• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.77-83
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• 2009

In this parer, an improved backoff algorithm is proposed by supplementing a multiple of persistence factor for IEEE 802.11 Wireless LAN MAC. This algorithm is proposed to complement the shortcomings of the conventional BEB (Binary Exponential Backoff) algorithm which is used for retransmission to control a new contention window in DCF/EDCF MAC. In channel utilization, collision rate and Goodput viewpoint, we analysis the improved backoff algorithm and compared the result with that of the conventional algorithm In this result, we showed that the performance for PFA backoff algorithm is 10% higher than that for the conventional BEB algorithm when the number of station is 40.

• Korean Journal of Social Welfare
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• v.62 no.4
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• pp.103-128
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• 2010

This study applied self-determination theory to investigate the relationships between volunteers' perception of supervisors' autonomy support, volunteering motivation, and persistence intentions among collegiate students. Collegiate volunteers(n=515) involved in volunteer activities completed measures of supervisors' autonomy support, 5 forms regulation, and persistence intentions. Bivariate correlations indicated that volunteer motivation demonstrated an ordered pattern of relationships, such that adjunct points along the regulatory continuum would be more positively associated with on another than distal points. Analyses using structural equation modeling revealed that supervisors' autonomy support was positively related to more autonomous motivation(intrinsic motivation and identified regulation), while was natively associated with amotivation. Amotivation was negatively related with persistence intentions, and more autonomous motivations(intrinsic and identified) predicted grater intentions to continue with volunteer activity for next 6 months. The findings are discussed in light of the self-determination theory.

• The Journal of Korean Association of Computer Education
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• v.14 no.3
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• pp.73-82
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• 2011

The purpose of the present study is to examine the structural relationship among academic stress, achievement motivation, learning environment, school flow and learning persistence in cyber education. For this study, 879 students who were enrolled in S cyber university in Korea was chosen to conduct the survey. Achievement motivation was measured in the beginning of the semester. Academic stress, learning environment, school flow, and learning persistence were measured at the end of the semester through the web survey system. The results of this study were as follows: First, academic stress, achievement motivation, and learning environment significantly affected school flow. Second, academic stress, achievement motivation, and school flow affected learning persistence, but didn't affect learning environment significantly. The results imply that academic stress, achievement motivation, and school flow should be considered as the significant elements for constructing cyber education environments to enhance students' learning persistence.

• The Korean Journal of Applied Statistics
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• v.27 no.2
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• pp.291-305
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• 2014

Persistence is one of the typical characteristics appearing in the volatility of financial time series. According to the recent researches, the volatility persistence may be due to either volatility shifts or long-range dependence. In this paper, we consider residual-based CUSUM tests to distinguish volatility persistence, long-range dependence and volatility shifts in GARCH models. It is observed that this test procedure achieve reasonable powers without a size distortion. Moreover, we employ AIC and BIC criteria to estimate the change points and the number of change points in volatility. We demonstrate the superiority of residual-based CUSUM tests on various Monte Carlo simulations and empirical data analysis.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.549-556
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• 2008

Web-based Enterprise Intranet System is developed Object-oriented programming language and data management is constructed using RDBMS. Between Object-oriented programming language and RDBMS bring about "Object-Relational Impedance Mismatch" due to heterogeneous paradigm. To solve this kinds of problems commonly use the ORM Framework that it is converting data between incompatible type systems in databases and object-oriented programming languages, uses complex mapping metadata. It causes difficult to develop and maintain because of inflexible in changes. This paper proposed persistence framework that solve the existing complexity of ORM framework and has more flexible in evolution of database table. This persistence framework is unnecessary meta information that connecting with entity of database table and the objects, it offers users convenience of maintenance and it allows far more flexible and affordable systems to be built because of automatically code generation. The result of testing based on the proposed persistence framework with Hibernate, iBATIS, It is similar response time with iBATIS and it has more about three times faster than Hibernate. But iBATIS has problems of mass data processing.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.109-122
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• 2018

