• Journal of applied mathematics & informatics
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• v.33 no.1_2
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• pp.185-191
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• 2015

This paper considers a discrete-time buffer system with session-based arrivals, an infinite storage capacity and one unreliable output line. There are multiple different types of sessions and the output line is governed by a finite state Markov chain. Based on a generating functions approach, we obtain an exact expression for the mean buffer content.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.56-62
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• 2017

Background: To help future generations make accurate value judgments about nuclear power generation and radiation, this study will provide an effective education plan suitable for South Korea by applying and analyzing programs for the understanding of nuclear power within the diversely operated programs in the current Korean education system. Materials and Methods: This study analyzed the difference in educational effects by operating a 13-session regular curriculum for one semester and a one-session short-term curriculum from March to July 2016. Results and Discussion: As a result of operating a 13-session model school and a one-time educational program to analyze behavior changes against the traditional learning model, it was found that all elementary, middle and high school students showed higher acceptability of nuclear power in South Korea. The variation was greater for the model school than the short-term program. Conclusion: To prevent future generations from making biased policy decisions stemming from fear regarding nuclear power, it is necessary to bolster their value judgments in policy decisions by acquiring sufficient information about nuclear power generation and radiation through educational programs.

• Journal of Korea Multimedia Society
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• v.11 no.8
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• pp.1101-1110
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• 2008

Nespot provides a convenient wireless internet connection service. The existing IEEE 802.1X EAP-MD5 authentication mechanism can be achieved based on ID/password information for a wireless connection. The Nespot system offers an advanced accounting and authorization procedure for providing wireless user authentication mechanism. However, many problems were found on the existing Nespot EAP-MD5 mechanism such as a ill value exposure, a leakage of personal information on wireless authentication procedure and a weakness on Nespot mutual authentication mechanism. Therefore, we analyzed the limitation of the existing IEEE 802.1X EAP-MD5 certification system, and suggested a one-time session key based authentication mechanism. And then we offered a simplified encryption function on the Nespot certification process for providing secure mutual authentication process.

• Journal of Internet Computing and Services
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• v.13 no.3
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• pp.31-47
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• 2012

The mobile Virtual Private Network (MVPN) of Internet Engineering Task Force (IETF) is not designed to support NEwork MObility (NEMO) and is not suitable for real-time applications. Therefore, an architecture and protocol which supports VPN in NEMO are needed. In this paper, we proposed the cost-reduced secure mobility management scheme (CR-SeMMS) which is designed for real-time applications in conjunction with VPN and also which is based on the session initiation protocol (SIP). Our scheme is to support MVPN in NEMO, so that the session is well maintained while the entire network is moved. Further, in order to reduce the authentication delay time which considers as a delaying factor in hands-off operations, the signaling time which occurs to maintain the session is shortened through proposing the hands-off scheme adopting an authentication method based on HMAC based One Time Password (HOTP). Finally, our simulation results show the improvement of the average hands-off performance time between our proposed scheme and the existing schemes.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.157-174
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• 2006

Ajax interaction model changes the posture of web application to become a stateful over HTTP. Ajax applications are long-lived inthe browser. XMLHTTPRequest (XHR) is used to facilitate the data exchange. Using HTTPS over this interaction is not viable because of the frequency of data exchange. Moreover, switching of protocols form HTTP to HTTPS for sensitive information is prohibited because of server-of-origin policy. The longevity, constraint, and asynchronous features of Ajax application need to hove a different authentication and session fondling mechanism that invoke re-authentication. This paper presents an authentication and session management scheme using Ajax. The scheme is design lo invoke periodic and event based re-authentication in the background using digest authentication with auto-generated password similar to OTP (One Time Password). The authentication and session management are wrapped into a framework called AWASec (Ajax Web Application Security) for coupling to avoid broken authentication and session management.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1367-1372
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• 2007

