• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.33-42
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• 2010

This research propose a practical guidance system considering ocean currents in real sea operation. Optimality of generated path is not an issue in this paper. Way-points from start point to possible goal positions are selected by experienced human supervisors considering major ocean current axis. This paper also describes the implementation of a precise underwater navigation solution using multi-sensor fusion technique based on USBL, GPS, DVL and AHRS measurements in detail. To implement the precise, accurate and frequent underwater navigation solution, three strategies are chosen. The first one is the heading alignment angle identification to enhance the performance of standalone dead-reckoning algorithm. The second one is that absolute position is fused timely to prevent accumulation of integration error, where the absolute position can be selected between USBL and GPS considering sensor status. The third one is introduction of effective outlier rejection algorithm. The performance of the developed algorithm is verified with experimental data of mine disposal vehicle and deep-sea ROV.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.3
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• pp.6-12
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• 2011

Electric vehicles and robots are real-time distributed control systems composed of multiple drive subsystems using micro controller units. Each control subsystem should be modular, compact, power saving, interoperable and fault tolerable in order to be incorporated into the networked real-time distributed control system. Under the networked real-time distributed control the synchronization problem can be occurred to the position and orientation tracking control due to the load variance, mismatch and time delay between the multiple drive subsystems. This paper suggests two types of position synchronization control of the single link manipulators. One of them is composed of cross controller, Kalman filter and disturbance observer, and the other uses the generation of target trajectories to minimize the gradient vector of the scalar function which is composed of the sum of square errors between the reference input vector and the output vectors. The availability of the proposed control schemes is shown through the control experiments.

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.225-229
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• 2007

Recently, wireless sensor networks are deployed in various applications range from simple environment monitoring systems to complex systems, which generate large amount of information, like motion monitoring, military, and telematics systems. Although wireless sensor network nodes are operated with low-power 8bit processor to execute simple tasks like environment monitoring, the nodes in these complex systems have to execute more difficult tasks. Generally, MAC protocols for wireless sensor networks attempt to reduce the energy consumption using duty cycling mechanism which means the nodes periodically sleep and wake. However, in the duty cycling mechanism. a node should wait until the target node wakes and the sleep latency increases as the number of hops increases. This sleep latency can be serious problem in complex and sensitive systems which require high speed data transfer like military, wing of airplane, and telematics. In this paper, we propose a solution for reducing transmission latency through distributed duty cycling (DDC) in wireless sensor networks. The proposed algorithm is evaluated with real-deployment experiments using CC2420DBK and the experiment results show that the DDC algorithm reduces the transmission latency significantly and reduces also the energy consumption.

• Journal of the Korean Geographical Society
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• v.49 no.2
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• pp.310-319
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• 2014

The purpose of this study was building a new method for map making with a toponym by connecting a toponym DB with a digital topographic map DB. First, the table of toponym history in the toponym DB was revised. Second, a table linking the toponym DB and the digital topographic map DB was added. To integrate the toponym DB and the digital topographic map DB, a loose-coupling method was suggested and the combination of legal Dong and a toponym could be used as ID for liking those two databases. Thus, the method presented in this study would be used for effective map making using a toponym. Through the improvement of a toponym DB, it is expected the active use of the toponym DB such as map making.

• Convergence Security Journal
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• v.15 no.3_1
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• pp.11-22
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• 2015

The military technological surprise has been delivered in many warfares as a surprise tactic. It can be used both strategic and tactical level. As the weapon systems have been escalated their capabilities by the modern science and technology advancement, the possibility of technological surprise has been increased. Technological surprise can spring from sources like scientific breakthrough in the laboratory, rapid fielding of known technology, and new operational use of an existing weapon and technology. There are 2 types of surprise, known surprises are those which the nation should have known but did not adequately prepare, and surprising surprises are those which the nation might have known but which were buried among other possibilities. The nine cases of modern technological surprises are presented and the sources and types are analyzed. The recommendations for the ROK MND to prepare for the future technological surprises are proposed.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.195-207
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• 2012