This study investigates factors to disturb the e-Learning persistence of adult learners based on a case study of Cyber University students located in Seoul Korea. Main findings of our research show that economic burden, shortage of studying hours, digital literacy problem, perceived isolation, inefficient interaction between lecturer and student, and support of family are primary factors to influence the persistence of online education in a Cyber university. From our case study, we recommend to improve the scholarship system, and supplement the offline special lectures at weekends in order to alleviate perceived isolation. A novelty of this paper is that economic burden is highlighted to influence the persistence of adult learners.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.221-230
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• 2021

In this study, a firm's internationalization level was measured as the ratio of foreign sales to total sales (FSTS) of individual firms. A demonstration was conducted with several control variables that affect the persistence of the firm's profits using the Sloan (1996) model as a proxy for its primary relationship between net profit and the next profit. An empirical analysis of the end-December settlement firms listed on the securities market from 2011 to 2016 was conducted using a fixed-effect model to confirm that the persistence of the firm's internationalization and accounting profits was positive at the 1% significant level, indicating that the persistence of the firm's profits also increased as the level of individual firm's internationalization increased. In addition, the firm size, financial soundness, cash accompanying, growth, and investment ability, consistent with forecasts, represented a statistically significant (+) relationship with globalization. These results suggest that firms can maintain and expand their value stably by securing new overseas markets and promoting growth by implementing internationalization strategies.

• Industry Promotion Research
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• v.9 no.3
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• pp.1-11
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• 2024

At shareholders' meetings, minority shareholders are inferior in information to owners and majority shareholders, and they are often excluded from important decision-making. As a result, the rights and interests of minority shareholders are often damaged, which acts as a factor that hinders corporate value. The electronic voting system is expected to encourage minority shareholders to participate in management decision-making, which is expected to help increase corporate value. The results of the analysis in this study are summarized as follows. First, it was found that there was no difference between the earnings persistence of companies that introduced the electronic voting system and the earnings persistence of companies that did not. Second, we found no evidence that the introduction of the electronic voting system would increase the value of firms. Third, the effect of earnings persistence on corporate value of companies that adopted the electronic voting system was no different from that of firms that did not adopt it.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.8-13
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• 1997

Distribution and persistence of fenitrothion in rats were studied following oral administration of a single dose 300 mg/kg of body weight. Residue of the parent compound was analyzed in blood, liver, kidney, brain, lung and heart 2, 4, 6, 8 hours and 1, 2, 3, 5, 7 days after oral administration. The maximum concentration of fenitrothion appeared in the blood, kidney, heart on the 2 hour and liver, brain, lung on the 4 hour. Residues of the parent compound in kidney were much higher and persistent than other tissues and the pesticide was not detected on the 7th day. Recoveries were ranged from 83.0(lung, $1 \mu g/g$) to 97.5%(blood, $1.5 \mu g/ml$).

• Journal of the Korean Home Economics Association
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• v.38 no.6
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• pp.29-41
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• 2000

This primary purpose of this study was to analyze relations between child temperament and parental disciplinary practices. The subjects were 220 mothers and 220 fathers of kindergarten children. Child temperament was assessed using Colorado Childhood Temperament Inventory and parental disciplinary practices were measured by Parenting Scale. Resets indicated that (1) Fathers recognized their male children's temperament as more soothable and less emotional than those of female children whereas mothers recognized their male children's temperament as more active than those of female children. (2) Fathers recognized their children's temperament as more active than did mothers, but mothers recognized their children's temperament as more soothable than did fathers. (3) Children who were more sociable, less emotional, more sootable, and had longer attention span and persistence were related to more effective patemal disciplinary practices. (4) Children who were less emotional and had longer attention span and persistence were related to more effective maternal disciplinary practices. (5) Paternal disciplinary practices were explained by children's emotional temperament, whereas the best predictors of maternal disciplinary practices were children's emotional temperament and attention span and persistence.