Target Peer Research Articles

QoS에 민감한 멀티미디어 멀티캐스트 응용을 위한 P2P 스트리밍 기법

As the IP multicast function is very slowly deployed in Internet due to its scalability problem and inter-domain interoperability problem, interest in the P2P(Peer-to-Peer) streaming technologies for the realtime multimedia multicast applications such as IPTV is highly growing. This paper proposes a P2P streaming method for the QoS-sensitive multimedia multicast applications such as highly-interactive personal IPTV and video conferences. The proposed P2P streaming method allows an application to construct a reliable streaming tree in which a proper number of backup peers are placed according to its reliability requirement. The reliable streaming tree reduces the reconnection delay, occurred in the case of a normal and/or abnormal peer leave, so as to minimize the loss of streaming data. In the proposed P2P streaming method, the join delay of a peer called startup delay is also substantially reduced because the bandwidth and end-to-end delay information of every peer kept in a distributed way allows the target peer for a joining peer to be able to be quickly determined. Moreover, the proposed method`s peer admission control mechanism based on the bandwidth and end-to-end delay enables the delay-bounded streaming services to be provided for its corresponding applications.

Increasing social skills and pro-social behavior for three children diagnosed with autism through the use of a teaching package

This study assessed the effectiveness of a Teaching Interaction procedure for four social skills across three participants diagnosed with autism. All social skills fell into four broad domains (i.e., social-communication, play, emotion skills, and choice/selection skills). In addition, a teaching package was used to increase communication between the three participants and three selected target peers. The teaching package consisted of the Teaching Interaction procedure, reinforcement, and priming of participants to demonstrate social skills and to engage with their target peers. Prior to intervention, participants displayed near zero levels of the four social skills that were targeted; after intervention, all three participants were able to demonstrate these skills. Prior to intervention, participants did not communicate or play with their selected target peer; after intervention, participants were able to increase the amount of play and communication. A multiple baseline design showed that the teaching package was effective in teaching both the targeted social skills and in increasing the development of initial associations that could lead to friendships for three children diagnosed with autism.

Affect‐Congruent Social‐Cognitive Evaluations and Behaviors

This study examined whether the affect children feel toward peers would influence children's social-cognitive evaluations and behaviors. The sample consisted of 209 fifth-grade children (11- to 12-year-olds; 119 boys and 90 girls). For each child, 3 target peers (liked, disliked, and neutral) were identified via a sociometric nomination procedure. The names of the targets were then inserted into hypothetical vignettes in which the target peer's behavior had a negative consequence for the child. After each vignette, questions about intent, outcome expectations, and self-efficacy beliefs were asked. In addition, self-reports regarding relationship-specific proactive and reactive aggression and regarding victimization were collected. The results demonstrate that children social-cognitively differentiate between the relationship types and that relationship-specific evaluations are associated with relationship-specific behaviors.

Hostile attributions and behavioral strategies in children: Does relationship type matter?

The purpose of this study was to test the hypothesis that children's hostile attributions and behavioral strategies in response to peer provocation and rebuff situations will depend on the relationship with the target peer (i.e., friend, enemy, neutral). The sample consisted of 144 fourth graders (75 boys and 69 girls; mean age=10.47 years, SD=0.55 years). The participants were randomly selected from a pool of 442 children who completed a measure of social adjustment in Grade 3. In Grade 4, children participated in the individual interviews in which they were verbally presented with 6 hypothetical situations. The target peers were identified on the basis of the relationship descriptions. The results clearly demonstrate that children do indeed differentiate between relationship types in regard to hostile attributions and hostile strategies, with more hostility attributed and more hostile responses proposed toward enemies than toward other peers (ps<.05). In addition, this relationship effect holds even when the social and behavioral reputation of the target peers is accounted for (ps<.05).

Peer data exchange

In this article, we introduce and study a framework, called peer data exchange , for sharing and exchanging data between peers. This framework is a special case of a full-fledged peer data management system and a generalization of data exchange between a source schema and a target schema. The motivation behind peer data exchange is to model authority relationships between peers, where a source peer may contribute data to a target peer, specified using source-to-target constraints, and a target peer may use target-to-source constraints to restrict the data it is willing to receive, but cannot modify the data of the source peer.A fundamental algorithmic problem in this framework is that of deciding the existence of a solution: given a source instance and a target instance for a fixed peer data exchange setting, can the target instance be augmented in such a way that the source instance and the augmented target instance satisfy all constraints of the setting? We investigate the computational complexity of the problem for peer data exchange settings in which the constraints are given by tuple generating dependencies. We show that this problem is always in NP, and that it can be NP-complete even for “acyclic” peer data exchange settings. We also show that the data complexity of the certain answers of target conjunctive queries is in coNP, and that it can be coNP-complete even for “acyclic” peer data exchange settings.After this, we explore the boundary between tractability and intractability for deciding the existence of a solution and for computing the certain answers of target conjunctive queries. To this effect, we identify broad syntactic conditions on the constraints between the peers under which the existence-of-solutions problem is solvable in polynomial time. We also identify syntactic conditions between peer data exchange settings and target conjunctive queries that yield polynomial-time algorithms for computing the certain answers. For both problems, these syntactic conditions turn out to be tight, in the sense that minimal relaxations of them lead to intractability. Finally, we introduce the concept of a universal basis of solutions in peer data exchange and explore its properties.

