• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.81-90
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• 2018

The 'Hyper-connected society' in which all objects such as people, device, place are connected via networks and share information being realized. As the information and communication environment changes, spatial information also faces a significant challenge. Korean government is striving to meet the social demand for spatial information that will bring 'Hyper-connectivity' such as autonomous vehicles, drones. Until now, however, it has only partially responded to urgent demand and has not prepared a fundamental countermeasure. In order to effectively and actively respond to the demand for spatial information that is needed in the Hyper-connected society, a strategy that can lead to mid- to long-term fundamental changes is needed. The purpose of this study is to analyze the future demand and application characteristics of spatial information confronted with a big paradigm shift called 'Hyper-connected society', and to search spatial information strategy that can cope with the demand of spatial information in future society.

• Journal of IKEEE
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• v.23 no.3
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• pp.858-864
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• 2019

A clock system is proposed to eliminate data loss due to frequency difference between sensor nodes in a sensor utility network. The proposed clock system for each sensor node consists of a bust clock-data recovery (CDR) circuit, a digital phase-locked loop outputting a 32-phase clock, and a digital frequency synthesizer using a programmable open-loop fractional divider. A CMOS oscillator using an active inductor is used instead of a burst CDR circuit for the first sensor node. The proposed clock system is designed by using a 65 nm CMOS process with a 1.2 V supply voltage. When the frequency error between the sensor nodes is 1%, the proposed burst CDR has a time jitter of only 4.95 ns with a frequency multiplied by 64 for a data rate of 5 Mbps as the reference clock. Furthermore, the frequency change of the designed digital frequency synthesizer is performed within one period of the output clock in the frequency range of 100 kHz to 320 MHz.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.119-129
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• 2009

In The increasing use of computers and high-speed Internet network has greatly influenced education, causing a veering away from the typical and traditional way of delivering instruction. Specifically, the various kinds of Web-based multimedia technology, the interactive activities on the Internet, and satellite broadcasting technology are accelerating the emergence of a virtual-lectures-based educational model, which transcends time and space. Such virtual lectures make it possible for the entire teaching-learning process to be done in a virtual learning environment, thus giving rise to problem regarding learning guidance, feedback, and appraisal. In this paper, we propose a system for attendance appraisal for learner participation degree based virtual lecture, an appraisal element in virtual learning environments. This appraisal model can set the elements of virtual learning environments in such a way as to reflect in the attendance appraisal of the opened virtual learning environment information regarding the learner's participation in class. In addition, this model motivates the learners to actively participate in the virtual learning environment and to support instructors by accomplishing the activities that are needed for attendance appraisal.

• Journal of the Korea Computer Graphics Society
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• v.16 no.1
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• pp.21-27
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• 2010

Today the lectures are usually practiced in a teacher-led traditional classroom system or a student-led e-learning system. Students passively follow the teacher's lectures in both systems, though. Also due to the advances in 3D Computer Graphics and Game technologies, there are trials to exploit the positive effect of games in learning. The serious games, specifically designed games for an educational goal, or existing games for a special class have been used as lectures. Still these games have a great difficulty in being integrated into the educational system technically and economically. Therefore a new 3D MMORPG based lecturing system is presented in this paper. In our new lecturing system, the characteristics of a 3D MMORPG, achievement, sociality, and immersion, are provided to motivate students to participate actively in a lecture. A teacher and students interact with each other in realtime as 3D characters in a 3D virtual classroom on-line. An ordinary teacher can also easily apply our new system to existing classes since a teacher only needs to specify a slide file to prepare a lecture. For the future work, a user study and the effect of our new lecturing system will be performed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.106-116
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• 2011

USN(Ubiquitous Sensor Network) environment permits us to access whatever information we want, whenever we want. The technologies to provide a basement to these environments premise an accurate location establishment. Especially, ITS(Intelligent Transportation Systems) is easily constructed by applying USN technology. Localization can be categorized as either Range-based or Range-free. Range-based is known to be not suitable for the localization based on sensor network, because of the irregularity of radio propagation and the additional device requirement. The other side, Range-free is much appropriated for the resource constrained sensor network because it can actively locate by means of the communication radio. But, generally the location accuracy of Range-free is low. Especially, it is very low in a low-density environment. So, these two methods have both merits and demerits. Therefore, it requires a new method to be able to improve tracking accuracy by combining the two methods. This paper proposes the tracking scheme based on range-hybrid, which can markedly enhance tracking accuracy by effectively using the information of surrounding nodes and the RSSI(Received Signal Strength Indication) that does not require additional hardware. Additionally, we present a method, which can improve the accuracy of vehicle tracking by adopting the prediction mechanism. Simulation results show that our method outperforms other methods in the transportation simulation environment.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.133-140
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• 2012

In SIP(Session Initiation Protocol) service, users should send SIP SUBSCRIBE messages to the SIP server to get subscription informations of the other parties, and total amount of SIP messages becomes large in network as refresh messages and notification messages are generated to each SIP subscription. In this paper, a new resource lists architecture using dynamic notification control method has been proposed to solve these problems. In this architecture, service users can control event notification generation rate dynamically from the server according to the operation circumstances, and users can control generation of notification messages during refresh for maintaining SIP session. Furthermore users can also control generation of notification messages according to session connection conditions. A new resource lists MIME type has been designed, and several parameters for dynamic notification message control have been added to the extended SIP message headers. In this system new resource lists MIME type can be used for processing of the event package. Therefore total amount of SIP messages in network can be largely reduced, and load of the resource lists server for processing messages can be reduced also. The performance of the proposed method has been evaluated by experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.7
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• pp.573-586
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• 2013

