• Journal of muscle and joint health
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• v.22 no.1
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• pp.13-19
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• 2015

Purpose: The purpose of this study was to identify the relationships among network centrality, psychological well-being (PWBS), and intention to exercise maintenance in participants of an aquatic exercise program. Methods: Using a single-experimental design, 17 osteoarthritis patients participated in an aquatic exercise program. The questionnaire to connect the network of members was used to peer nomination by Moreno (1953). Data were analyzed with the UCINET using centrality (degree, closeness, betweenness) and SPSS using descriptive statistics, wilcoxon signed ranked test, and spearman's rho. Results: Closeness centrality, PWBS, and intention to exercise maintenance were significantly different between 4 weeks and 8 weeks. At 4 weeks, PWBS was positively correlated with closeness centrality. Intention to exercise maintenance was positively correlated with degree, closeness, and betweenness centrality. At 8 weeks, PWBS was positively correlated with closeness centrality. Intention to exercise maintenance was positively correlated with closeness centrality. Conclusion: The aquatic exercise program can be effective in increasing closeness centrality, psychological well-being, and intention to exercise maintenance. This was the first study attempted to analyze construction of member relationships in osteoarthritis patients participating an exercise program by using social network analysis.

• Journal of Yeungnam Medical Science
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• v.40 no.2
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• pp.156-163
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• 2023

Background: Interest in digital medical information has increased because it allows doctors to easily access a patient's medical records and provide appropriate medical care. Blockchain technology ensures data safety, reliability, integrity, and transparency by distributing medical data to all users over a peer-to-peer network. This study attempted to assess pediatricians' thoughts and attitudes toward introducing blockchain technology into the medical field. Methods: This study used a questionnaire survey to examine the thoughts and attitudes of 30- to 60-year-old pediatricians regarding the introduction of blockchain technology into the medical field. Responses to each item were recorded on a scale ranging from 1 (never agree) to 7 (completely agree). Results: The scores for the intentions and expectations of using blockchain technology were 4.0 to 4.6. Pediatricians from tertiary hospitals responded more positively (4.5-4.9) to the idea of using blockchain technology for hospital work relative to the general population (4.3-4.7). However, pediatricians working in primary and secondary hospitals had a slightly negative view of the application of blockchain technology to hospital work (p=0.018). Conclusion: When introducing the medical records of related pediatric and adolescent patients using blockchain technology in the future, it would be better to conduct a pilot project that prioritizes pediatricians in tertiary hospitals. The cost, policy, and market participants' perceptions are essential factors to consider when introducing technology in the medical field.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2285-2301
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• 2012

Peer-to-Peer (P2P) networks are becoming more and more popular in video content delivery services, such as Video on Demand (VoD). Scalability feature of P2P allows a higher number of simultaneous users at a given server load and bandwidth to use stream service. However, the quality of service (QoS) in these networks is difficult to be guaranteed because of the free-riding problem that nodes download the recourses while never uploading recourses, which degrades the performance of P2P VoD networks. In this paper, a distributed trust model is designed to reduce node's free-riding phenomenon in P2P VoD networks. In this model, the P2P network is abstracted to be a super node hierarchical structure to monitor the reputation of nodes. In order to calculate the reputation of nodes, the Hidden Markov Model (HMM) is introduced in this paper. Besides, a distinction algorithm is proposed to distinguish the free-riders and malicious nodes. The free-riders are the nodes which have a low frequency to free-ride. And the malicious nodes have a high frequency to free-ride. The distinction algorithm takes different measures to response to the request of these two kinds of free-riders. The simulation results demonstrate that this proposed trust model can improve QoS effectively in P2P VoD networks.

• International journal of advanced smart convergence
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• v.12 no.3
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• pp.1-12
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• 2023

A public address (PA) system installed in a building is a system that delivers alerts, announcements, instructions, etc. in an emergency or disaster situation. As for the products used in PA systems, with the development of information and communication technology, PA products with various functions have been introduced to the market. PA systems recently launched in the market may be connected through a single network to enable efficient management and operation, or use voice recognition technology to deliver quick information in case of an emergency. In addition, a system capable of locating a user inside a building using a location-based service and guiding or responding to a safe area in the event of an emergency is being launched on the market. However, the new PA systems currently on the market add some functions to the existing PA system configuration to make system operation more convenient, but they do not change the complex PA system configuration to reduce facility costs, maintenance, and management costs. In this paper, we propose a novel PA system configuration for buildings using audio networks and control hierarchy over peer-to-peer (Anchor) technology based on audio over IP (AoIP), which simplifies the complex PA system configuration and enables convenient operation and management. As a result of the study, through the emergency signal processing algorithm, fire broadcasting was made possible according to the detection of the existence of a fire signal in the Anchor system. In addition, the control device of the PA system was replaced with software to reduce the equipment installation cost, and the PA system configuration was simplified. In the future, it is expected that the PA system using Anchor technology will become the standard for PA facilities.