Measuring peer caring behaviors of nursing students: Scale development

Background Caring is one of the most important domains of nursing research, peer caring among student nurses, and its potential effects on nurse caring behaviors remains largely unexplored. Few tools in the literature target peer caring interactions, and which were either irrelevant to our research purpose or culturally inappropriate for nursing student population in Taiwan. Objectives The purpose of this study was to develop a culturally sensitive instrument to measure peer caring behavior from the student perspective and to offer a descriptive answer to “what is peer caring in Taiwan.” Design The study uses both qualitative and quantitative methods in developing the “Peer Caring Measurement (PCM)” questionnaire. Settings Students from a 5-year associate degree nursing program in a university of technology in southern Taiwan were recruited into this study. Participants Thirteen first- through fourth-year student volunteers between the ages of 16 and 20 were interviewed to explore caring behavior in student peer-to-peer interactions. Two classes from each of the first, second, third, and fourth year students, a total of 360 students were randomly selected to assess the internal consistency of “PCM”, and 47 first-year students were conveniently selected to examine the stability of the tool. Methods Interviews were conducted in an unstructured manner. Qualitative data were analyzed by a constant comparative method. The questionnaire survey was used to assess the validity and reliability of “PCM”. Results A 17-item “PCM” was developed; the content validity, construct validity, and reliability of the tool were ensured by expert review, factor analysis, and internal consistency. Three factors, labeled assistant caring, academic caring, and affective caring, accounted for 63.197% of the variance. Conclusions The “PCM” addressed the multidimensional construct of peer caring. It was validated in a Chinese language version and can be used in college settings to evaluate student interactions and their peer caring behaviors.

On the effectiveness of movement prediction to reduce energy consumption in wireless communication

Node movement can be exploited to reduce the energy consumption of wireless network communication. The strategy consists in delaying communication until a mobile node moves close to its target peer node within an application- imposed deadline. We evaluate the performance of various heuristics that, based on the movement history of the mobile node, estimate an optimal time (in the sense of least energy use) of communication subject to the delay constraint. We evaluate the impact of the node movement model, length of movement history maintained, allowable delay, single hop versus multiple hop communication, and size of data transfer on the energy consumption. We also present measurement results on an iPAQ pocket PC that quantity energy consumption in executing the prediction algorithms. Our results show that, with relatively simple and, hence, efficient prediction heuristics, energy savings in communication can significantly outweigh the energy expenses in executing the prediction algorithms. Moreover, it is possible to achieve robust system performance across diverse node movement models.

CBF: LOOK-UP PROTOCOL FOR DISTRIBUTED MULTIMEDIA OBJECTS IN PEER-TO-PEER OVERLAY NETWORKS

Various types of applications take usage of multimedia objects like music and movies. Multimedia objects are distributed in peer-to-peer (P2P) overlay networks since the objects are downloaded and personalized in computers, mainly personal computers interconnected with the Internet. An application would like to take some service of a target object. A target peer is a peer which can manipulate a target object. First, the application has to find target peers which can support enough quality of service (QoS) of target multimedia objects. Due to the scalability and variety of peers in P2P overlay networks, it is difficult, possibly impossible to maintain a centralized directory showing in which peer each object is distributed. In this paper, we newly take an acquaintance approach where each peer maintains its acquaintance peers. An acquaintance peer of a peer p is a peer whose service the peer p knows and with which the peer p can directly communicate in P2P overlay networks. We discuss types of acquaintance relations of peers with respect to what objects each peer holds, is allowed to manipulate, and can grant access rights on. In addition, we discuss a new type of flooding algorithm named charge-based flooding (CBF) algorithm to find target peers based on charge and acquaintance concepts so that areas in P2P overlay networks where target peers are expected to exist are more deeply searched. We evaluate the charge-based flooding (CBF) algorithm compared with a traditional TTL-based flooding algorithm in terms of the number of messages transmitted in networks.

