• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.259-261
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• 2004

정보의 불법적 유출 및 해킹 등과 같은 정보화 역기능을 해결하기 위해서 안전성과 신뢰성이 검증된 정보보호시스템을 사용하여 정보보호 수준 강화가 요구되고 있다. 우리나라를 비롯한 각 국에서는 안정성과 신뢰성 평가를 위한 ITSEC, CC 등과 같은 평가기준들이 개발되어 평가를 시행중이며 이러한 평가기준들에 현존하는 보안위협에 정보보호시스템이 잘 대처하고 있는지를 평가하는 침투시험 항복이 공통적으로 존재한다. 본 논문에서는 정보보호시스템 개발자 및 평가자의 이해를 돕기 위하여 침투시험을 이용한 평가방법론에 대하여 기술한다.

• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.155-172
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• 2002

Airship technical regulations for certification system of each countries are reviewed to assist the development of medium size airship that can be applied observation and communication relay with the ability of holding position at high altitude.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.7-8
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• 2022

국내 해상풍력발전단지가 증가함에 따라 소형선박의 단지 내 위험통항이 증가하고 있으며, 제한된 시계 또는 야간항해 시 해양풍려발전단지 부근을 항해하는 선박들의 안전항행 우도 및 해양풍력단지 시설물 보호의 필요성이 높아지는 등 해상풍력발전단지 내 항로표지가 중요한 의미를 갖게 되었다. 이 연구에서는 국제항로표지협회의 권고안과 주요국가의 국내규정 그리고 국내관련 규정을 비교·분석하여 항로표지의 기능 및 규격에 관한 기준의 개정방안을 제시하였다.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.375-381
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• 2012

If a mobile station requests a channel allocation in its mobile networks, the switching center assigns a channel to a mobile station that belongs to each base station. There are three kinds of channel allocation schemes; a fixed channel allocation, a dynamic channel allocation and a hybrid combination of these two forms. In assigning a good frequency, it is our intention to provide quality service to our customers as well as to use resources efficiently. This paper proposes methods of assigning frequencies that minimize interference between channels and that also minimize the amount of searching time involved. In this paper, we propose an algorithm to per specific equipment, regardless of the number of channels that can be used as a general-purpose system, such as base stations, control stations, central office model is proposed, the existing operators manner similar to the fixed channel allocation based statistics and assigned when the conventional method and the improved method is proposed. Different ways and compared via simulations to verify the effectiveness of the proposed approach.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.9
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• pp.944-951
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• 2014

In this paper, evaluation indices of the location selection of satellite ground station is proposed to maximize satellite applications. The evaluation index has been developed based on radio-wave environmental conditions to avoid the radio interference to perform the missions of ocean observation satellite. The radio interference investigation was generated based on professionals of satellite control/operation, calibration/validation, applications. And evaluation index was applied to a candidate site of ground station. In the future, this result may be able to compare with the results of other candidate sites for the best location selection of 'marine mission-oriented ground stations'. According to recent trends of mission-oriented ground stations, the results can be used for location selection of 'marine mission-oriented ground station' as reference.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.310-317
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• 2017

Recently, many nations are operating and developing Global Navigation Satellite System (GNSS). Also, Satellite Based Augmentation System (SBAS), which uses the geostationary orbit, is operated presently in order to improve the performance of GNSS. The most widely-used SBAS is Wide Area Augmentation System (WAAS) of GPS developed by the United States. SBAS uses various algorithms to offer guaranteed accuracy, availability, continuity and integrity to its users. There is algorithm for guarantees the integrity of the satellite. This algorithm calculates the satellite errors, generates the correction and provides it to the users. The satellite orbit errors are calculated in three-dimensional space in this step. The reference placement is crucial for this three-dimensional calculation of satellite orbit errors. The wider the reference placement becomes, the wider LOS vectors spread, so the more the accuracy improves. For the next step, the regional features of the US and Korea need to be analyzed. Korea has a very narrow geographic features compared to the US. Hence, there may be a problem if the three-dimensional space method of satellite orbit error calculation is used without any modification. This paper suggests a method which uses scalar values to calculate satellite orbit errors instead of using three-dimensional space. Also, this paper proposes the feasibility for this method for a narrow area. The suggested method uses the scalar value, which is a projection of orbit errors on the LOS vector between a reference and a satellite. This method confirms the change in errors according to the baseline distance between Korea and America. The difference in the error change is compared to present the feasibility of the proposed method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.3
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• pp.259-267
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• 2020

For real-time precise positioning, N-RTK (Network Real-Time Kinematic) technology is widely used these days. However, the currently operating N-RTK system has a limitation in terms of the number of users. Therefore, if reference points generate correction messages with no limit on the number of users are developed later, it is determined that an appropriate reference point installation interval is required, so that the accuracy of the N-RTK system according to the baseline distance was analyzed. This experiment utilized receivers with varying performance that estimated the rover position, and RTKLIB, an open-source software, is used for processing data. As a result, the rover position was estimated accurately with a high rate of fixed ambiguity for all the receivers. When the reference station with a baseline length of 40 km was used, the vertical RMSE (Root Mean Squared Error) was quite similar to the short baseline case, but only half of the ambiguity fixing rate was achieved. The outlier in the estimated rover position was not observed for the longer baselines in the case of a high-end receiver. It is necessary to analyze the ambiguity fixing and the accuracy of the kinematic positioning with scientific GNSS processing software.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.859-864
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• 2007

In the future, it is necessary that using the Satellite-based radio navigation augmentation system such as Differential Global Positioning System(DGPS) to achieve a position accuracy of sub-meter level in port. Generally, the receiver for DGPS reference station should meet performance specifications of RSIM Ver. 1.1 presented by RTCM. This paper proposes a method to verify performance of the receiver for DGPS reference station according to the RSIM Ver. 1.1. And this paper presented that performance evaluation of the commercial receiver for DGPS reference station through the proposed method is satisfied with RSIM Ver. 1.1.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.273-279
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• 2007

As the number of mobile telephone users increases, technologies fur increasing quality of services between a mobile terminal and the base station transceiver system become more important than ever. The important criteria of quality of service includes minimum interference of base station, the success rate of network access and portability between different mobile companies. Among many factors, the successful rate of network connection between a mobile terminal and the base station is the most important. In this paper, we introduce an analysis system of mobile terminals using RS-232C communication after considering such environments. This application software simulates the communicational signals between and mobile terminals and the base station and shows the results through the graphs. Using this system, the task about testing communication performance of mobile terminals will be easy since it helps to analyze the status of communication.

• Journal of Energy Engineering
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• v.11 no.4
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• pp.359-369
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• 2002

Nuclear power plant is a huge system with multidisciplinary technology. So, R & D prioritization is a not a simple task and the relative importance of each prioritization criterion is not well established. This study built a technology classification chart for nuclear power plant operation and maintenace, established the relative importance of prioritization criteria and assigned the relative importance of each technology at each level. Analytical Hierarchy Process was used for the prioritization and the result was validated with Consistency Index and outcomes of fields interview.