• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.165-173
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• 2009

Recent portable devices are so versatile that they have multiple communication channels and play several multimedia formats. Especially, many services are under development for users who connect Internet or nearby devices via WWAN (Wireless Wide Area Network) and/or WLAN (Wireless LAN). In case of paying the telecommunication cost proportional to the amount of data downloaded, it is necessary to reduce the cost by constructing a special ad hoc network in which each participating peer downloads a specific portion of the want-to-be-shared content over the payable WWAN channel and exchanges the remaining portion with other peers using the cost-free WLAN channel. If all peers participate in forwarding packets, some transmissions are redundant which results in the unnecessary consumption of bandwidth as well as the delayed content distribution time. In order to reduce the redundant transmission, this paper proposes both the excluding method which discourages some peers not to forward redundant packets, and the minimum cover set method in which only the minimum number of peers are in charge of forwarding packets. These two methods obviate redundant packet forwarding, and result in reduction of content distribution time by up to around 29%.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.2
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• pp.95-106
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• 2014

In this study, the applicability of a standard vector model was evaluated using RIMGIS vector data and a portal based river-geospatial information web service system was developed using XML and JSON based data linkage between the server and the client. The RIMGIS vector data including points, lines, and polygons were converted to the Geospatial Data Model(GDM) developed in this study and were validated by layers. After the conversion, it was identified that the attribute data of a shape file remained without loss. The GeoServer GDB(GeoDataBase) that manages a DB in the portal was developed as a management module. The XML-based Geography Markup Language(GML) standards of OGC was used for accessing to and managing vector layers and encoding spatial data. The separation of data content and expression in the GML allowed the different expressions of the same data, convenient data revision and update, and enhancing the expandability. In the future, it is necessary to improve the access, exchange, and storage of river-geospatial information through the user's customized services and Internet accessibility.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.21-24
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• 1997

강원도 동해안 지역 하천은 유로연장과 유역면적이 작고 하천 상류부는 급경사이며 하류부는 완경사의 특징을 보여주고 있다. 이 지역 대부분의 하천이 바다로 직접 유입되고 있어 바다와 하천을 옮겨 다니는 회유성 어류가 서식하고 있으며 이들은 소하성, 강하성 및 양측성 어류로 구분된다. 이러한 회유성 어류의 이동은 동해안 지역 하천 하류부 완경사지에서 농업용수를 취수하기 위한 보의 설치로 인하여 어려워졌으며, 이러한 문제에 대처하기 위하여 수산자원 보호령(대통령령 제 5027호) 제 21조에서 어도설치를 규정하고 있다. 강원도 동해안 지역 하천에 설치되어 있는 어도의 실태를 보면 총 19개 하천에 있는 83개소의 농업용 취수보에 약 130개의 어도가 있다. 기존에 설치되어 있는 전어도에 대한 현장조사결과 어도의 기능에 장애를 일으킬 만한 원인은 어도시설의 구조적인 문제와 관리문제로 대별할 수 있다. 본 연구는 어도의 기능이 원활하게 유지되도록 어도시설물에 대한 각종 자료를 체계적으로 집적한 어도정보시스템을 구축하여 어도시설에 대한 현황파악을 용이하게 하고, 지방자치단체에서 개별적으로 수행하던 어도관리를 통합관리할수 있게 하며, 어도시설 표준모형 설계의 기초자료 및 하천 정보, 어류생태정보와 연결된 정보시스템으로의 확장을 가능하게 한다. 본 어도 정보시스템은 기본적으로 인터넷상에서 서비스가 이루어진다. 사용자는 웹 브라우저를 이용하여 어도 정보시스템이 탑재된 웹 서버에 접속하여 서비스를 요청한다. 사용자의 요청을 받은 웹 서버는 게시판과 DBMS를 제어하여 그 결과를 사용자에게 건네준다. 사용된 기술은 ISAPI 규격의 확장인 IDC, HTX이다. 관리자와 사용자의 입력, 수정, 검색, 삭제등에 관한 읽고 쓰기 권한을 구분한다.이 경과함에 따라 소멸하며 약산성에서 높은 생성능을 보임을 알 수 있었다, 강별로는 낙동강에서 THMs파 HANs의 생성능이 비교적 높았고, 영산강에서는 HAAs의 생성능이 높았다. 각 원수의 특성에 따른 생성능을 파악함으로써 생성능 저감방안을 마련하며, 소독 부산물질의 인체노출평가에 따른 위해성평가를 통해 관리기준을 설정해야 할 것이다.는 것으로 나타났다. 본 연구는 한국 문화의 특징이라 할 수 있는 교수-학생간의 인간적인 관계가 중시되는 교육환경하에서, 정보화 사회의 한 수업형태인 재택수업을 외국(특히 미국)의 방법을 그대로 따라 실시할 경우, 많은 부작용이 있을 수 있다는 것을 암시하며, 따라서 우리 교육문화에 맞는 재택수업 형태의 개발이 시급함을 제시한다고 하겠다.column density of HCaN is (1-3):n1014cm-2. Column density at distant position from MD5 is larger than that in the (:entral region. We have deduced that this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문제를 해결하기 위한 연구가 수행되어야 할 것이다.로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulco

• Convergence Security Journal
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• v.18 no.5_1
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• pp.113-120
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• 2018

