• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.409-411
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• 2002

Enterprise JavaBeans(EJB)에서 영속적인 데이터들을 표현하고 관리하는 엔티티빈의 두 가지 구현 방법은 Bean Managed Persistence(BMP)와 Container Managed Persistence(CMP)기법이있다. 이렇게 엔티티빈이 데이터 베이스와 연결되어 사용되기 때문에 생기는 특성이 있는데, 이런 특성들이 BMP 와 CMP를 사용하여 구현. 운용. 유지보수 및 재사용을 알 때 많은 차이점을 만든다. EJB를 사용하는 소프트웨어 산업계에서, 이런 차이점에 대한 연구가 부분적으로는 이루어지고 있지만, 체계적인 비교 평가는 아직 미흡한 실정이다. 본 논문에서는 BMP와 CMP를 이용해서 빈을 구현할 때 나타나는 각각의 장점과 단점을 몇 가지 측면에서 살펴본다. 그리고 그 차이를 비교함으로써 BMP 와 CMP 기법을 평가한다

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.187-192
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• 2017

In this paper, we have studied scale tools for measure programming task value and learning persistence at elementary school students. In order to develop complete test tools, we have improved the completeness by revising tests through stepwise verification. The first scales were constructed based on the previous studies. As a result of the content validity test, 5 out of 14 items of the task value test tool and 1 out of 10 items of the learning persistence test were not suitable. The second test tools were constructed by revising and supplementing the first scale, and consisted of 13 items of task value and 8 items of learning persistence. As a result of the contents validity test, all the items included in the test tool proved to be valid. The reliability of the secondary testing tools were also found to be reliable at ${\alpha}=.970$ and ${\alpha}=.975$, respectively.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.10-13
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• 2006

통신 기술의 발달로 많은 통신기기들이 하나의 채널을 공유하여 사용하게 되었다 여러 통신기기가 채널을 공유하여 사용하므로 동시에 데이터를 전송하여 발생하는 충돌 가능성이 증가하였다 이러한 충돌로 인한 네트워크 성능의 저하를 방지하기 위하여 다양한 다중 접속(Multiple Access) 기술이 연구되고 있다. CSMA(Carrier Sense Multiple Access)는 다양한 다중 접속 기술의 기반이 되는 기술이다. CSMA는 nonpersistence, 1-persistence, p-persistence와 같이 다양한 전송 방식을 지원하기 때문에 여러 네트워크 환경에 널리 적용된다. 그러나 CSMA가 다양한 네트워크 환경에 적용이 가능하지만 네트워크의 빈번한 상태 변화를 고려하여 최적의 성능을 유지하지는 못한다. CSMA의 전송 방식들은 네트워크 환경에 따라 그 성능의 변화가 심하다 본 논문에서는 동적 네트워크 환경을 고려하여 성능을 향상시키기 위한 적응형 persistence 방법을 제안한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.301-306
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• 2023

Attention is a fundamental aspect in the cognitive process of human. Cognitive system of human body requires to focus on selected information among a vast amount of information from sensory organs. It has widely studied that various environmental factors affected the level of attention; however, few researches have aimed to the effect of direct cryotherapy. In this research, level of attention was studied comparing sub-indexes of FAIR test between groups with different duration of direct cryotheapy to the back of neck. FAIR test is a evaluation tool for visual attention consisting of three sub-indexes. Selective attention, accuracy of attention, and persistence of attention can be independently analyzed by FAIR test. In the analysis of selective attention, cryotherapy for 5 to 20 minutes showed higher result than cryotherapy for 40 minutes. In the analysis of persistence of attention, cryotherapy for 5 to 15 minutes showed higher result than cryotherapy for 40 minutes. Overall, selective attention and persistence of attention turns out to be maximized between 5 to 20 minutes of cryotherapy and tends to decrease afterwards. However, accuracy of attention does not seem to be affected by the duration of cryotherapy. Correlation between selective attention and the skin temperature by cryotherapy tends to be negative supporting the findings by ANOVA and post-hoc test. Correlation between persistence of attention and the skin temperature showed similar results.

