• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.197-199
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• 2020

환경문제와 더불어 우리나라의 신재생 에너지에 대한 관심이 증가하고 있다. 현재 한전과의 상계거래 체결을 통해 관리되고 있는 태양광 에너지 관리는 친환경 신재생 에너지의 대표적 모델이다. 본 논문에서는 가정에서 발생하는 태양광패널의 잉여 전력량을 이웃과 거래하는 P2P(Peer to Peer)방식을 제안하였다. 제안하는 방식을 통하여 각 가구의 데이터를 활용하여 에너지에 대한 수요-공급량을 도출하고 균형거래가격을 결정하여 참여자 간 합리적 에너리 관리가 가능하다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.89-92
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• 2005

Centralized P2P system, Napster and Unstructured P2P system, Gnutella accomplish main current. Centralized system and unstructured system have a restriction in a scalability. To solve the this problem, structured system is appeared. CAN, Chord, Pastry and Tapestry are delegation of this system. Although structured system don't aware physical proximity of node because it uses Distribute Hash Table. In proposing system, a node can communicate with physical proximity of node using concept of LAN. Internet traffic is also decreased because communication in the Chord network divide in two(original network and sub network).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.695-698
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• 2007

The control of electrical appliances residing in the home network can be accomplished via Internet with the UPnP expansion without modifying an existing UPnP. In this paper, we propose the Internet Gateway that consists of an UPnP IGD(Internet Gateway Device) DCP(Device Control Protocol) and an UPnP Bridge as a system to control electrical appliances of home network. UPnP IGD DCP is to enable the configurable initiation and sharing of Internet connections as well as assuring advanced connection-management features and management of host configuration service. It also supports transparent Internet access by non-UPnP-certified devices. UPnP Bridge searches for local home network devices by sending control messages, while control point of UPnP Bridge looks up devices of interest on the Internet, subsequently furnishing the inter-networking controlling among devices which belong to different home network systems. With our approach, devices on one home network can control home electrical appliances on the other hone network via Internet through IGD DCP with control commands of UPnP.

• Journal of Korean society of Dental Hygiene
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• v.9 no.4
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• pp.659-669
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• 2009

Objectives : The degree of depression in dental hygienist was analyzed to reveal the various factors related to them. Methods : The self-administered questionnaires were filled out from 202 dental hygienist in Daejeon City. The survey items included subjects' socio-demographic and job-related characteristics, health-related behaviors, depression. Chi-Square analysis and Pearson's correlation coefficient was put into survey results, in which a degree of depression was dependent variable and others were independent variable. Results : 1. The distribution for depression degree has shown the rate as 80.2% in normal range group and 19.8% in depression group. 2. As for depression, long working hours(p=0.042), poor sense satisfaction in work(p=0.000), not fit to the job(p=0.003), low personal relation with peer works or supervisors(p=0.039), without alcohol drinking(p=0.048), poor subjective condition of health(p=0.000) than their respective counterparts. 3. Concerning correlation between depression and various factors, poor sense satisfaction in work(r=-0.332, p=0.000), not fit to the job(r=-0.353, p=0.000), low personal relation with peer works or supervisors(r=-0.215, p=0.002), without alcohol drinking(r=-0183, p=0.009), poor subjective condition of health(r=-0.333, p=0.000). Conclusions : These results showed that depression state could be influenced by various factors, which include socio-demographic, job-related characteristics and health-related behaviors. Therefore, in order to reduce depression state of dental hygienists, development and application of programs to manage and research for them are required to be revitalized as well as socio-demographic and job-related characteristics and health-related behaviors.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.277-285
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• 2011

Real-time multimedia streaming over the Internet is rapidly increasing with the popularity of user-created contents, Web 2.0 trends, and P2P (peer-to-peer) delivery support. While many homes today are broadband-enabled, the quality of experience (QoE) of a user is still limited due to frequent interruption of media playout. The vulnerability of TCP (transmission control protocol), the popular transport-layer protocol for streaming in practice, to the packet losses, retransmissions, and timeouts makes it hard to deliver a timely and persistent flow of packets for online multimedia contents. This paper presents TCP-real-time online multimedia environment (ROME), a novel transport-layer framework that allows the establishment and coordination of multiple many-to-one TCP connections. Between one client with multiple home addresses and multiple co-located or distributed servers, TCP-ROME increases the total throughput by aggregating the resources of multiple TCP connections. It also overcomes the bandwidth fluctuations of network bottlenecks by dynamically coordinating the streams of contents from multiple servers and by adapting the streaming rate of all connections to match the bandwidth requirement of the target video.