Today, the development of information and communication technology is rapidly increasing the number of users of network-based service, and enables real-time information sharing among users on the Internet. There are various methods in the information sharing process, and information sharing based on portal service is generally used. However, the process of information sharing serves as a cause of illegal activities in order to amplify the social interest of the relevant stakeholders. Public opinion attack using macro function can distort normal public opinion, so security measures are urgent. Therefore, security measures are urgently needed. Macro attacks are generally defined as attacks in which illegal users acquire multiple IP or ID to manipulate public opinion on the content of a particular web page. In this paper, we analyze network path information based on traceback for macro attack of a specific user, and then detect multiple access of the user. This is a macro attack when the access path information for a specific web page and the user information are matched more than once. In addition, when multiple ID is accessed for a specific web page in the same region, it is not possible to distort the overall public opinion on a specific web page by analyzing the threshold count value.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.183-194
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• 2010

A company's private network protected by a firewall and NAT(Network Address Translation) is not accessible directly through an external internet. However, as Reverse Connection technology used by NetCat extends to the technologies such as SSH Tunnel or HTTP Tunnel, now anyone can easily access a private network of corporation protected by a firewall and NAT. Furthermore, while these kinds of technologies are commercially stretching out to various services such as a remote control and HTTP Tunnel, security managers in a company or general users are confused under the circumstances of inner or outer regulation which is not allowed to access to an internal system with a remote control. What is more serious is to make a covert channel invading a company's private network through a malicious code and all that technologies. By the way, what matters is that a given security system such as a firewall cannot shield from these perceived dangers. So, we analyze the indirect access of technological methods and the status quo about a company's internal network and find a solution to get rid of the related dangers.

• Management & Information Systems Review
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• v.29 no.4
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• pp.143-167
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• 2010

Diverse research topics relating to Social Network Services (SNS) such as, social affective factors in relationships among internet users, social capital value of SNS, comparing attributes why users are intending to participate in SNS, user's lifestyle and their preferences, and the exploratory seeking potential of SNS as a social capital need to be focused on. However, these researches that have been undertaken only consider facts at a particular period of the changing computing environment. In accordance with this indispensability, the integrated view on what technical, social and business characteristics and attributes need to be acknowledged. The purpose of this study is to analyze the evolving attributes and characteristics of SNS from Web 1.0 to Mobile web 2.0 through the Web 2.0 and Mobile 1.0 period. Based on the relevant literature, the attributes that drive the changing technological, social and business aspects of SNS have been developed and analyzed. This exploratory study analyzed major attributes and relationships between SNS and users by changing the paradigms which represented each period. It classified and chronicled each period by representing paradigms and deducted the attributes by considering three aspects such as technological, social and business administration. The major findings of this study are, firstly, the web based computing environment has been changed into the platform attribute for users in the aspect of technology. Users can only read, listen and view information through the web site in the early stages, but now it is possible that users can create, modify and distribute all kinds of information. Secondly, the few knowledge producers of web services have been changed into a collective intelligence by groups of people in the aspect of society. Information authority has been distributed and there is no limit to its spread. Many businesses recognized the potential of the SNS and they are considering how to utilize these advantages toward channel of promotion and marketing. Thirdly, the conventional marketing channel has been changed into oral transmission by using SNS. The market of innovative mobile technology such as smart phones, which provide convenience and access-ability toward customers, has been enlarged. New opportunities to build friendly relationship between business and customers as a new marketing chance have been created. Finally, the role of the consumer has been changed into the leading role of a prosumer. Users can create, modify and distribute information, and are performing the dual role of customer and producer.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.1-22
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• 2015

Due to recent growth in IT industry along with the expansion of smartphone, we came to connect to the Internet wherever and whenever we are. However, this causes negative side effects, though. One of them is a rapid increase of the financial crimes such as the Phishing and the SMishing. There have been many on-going researches about crimes such as Phishing and SMishing to protect users. However, the study about sharing knowledge on SNS to prevent such a crime can be hardly found. Based on social identity theory, we conduct the research about factors on SNS users' intention to share the information security knowledge on SNS. As a result, we found that knowledge provision self-efficacy has a significant impact on self-expression. In addition, it also found out self-expression, awareness about information security and the sense of belonging have a significant impact respectively on the intention to share the information security knowledge on SNS. On the other hand, the altruism didn't have a significant impact to the intention to share information security knowledge on SNS. With this research as a starting point, it seems necessary to expand its range to all types of online community in the future for the generalization of the hypotheses.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3A
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• pp.209-216
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• 2005

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.149-155
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• 2003

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP. According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• Journal of Korea Game Society
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• v.7 no.3
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• pp.67-76
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• 2007

As the performance of game consoles is so highly progressed that services such as internet browsing become available on the consoles, the need for text input schemes on game consoles is rapidly raised. In this paper, we present a text input method of alphabet characters and several symbols using a gamepad, which is a widely used input device for most game consoles. Just like other text input methods using gamepad, our method allows users to enter texts by manipulating the gamepad with a user interface displayed on the screen of the console. A key idea of this paper is to present the user interface that is similar to the $4{\times}3$ keypad on mobile phones. The motivation of this idea is a principle that the experience of using a text input tool can be transferred to another tool that has similar interface. Another motivation is that the keyboard-based interface is too complex to be easily manipulated by simple input from a keypad, which is four orthogonal directions and several fire signals. Since most of keys on keypad of $4{\times}3$ keys are represented by a combination of two orthogonal directions, users feel easier in entering texts using keypad-based interface. We prove this argument in this paper by a user test of ten subjects. After about two experiment sessions, subjects reach 13 WPM in average, which proves that the proposed text input method enables much faster text input than the existing keyboard-based text input methods.