This paper suggests One-time Password key exchange authentication technique for a strong authentication based on MANET and through identify wireless environment security vulnerabilities, analyzes current authentication techniques. The suggested authentication technique consists of 3 steps: Routing, Registration, and Running. The Routing step sets a safe route using AODV protocol. The Registration and Running step apply the One-time password S/key and the DH-EKE based on the password, for source node authentication. In setting the Session key for safe packet transmission and data encryption, the suggested authentication technique encrypts message as H(pwd) verifiers, performs key exchange and utilizes One time password for the password possession verification and the efficiency enhancement. EKE sets end to end session key using the DH-EKE in which it expounds the identifier to hash function with the modula exponent. A safe session key exchange is possible through encryption of the H(pwd) verifier. The suggested authentication technique requires exponentiation and is applicable in the wireless network environment because it transmits data at a time for key sharing, which proves it is a strong and reliable authentication technique based on the complete MANET.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.41-47
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• 2016

PURPOSE: The purpose of this study was to investigate the effects of differences in exercise time arrangement on the functional recovery of the lower limbs and balance of stroke patients. METHODS: The subjects of this study were 100 patients who were hospitalized in two hospitals located in Gyeonggi-do. Before the experiment, 60 of these patients who met the inclusion criteria and did not meet the exclusion criteria were randomly divided into an experimental group (n = 30), whose exercise time was concentrated, and a control group (n = 30), whose exercise time was diffuse. The two groups underwent six weeks of physical and occupational therapy four times a day for five days a week. One session of therapy took 30 minutes, including three sets of physical therapy and one set of occupational therapy. The rest time between the sessions was different for each group. The experimental group had five minutes of rest between each therapy session, and the control group had two hours of rest time between each session. The Fugl-Meyer assessment (FMA), an assessment of each patient's limit of stability (LOS), and a timed up and go test (TUG) were used as test tools. RESULTS: Both groups showed statistically significant increases in their FMA results, LOS measurements, and TUG results. The FMA results of the experimental group were significantly higher than those of the control group. CONCLUSION: Thus, concentrated exercise time was more effective than diffuse exercise time for the recovery of motor function.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.271-279
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• 2001

Sequential pattern discovery is one of main interests in web usage mining. the technique of sequential pattern discovery attempts to find inter-session patterns such that the presence of a set of items is followed by another item in a time-ordered set of server sessions. In this paper, a tree-based sequential pattern finding method is proposed in order to discover navigation patterns in server sessions. At each learning process, the suggested method learns about the navigation patterns per server session and summarized into the modified Rymon's tree.

• Journal of Families and Better Life
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• v.22 no.6 s.72
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• pp.47-61
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• 2004

The purpose of this study is to develop a life planning program for retired elderly people. This program is not a preparation program for elderly people prior to their retirement but a readjustment and re-planning their life after retirement. This program help retired elderly people to solve the life problem and set up a affirmative ones future image. Also this program pay regard to social, home backgrounds of this generation. The program consists of four session curriculums session 1 is entitled to &Make my future by oneself&, session 2 is &Enjoy healthy life as much as one can&, session 3 is &Have a heart for family& and session 4 is &Set up a mature old age&. A fled study has been conducted with ten retired elderly people who want to participated in the program voluntarily. 4 sessions each of which consists of 2 hours were performed at Korean Association of Retired Persons. Field test for program evaluation is designed to three steps: pre-test, post-test and one month follow-up test to measure the effectiveness of the program. According to evaluation results, the program shows a significantly positive effect on the improvement of elderly people's understanding about elderly life. At the one month follow-up assessment, the effect of program is still remained strongly even though there is a Partial slight increase or reduction which is not statistically significant. Most of the program participants have expressed high level of satisfaction with the program. For further study, we need various contents which are suited to larger group with diverse socio0-demographic backgrounds. At the same time, the program has diverse instruction methods which are pertinent to levels of participants. Also, the program needs to continuous adjustment to the next generation with their social, home backgrounds.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.713-716
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• 2007

This paper suggests One-time Password key exchange authentication technique for a strong authentication based on Ad-hoc Networks and through identify wireless environment security vulnerabilities, analyzes current authentication techniques. The suggested authentication technique consists of 3 steps: Routing, Registration, and Running. The Routing step sets a safe route using AODV protocol. The Registration and Running step apply the One-time password S/key and the DH-EKE based on the password, for source node authentication. In setting the Session key for safe packet transmission and data encryption, the suggested authentication technique encrypts message as H(pwd) verifiers, performs key exchange and utilizes One time password for the password possession verification and the efficiency enhancement. EKE sets end to end session key using the DH-EKE in which it expounds the identifier to hash function with the modula exponent. A safe session key exchange is possible through encryption of the H(pwd) verifier.