• Journal of Internet Computing and Services
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• v.7 no.5
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• pp.71-79
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• 2006

The GNUnet proposed a file encoding method by lKB block size to support anonymity of files and decentralizes encoded block to peers through unstructured model. but, the encoding and block decentralizing method with 600$\sim$700MB large multimedia file appeared two problems. First problem. it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructured model added network load by broadcasting decentralizing method. This paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation to 1% and network load by proposal structured model sending answer through dedicated peer to decentralize block.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.121-129
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• 2011

With advances in wireless networks and advent of powerful mobile devices such as smart phones, the demand for mobile IPTV services has been increasing. It is essential to minimize the energy consumption of mobile devices because their battery capacity is limited. In this paper, we therefore propose a new streaming structure in P2P-based mobile IPTV systems to minimize the energy consumption of mobile peers using agent peers. Agent peers can decrease the energy consumption of mobile peers significantly by performing streaming functionality and exchanging control messages for joining and leaving overlay networks in place of corresponding mobile peers. Finally, by simulation experiments using an energy model, we show that our proposed streaming structure can increase the lifetime of mobile peers using agent peers.

• Journal of the Korean Society of School Health
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• v.22 no.1
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• pp.49-59
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• 2009

Purpose: The aim of this study was to identify the factors related with the intention of smoking abstinence among elementary students in a metropolitan city in Korea. Methods: All the elementary schools in the city were stratified by region, and then schools as a primary sampling units (PSU) were selected by probability proportional to size (PPS) sampling. One class per grade was sampled randomly from 5th and 6th grade in the sampled schools from October to December in 2004. The students completed a standardized self-administered questionnaire anonymously. A total number of 1,712 respondents who did not smoke was included in the final analysis. The dependent variable was an intention of smoking in the future, and it was dichotomized into 'absolutely confident in smoking abstinence' and 'others'. The risk of non-absolute confidence in smoking abstinence was calculated with simple and multiple logistic regression, which were conducted with STATA 9.0 by a design-based analysis considering strata variable, PSU, and sampling weight. Results: In the final model of multiple logistic regression analysis, those who were more likely to have non-absolute confidence in smoking abstinence were male students (OR=2.66, p<0.001); barely attending religious services (OR=3.32, p=0.002) or having no religion (OR=1.95, p=0.027); exposure to environmental tobacco smoke outside home 1${\sim}$2 days per week (OR=1.60, p=0.013); having friends who smoked (OR=1.93, p=0.011); non-absolute confidence in refusing to smoke (OR=5.35, p<0.001); having relatively less negative attitude (OR=2.88, p<0.001), positive attitude (OR=2.35, p<0.001), and indifference (OR=4.05, p=0.034) toward peer smoking; not good relationship with mother (OR=1.52, p=0.016). Conclusion: The factors related with non-absolute confidence in smoking abstinence were coincided with those of smoking among children. The results of this study suggest the smoking prevention education should be applied to the children more actively, especially who are not confident in smoking abstinence in the future.

• Journal of Korean Public Health Nursing
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• v.31 no.3
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• pp.505-517
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• 2017

Purpose: This study was conducted to investigate factors affecting the somatizationof 4th grade elementary school students in South Korea. Methods: The research used cross-sectional data of 2,031 first grade elementary school students that participated in 4th-year Korean Children and Youth Panel Survey (KCYPS). Data analysis, which included descriptive statistics, t-tests, one-way ANOVA, Pearson's correlation, and hierarchical regression,was performed using SPSS/WIN 23.0. Results: Aggression (r=0.60, p<.001) and depression (r=0.69, p<.001) showed significant positive correlation, while affection (r=-0.22, p<.001), reasonable explanation (r=-0.28, p<.001), peer relationship (r=-0.06, p=.001), and teacher relationship (r=-0.20, p<.001) were negatively correlated with somatization of elementary school students. Hierarchical regression analysis revealed that depression (${\beta}=0.52$, t=25.52, p<.001), aggression (${\beta}=0.27$, t=13.30, p<.001), reasonable explanation (${\beta}=0.05$, t=2.99, p=.002), and affection (${\beta}=0.04$, t=2.13, p=.031) were significant predictors of somatization. This regression model has an explanatory power of 52.8%. Conclusion: To reduce somatization, it is necessary to develop a therapeutic intervention to change student emotions into a positive coping mechanism and strategy. The results of this study will contribute to the development of programs and practices for healthy school life.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.2
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• pp.2096-2101
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• 2020

Background: The effect of mobilization on lumbar back pain has been fully described in several clinical aspects, but evidence for muscle strength would be still less clear. Objective: To assess the effect of lumbar mobilization on lower limb strength in healthy individuals. Methods and Analysis: Healthy people aged 18-65 will be included regardless of race or sex. Original peer-reviewed primary reporting randomized controlled trials (RCTs) will be included. Electronic databases, such as MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, Pedro, CINAHL, ClinicalTrials.gov will be searched from inception until July 30. Only studies published in English will be included in this review. Two reviewers will complete the screening for eligibility independently, and the other two reviewers will also complete the risks of data extraction and bias assessment independently. Lower Limb strength will be assessed as primary outcome, and particular intervention or participant characteristics will be assessed as the secondary outcomes. Meta-analysis will be conducted using Review Manager 5.3.3, and evidence level will be assessed using the method for Grading of Recommendations Assessment, Development and Evaluation. Outcomes will be presented as the weighted mean difference or standardized mean difference with 95% CI. If I² ≤ 50%, P>.1, the fixed effect model will be used, otherwise, random-effects model will be used. Ethics and dissemination: This review might not be necessary ethical approval because it does not require individual patient's data; these findings will be published in conference presentations or peer-reviewed journal articles. PROSPERO registration number: CRD42020150144.

