• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.975-982
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• 2004

In current P2P concept, pure P2P and Hybrid P2P structures are used commonly. Gnutella and Ktella are forms of pure P2P. and forms of Hybrid P2P are innumerable. File searching models exist in these models. These models provide group management for file sharing, searching and indexing. The general file sharing model is good at maintaining connectivity. However, it is defective in group management. Therefore, this study approaches hierarchical structure in file sharing models through routing technique and backup system. This system was designed so that the user was able to maintain group efficiency and connection reliability in large-scale network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.759-761
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• 2016

Recent changes in the information security environment have led to persistent attacks on intelligent assets such as cyber security breaches, leakage of confidential information, and global security threats. Since existing information security systems are not adequate for Advanced Persistent Threat; APT attacks, bypassing attacks, and attacks on encryption packets, therefore, continuous monitoring is required to detect and protect against such attacks. Accordingly, this paper suggests an operation plan for managing an information security system to block the attack routes of advanced persistent threats. This is achieved with identifying the valuable assets for prevention control by establishing information control policies through analyzing the vulnerability and risks to remove potential hazard, as well as constructing detection control through controlling access to servers and conducting surveillance on encrypted communication, and enabling intelligent violation of response by having corrective control through packet tagging, platform security, system backups, and recovery.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.111-118
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• 2009

Against Anomaly of GPS, there are several projects of independent satellite navigation systems like Galileo of Europe and QZSS of Japan and modernization of terrestrial navigation system like Loran. In domestic, the need of independent navigation system was proposed and DGPS signal was nominated as the possible substitute. The DGPS signal uses medium frequency, which travels through the surface and cause the additional delay rather than the speed of light according to Conductivities and elevations of the irregular terrain. The similar approach is Locan-C. Loran-C has been widely used as the maritime location system. Loran-C uses the ASF estimation method and provides more precise positioning. However there was rarely research on this area in Korea Therefore, we introduce the legacy guaranteed model of additional delay(ASF) and present the results of implementation. With the comparison of the original Monteath results and BALOR results respectively, we guarantee that the implementation is absolutely perfect. For further works, we're going to apply the ASF estimation model to Korean DGPS system with the Korean terrain data.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.1
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• pp.36-44
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• 2006

In this study, we constructed a forest fire danger map in the Yeongdong area of Gangwon-do and Northeastern area of Gyeongsangbuk-do using a forest fire rating model and geographical information system (GIS). We investigated the appropriate positions of the automatic weather station (AWS) and a comprehensive network solution (a system including measurement, communication and data processing) for the establishment of an optimum mountain meteorological observation network system (MMONS). Also, we suggested a possible plan for combining the MMONS with unmanned monitoring camera systems and wireless relay towers operated by local governments and the Korea Forest Service for prevention of forest fire.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.467-472
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• 2013

Recently, the value of ICT-based medical devices, equipments, software and service development are is increased according to strengthening the convergence among ICT, medical technologies and services. This paper presents the new convergence business models by applying cloud service to medical industry. In order to develop the new convergence business models, we checked the validity and feasibility through analyzing the medical market environments such as medical data backup, medical regulation etc. and present the new convergence business models and the direction of commercial business models for customer acquisition, market expansion and competitiveness improvement. This study is to provide the guidelines for establishing the core capacity strengthening strategy and partnership cooperation strategy when we design a new convergence business models in various industrial fields.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.103-111
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• 2010

For that reason, more and more growing of the internet speed, many kind of the multimedia as if the voice, a letter, a photograph, a moving picture are appearance and integration of the internet as if the wireless internet, the CATV, a satellite is forming. Today, many changes in the communication environment are occurrence. therefore a demands of the user keep up increase. so, in this paper, we developed the SOHO IP-PBX embedded which can automatically exchange the call. the developed IP-PBX have many functions as if the exchange call function, the gateway function, the PSTN backup function, the FAX function, the VPN function, etc. and verified it by an experiment on the rules in KT.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.98-107
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• 2003

In this study, a survey of time synchronization methods between the remote places. Generally, there are many kinds of time synchronization methods for distant places and they can be grouped three categories according to the type of time transfer methods. The three methods are ground based network, GPS/NAVSTAR and geostationary satellite. Especially, the relay base stations for wireless digital communication are operated based on the timing signal service of the GPS/NAVSTAR satellite network. And as the back-up of the timing signal service of the GPS/NAVSTAR, the geostationary satellite based time synchronization method have researched. In this short paper, the brief explanations about each category were presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.7
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• pp.563-572
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• 2013

Based on this paper, in case of the on-line account system in finance industry temporarily stops working because of the on-line data change from 00:00 to 00:30, it conducts in extra placement server and the director update is carried out via center cut or on-line server to make the service possible through customer director reproduction revision. So, from the simulation result in financial operating system, We retain the batch director & backup director securely about the important time data in each account classes on-line director without even one second interruption.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.7
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• pp.1003-1010
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• 2013

In this paper, TCP/IP based Machine-to-Machine (M2M) communication uses CDMA/GSM network for data communication. This communication method is widely used by offshore moored buoy for data transmission back to the system server. Due to weather and signal coverage, the TCP/IP M2M communication often experiences transmission failure and causing data losses in the server. Data losses are undesired especially for meteorological and oceanographic analysis. This paper discusses a software approach to minimize M2M data losses by handling transmission failure and re-attempt which meant to transmit the data for recovery. This implementation was tested for its performance on a meteorological buoy placed offshore.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.91-94
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• 2015

최근 들어 공용 클라우드 서비스의 이용이 크게 증가하였다. 클라우스 서비스는 관리비용이 저렴하고 다양한 디바이스로 접근이 가능한 장점이 있는 반면, 데이터 접근을 통제하기 힘들어 내부정보가 유출되는 등의 보안 위협이 공존한다. 따라서 본 논문은 클라우드 스토리지의 기밀문서 유출 방지를 위해 사후 감시방법을 연구한다. 문서 내 포함된 보안 키워드 개수를 통해 보안지표를 계산하고 이 지표로 기밀문서 여부를 판단한다. 또한, 관리자용 대시보드를 통해 기밀문서가 탐지 되었을 때 백업/삭제 등의 사후처리 기능을 제공한다. 본 감시방법을 통해 클라우드 스토리지 내 기밀문서가 업로드 되는 것을 감시함으로써 기밀문서 유출 위협을 효과적으로 줄일 수 있다.