• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.1-10
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• 2021

The purpose of the study is to contribute to the positive development of blockchain technology by providing data to examine security vulnerabilities and threats to blockchain-based services and review countermeasures. The findings of this study are as follows. Threats to the security of blockchain-based services can be classified into application security threats, smart contract security threats, and network (P2P) security threats. First, application security threats include wallet theft (e-wallet stealing), double spending (double payment attack), and cryptojacking (mining malware infection). Second, smart contract security threats are divided into reentrancy attacks, replay attacks, and balance increasing attacks. Third, network (P2P) security threats are divided into the 51% control attack, Sybil attack, balance attack, eclipse attack (spread false information attack), selfish mining (selfish mining monopoly), block withholding attack, DDoS attack (distributed service denial attack) and DNS/BGP hijacks. Through this study, it is possible to discuss the future plans of the blockchain technology-based ecosystem through understanding the functional characteristics of transparency or some privacy that can be obtained within the blockchain. It also supports effective coping with various security threats.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.53-62
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• 2020

In the end-user domain of an IoT environment, there are more and more intelligent M2M devices that provide resources to create and share application services. Therefore, it can be very useful to manage trust by transferring the role of the existing centralized service provider to end users in a P2P environment. However, in a decentralized M2M computing environment where end users independently provide or consume services, mutual trust building is the most important factor. This is because malicious users trying to build malfunctioning services can cause security problems in M2M computing environments such as IoT. In this paper, we provide an integrated analysis and approach for trust evaluation of M2M application services, and an optimized trust evaluation model that can guarantee reliability among users of the M2M community.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.51-63
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• 2013

Recently with base apply MANET with the application for the service discovery and delivery which are various techniques are being proposed the result of such MANET base research techniques from actual inside. This dissertation proposes T-Chord(Trustworthy-based Chord) Ring system for MANET to guarantees from such requirements. T-Chord Ring system in order to manage Efficiently the services which the mobile nodes provide is the service discovery system which uses P2P overlay network Technique in mobile environment. The system which is proposed MANET communications in order to accomplish a service discovery operation with physical network class and logical network class will be able to minimize problems from about MANET service discoveries, and uses the dispersive hash table technique for a service discovery and effectiveness of service discovery improves and will be able to guarantee the expandability of network size. The mobile nodes(mobile device) have a mobility from MANET and operate with service request node, service provide node and service transmit node. The mobile nodes will be able to elect cluster header using Trustworthy that was evaluated service request, provision and delivery in each other. The system which is proposed a service discovery and a delivery efficiently will compose the cluster head which will grow of P2P overlay networks and will be able to accomplish. The system which proposes from dissertation is composed of Trustworthy evaluations of MANET mobile nodes, service information collection which is dispersed and P2P overlay networks that composed of Chord algorithm modules which provide O(Log N) efficiencies. The system comparison evaluation analyzes an efficiency from the expandability side of effectiveness and the network of service discovery technique and the service discovery message over head, service discovery and delivery of former times and service discovery and delivery is excellent gives proof from MANET.

• Journal of the Korean Dietetic Association
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• v.25 no.1
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• pp.17-29
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• 2019

This study examined sanitary education and performance of sanitary management among employees related to cooking in school food services in Sejong. A total of 193 subjects (19.2% for kindergarten, 42.5% for elementary school, and 38.3% for middle and high school) participated in this questionnaire survey. The frequency of sanitary education was highest at 63.7% once a month, and it was higher in the order of middle and high school, elementary school, and kindergarten (P<0.001). The most important contents of sanitary education were personal sanitary management (43.5%), food material management (25.9%), and sanitary and safety management of equipment and utensils (17.6%). The necessity of sanitary education recognized by the subjects was absolutely necessary at 69.9% and necessary at 28.0%. The application of knowledge from sanitary education is high in proper application at 50.8% and absolute application at 40.4%. The improvement effect after sanitary education was higher in kindergarten than in elementary school and middle and high school (P<0.01). The performance of sanitary management was high at 4.7 out of 5. In particular, personal sanitary management was the highest in elementary school at 4.8 followed in order by middle and high school (4.7) and kindergarten (4.6) (P<0.01). The necessity of sanitary education and the application of knowledge obtained from sanitary education to the food service showed a significant and positive correlation with the sanitary management performance (P<0.05, P<0.001). These results highlight that the need for customized sanitary education for institution types and an awareness of sanitary education by employees will enhance sanitary management in school food service.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.2
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• pp.18-25
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• 2008

The traditional a roaches to software development, such as XP, UP, CBD and other CASE tools, are useful for constructing various software components. However, they are not designed to face the challenges of open environments that focus on service. The Service-Oriented Architecture(SOA) is a component architecture that interconnects an application's different functional units, called services. SOA provides a good way to integrate the business process through well-defined interfaces and contracts between business services. In this paper, we propose a method of business process modeling based on SOA with a P2P approach. Also, A P2P business process modeling system is presented. This, results in admitting the reality of enterprise that changes on the basis of services, and suggests more efficient and visual direction for the process integration between enterprises.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.249-254
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• 2007

