• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1160-1169
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• 1996

In this study, an experiment of information retrieval using fuzzy connection matrix of keywords was conducted. A query for retrieval was constructed from each keyword and Boolean operator such as AND, OR, NOT. In a workstation environment, the performance of the fuzzy retrieval system was proved to be considerably effective than that of the system using the crisp set theory. And both recall ratio and precision ratio showed that the proposed technique would be a possible alternative in future information retrieval. Some special features of this experimental system were ; ranking the results in the order of connectivity, making the retrieval results correspond flexibly by changing the threshold value, trying to accord the retrieval process with the retrieval semantics by treating the averse-connectivity (fuzzy value) as a semantic approximation between kewords.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.281-292
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• 2008

A main application of sensor networks are to monitor and to send information about a possibly hostile environment to a powerful base station connected to a wired network. To conserve power from each sensor, intermediate network nodes should aggregate results from individual sensors. However, it can make it that a single compromised sensor can render the network useless, or worse, mislead the operator into trusting a false reading. In this paper, we propose a protocol to give us a key aggregation mechanism that intermediate network nodes could aggregate data more safely. The proposed protocol is more helpful at multi-tier network architecture in secure sessions established between sensor nodes and gateways. From simulation study, we compare the amount of the energy consumption overhead, the time of key transmission and the ratio of of key process between the proposed method and LHA-SP. The simulation result of proposed protocol is low 3.5% a lord of energy consumption than LHA-SP, the time of key transmission and the ration of key process is get improved result of each 0.3% and 0.6% than LHA-SP.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.2
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• pp.164-171
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• 2013

Since plenty of spacecrafts were launched in space after 1957, the number of space debris has been increased. According to the JSpOC, the number of space debris which diameter is bigger than 10 cm are more than 22,000. Recently there were two critical events. Which one is that China shot down their satellite using missile and the other is that two satellite, Iridium and Cosmos 2251, collied. Space environment in low-earth orbit has been severe. JSpOC analyzes the collision risk between 15,000 space debris and all operation satellites and then they send CSM to the satellite operator to utilize its orbital information if collision risk might be occurred. This paper analyzes the CSM orbit data by comparing with KOMPSAT-2 precise orbit data and shows conjunction assessment results.

• Journal of The Korea Institute of Healthcare Architecture
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• v.22 no.3
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• pp.7-15
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• 2016

Purpose: As medicare services have gotten spreaded, clinical laboratory has been dominant position. So, it has been acted for quality control and clinical pathology accreditation. But there has been quite deficient information to evaluate working space and technical standards of medical laboratory for accreditation. This study goals to figure out accreditation standard and design guideline for clinical laboratory, and to give safe and efficient design information. Methods: This study has been searched by literature for accreditation standards and design guidelines of clinical pathology in USA, UK, and Germany. Results: Three countries have accredited based on working lab space, staff space, storage space, patient space and health and safety equipment. Design guidelines of three countries commonly have focused on worktable layout, worktable distance and module, and specific laboratory biosafety level. And USA guidelines stress on the architectural design such as design process and passage distance for escape, UK stress on the efficiency as functional work flow and construction cost, lastly Germany design guidelines stress on the operator's safety distance and workstation. Three countries have not only accreditation standards but also design guidelines for more specific quality management, separating from accrediting institute. Implications: In korea, it has been needed to make clinical laboratory design guideline for the safe and efficient environment and reliable and competitive medical service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.440-451
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• 2013

Recently, researches of technology and standardization for maritime safety are proceeding internationally. In particular, some technologies and strategies for e-Navigation have been developed and the necessity of development of next generation VTS (Vessel Traffic Service) has been raised in Korea. In order to construct user oriented VTS system for domestic environment, VTS operators are asked for their requirements related to developing VTS and the opinions should be reflected in the VTS. So in this paper, we collect the requirements from fifteen VTS centers in the country and we also analyze them. Furthermore, we propose an ASM (Application Specific Messages) service, which was not supported by current VTS, and we verify the proposed ASM through AIS (Automatic Identification System) system and simulation terminal for maritime safety.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.513-521
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• 2014

Korea's traffic congestion costs including other social costs due to accidents, environmental pollution and increased demand is increasing every year. In this regard, direction of government policy was geared toward suppression of vehicle demand and activation of public transportation, which is determined to be the best solution with limited supply of infrastructure such as road facilities. This study aims to implement public transport bus-only Head-Up Display (hereafter called HUD) technology which displays public transport information required for a bus driver on the front glass of a bus. The public transport bus-only HUD not only prevents gaze dispersion of bus drivers but also helps to reduce the heavy workload of bus drivers by providing information required for driving. Ultimately, the final research purpose is a reduction of bus traffic accidents by 50% caused by negligence in keeping eyes forward or sideways.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.549-557
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• 2012

Spatial phenomena such as environment pollution, disease and the risk of spreading information need a rapid initial response to perceive spread event. Moving data perceive spread event through real-time processing and analysis. To process and analysis the event, spatial-temporal complex event processing is used. Previous spatialtemporal complex event processing is possible basis spatial operator but insufficient apply to design spatialtemporal complex event processing to perceive spatial phenomena of high complexity. This study proposed hierarchical spatio-temporal CEP design which will efficiently manage the fast growing incoming sensor data. The implementation of the proposed design is evaluated with GPS location data of moving vehicles which are used as the incoming data stream for identifying spatial events. The spatial component of existing CEP software engine has been extended during the implementation phase to broaden the capabilities of processing spatio-temporal events.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5229-5252
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• 2016

With proliferation of diverse network access technologies, users demands are also increasing and service providers are offering a Quality of Service (QoS) to satisfy their customers. In roaming, a mobile node (MN) traverses number of available networks in the heterogeneous wireless networks environment and a single operator is not capable to fulfill the demands of user. It is crucial task for MN for selecting a best network from the list of networks at any time anywhere. A MN undergoes a network selection situation frequently when it is becoming away from the home network. Multiple Attribute Group Decision (MAGD) method will be one of the best ways for selecting target network in heterogeneous wireless networks (4G). MAGD network selection process is predominantly dependent on two steps, i.e., attribute weight, decision maker's (DM's) weight and aggregation of opinion of DMs. This paper proposes Multi-Attribute Intuitionistic Fuzzy Group Decision Method (MAIFGDM) using TOPSIS for the selection of the suitable candidate network. It is scalable and is able to handle any number of networks with large set of attributes. This is a method of lower complexity and is useful for real time applications. It gives more accurate result because it uses Intuitionistic Fuzzy Sets (IFS) with an additional parameter intuitionistic fuzzy index or hesitant degree. MAIFGDM is simulated in MATLAB for its evaluation. A comparative study of MAIFDGM is also made with TOPSIS and Fuzzy-TOPSIS in respect to decision delay. It is observed that MAIFDGM have low values of decision time in comparison to TOPSIS and Fuzzy-TOPSIS methods.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.6
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• pp.593-601
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• 2001

This paper presents an efficient system for power system education using 3-D computer graphics animation in the PC environment. Several power system phenomena are simulated using Real-Time Digital Simulator. Results are transmitted through on-line communication line to PC for graphic animation, and simulated in the 3-D graphics animation. It can immediately reflect user control input and re-simulated this result. The proposed method was tested on both the sub-synchronous resonance phenomena and multi-bus system. It is expected that the proposed method would be helpful for the operator training as well as power system education.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.