• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.299-319
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• 2016

The National Forest Inventory (NFI) is important for providing fundamental data for basic forest planning and the establishment of forest policies for the purpose of implementing sustainable forest management. The purpose of this study is to present the development of Korea's NFI including legal basis, sampling design, and measured variables and to review the usage of NFI data. The survey methods and forestry statistics among the Unites States, Canada, Japan, China, and European countries were briefly compared. Total 140 publications utilizing NFI data between 2008 and 2015 were categorized with 15 subjects. Korea has conducted the NFI 6 times since 1971, but only the $6^{th}$ NFI is comparable with the fifth, the previous NFI, because the permanent sampling plots have been shared between the periods. The Korean Forestry Statistics contains only half as many variables as that of advanced countries in Forestry. More researches were needed to improve consistent measurement of diverse variables through implementation of advanced technologies. Additional data for Forest Health Monitoring since the NFI $6^{th}$ must be under quality control which will be an essential part of the inventories for providing the chronological change of forest health.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.189-200
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• 2011

With rapid development and contribution of IT technology IT fushion healthcare service which is a form of future care has been changed a lot. Specially, as IT technology unites with healthcare, because delicate personal medical information is exposed and user's privacy is invaded, we need preperation. In this paper, u-healthcare service model which can manage patient's ID information as user's condition and access level is proposed to protect user's privacy. The proposed model is distinguished by identification, certification of hospital, access control of medical record, and diagnosis of patient to utilize it efficiently in real life. Also, it prevents leak of medical record and invasion of privacy by others by adapting user's ID as divided by user's security level and authority to protect privacy on user's information shared by hospitals.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.3
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• pp.168-175
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• 2013

Key escrow is a default property that is inherent in identity-based cryptography, where a curious private key generator (PKG) can derive a secret value shared by communicating entities in its domain. Therefore, a dishonest PKG can encrypt and decrypt ciphers or can carry out any attack on the communicating parties. Of course, the escrow property is not completely unwanted but is acceptable in other particular applications. On the other hand, in more civil applications, this key escrow property is undesirable and needs to be removed to provide maximum communication privacy. Therefore, this paper presents an escrow-free identity-based key agreement protocol that is also applicable even in a distinct PKG condition that does not use pairings. The proposed protocol has comparable computational and communicational performance to many other protocols with similar security attributes, of which their security is based on costly bilinear pairings. The protocol's notion was inspired by McCullagh et al. and Chen-Kudla, in regard to escrow-free and multi-PKG key agreement ideas. In particular, the scheme captures perfect forward secrecy and key compromise impersonation resilience, which were lacking in McCullagh et al.'s study, as well as all other desirable security attributes, such as known key secrecy, unknown key-share resilience and no-key control. The merit in the proposed protocol is the achievement of all required security requirements with a relatively lower computational overhead than many other protocols because it precludes pairings.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.9-19
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• 2004

WLAN (Wireless Local Area Networks) needs error recovery and flow control schemes to support reliable multicast protocol. Limited wireless bandwidth, as well as queuing losses caused by the asymmetric wired/wireless interactions, demands more effective approaches for reducing packet losses. Moreover, since the wireless channel is a shared broadcast medium, if sender receives feedback information simultaneously from several receivers, the feedback delays data frame transmission of forward direction by introducing channel congestion and burden at the sender. Therefore, it is important to minimize the amount of feedback information from receivers. In this paper, we propose an ARS(Adaptive Redundancy Scheme) that combines FEC(Forward Error Correction) using channel state estimation and ARQ(Automatic Repeat Request) both to reduce the amount of feedback information and the number of retransmissions and to guarantee high data reliability in a WLAN multicast environment. Performance of the proposed scheme is evaluated by means of analysis and simulations in AWGN and Rayleigh fading channels. The results show that the proposed scheme reduces the amount of feedback information and the number of retransmissions and guarantees high data reliability, while keeping throughput efficiency similarly with the conventional FEC and ARQ scheme.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.269-275
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• 2004