일반 PC 자원만을 활용하는 기존 P2P 서비스 방식에서 Wibro망을 통한 다양한 이동 단말까지 P2P 네트워크를 구성하여, 기존 파일 공유 및 Instance Message 교환 등의 일반적 기능을 포함한 P2P 기반 실시간 Streaming Service를 제공하는 Application 구현 방안에 대해 설명한다. 또한 안전한 네트워크 구성을 위하여, P2P 네트워크 참여시 사용자 인증, 공개키 암호화 기반의 메시지 보안 적용 사항과 동영상 콘텐츠의 보안을 위하여, 스트리밍 데이터를 일부 구간(Chunk)단위로 나누어 별도의 Key로 암호화하여 제공함으로써, 인증된 사용자만이 요청된 콘텐츠만을 활용할 수 있는 방안을 제시한다.

• 재활복지
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• v.22 no.4
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• pp.1-22
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• 2018

We aimed to analyze the effects of Kinesio-Taping on pain, satisfaction, and gait, and to provide basic data on the self-application of this method. The participants were 30 adult women with chronic low back pain. Kinesio-Taping was applied for 2 weeks, followed by 4 weeks of self-application education and self-application. The participants' pain levels were analyzed using the visual analog scale, satisfaction was analyzed using the Canadian Occupational Performance Measure, and gait was analyzed in terms of stride length, step length, step width, and gait time using the Walkway MG-1000 gait analyzer. The results of the pain showed the statistically significant decrease steadily (p<0.001) and the results of the satisfaction showed the statistically significant increase steadily (p<0.001) from the application of the Kinesio-Taping. Also, according to the In-Object verification between pre-test, taping application (after 2 weeks) and Self-application (after 4 weeks), the results of the satisfaction showed statistically significant difference (p<0.001). According to the gait analysis, the results of the stride length and step length showed the statistically significant increase steadily (p<0.001) and the results of the step width and gait time showed the statistically significant decrease steadily (p<0.001) from the application of the Kinesio-Taping. Also, according to the In-Object verification between pre-test, taping application (after 2 weeks) and Self-application (after 4 weeks), the results of the step width showed statistically significant difference (p<0.001). Thus, the self-application education about the Kinesio-Taping should be considered to reduce the pain and improve the performance level of the activities of daily life through the improvement of the self-management ability and to induce the active participation in the self-management activities and increase the satisfaction.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.103-109
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• 2008

Many Internet application provide the PKI(public key infrastructure)-based service to provide authentication and message integrity. Several researchers proposed PKI-based p2p network framework. However, in the real world, the use of PKI is not suitable for peer to peer network, because the peer-to-peer network is an open and dynamic network. Moreover, currently there is no nation-to-nation interoperable certificate. In this paper, we designed reliable p2p file sharing application without public key infrastructure. To do this we propose reliable public key distribution mechanism to distribute public key safely without PKI infrastructure for two-tier super-peer architecture. In our system, each peer generates and distributes its public/private key pairs, and the public key is securely distributed without PKI. The proposed mechanism is safe against MITM attack. This mechanism can be applied various P2P applications such as file sharing, IPTV, distributed resource sharing and so on

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.2
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• pp.99-102
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• 2012

The performance of P2P application services may be improved by reducing unnecessary inter-network traffic through intelligent peer selection. However, since a logical link between peers in a P2P overlay network is composed of a set of physical links in an underlay network, the traffic pattern determined by the sending rates of selected peers imposes loads on each underlay links. Thus, if the sending rates are not determined carefully, the loads between underlay links may not be balanced, which means some links are underloaded while the other links are congested. In this paper, we take an optimization approach to determine the sending rates of peers strategically to avoid the inefficient use of underlay links. The proposed scheme also guarantee the minimum receiving rates of peers while minimizing the maximum link utilization of underlay links, which is beneficial both to P2P applications and an underlay network.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1785-1793
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• 2009

Meal service menu for the elderly on busy farming season in Hongchun, Gangwon was developed and applied using seasonal foods from local crops. Acceptance of each menu right after the meal service was investigated while unit cost and leftover of each menu were also monitored. Acceptance of the staple food in Menu 4 showed the highest value with a score of 8.97.and side dishes of Menu 4 were greatly prdferred with a score of 8.69(p<0.05). General preference on menu was the highest at Menu 4 scoring 8.87(p<0.05). The amount of leftover for a special meal of Menu 3 was 75.80 g, which was the highest (p<0.05). Males left the least of Menu 4(30.82 g) whereas females did of Menu 2 (10.63 g, p<0.05). The foeld application of preference and satisfaction, and the small amount of leftover of the supplied meals.