• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.9
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• pp.2739-2763
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• 2024

In wide area SDP networks, the failure of SDP components caused by malicious attacks will be accompanied by different deployment locations, profoundly affecting network service latency. However, traditional deployment methods based on prior knowledge are no longer applicable to dynamic SDP networks. This article proposes a dynamic and dimensionally variable deployment mechanism DDPG-SDPCR for SDP components based on DDPG, which enhances the network's endogenous security capability and improves attack tolerance. Based on this, we constructed corresponding mathematical models for latency, load balancing, and attack tolerance. The DDPG-SDPCR mechanism dynamically deploys new SDP nodes to replace faulty nodes based on the real-time status of the network, thereby achieving imperceptible attack tolerance for users. We have implemented a wide area SDP prototype with endogenous security capabilities and evaluated it under different network topologies, traffic sizes, and network attacks. The evaluation results indicate that under high traffic conditions, our proposed redeployment mechanism outperforms the baseline by 36.42% in latency, and only increases by 19.24% compared to the non attacked situation.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1291-1300
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• 2018

Objective: This experiment was conducted to investigate the effects of dietary crude protein (CP) level and exogenous protease supplementation on growth performance, serum metabolites, carcass traits, small intestinal morphology and endogenous protease activity in broiler chickens reared under a tropical climate. Methods: A total of 480 day-old male broiler chicks were randomly assigned to eight dietary treatments in a $4{\times}2$ factorial arrangement. The main effects were CP level (21.0%, 19.7%, 18.5%, or 17.2% from 1 to 21 days and 19.0%, 17.9%, 16.7%, or 15.6% from 22 to 35 days) and protease enzyme supplementation (0 ppm or 500 ppm). All experimental diets were fortified with synthetic feed-grade lysine, methionine, threonine and tryptophan to provide the minimum amino acid recommended levels for Cobb 500. Results: Reducing dietary CP linearly reduced (p<0.05) growth performance, serum albumin, total protein, and carcass traits and increased (p<0.05) serum triglycerides and abdominal fat. There was no consistent effect of reducing dietary CP on morphological parameters of the intestine and on the pancreatic and intestinal endogenous protease activity (p>0.05). Protease supplementation improved (p<0.05) feed conversion ratio, body weight gain, carcass yield and intestinal absorptive surface area. Conclusion: Protease supplementation, as measured by growth performance, intestinal morphology and carcass yield, may alleviate the detrimental effects of low protein diets in broiler chickens.

• 한국사회정책
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• v.23 no.1
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• pp.95-123
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• 2016

As Korean society grows rapidly older, a systematic analysis of the determinants of labor supply behavior among the elderly becomes a prerequisite for designing more effective senior employment policies and income security regime for the elderly. Literatures review shows that a majority of previous researches have been ignoring the problem of "endogenous predictor" especially when it comes to the estimation of the effects of the two key variables, education and non-labor income, on labor supply decisions among older people. They have failed to take into consideration the unobserved heterogeneities which might affect both labor supply decisions of the elderly and their levels of education and non-labor income, which means, according to some econometric literatures, that the estimated coefficients of the two predictors can be inconsistent. The paper tries to redress the endogeneity problem by employing a panel logit model with data from the 1st. to 4th. wave of the KLoSA(Korean Longitudinal Survey of Ageing) to estimate the effects of key predictors on the probability of getting jobs among older people(ages of 60 or older). Both a random effects and a fixed effects model reaffirms that non-labor income has a negative effect on the chances of being employed. And a random effects model shows that the effect of education is also negative, as has frequently been reported by previous studies. That means the effects of education and non-labor income on elderly employment remain negative after the effect of unobserved heterogeneities is controled for and the problem of endogenous predictors is redressed through an appropriate panel data analysis. These findings mean, in turn, that when Korean baby-boomers, who had acquired an unprecedentedly higher level of education and were expected to enjoy ever-larger amount of non-labor income than their preceding generations, retires in near future, their incentives to work will become much weaker and the lack of labor-force and the burden of financing increased public pension expenditure will become more troublesome. The paper concludes with recommending some policy initiatives helpful to solve these expected problems.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.404-414
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• 2013