This paper deals with attitude controller design and integrated performance tests on the nitrogen gas reaction control system of KSLV-I. Some major factors which are necessarily required in designing a stabilizing controller of reaction control system are investigated, and the corresponding equations are given. Experimental configurations and test conditions for system level integrated performance tests of the KSLV-I nitrogen gas reaction control system are summarized. It is shown that, based on the experimental data, operational performances of nitrogen gas reaction control system can be analyzed in terms of gas consumption, thrusting force, time delay, and specific impulse. It is also shown that a conformance of the controller to flight can be evaluated. Finally the onboard controller of KSLV-I reaction control system is shown to perform normally with enough stability margin via the first flight test result.

• Korean Journal of Construction Engineering and Management
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• v.2 no.4 s.8
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• pp.127-134
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• 2001

Effectiveness of Just in time managing system can be obtained by removing unexpected lead-time and maintaining consistency on the physical transportation of construction resource. Construction resource management is essential on checking on load data from production of shop to field, and it is based on building resource life cycle information. In this study, production, transportation, and assembly disciplines of concrete construction should real time communications exchanging information related to shop-field with each other, Establishing information support system is an important initial step for promoting active cooperations among these resource life cycle on data flow. To achieve this, on suitable using management point, we suggest a concrete construction control model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.375-381
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• 2015

In the past few years, data leakage of information assets has become prominent issue. According to the NIS in South Korea, they found 375 cases of data leakage from 2003 to 2013, especially 49 of cases have been uncovered in 2013 alone. These criminals are increasing as time passes. Thus, it constitutes a reason for establishment, operation and certification of ISMS, even for private enterprises. The purpose of this study is to examine the factors influencing the certification intention of ISMS using EFA (Exploratory Factor Analysis) and regression analysis. We identified expectation factors for certification of ISMS from 13 elements using EFA (Strengthening practical ability & economic effect factor and Improvement of security level & handling incident factor). Next, we examined that the certification intention of ISMS using regression analysis. As a result of regression analysis, Strengthening practical ability & economic effect factor is not significant for the certification intention of ISMS (p<.05). Also, Improvement of security level & handling incident factor have a significant and positive effect on the certification intention of ISMS (p<.05).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.93-97
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• 2000

In an era of very rapid technological change, standardization organizations have been confronted with the problem that they should develop more new and more complex standards as strategic tools for enforcement of competitive power in shorter time according to the reduction of Life Cycle of products and the increase in the number of standards and their complexity. To cope with this challenge, we introduce the functionalities and development directions for implementing standardization information system. Also this paper describes the architecture of the next generation system for standard information that enabling information sharing and exchanging using XML. Finally, we suggest implementation framework of Standardization Vortal Site for the One-stop service of integrated standards information which provide users with standards development roadmap and give brief introduction to SOL(Standards On-Line) site which is operated by ETRI/PEC.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.763-770
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• 2005

Global Navigation Satellite System (GNSS) has become an indispensable tool for providing precise position, velocity and time information for many applications like traditional surveying and navigation etc. However, Global Positioning System (GPS), which was developed and is maintained and operated by the U.S. Department of Defence (DoD), has monopolized the world industry and market, and hence there exists the situation that most of GNSS users absolutely depend upon the GPS. In order to overcome the monopoly, some countries, such as Russia, Japan and European Union (EU), have developed their own GNSSs, so-called GLONASS, JRANS and Galileo systems. Among them, the most prospective system in near future is EU's Galileo system scheduled to launch in 2008. This research has focused on the next generation GNSS system based on GPS and Gralileo system with developing a GNSS simulation software, named as GIMS2005, which generates and analyzes satellite constellation and measurements. Based on the software, a variety of simulation tests have been carried out to recognize limits of GPS-only system and potential benefits of integrated GPS/Galileo positioning. Geometry simulation results have showed that comparing with GPS-only case, the number qf visual satellites, Dilution of Precision (DOP) values, internal reliabilities and external reliabilities.