• Knowledge Management Research
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• v.10 no.4
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• pp.31-42
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• 2009

With the rapid development of information technology, e-learning is growing in corporate. However, there are still problems in learning, such as low learning persistence rate. Learning outcomes are complex phenomenon influenced by a multitude of factors, it is need to considering the direct and indirect causal relationship among various factors. Therefore, the purpose of this study was to develop the causal model that explains the learning outcomes (satisfaction learning persistence) in corporate e-learning. This study was also intended to examine the causal relationship between the interaction and learning persistence through satisfaction mediators. For this, online survey was conducted with a sample of 270 learners who enrolled in cyber training course at A company. The major findings of this study are as follows: First, internality (internal locus of control, ${\beta}=.154$), interaction (${\beta}=.489$), satisfaction (${\beta}=.304$) have direct effect on learning persistence. Second, the interaction has direct effect on the satisfaction (${\beta}=.320$). Third, the satisfaction has direct effect on the learning persistence, and mediating the interaction and learning persistence. This result will contribute to build a learning strategy to improve learning outcomes.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.73-85
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• 2020

The study aims to provide better understanding of sustainable earnings by a comprehensive analysis of earnings persistence of business firms in Vietnam as an example of developing economies in South-East Asia. Dataset of 1,278 publicly listed firms (excluding banking and financial services firms) on Vietnam Stock Exchange for the period from 2008 to 2017 was collected. By applying fixed effect regression model, the empirical results provided the basis to measure the persistence index (Pers index) and find low level of their earnings persistence. The literature of earnings quality analysis in developed countries suggests earnings persistence as a noteworthy determinant of future earnings forecast and stock valuation. However, research of sustainable earnings in developing countries is still highly underdeveloped. For Vietnamese listed firms, the average Pers index was estimated for the period from 2008 to 2010, indicating low level of earnings persistence. We also incorporated earnings persistence level into future earnings forecast by running the quintile regression model divided the data into four equal levels and conducted each section independently to see the difference in each percentile, thence assessed the factors' influence on the specific model. The findings provide important information on the expected returns of firms, especially helping investors make sound decisions.

• Journal of The Korean Association of Information Education
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• v.26 no.3
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• pp.175-186
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• 2022

This study has explored the facilitating factors affecting the learning persistence of university students and divided Emergency Remote Teaching(ERT) into two types based on its policies. The conclusions are as follows: First, perceived usefulness was the facilitating factor affecting learning persistence in Synchronous ERT. Therefore, learning persistence would improve by establishing various strategies such as exploring appropriate teaching strategies and building a stable infrastructure. Second, it was perceived usefulness, social presence, and system quality that were the facilitating factors affecting learning persistence in Asynchronous ERT. Thus, learning persistence would increase accompanied by immediate feedback, more active interaction, and so on.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.523-530
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• 2008

In this paper, we analyze the mean queuing delay of selective-repeat automatic repeat request (SR-ARQ) protocol with the finite retransmission persistence. The retransmission persistence means the willingness of the protocol to retransmit a lost (or corrupted) packet to ensure reliable packet delivery across a lossy link. According to the retransmission persistence, SR-ARQ protocols have a different performance in terms of both packet delay and link reliability. So far, however, there is no serious study in the effect of the retransmission persistence on the SR-ARQ performance. We present a simple M/G/1 queuing model for the SR-ARQ protocol with the finite retransmission persistence by using the ideal SR-ARQ approximation. The mean queuing delay is obtained from the queuing model and verified its accuracy through the simulation results using the OPNET simulator. Both the analytical predictions and simulation results clearly show the effect of retransmission persistence on the queuing delay of the SR-ARQ protocol in various network conditions: packet loss rate and traffic condition over a wireless link.

• Journal of The Korean Association of Information Education
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• v.14 no.3
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• pp.341-353
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• 2010

The purpose of the present study is to verify the structural relationship among on-line task value, university support, satisfaction, learning persistence in Cyber University. For this study, W cyber university in Korea was chosen to conduct web survey. A hypothetical model was proposed, which was composed of on-line task value, university support as exogenous variables, satisfaction, learning persistence as endogenous variables. And satisfaction have been suggested as intervening endogenous variables. The result of this study is as follows: First, on-line task value and university support affect satisfaction. Second, university support and satisfaction affect learning persistence. Lastly, satisfaction mediated on-line task value, university support and learning persistence.

• 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.