• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.1-5
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• 2010

In this paper, we propose for improving QoS in wireless micro cellular network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it bas its vulnerability in frequent handoff environment. On the other hand, Cellular IP combines the capability of cellular networks to provide high performance handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks. Also Cellular-IP/PRC use semi-soft handoff. During semi-soft hand off a mobile host may be in contact with either of the old and new base stations and receive packets from them. Packets intended to the mobile node are sent to both base stations and buffered, so when the mobile host eventually moves to the new location it can continue to receive packets without interruption. It should be suitable for realtime service such as multimedia traffic. But, much waste of resource will occur in this method, especially for non-real time services such as FTP and E-mail. Therefore, a new algorithm that performs different handoff according to characteristic of each traffic by use of reserved field in IP packet is proposed in this thesis. This hand off state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. Matlab simulation results are improving QoS, show call drop and call blocking provided to Paging Router Cache during handoff state machine in Cellular-IP/PRC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.375-390
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• 2004

Domain Name System(DNS), one of the most important Internet services, handles mapping from host names to Internet addresses and vice versa, and precedes many Internet applications such as Web, e-mail, file transfer, etc. In this paper, we propose a structural design of a generic name server system providing name services for a huge domain for the purpose of improving the performance as well as the reliability of the system. We demonstrate the validity of the design by implementing and running a testbed system. Our testbed employs a couple of master name sowers for distributing the service overhead over two, rather than one, servers and for achieving high availability of the system as a whole. We suggest the use of dynamic update to add and delete records from a zone for which the name server has authority. The slave name servers located remotely then get a new, updated copy of the zone via incremental zone transfers(IXFRs). The experiments with the implemented testbed show that the proposed structure would easily manage increasing demands on the server power, and be highly available in the face of transient faults of a module in the system.

• International Commerce and Information Review
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• v.14 no.1
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• pp.391-418
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• 2012

The use of SNS (Social Network Service) has been increasing in world society and the SNS has been used to satisfy different purposes of social groups over the years. In the beginning, the SNS were formed using e-mail, listserve, newsgroup, etc., where information was shared among relatively homogeneous groups of people. Now different groups including corporations have been using SNS such as personal web pages, blogs, Facebook and Twitter for their social media marketing. This study intends to verify the relationship between SNS use and export marketing performance. To achieve this, different types of SNS use were analyzed in order to verify their relationship with export marketing performance. The conceptual model is suggested in this paper and several research constructs are identified. The constructs used in this paper include export marketing performance, SNS use, degree of innovation, product online fitness, marketing competence, and internationalization competence. According to the results, the SNS use directly influences the export marketing performance. In addition, the factors which determine the level of SNS use are product's online fitness and organizational willingness to undertake innovation. Therefore, it is suggested to increase SNS use in different marketing purposes for future research.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.555-561
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• 2014

Data processing service via internet help user to get the GNSS data processing result more precise and easily. Thus, online data process system is operated and developed by various research groups and national. But this service is difficult to use in domestic cadastral survey. In this study, we developed the online data processing system for a domestic cadastral survey. This is calculated coordinate using NGII CORS(SUWN) fiducially. And use PPP technique by GIPSY-OASIS. If user choose the observation data which want to calculate the coordinate, then is uploaded to GIPSY-OASIS server through FTP. After upload is complete, server automatically calculate coordinate, and send the report about result using e-mail. And it takes 2 minutes runtime on the basis of the 3 sessions. To verify the result, we used the data on SOUL, JUNJ as compared with notified-coordinate from NGII. As a result, got the difference for east-west 1.4 cm, north-south -1.0 cm, vertical 0.5 cm.

• Journal of KIISE:Software and Applications
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• v.32 no.5
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• pp.378-384
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• 2005

In this paper, we describe a novel method of spam-filtering to improve the performance of conventional spam-filtering systems. Conventional systems filter emails by investigating words distribution in email headers or bodies. Nowadays, spammers begin making email accounts in web-based email service sites and sending emails as if they are not spams. Investigating the email accounts of those spams, we notice that there is a large difference between the automatically generated accounts and ordinaries. Based on that difference, incoming emails are classified into spam/non-spam classes. To classify emails from only account strings, we used decision trees, which have been generally used for conventional pattern classification problems. We collected about 2.15 million account strings from email service sites, and our account checker resulted in the accuracy of $96.3\%$. The previous filter system with the checker yielded the improved filtering performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.6
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• pp.473-484
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• 2013