Geographic data have widely been applied in different areas including landuse, city planning and management, environment, disaster management and even daily use of citizens. Since geographic data have been built individually using different methods, many problems such as data inconsistency, duplicated investment, and confusion in decision making have arisen. Thus, the necessity of national framework database that can be shared by different areas has increased. As a result, eight fields of the framework database were defined by NGIS Law and 19 detailed items were selected. This study used the AHP (Analytical Hierarchy Process) and the decision tree to evaluate the relative importance of the items (eg. roads, railroads, coastline, surveying control points, and etc.) and presented the groups classified according to the priorities of the items. The result of this study is believed to contribute to effective budget planning for building national framework database.

• Journal of the Korean earth science society
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• v.27 no.3
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• pp.269-278
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• 2006

In this study, we used Virtual Reality (VR) materials on an introductory earth science course consisted of thirty six pre-service science teacher program students. Before and after class an instrument of Constructivist Learning Environment Survey (CLES) was administered. The main focus of the CLES was to evaluate how the classroom was prepared for student centered learning environment. The pre and post tests of student perceptions regarding their learning environment were compared in six domains: personal relevance, critical voice, shared control, student negotiation, scientific uncertainty, and attitude. Questionnaire regarding the general perception of the VR materials was administered as well. How future science teachers valued the use of VR materials in their classrooms was found from this study. Based on these results, we intend to contribute for a more complete understanding of the potential of VR materials in achieving better learner-centered classroom environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4B
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• pp.270-281
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• 2003

E-PON supports efficiently the increased Internet data traffic and efficient bandwidth assignment function by which the shared upstream bandwidth in the broadband access networks. In this paper, when different types of incoming sources are mapped into QoS-aware source and Best-Effort(BE) source, we propose the Dual-GPS schedulaer in E-PON that has the characteristics to provide delay and delay-constraint application, and maximizes the bandwidth to best-effort service. When transmit upstream data in E-PON, The proposed scheme supports the control capabilities of delay and delay-variation for required QoS flow through the novel bandwidth assignment scheme. Simulation results show our scheme outperforms the conventional bandwidth allocation scheme in controlling the delay and delay-variation of E-PON system.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.112-121
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• 2010

Distributed video coding is a coding paradigm that allows complexity to be shared between encoder and decoder, in contrast with conventional video coding. We propose that complexity balancing method of encoder/decoder by phase motion estimation algorithm. The encoder performs partial motion estimation. The result of the partial motion estimation is transferred to the decoder, and the decoder performs motion estimation within the narrow range. When the encoder can afford some complexity, complexity balancing is possible. The method proposed is able to know relativity between complexity balancing and coding efficiency. The coding efficiency increase rate by the encoder complexity increases is higher than that by the decoder complexity increases. The proposed method can control the complexity and coding efficiency according to devices' resources and channel conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.481-484
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• 2010

In this paper, we implements the USN based context-aware vessel system for a group of ships which receives the specific sensor data that is the result of context-aware after collecting from each of the among a group of ships. The received date is shared and managed by monitoring system. If this monitoring system have trouble the sensor from any ship, the it's control was transferred from the main monitoring ship to the any ship and the second main ship collect the data then recognize the context-aware. Also, this system have the advantage of that reduce the load due to the sensor node communication because just collect the optional sensor data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.509-516
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• 2008

Recently, the operator modules to control external devices are concerned about automatic management system to process continuously changed signals. These signals are the stream data of which characteristics are several numbers. a short report interval and asynchronous report time. It is necessary that the system brings about high accuracy and real time process for stream data. The typical queries of these systems consist of the current query to search the latest signal value, the snapshot query at a past time, the sliding window query from a past time to current. In this paper, we propose the efficient method to manage the above signals by using a file structured database in small-size operating systems. We also propose a query model to accommodate various queries including the sliding window query. The file database in the QNX adopts a delta version and a shared memory buffering method for the resource limit of a small storage and a low computing power.