• The KIPS Transactions:PartA
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• v.17A no.5
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• pp.237-248
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• 2010

UPnP(Universal Plug and Play) is a middleware of DLNA (Digital Living Network Alliance) services a home network. UPnP supports the connections between each other devices in networks and also provides service discovery and advertisement with SSDP(Simple Service Discovery Protocol), which is generally designed for wired networks. SSDP operates on multicasting discovery request and advertisement and unicasting a reply in networks. It is a challenge issue for service discovery protocol such as SSDP to provide a stable and effective service in wireless ad-hoc networks. Wired based service discovery protocol does not consider the dynamics of wireless ad-hoc network. In that case, the nodes are freely in or out. Therefore, this paper proposes a flexible SSDP(fSSDP) which is a peer-to-peer(P2P) discovery protocol adopted for wireless ad-hoc Networks. It is implemented on the extension of SSDP. fSSDP supports a functionality that the broadcast area of service discovery dynamically changes with the periodically updated area of advertisement. It is good for reducing messaging overhead caused from the broadcast flooding of service discovery in wireless ad-hoc network.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.829-834
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• 2004

Nodes communicate through wireless channels under peer-to-peer level in ad-hoc mobile networks. The nodes are free to move around in a geographical area and are loose]y bounded by the transmission range of the wireless channels. Also, a node is completely free to move around, there is no fixed final topology. Hence, to manage the inter-node communication and data exchange among them a leader node is required. In this paper we introduce an efficient leader election algorithm for mobile ad hoc networks where inter-node communication is allowed only among the neighboring nodes. Furthermore we present the result of performance evaluation through simulation. The algorithm is efficient and practical since it uses least amount of wireless resources and does not affect the movement of the nodes.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.111-120
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• 2012

As the P2P System is a distributed system that shares resources of nodes that participate in the system, all the nodes serve as a role of server and client. Currently, although systematic, structured P2P systems such as Chord, Pastry, and Tapestry were suggested based on the distributed hash table, these systems are limited to $log_2N$ for performance efficiency. For this enhanced performance efficiency limited, the article herein suggests group routing algorithm. The suggested algorithm is a node-to-group routing algorithm which divides circular address space into groups and uses a concept of pointer representing each group, which is an algorithm where routing is performed based on pointer. To evaluate algorithm performance, a comparative analysis was conducted on average hops, routing table size, and delayed transmission for chord and routing, a signature algorithm in P2P systems. Therefore, enhanced performance is verified for comparative items from the simulation results.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.138-149
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• 2003

As the Internet is quickly evolving from best-effort networks to business quality networks, billing based on the precise traffic measurement becomes an important issue for Internet Service Providers (ISPs). Billing settlement is necessary not only between ISP and customers but also between ISPs. Currently, most ISPs use a flat rate charging policy. Besides the degree of difficulty in deriving appropriate charging policies agreeable by a concerned party, there are substantial technical challenges to come up with a good usage-based accounting system. Usage-based accounting depending on IP packet header information only is not sufficient anymore due to highly dynamic nature of the development and the use of the Internet applications such as peer-to-peer and network games. They are using port numbers dynamically and even several applications can use the same port number. Thus, more precise means of classifying them and accounting their traffic usages are required. In this paper, we propose a high performance, adaptable, configurable, and scalable content-aware application traffic measurement and analysis system which can achieve very accurate usage-based accounting.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.859-864
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• 2006

The openness of the Web allows any user to access almost any type of information easily at any time and anywhere. However, with function of easy access for useful information, internet has dysfunctions of providing users with harmful contents indiscriminately. Some information, such as adult content, is not appropriate for all users, notably children. Additionally for adults, some contents included in abnormal porn sites can do ordinary people's mental health harm. In the meantime, since Internet is a worldwide open network it has a limit to regulate users providing harmful contents through each countrie's national laws or systems. Additionally it is not a desirable way of developing a certain system-specific classification technology for harmful contents, because internet users can contact with them in diverse way, for example, porn sites, harmful spams, or peer-to-peer networks, etc. Therefore, it is being emphasized to research and develop context-based core technologies for classifying harmful contents. In this paper, we propose an efficient text filter for blocking harmful texts of web documents using context-based technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.296-303
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• 2020

The purpose of this study was to examine the keywords of studies related to young children's play in the selected registered and candidate academic journals and the network of the keywords by conducting a semantic network analysis. The selected journals were published over the past decade in diverse fields of study that included social sciences and life sciences such as education and early childhood education. The findings of the study were as follows: First, there was a great increase in the studies related to early childhood play over the last five years in comparison with the first term(2009-2013). As a result of analyzing how many studies were included in the journals by field, the largest numbers of the studies were published in the field of education, followed by early childhood education, and life sciences. Second, when the network of the keywords was analyzed, the major keywords in the first term were playfulness, role play, young children, creativity, play, and peer play interaction. In the second term(2014-2018), playfulness was also the most frequently exhibited keyword, followed by young children, play, and peer play behavior. Keywords such as teacher-child interaction, language skills, happiness, cognitive ability, early childhood education newly appeared.