of knowledge and actively pursue knowledge management at an entire firm level.

• Convergence Security Journal
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• v.12 no.2
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• pp.23-32
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• 2012

This study of transformational leadership impact on followership, job satisfaction and organizational commitment to investigate the relationship. Private security guards and managers that works private security firms located in Seoul, Gyeonggi-do, and Incheon in 2011 were set as a population and purposive sampling method to extract the sample by 880 people, but final samples of 790 people were drawn from the results. This study SPSSWIN 16.0 using factor analysis, reliability analysis, Pearson's Correlation Analysis, multiple regression analysis, path analysis was carried out. In addition, this study is to investigate the influence of transforming leadership with followership, job satisfaction and organizational commitment. The results are as follows. First, transforming leadership affects followership. Second, transforming leadership affects job satisfaction and organizational commitment. Third, followership affects partially In other words, behavioral tendencies increases job satisfaction and organizational commitment. Thinking tendencies is also job satisfaction and organizational commitment does not affect.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.5
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• pp.817-838
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• 2014

Test environment on the company that handles a large amount of data such as telecommunications companies and financial institutions, may not always be the same as the production environment, which is caused by conversion of important columns about information and limitation of storage capacity due to the construction cost. Therefore, SQL performance degradation that occurs when the test and production environments are not the same, which is an important cause of connecting to the unexpected failures of online transactions, and it generates financial loss of business, customer complaints, a decrease in reliability. In studies related SQL performance, it has so far been conducted mainly studies of tuning associated with DBMS Optimizer, and it has not been addressed issues of this sector. Therefore, in this paper, I verify the validity about presentation of the advanced SQL Performance-based IT application change management process, in order to prevent failures of the online transactions associated with poor performance of SQL generated by differences in test and production environments.

• Journal of the Korean Society of Food Culture
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• v.9 no.3
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• pp.289-301
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• 1994

The purpose of this study was to investigate housewives' perception, interest and consumption of organic food, and to identify the variables influencing on them. The sample was selected from 411 housewives living in Seoul from 1st of September to 20th of September in 1993. Used statistical methods were frequency, percentage, mean, Cronbach's ${\alpha}$, factor analys, ANOVA, Duncan's multiple range test, t-test, correlation, regression analysis and Path analysis. The major results are as follows: 1) Housewives' perception degree of organic food in its variety, easy availability and contribution to health was relatively high level, but price level, reliability and packing condition was somewhat low level. Out of housewives' many images of organic food, taste health care, quality and necessity factors can be implicated. 2) Housewives' interest degree of organic food is somewhat high level 3) Housewives' consumption degree of organic food was relatively low level and was affected by their perception of oraganic food. 4) Frequency to use seasonings was the major independent variable which influenced to housewives' perception degree of organic food, while recognition on enviornmental contamination was the major independent variable which influenced to their interest degree of organic food, and their total perception on organic food was the major independent variable which influenced to their consumption degree of oragnic food. Therefore, it is considered that their total perception to it can decide the demand of organic food 5) Housewives' perception and interest degree of it was the major intervening variable which influenced to their consumption degree of oragnic food.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.115-130
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• 2021

This study is to study the overall structural relationship between work-life balance(WLB), superior trust, workplace happiness, and organizational commitment. The goal of this study is to study how WLB and superior trust affect workplace happiness, how workplace happiness affects organizational commitment, and the mediating effect of workplace happiness. Survey data were collected from incumbents working in large companies and SMEs, validity and reliability of research items were reviewed, and research hypotheses were tested using path analysis. As a result of testing the research hypothesis, WLB and superior trust have a positive (+) effect on workplace happiness, and workplace happiness has a positive (+) effect on organizational commitment. Also, job satisfaction plays a role as a partial parameter between WLB, superior trust, and organizational commitment. Based on the hypothesis test results, it was confirmed that the higher the level of WLB and superior trust, the higher the level of work satisfaction. Based on the research results, a plan was suggested for Korean corporate members to achieve workplace happiness and organizational commitment.

• International Area Studies Review
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• v.12 no.3
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• pp.111-133
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• 2008

This study tries to analyze what the most significant factors are in Russia, where the Korean investing enterprises have to overcome and adapt to various difficulties, especially in terms of local circumstance politically. This main purpose of the research is to test empirically some relations between the managing strategy of Korean enterprises and the circumstance factors of politics in Russia while this is conducted in two stages. First, the research model is designed by reviewing relevant theories, previous studies, and the current investment conditions in local Russia. Second, the survey of Korean enterprises engaged in investment activities in there is done by collecting questionnaires from them with this survey. And the statistic method of structural equation modeling is used to testing some hypotheses. Explaining the analyzing tools, SPSS 12.0 for windows is being used for Correlation, Reliability, Validity and Multi regression and Finally the Path analysis is implemented by AMOS 7.0 for windows.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.1
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• pp.58-65
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• 2019

The stability, reliability and efficiency of a smart ship are important issues as the interest in an autonomous ship has recently been high. An automatic collision avoidance system is an essential function of an autonomous ship. This system detects the possibility of collision and automatically takes avoidance actions in consideration of economy and safety. In order to construct an automatic collision avoidance system using reinforcement learning, in this work, the sequential decision problem of ship collision is mathematically formulated through a Markov Decision Process (MDP). A reinforcement learning environment is constructed based on the ship maneuvering equations, and then the three key components (state, action, and reward) of MDP are defined. The state uses parameters of the relationship between own-ship and target-ship, the action is the vertical distance away from the target course, and the reward is defined as a function considering safety and economics. In order to solve the sequential decision problem, the Deep Deterministic Policy Gradient (DDPG) algorithm which can express continuous action space and search an optimal action policy is utilized. The collision avoidance system is then tested assuming the $90^{\circ}$intersection encounter situation and yields a satisfactory result.

• Journal of Ocean Engineering and Technology
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• v.33 no.3
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• pp.259-271
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• 2019

It is important to obtain reasonable predictions of the extent of the damage during maritime accidents such as ship collisions and groundings. Many fracture models based on different mechanical backgrounds have been proposed and can be used to estimate the extent of damage involving ductile fracture. The goal of this study was to compare the damage extents provided by some selected fracture models. Instead of performing a new series of material constant calibration tests, the fracture test results for the ship building steel EH36 obtained by Park et al. (2019) were used which included specimens with different geometries such as central hole, pure shear, and notched tensile specimens. The test results were compared with seven ductile fracture surfaces: Johnson-Cook, Cockcroft-Latham-Oh, Bai-Wierzbicki, Modified Mohr-Coulomb, Lou-Huh, Maximum shear stress, and Hosford-Coulomb. The linear damage accumulation law was applied to consider the effect of the loading path on each fracture surface. The Swift-Voce combined constitutive model was used to accurately define the flow stress in a large strain region. The reliability of these simulations was verified by the good agreement between the axial tension force elongation relations captured from the tests and simulations without fracture assignment. The material constants corresponding to each fracture surface were calibrated using an optimization technique with the minimized object function of the residual sum of errors between the simulated and predicted stress triaxiality and load angle parameter values to fracture initiation. The reliabilities of the calibrated material constants of B-W, MMC, L-H, and HC were the best, whereas there was a high residual sum of errors in the case of the MMS, C-L-O, and J-C models. The most accurate fracture predictions for the fracture specimens were made by the B-W, MMC, L-H, and HC models.