This study establishes structure pattern about private security guard major under graduate students career preparation conduct and reality adaptability wishes to deduce high theoretical pattern. Then, I wish to verify causality of variables included in pattern. This study established private security guard major of 3 university by population to Seoul, Gyeonggi Province in 2012. Using purposive sampling method, 130 samples were drawn and were used for the final analysis. Validity and reliability of questionnaire verified to be through confirmatory factor analysis and reliability analysis. Validity of questionnaire came out to be over exogenous variable value .664, endogenous variable value .787. In this study, utilizes AMOS 18.0 and SPSS WIN 18.0 programs for reliability analysis and took advantage of technique of covariance structure analysis. The conclusion is following : First, private security guard major self-clearness shortage exerts contradictory influence on career decision efficacy. Second, private security guard major self-clearness shortage does not affect on career preparation behavior. Third, problem about private security guard major age exerts contradictory influence on career decision efficacy. Fourth, problem about private security guard major age does not affect on career preparation behavior. Fifth, physical inferiority complex of a private security guard major does not affect in career decision efficacy. Sixth, physical inferiority complex of a private security guard major does not affect on career preparation behavior. Seventh, private security guard major course decision efficacy affects on career preparation behavior.

• Journal of Fashion Business
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• v.15 no.4
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• pp.87-109
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• 2011

This study was to examined the relationship between goal setting, self improvement, social support of parents, friendship, school adaptation, drop out. In our research model, goal setting, self improvement, social support of parents, and friendship is exogenous variable and school adaption and drop out is endogenous variable. A total of 323 undergraduate student(254 female, 69 male) complete the questionnaires. Structural equation modelling showed that, as hypothesized, establishment of goals, social support of parent and friendship have effect on school adaptation, and friendship also have direct effect on drop out. School adaptation mediate path from goal setting, social support of parents, and friendship. This study provides empirical evidence for a model that show how to control the drop out of students.

• The Journal of Industrial Distribution & Business
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• v.9 no.4
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• pp.63-72
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• 2018

Purpose - The purpose of this paper is to investigate the effects of online game properties, social interaction, and player satisfaction on intention to online games in Chinese gamers. Research design, data, and methodology - This study is an empirical analysis assuming that properties of online games, social interaction and satisfaction will induce Chinese gamers' intention to play online games. We set the relationship between the six variables as follows. First, the properties of online games, exogenous variables, were identified by three factors: entertainment, security, participation and challenge. Second, we had input social interaction among gamers as another exogenous variables. Third, the gamer's satisfaction of online games was added to the research model as a mediating variable between exogenous variables and endogenous variables. Finally, gamer's intention to play influenced by satisfaction and social interaction was used as final endogenous variable. The data used for the empirical analysis were collected through questionnaires for Chinese under age 35 who enjoy the online games. The data used in the research were finally extracted from 195 questionnaires. The collected data were tested through the analysis of the measurement model (Step 1) and the analysis of the structural model (Step 2). The covariance structure equation model (SEM) was used for the analysis. The measurement model and structural model were evaluated by the maximum likelihood method. Results - The results of the empirical analysis are as follows. The satisfaction of online games were entertainment and security had a significant effect to satisfaction; but participation and challenge and social interaction had no significant effect on satisfaction. The social interaction among gamers and the satisfaction with online games have a significant influence on the intention to play online games. As a result, the attributes of the game were affecting the intention to play the game after satisfaction. Social interaction influenced the intention to play online games rather than satisfaction itself. Conclusions - This study provide some practical implications for the new companies who want to enter the online game industry and seek to competitiveness in China, and provide theoretical implications on the role of interaction among gamers in the study of online games.