• Journal of Intelligence and Information Systems
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• v.13 no.3
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• pp.119-140
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• 2007

Recommender systems enable a user to decide which information is interesting and valuable in our world of information overload. As the recent studies of distributed computing environment have been progressing actively, recommender systems, most of which were centralized, have changed toward a peer-to-peer approach. Collaborative Filtering (CF), one of the most successful technologies in recommender systems, presents several limitations, namely sparsity, scalability, cold start, and the shilling problem, in spite of its popularity. The move from centralized systems to distributed approaches can partially improve the issues; distrust of recommendation and abuses of personal information. However, distributed systems can be vulnerable to attackers, who may inject biased profiles to force systems to adapt their objectives. In this paper, we consider both effective CF in P2P environment in order to improve overall performance of system and efficient solution of the problems related to abuses of personal data and attacks of malicious users. To deal with these issues, we propose a multi-agent framework for a distributed CF focusing on the trust relationships between individuals, i.e. web of trust. We employ an agent-based approach to improve the efficiency of distributed computing and propagate trust information among users with effect. The experimental evaluation shows that the proposed method brings significant improvement in terms of the distributed computing of similarity model building and the robustness of system against malicious attacks. Finally, we are planning to study trust propagation mechanisms by taking trust decay problem into consideration.

• Knowledge Management Research
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• v.23 no.3
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• pp.23-44
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• 2022

With the development of blockchain technology, play-to-earn (P2E) games, one of the decentralized applications (dApps), are receiving great social attention. P2E games are positively evaluated as areas with high growth potential based on blockchain technology, and at the same time, they are negatively evaluated as speculative as people can cash P2E game items in the form of cryptocurrency. In this situation, the purpose of this study is to investigate factors affecting the intention to use P2E games. Along with the discussion of hedonic system adoption, we consider the factors with perceived enjoyment, economic incentive, and social influence. In order to verify our research model, data were collected from 350 adults with P2E game experience or recognition, and a structural equation model was carried out. The analysis results find that perceived enjoyment and subjective norm have a significant positive effect on the intention to use P2E games, and economic incentive does not have a significant effect. In addition, peer influence and external influence have a significant positive effect on subjective norm. Drawing on these findings, we present several academic and practical implications for future research.

• The Journal of Korean Academic Society of Nursing Education
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• v.24 no.3
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• pp.250-258
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• 2018

Purpose: This study aimed to investigate the influence of health status and types of health management on depression in middle-aged women. Methods: A convenience sample of 188 participants was recruited from health centers in S city. Using a structured questionnaire, data was collected and analyzed by t-test, ANOVA, Pearson's correlation, and linear regression using SPSS/WIN 23 program. Results: Results of the regression analysis showed that perceived current health status (${\beta}=-0.55$, p<.001), no caregiver (${\beta}=0.47$, p<.001), chronic diseases lasting more than three months (${\beta}=0.36$, p<.001), perceived health status compared to peer group (${\beta}=0.32$, p<.001), walking for health (${\beta}=-0.20$, p=.002), caregiver except family (${\beta}=0.18$, p=.001), and gastrointestinal disease (${\beta}=0.10$, p=.022) influenced depression in middle-aged women. Overall, approximately 69.7% of total variance explained this model (adjusted $R^2=0.678$, F=57.21, p<.001). Conclusion: This study suggests that it is more important to understand the level of perceived health status in middle-aged women. Furthermore, it is necessary to develop programs that include various health management methods and strengthen the health care with the help of families and neighbors in order to manage depression in middle-aged women.

• The Journal of Engineering Research
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• v.7 no.1
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• pp.89-97
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• 2005

The GNUnet proposed a file encoding method by 1KB block size to support anonimity of file and decentralizes encoded block to peers through unstructed model. but, the encoding and block decentralizing method with 600~700MB large multimedia file appered two problems. First problem, it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructed model added network load by broadcasting decentralizing method. The paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation from 4% to 1%. and network load by proposal structured model sending answer through dedicated peer to decentralize block.

• Smart Structures and Systems
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• v.31 no.2
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• pp.101-111
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• 2023

Structural health monitoring (SHM) covers a range of damage detection strategies for buildings. In real-time, SHM provides a basis for rapid decision making to optimise the speed and economic efficiency of post-event response. Previous work introduced an SHM method based on identifying structural nonlinear hysteretic parameters and their evolution from structural force-deformation hysteresis loops in real-time. This research extends and generalises this method to investigate the impact of a wide range of flag-shaped or pinching shape nonlinear hysteretic response and its impact on the SHM accuracy. A particular focus is plastic stiffness (K_p), where accurate identification of this parameter enables accurate identification of net and total plastic deformation and plastic energy dissipated, all of which are directly related to damage and infrequently assessed in SHM. A sensitivity study using a realistic seismic case study with known ground truth values investigates the impact of hysteresis loop shape, as well as added noise, on SHM accuracy using a suite of 20 ground motions from the PEER database. Monte Carlo analysis over 22,000 simulations with different hysteresis loops and added noise resulted in absolute percentage identification error (median, (IQR)) in K_p of 1.88% (0.79, 4.94)%. Errors were larger where five events (Earthquakes #1, 6, 9, 14) have very large errors over 100% for resulted K_p as an almost entirely linear response yielded only negligible plastic response, increasing identification error. The sensitivity analysis shows accuracy is reduces to within 3% when plastic drift is induced. This method shows clear potential to provide accurate, real-time metrics of non-linear stiffness and deformation to assist rapid damage assessment and decision making, utilising algorithms significantly simpler than previous non-linear structural model-based parameter identification SHM methods.