Age-Related Changes in Children's Orientations Toward Strategic Peer Interaction: Implications for Social Perception and Behavior

Two studies examined age-related changes in children's orientations toward strategic peer interaction in middle childhood. In Study 1, first graders did to some extent recognize the pragmatic value of ingratiation in eliciting desired outcomes from a target peer. However, they were less likely than older children (third and fifth graders) and adults both to spontaneously infer an ulterior motive, and to negatively evaluate ingratiation, when ulterior motivation was relatively likely. Study 2 extended work by Feldman and Ruble (1988) by providing additional evidence that the activity partner choices of younger children were based primarily on affective reactions to potential partners, while those of older children were based more on strategic factors. Together these studies provide convergent evidence that younger children focus more on affective properties of peer behavior. The contribution of parallel age-related changes in a number of psychological processes and mechanisms to the development of children's strategic peer orientations are discussed.

Impression Formation in Children: Influence of Gender and Expectancy

The effect of expectancy-congruent and -incongruent information on subsequent impression formation and recall of a target peer was examined. 64 boys and 50 girls (ages 8 to 12) were given an expectancy that a stimulus child was either shy or outgoing. Subjects rated the target on several dimensions (e.g., friendly, shy) and then watched a videotape of a boy or girl confederate acting out a script containing both expectancy-congruent and -incongruent information. Subjects then rated the target child again and freely recalled as much of what the target said as they could remember. Results revealed that when children are presented with both expectancy-congruent and -incongruent information, impression formation appears largely attribute based, and the influence of the initial expectancy appears mitigated. However, ratings of liking appeared to be more influenced by the initial expectancy than by subsequent behavioral information. In addition, the results indicated that many of Maccoby's conclusions regarding the effects of gender on social interactions also apply to children's social information processing, indicating a strong bias toward same-sex peers.

Increasing generalized social interactions in psychotic and mentally retarded residents through peer-mediated therapy.

This study investigated whether withdrawn adults living in a residential center for psychotic and mentally handicapped persons could serve as peer therapists to increase the social interaction of other withdrawn residents. Two pairs of residents served as participants. Treatments were introduced and evaluated within a multiple baseline with reversal design. After baseline, the peer therapist was instructed to increase the social interactions of a target peer through engagement in social interactions. The results demonstrated that the peer therapist increased the social interactions of target peers. However, these increases did not generalize to other residents until the introduction of a multiple peer therapist condition. The percentage of time the peer therapists interacted with other nontarget residents also increased throughout the study. These results were maintained during a 4-month follow-up condition.

Social cognition as segmentation of the stream of behavior.

This study examined the influence of familiarity with peers on social cognition in children. Secondand fourth-grade children were given information about an unfamiliar peer before viewing a videotape of that peer. Children were then instructed to segment the ongoing behavioral stream of the target peer into units by pressing a button. Extrapolating from research on the influence of expert knowledge on cognition, we predicted that children who were given prior information about the peer would break the behavioral stream into fewer, larger segments than would children in no-priorinformation control conditions. We also predicted that prior information would exert more influence on the segmentation of fourth graders than that of second graders. Results were consistent with these hypotheses. These and other results are discussed in terms of developmental and contextual influences on social cognition in children. In recent years, research on children's social cognition has been dominated by cognitive-developmental theory (Higgins, Ruble, & Hartup, 1983; Shantz, 1983). The emphasis in this approach has been on intellectual development as a determinant of age-related changes in understanding the social environment. \bunger children differ from older children in their pattern of social cognition because of cognitive-structural limitations in younger children. An alternative to the cognitive-developmental approach is a contextualist account (e.g., Higgins & Eccles Parsons, 1983; Laboratory of Comparative Human Cognition, 1983; Lerner & Lerner, 1986; McGuire, 1983). This approach does not deny that in fact there may be structural bases for some age-related differences in social cognition. This approach suggests, however, that some of the age and group differences reported in the literature may reflect not structural differences in basic cognitive capacities so much as differential familiarity with certain kinds of tasks and persons as well as differences in the contexts in which the behavior is typically assessed. There are data consistent with this view. Livesley and Bromley (1973) found that children provide more complex, differentiated, inferential statements in describing other children than in describing adults. One explanation for this is that children are more familiar with the behavior of peers than with that of adults (see Shantz, 1983, p. 506). Children have more diverse interaction with other children and more experience with the range of activities in which other children engage and thus perceive children differently. Similarly, children may have more differentiated concepts of friends than of disliked peers (e.g.,