Shorten URL service is the method of using short URL instead of long URL, it redirect short url to long URL. While the users of microblog increased rapidly, as the creating and usage of shorten URL is convenient, shorten url became common under the limited length of writing on microblog. E-mail, SMS and books use shorten URL well, because of its simplicity. But, there is no relativeness between the most of shorten URLs and their target URLs, user can not expect the target URL. To cover this problem, there is attempts such as changing the shorten URL service name, inserting the information of website into shorten URL, and the usage of shortcode of physical address. However, each ones has the limits, so these are the trouble of automation, relatively long address, and the narrowness of applicable targets. SHRT is complementary to the attempts, as getting the idea from the writing system of Arabic. Though the writing system of Arabic has no vowel alphabet, Arabs have no difficult to understand their writing. This paper proposes SHRT, new method of URL Shortening. SHRT makes user guess the target URL using Relative word of the lowest domain of target URL without vowels.

• Journal of Korean Academy of Rural Health Nursing
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• v.3 no.1
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• pp.24-33
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• 2008

Purpose: To analyze health programs of the PHCP (Primary Health Care Posts) Method: From August 2006 to July 2007, data on the general quality and health program of the PHCP was requested by official letter and replies were received via E-mail. From December 8 to December 30, 2007, data from 1,268 (66.8%) PHCP out of 1,897 PHCP were analyzed using SPSS 12.0 Win program. Results: The average population covered by each PHCP is 878.3 people. For the health and special programs, Community Health Practitioners report high motivation for programs on health promotion, management of chronic illness, social welfare (40-50%). Demand by the residents was reported at 10% and increases in the health of the residents were attributed to high interest and demand. Volunteer work was 83.3% for bathing, 54.5% for equipment support and 46% for exercise programs. As elders make up 30% of the population in rural areas, there is an increasing demand for volunteer work in bathing programs. Conclusions: As the number of elders in the population increases and there is an increased need for more medical treatment for older people who are sick, the role of PHCP must be strengthened to include visits to homes of community residents. Where financial support for the PHCP is difficult, it is necessary to develop sound data on demographic characteristics of the population in order to develop efficient and effective health promotion programs. The finding that 54.7% of the population need management of chronic illness has difficulty in seeing a physician indicates a need to enhance the health care delivery system by strengthening the role of the Community Health Practitioners and including them in the civil service system to ensure stability of the PHCP.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.75-83
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• 2004

We live in the information technology era and experience the rapid global information environment change through Internet. Therefore, as distribution channels and service qualities in our daily lives are provided through Internet, these changes have been the foundation of constructing a new society. Naturally, the use of computer is widely spread out and it is hard to find any company that doesn't use computer in its work. However, the computer skills of those who are in their fifties cannot reach to what the companies need for them even though they are main working groups in our society. In addition, the Internet access rate of homemakers in their late forties and over fifties are low due to their lack of computer knowledge even though they are the target customers of the Internet service. Under these circumstances, we offer a lecture using simulation techniqe through which anybody can easily follow the instructions via the "Help" menu not a boring lecture that just show the text and reads it. Besides, each class will show you how to start Internet/ how to finish it, how to register a website, how to use e-mail, etc. So, it will let you know every detailed aspect that average people may disregard but a beginner may be afraid of starting the Internet.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.25-32
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• 2019

The core of the block chain technology is solving the problem of agreement on double payment, and the PoW, PoS and DPoS algorithms used for this have been studied. PoW in-process proofs are consensus systems that require feasible efforts to prevent minor or malicious use of computing capabilities, such as sending spam e-mail or initiating denial of service (DoS) attacks. The proof of the PoS is made to solve the Nothing at stake problem as well as the energy waste of the proof of work (PoW) algorithm, and the decision of the sum of each node is decided according to the amount of money, not the calculation ability. DPoS is that a small number of authorized users maintain a trade consensus through a distributed network, whereas DPS provides consent authority to a small number of representatives, whereas PoS has consent authority to all users. If PoS is direct democracy, DPoS is indirect democracy. This study aims to contribute to the continuous development of the related field through the study of the algorithm of the block chain agreement.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.141-148
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• 2011

Recently, various social network services have been grown. Among them, personal relationships based social network services such as Facebook and Twitter make a remarkable growth of industry. In such services, users' profiles are very important for establishing the relationship between two users. However some information in a user's profile causes the leakage of the user's privacy, and thus we have to deal with the information in the profile. Especially, we have to treat contact information, such as the phone number and the e-mail address, very carefully since an adversary can use the information to violate the user's privacy in real life. In this paper, we propose two profile management systems that can enhance the privacy of users in social network services. We compare our systems with existing profile management techniques in well-known social network services such as Facebook and Twitter, and show that our systems provide enhanced privacy.