• Journal of dental hygiene science
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• v.18 no.4
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• pp.234-240
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• 2018

The purpose of this study was to provide basic data on counseling, education, and treatment related to orthodontic practices through an understanding of the relationships between orthodontic treatment, oral health-related quality of life, and happiness of high school students. The subjects in this study were 500 students in Grades 1~3 of a high school in Jeollabuk-do. We conducted a survey targeting this group; the results revealed the following: in the social support item, peer support showed significant differences in the matter of orthodontic treatment (p<0.05). In oral health-related quality of life, the students without orthodontic treatment showed 14.09 scores that were higher than the students with treatment (p<0.05). Regarding happiness, the students with orthodontic treatment showed higher scores which were significantly different from the those of the non-orthodontic treatment group (p<0.05). Additionally, upon examining the correlations between self-esteem, social support, oral health-related quality of life, and happiness, oral health-related quality of life, peer support, and happiness showed the negative (-) correlations while the rest of the variables showed the positive correlations (p<0.05). The factors having effects on oral health-related quality of life included the stress, matter of orthodontic treatment, and teachers support (p<0.05). The factors having effects on happiness included self-esteem, peer support, and family support (p<0.05). Based on the above results, even though dental orthodontic treatment had negative effects on oral health-related quality of life, it had positive effects on happiness. Consequently, it would seem necessary to seek active methods to increase oral health-related quality of life. This improvement could be achieved by minimizing inconveniences, such as mastication, in the process of dental orthodontic treatment, and developing programs that could enhance happiness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.89-99
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• 2017

Many works have attempted to solve the scalability, the availability, and the low-latency problems of peer-to-peer (P2P) live video streaming; yet, the problems still remain. While tree-based systems are vulnerable to churn, the mesh-based systems suffer from high delay and overhead. The DHT-aided chunk-driven overlay (DCO) [1] tried to tackle these problems by using the distributed hash table (DHT), which structures into a mesh-based overlay to efficiently share the video segment. However, DCO fully depends on the capacity of the users' device which is small and unstable, i.e., the users' device may leave and join the network anytime, and the video server's bandwidth can be insufficient when the number of users joining the network suddenly increases. Therefore, cloud assist is introduced to overcome those problems. Cloud assist can be used to enhance the availability, the low-latency, and the scalability of the system. In this paper, the DHT is used to maintain the location of the streaming segments in a distributed manner, and the cloud server is used to assist other peers when the bandwidth which required for sharing the video segment is insufficient. The simulation results show that by using the threshold and cloud assist, the availability and the low-latency of the video segments, and the scalability of the network are greatly improved.

• Journal of Information Technology Services
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• v.9 no.3
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• pp.83-93
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• 2010

P2P streaming technology has advantages of scalability and availability comparing to the popular IP multicast. This paper proposes an approach to apply the P2P streaming technology to the delay-sensitive multimedia multicast applications. In order for the P2P streaming to be applied to the delay-sensitive applications, prior construction of delay-guaranteed overlay network is necessarily required. Moreover, the delay-guaranteed overlay network should be able to be kept even when the hand-overs occur owing to the departures of the intermediate P2P peers. This paper proposes a delay-guaranteed overlay network construction method by using the bandwidth and end-to-end delay based admission control and the backup peer based hand-over control mechanism.

• Journal of KIISE:Information Networking
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• v.35 no.4
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• pp.268-281
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• 2008

It is difficult to construct streaming services based on the overlay networks without any loss of scalability. DONet is one of the most representative streaming overlay network protocols without managing any specific structure. Since DONet does not support the nodes on private networks, it can be considered that the performance of the overlay is not the best. Hole Punching is one of the famous techniques participating the nodes on private networks to streaming overlay networks by using a rendezvous server. However, using only a single rendezvous server cannot be suggested in P2P environment, because it can cause problems in terms of scalability and so on. In this paper, we propose DONet-p, an extension of DONet with Distributed Hole Punching techniques. It supports the nodes on private networks without toss of scalability. The experimental results show the better performance and scalability than DONet with a minimum overhead for additional control messages.

• Journal of Music and Human Behavior
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• v.7 no.1
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• pp.37-59
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• 2010

The purpose of this study was to examine how a creative musical play program affected peer relational skills of children in a community child center. The creative musical play program was implemented with six children in K Community Child Center for twenty (20) sessions. To investigate quantitative change, the Peer Relational Skills Scale and the Revised Social Skills Scale (for teachers) were filled out by children and teachers before and after the program. Also, to investigate musical and behavior changes related with peer relational skills in the creative musical program, the responses of children were categorized from the data of the children's responses according to previously identified sub-factors of peer relational skills. The results show that the participants' average scores presented an improvement in peer relational skills. Qualitative analysis of session logs presented that negative factors which had appeared in early sessions changed to positive traits as the sessions went on. In conclusion, the creative musical play program was effective in increasing peer relational skills of children in the community child center.