• The Journal of Society for e-Business Studies
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• v.25 no.2
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• pp.109-126
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• 2020

This study attempts to find out the characteristics of digital currency and currency transformation through the analytical descriptions of the literature. In the early days of the emergence of new currency, market-oriented autonomous monetary adjustment was made along with various attempts by the private sector, and then government-centered central currency management and coordination were made for the national monopoly of profits and power. Digital currency can be seen as the emergence of a new form of money that will bring about paradigm changes. CBDC can be divided into direct and indirect types. CBDC is expected to require a strategic approach by the government or firm as it will bring about changes in the ecosystem of related industries. Libra is a stablecoin designed to minimize price fluctuations, and if it succeeds in commercializing it, it is expected to bring about revolutionary changes in the financial industry around the world.

• Journal of the Korean housing association
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• v.25 no.4
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• pp.125-133
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• 2014

The purpose of this study was to find the role of participation in common activities and satisfaction with common space in a tentative housing adjustment framework for Swedish cohousing residents, applying the housing adjustment behavior model of Morris and Winter (1978, 1996). The data used for this research were a subset of data Choi and Paulsson (2011) surveyed from 12 Swedish cohousing units. Number of 216 cases whose age was 40 and over were selected and analyzed with Pearson correlations and hierarchical linear regressions by SPSS. The regression analyses included four main concepts as endogenous variables, which were participation in common activities, satisfaction with common space, overall life satisfaction, and intention to move out. The results showed that participation in common activities raised satisfaction with common space and overall life satisfaction but reduced intention to move out. Meanwhile, satisfaction with common space diminished intention to move out but did not impact overall life satisfaction. When overall life satisfaction was added to the final regression model, the direct impacts of security reasons, participation in common activities, and satisfaction with common space on intention to move out disappeared. It may be concluded that participation in common activities and satisfaction with common space acted as intervening variables in the tentative cohousing adjustment framework. Even though this study leaves further research on specifying the framework, it may be noteworthy as a first attempt that explains the flow of main concepts. This study may broaden the possibility of empirical studies to develop an analytical path model of housing adjustment for cohousing residents.

• Korea journal of population studies
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• v.19 no.1
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• pp.139-159
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• 1996

This study comparatively examines a causal model of employee attatchment which focuses on employee's organizational commitment and intent to stay with an organization. This study is based on two separate studies of employee attachment among teachers : the U.S. case of the Chicago Public Schools (CPS) and the South Korean case of the Seoul Educational District (SED). The main purpose of this study is to replicate in Korea the CPS study. A revised model based on the unique characteristics of Korean teachers is also developed and estimated. The Price Mueller model of employee attachment provides the basic theoretical framework for this study. It includes five general classes of variables : 1) employee responses to work variables : job satisfaction, commitment, and intent to stay; 2) psychological stress variables: role ambiguity, role conflict, work overload, and quality of students; 3) social structural variables: autonomy, routinization, distributive justice, and legitimacy; 4) economic structural variables: pay, job security, promotional opportunities, and job opportunities; and 5) work orientation variables : career commitment, normative commitment, work motivation, affectivity, work values, and met expectations. The data was collected through questionnaire survey and a sample of 649 secondary school teachers in Seoul, South Korea, was included in the final analysis. Covariance structure analysis (LISREL) was used to estimate the causal model. The results indicate that the endogenous variables of job satisfaction and commitment play a considerably less important role than in the U.S. model in mediating the effects of the exogenous variables on intent to stay, and the model fails to explain the majority of the variance in intent to stay. In addition, the new variables added to the revised Korean model do not bave significant effects on intent to stay. The structural characteristics of the employment relationship and labor markets associated with Korean teachers forced mobility and closed external markets - are largely accountable for the major differences between the Korean and the U.S. cases. The study suggests that conceptual and empirical work on what produces employee attachment under these structural constraints needs to receive more attention in future studies.