Recently, the research, utilizing bio and environment sensors in agricultural and cattle industries, are drawing attention among the various IT convergence technologies. Among such research IT convergence techniques which aim to improve the quality of cattle industry management are necessary in particular. Real-time monitoring of the cattles health condition, identification of the cause of the diseases and timely response to such epidemic based on IT convergence techniques are among them. In order to achieve the better management of cattle industry, we propose a cattles management system which based on various bio environment sensors and wireless network technologies. The system consists of wireless environmental sensor data acquisition nodes, sensor data processing nodes, the gateway and the server. The proposed system is able to actively monitor the cattle field, to respond quickly in the case of massive cattle diseases and to control the environment of the cattle fields. We believe the proposed system will demonstrate the successful application of IT technologies to an applied field such as farming industries because of real-time crisis management capability in case of epidemic and optimal management of cattle industry.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.238-240
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• 2006

네트워크상에서 발생하는 다양한 형태의 대량의 데이터를 정확하고 효율적으로 분석하기 위해 설계되고 있는 마이닝 시스템들은 목표지향적으로 훈련데이터들을 어떻게 구축하여 다룰 것인지에 대한 문제보다는 대부분 얼마나 많은 데이터 마이닝 기법을 지원하고 이를 적용할 수 있는지 등의 기법에 초점을 두고 있다. 따라서, 점점 더 에이전트화, 분산화, 자동화 및 은닉화 되는 최근의 보안공격기법을 정확하게 탐지하기 위한 방법은 미흡한 실정이다. 본 연구에서는 유비쿼터스 환경 내에서 발생 가능한 문제 중 복잡하고 지능화된 침입패턴의 탐지를 위해 데이터 마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처리 방법에 의한 RTPID(Refinement Training and Post-processing for Intrusion Detection)시스템을 제안한다. 본 논문에서의 RTPID 시스템은 active learning과 post-processing을 이용하여, 네트워크 내에서 발생 가능한 침입형태들을 정확하고 효율적으로 다루어 분석하고 있다. 이는 기법에만 초점을 맞춘 기존의 데이터마이닝 분석을 개선하고 있으며, 특히 제안된 분석 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. 이는 관리자의 개입을 최소화하는 학습방법이면서 동시에 False Positive와 False Negative 의 오류를 매우 효율적으로 개선하는 방법으로 기대된다. 본 논문의 제안방법은 분석도구나 시스템에 의존하지 않기 때문에, 유사한 문제를 안고 있는 여러 분야의 네트웍 환경에 적용될 수 있다.더욱 높은성능을 가짐을 알 수 있다.의 각 노드의 전력이 위험할 때 에러 패킷을 발생하는 기법을 추가하였다. NS-2 시뮬레이터를 이용하여 실험을 한 결과, 제안한 기법이 AOMDV에 비해 경로 탐색 횟수가 최대 36.57% 까지 감소되었음을 알 수 있었다.의 작용보다 더 강력함을 시사하고 있다.TEX>로 최고값을 나타내었으며 그 후 감소하여 담금 10일에는 $1.61{\sim}2.34%$였다. 시험구간에는 KKR, SKR이 비교적 높은 값을 나타내었다. 무기질 함량은 발효기간이 경과할수록 증하였고 Ca는 $2.95{\sim}36.76$, Cu는 $0.01{\sim}0.14$, Fe는 $0.71{\sim}3.23$, K는 $110.89{\sim}517.33$, Mg는 $34.78{\sim}122.40$, Mn은 $0.56{\sim}5.98$, Na는 $0.19{\sim}14.36$, Zn은 $0.90{\sim}5.71ppm$을 나타내었으며, 시험구별로 보면 WNR, BNR구가 Na만 제외한 다른 무기성분 함량이 가장 높았다.O to reduce I/O cost by reusing data already present in the memory of other nodes. Finally, chunking and on-line compression mechanisms are included in both models. We demonstrate that we can obtain significantly high-performanc

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.1-8
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• 2016

Current indoor intrusion detection and location tracking methods have the weakness in seamless operations in tracking the objective because the object must possess a communicating device and the limitation of the single cell size (approximate $100cm{\times}100cm$) exits. Also, the utilization of CCTV technologies show the shortcomings in tracking when the object disappear the area where the CCTV is not installed or illumination is not enough for capturing the scene (e.g. where the context-awarded system is not installed or low illumination presents). Therefore, in this paper we present an improved in-door tracking system based on sensor networks. Such system is built on a simulated scenario and enables us to detect and extend the area of surveillance as well as actively responding the emergency situation. Through simulated studies, we have demonstrated that the proposed system is capable of supplementing the shortcomings of signal cutting, and of estimating the location of the moving object. We expect the study will improve the better analysis of the intruder behavior, the more effective prevention and flexible response to various emergency situations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.581-584
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• 2009

Recently, the cameras which used for observation are installed in children protection area and local crime prevention area in order to protect life and property and by its work being recognized and are installed more. Normal cameras have cost problem to observe multiple area and detail, because they can observe only one place. PTZ camera can observe multiple area by moving focus by schedule or remote control, but it can't automatically move the focus of it to the place where event occurred, because it can't recognize the place. In this study, we can monitor multiple area effectively, by installing a wireless sensor node equipped with temperature, lighting, gas and human detection sensor to each area, to monitor many place low-price and actively and to move the focus of PTZ camera to preset position, and send recorded video to the user, when the various sensor data received from wireless sensors in observation area are to be determined abnormal by analyzing. In addition, at night we can record a scene using infrared, but to reduce power consumption of lighting system which are installed to improve resolution, it supplies power to the lighting system when event occurred. So we were able to implement low power green monitoring system.