• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4207-4222
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• 2016

In a P2P (Peer-to-Peer) VoD (video-on-Demand) streaming system, the nodes' load is an important factor which affects the system performance. In the system, some nodes may receive too many requests, which leads to overload. On the other hand, some other nodes may receive too few requests, which leads to low utilization. Therefore, designing a reasonable load balancing strategy is important. However, existing related studies cannot handle this problem effectively, because they don't have an efficient dynamic load information management mechanism, and they don't distinguish the difference of requests when transfer the nodes' load. In this paper, to manage the dynamic load information efficiently, we design a load management table for each node. Based on the load information, we propose a load balancing strategy which uses a request migration algorithm (LBRM). Through simulations, our scheme can handle the load imbalance problem effectively and improve the users' playback fluency.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.1-9
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• 2007

We propose a novel framework for distributed resource management. The framework has the following novel features. First, the resource management system is distributed using resource content information that is characterized by system properties. We argue that a distributed system based on resource content is sufficient to satisfy specific scheduling requests for Quality of Service(QoS) considering workload balance across a grid. Second, the distributed system constructs a hierarchical peer-to-peer network. This peered network provides an efficient message routing mechanism. The simulation results demonstrate that the proposed framework is proficient to satisfy QoS in distributed environment.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.4
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• pp.121-127
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• 2011

Many peer-to-peer (p2p) systems have been studied in distributed, ubiquitous computing environments. Distributed hash table (DHT)-based p2p systems can improve load-balancing even though locality utilization and user mobility are not guaranteed. We propose a mobile locality-based hierarchical p2p overlay network (MLH-Net) to address locality problems without any other services. MLH-Net utilizes mobility features in a mobile environment. MLH-Net is constructed as two layers, an upper layer formed with super-nodes and a lower layer formed with normal-nodes. Because super-nodes can share advertisements, we can guarantee physical locality utilization between a requestor and a target during any discovery process. To overcome a node failure, we propose a simple recovery mechanism. The simulation results demonstrate that MLH-Net can decrease discovery routing hops by 15% compared with JXTA and 66% compared with Chord.

• Journal of the Korean Home Economics Association
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• v.44 no.4 s.218
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• pp.111-122
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• 2006

This study investigated different individual, family, friend and school variables that affect adolescents' deviant behaviors. The sample consisted of 897 eleventh grade adolescents. Statistics and methods used for the data analysis were Cronbach's alpha, two-way ANOVA, Pearson's correlation and hierarchical regression. The major results were as follows. Male and female students' deviant behaviors had a positive correlation with sensation seeking traits, deviant behaviors by peer groups, school maladjustment, and maltreatment-experiences from parents, but a negative correlation with communications with parents. In female students', deviant behaviors had a negative correlation with self-esteem. The important variables predicting deviant behaviors were deviant behaviors of peer groups, sensation seeking traits, emotional maltreatment-experience, kind of high-school and school maladjustment for male students, compared to deviant behaviors of peer groups, kind of high-school, sensation seeking traits and school maladjustment for female students'.

• Journal of Families and Better Life
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• v.28 no.3
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• pp.139-150
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• 2010

The main purpose of this study was to examine pathways from maternal parenting behavior to externalizing problem behavior through deviant peer affiliation and self-concept. A sample of 405 high school students (184 boys and 221girls) in the Gyeonggi-do region of South Korea completed questionnaires focusing on maternal monitoring and adolescent deviant peer affiliation, self-concept, and externalizing problem behavior. Data were analyzed by structural equation modeling. The results demonstrated that maternal monitoring indirectly influences adolescent externalizing problem behavior through deviant peer affiliation and/or self-concept. When maternal monitoring was perceived as low by adolescents, they were more involved with deviant peers. This was followed by a more negative self-concept. Finally, negative self-concept resulted in more externalizing problem behavior by adolescents. The results emphasize that deviant peer affiliation plays a crucial role in increasing adolescent externalizing problem behavior.

