• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12B
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• pp.818-830
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• 2005

Recently, Peer-to-Peer (P2P) overlay networks like CAN, Chord, Pastry and Tapestry offer a novel platform for scalable and decentralized distributed applications. These systems provide efficient and fault-tolerant routing, object location, and load balancing within a self-organizing overlay network. Content Delivery Network (CDN) is an intermediate layer of infrastructure that helps to efficiently deliver the multimedia content from content providers to clients. In this paper, We propose a topology-aware P2P overlay network for CDN, Rosary, in which CDN servers perform Intra-Pastry and Inter-Pastry routing based on a two-level structured overlay network. This proposed system extends pastry by adapting itself to CDN environments, where a semi-hashing based scheme for Intra-Pastry routing is introduced, and dynamic landmark technology is used to construct the topology-aware overlay network. Through simulations on NS-2, it is shown that Rosary is scalable, efficient, and flexible.

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.27-35
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• 2010

Accurately extracting skin color regions is very important in various areas such as face recognition and tracking, facial expression recognition, adult image identification, health-care, and so forth. In this paper, we evaluate the performances of several skin color detection algorithms in indoor environments by changing the distance between the camera and the object as well as the background colors of the object. The distance is from 60cm to 120cm and the background colors are white, black, orange, pink, and yellow, respectively. The algorithms that we use for the performance evaluation are Peer algorithm, NNYUV, NNHSV, LutYUV, and Kimset algorithm. The experimental results show that NNHSV, NNYUV and LutYUV algorithm are stable, but the other algorithms are somewhat sensitive to the changes of backgrounds. As a result, we expect that the comparative experimental results of this paper will be used very effectively when developing a new skin color extraction algorithm which are very robust to dynamic real environments.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.121-126
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• 2013

In the past several years there has been increasing the studies using P2P technology in the distributed system areas. In these P2P systems, the server to support the contents-information have less overloads than the composed system as the server to have resources generally. In this paper, we propose the system to support a social network P2P service based on the social network P2P system. The object of this study was to widen the use of this menu system to determine the price based on visual information by a software agent. Therefore, this system is suitable for micro, small and medium industries in the use of P2P servers and is more usable system interface for owners than previous study.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1103-1108
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• 2012

In the past several years there has been increasing the studies using P2P technology. In these P2P systems, the server to support the contents-information have less overloads than the composed system as the server to have resources generally. In this paper, we propose the system to support a menu based on the social network P2P system. The object of this study was to widen the use of this menu system to determine the price based on visual information. This system is based on previous research, showing excellent success rate. Therefore, this system is suitable for micro, small and medium industries in the use of P2P servers. This system is more usable than previous study.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.309-318
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• 2005

Learners show lower cooperation and responsibility at e-Learning(Electronic Learning) than face-to-face learners in class. Accordingly the LMS(Learning Management System) focus on collaborative learning design in order to promote the learner's interaction. In this paper, the Experience Learning Support System with JXTA-based P2P(Peer-to-Peer) architecture is proposed for an effective collaborative learning and a blended learning. It intends learners to develop a self-leading learning ability and a creative problem-solving ability through experience learning object's sharing. The experimental results described that the proposed system was more effective in an enhancing learner's learning ability and a cooperative learning than existing system.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.15-20
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• 2010

In this paper, we propose a novel approach to reduce spatial query access latency and energy consumption by leveraging results from nearby peers in wireless broadcast environments. We propose a three-tier Hierarchical Location-Based Sequential access index, called HLBS, which provides selective tuning (pruning and searching entries) without pointers using a linear accessing structure based on the location of each data object. The HLBS saves search cost and index overhead, since the small index size with a sequential index structure results in low access latency overhead and facilitates efficient searches for sequential-access media (wireless channels with data broadcast). Comprehensive experiments illustrate that the proposed scheme is more efficient than the previous techniques in terms of energy consumption.

• Korean Journal of Forensic Psychology
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• v.11 no.1
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• pp.63-87
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• 2020

Judgment and decision-making studies have shown that people are easily influenced and biased by information irrelevant to the object of judgment. There is a great deal of research that indicates that bias exists in the legal judgment scene. One of them is a bias induced by defendants' character evidence. This study examined whether cognitive activities such as discussion, counterfactual thinking, and peer assessment could reduce the bias induced by the character evidece. In Experiment 1, 121 college students were asked to give the percentage they believed the defendant to be guilty. There was no cognitive activity for the control group. There were three different cognitive activities for the experimental group: discussion, counterfactual thinking and discussion, and counterfactual thinking and peer assessment. Results showed reduction in bias for all the experimental groups, and there was no difference between them. In Experiment 2, there were 125 participants from general population for the same procedure as in Experiment 1. Results showed reduction in bias only for the counterfactual thinking and discussion group. In general discussion, we speculated the implication of the results and the reason for the difference between the two experiments.

• The KIPS Transactions:PartB
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• v.11B no.7 s.96
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• pp.821-830
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• 2004

In this paper, we model the downward collision of a falling object to the base. We aim to provide maximum diversity of response to physical. collision. To this end, the primary design concern of the model is to unfold the collision phenomenon in a logical and natural manner, detailed enough to construct an immersive virtual environment. To achieve these requirements, first we determine domains for the characteristic of the material of the falling objects, and select the dominant force of the collision. We formulate the collision phenomena with combination of primitive attributes and their relationships. The formulated function evaluates the results of the collision in qualitative aspects as well as in quantitative aspects. Between the collision issues, 'Collision Detection' and 'Collision Response', this paper focuses on Collision Response issue.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.49-56
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• 2006

A special feature of P2P distributed system isn't always the guarantee of online status for peers. In other words we want to download the file from the peer when we use the P2P system but it sometimes caused this system to fail the download. Many studies to resolve this problem depend on re-transmission method. It caused to lower performance so we have to resolve this problem. In this study, we analysis the average usage time of P2P application user and raise the resource transmission guarantee to apply the selection criteria of resource supplier. Moreover the combinations of distributed object replication techniques, the role to enhance the data transmission opportunity of high popularity resource. will cause this search algorithm to advance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.11
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• pp.2690-2701
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• 2013

Humans are able to recognize small number of people they know well by the way they walk. This ability represents basic motivation for using human gait as the means for biometric identification. Such biometric can be captured at public places from a distance without subject's collaboration, awareness or even consent. Although current approaches give encouraging results, we are still far from effective use in practical applications. In general, methods set various constraints to circumvent the influence factors like changes of view, walking speed, capture environment, clothing, footwear, object carrying, that have negative impact on recognition results. In this paper we investigate the influence of walking speed variation to different visual based gait recognition approaches and propose normalization based on geometric transformations, which mitigates its influence on recognition results. With the evaluation on MoBo gait dataset we demonstrate the benefits of using such normalization in combination with different types of gait recognition approaches.