• Journal of Families and Better Life
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• v.27 no.5
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• pp.101-113
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• 2009

The purpose of this study is to examine the relations between parenting behaviors, adolescents' attachment toward parents and peers, and adolescents' self-esteem. The differences in parenting behaviors and adolescents' attachment and self-esteem as a function of parent and adolescent gender are also examined. Participants were 405 high school students (Mage = 16.3, SD = 0.71) who completed questionnaires regarding parenting behavior, parent and peer attachment, and self-esteem. Results show that girls perceived a higher maternal behavioral control and peer attachment, whereas boys perceived a higher parental psychological control. The relative contributions of peer attachment and parenting differed depending on the adolescent's gender. Peer attachment was the only variable to predict boys' self-esteem, but mothers' behavioral control is also important to predict girls' self-esteem. The results underscore the importance of parenting behaviors and adolescents' attachment toward parents and peers in predicting an adolescent's positive self-esteem.

• Journal of Families and Better Life
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• v.31 no.6
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• pp.1-9
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• 2013

The purpose of this study was to investigate the relationships among control parenting, early adolescents' ego-resiliency and peer attachment. The subjects were 2,346 1st-year middle school students from all over the country. Korean Children and Youth Panel Survey(2010) data were analyzed by means of Pearson's correlation, hierarchical regression, and by the use of SPSS 19.0. The results of our study are as follows. First, parents' control parenting operated as a major determining factor with the effect that peer attachment decreased as parents' control parenting levels increased. Second, early adolescents' ego-resiliency operated as a major determining factor with the effect that peer attachment increased as adolescents' ego-resiliency levels increased. Finally, the interaction effects of parents' control parenting and early adolescents' ego-resiliency on peer attachment were observed.

• Journal of Families and Better Life
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• v.32 no.3
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• pp.45-63
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• 2014

The purpose of this study was to examine the effects of adolescents' school adjustment on depression in their transitional period and to find the moderating effects of parental support, parental monitoring, and peer support on the relationship between school adjustment and depression. The participants were 550 first graders in three middle schools in Incheon Metropolitan City and Kyung-gi Province. The major findings of this study were as follows: First, adolescents' school adjustment had significant effects on depression. The lower the level of school adjustment was, the higher the level of depression was. Second, parental support, parental monitoring, and peer support had moderating effects on the relationship between school adjustment and depression. Parental support decreased the depression of adolescents who were at a lower level of adjustment to peer relationship or school class. Parental monitoring decreased the depression of adolescents who were at a lower level of adjustment to school adjustment. On the contrary, parental monitoring increased the depression of adolescents who were at a higher level of adjustment to school adjustment. Peer support decreased the depression of adolescents who were at a lower level of adjustment to school class.

• Journal of Families and Better Life
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• v.28 no.6
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• pp.125-142
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• 2010

The main purpose of this study was to examine whether different cultures affect attachment style by comparing Korean and American adolescents, with a focus on parent attachment and peer attachment. Data were collected from middle and high school students(291 Korean adolescents, 158 American adolescents), and the participants were asked to report on the revised version of the Inventory of Parent and Peer Attachment(IPPA-R). The analysis showed significant differences on both parent and peer attachment between Korean and American adolescents: Korean adolescents had more negative relationships with their parents compared to American adolescents. In contrast, Korean adolescents had more positive relations(high trust and communication score, low alienation score) with their friends than American adolescents. More results on the relationships between attachment style and socio-environmental variables were presented, and each of these results could be interpreted by cultural difference. Based on these results, parent-child programs and peer programs that can enrich the relationships that a child has with his or her parents and friends were introduced for researchers, educators, teachers, and counselors. The implications and recommendations for future research were also presented.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.61-70
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• 2005

We propose and implement a flexible secure peer-to-peer(P2P) file sharing scheme which can be used for data sharing among closed user group (CUG) members. When a member wants to share data, notification messages are sent to the members with whom the member wants to share data. Each notification message includes one-time password encrypted with the receiver's public key. A member who received the notification message can download the data by using the one-time password. The proposed scheme provides selective sharing, download confirmation and efficient storage management. In terms of security, the proposed scheme supports authentication, entity privacy, replay attack protection and disguise prevention. We also implement the proposed system and find that the system is very useful among P2P service of closed user groups.