• 한국공간정보시스템학회:학술대회논문집
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• 1999.06a
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• pp.181-189
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• 1999

21세기 무한경쟁시대에서 국가경쟁력을 확보하기 위하여 현재 도로교통상황을 추정하고, 화물차의 공차(空車)를 줄이고, 차량운행상태를 관리할 필요성이 부각되었다. 본 연구에서는 실시간 교통정보산출 및 활용을 위하여 국가수치기본도에 GPS을 응용하는 기법을 제시하였다. 구체적으로는 GIS기능 중 하나인 공간결합(Spatial Join)기능을 활용하여 Map Matching, 통행시간추정 및 차량운행 관리기법 등을 제시하였다. 최종적으로는 제시된 기법을 서울시 강남구 지역일대에 시범적으로 적용시켜 보았다.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.493-498
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• 2017

Recently, traffic data is analyzed for efficiency of bus operation, D2D(: Door to Door) service, and self-driving of public transportation. However, various studies have been carried out to predict the delay time of public transportation, especially buses, but the research to date has been insufficient due to limitations of simple analysis and data acquisition. In this study, delay time estimation is performed by collecting and processing data such as day of the week, weather, and time of day based on bus operation information. The proposed method in this paper can be applied to autonomous public transport and public traffic control system by improving the accuracy by adding variables in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1387-1392
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• 2003

For the structure of VMS by converting on digital the position reporting of departure fishery ship in the fishery communication that be required the management & operation of information in organizational. In particular, Must be made the regional & concentrational of the position reporting information. The division of region is considered to the circumstance of radio wave, fishing area, quantity of fishery ship and communication traffic etc.. It is capable to the DB of VMS by concentrate in head quarters, which is acquisition the position reporting information of respective region. In this study have designed for building of fishery information network and automatic transmission of the position reporting information from a fishery ship.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.1
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• pp.58-71
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• 2019

This paper proposes architecture of a cognitive radio engine platform and the allowable frequency channel reasoning method that enables acquisition of the allowable channels for the military tactical network environment. The current military tactical wireless communication system is increasing need to secure a supplementary radio frequency to ensure that multiple wireless networks for different military wireless devices coexist, so that tactical wireless communication between the same or different systems can be operated effectively. This paper presents the allowable frequency channel reasoning method based on cognitive radio engine for realizing DSA(Dynamic Spectrum Access) as an optimal available frequency channel. To this end, a case-based allowable frequency channel reasoning method for cognitive radio devices is proposed through modeling of primary user's traffic status and calculation of channel occupancy probability. Also through the simulation of the performance analysis, changing rate of collision probability between the primary users' occupancy channel and the available channel acquisition information that can be used by the cognitive radio device was analysed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.95-117
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• 2006

In this paper, we describe the optimization of the link-level performance and the complexity of floating-point and fixed-point methods in IEEE 802.16e OFDMA/TDD mobile modem. In floating-point design, we propose the channel estimation methods for downlink traffic channel and select the optimized method using computer simulation. So we also propose efficent algorithms for time and frequency synchronization, Digital Front End and CINR estimation scheme to optimize the system performance. Furthermore, we describe fixed-point method of uplink traffic and control channels. The superiority of the proposed algorithm is validated using the performances of Detection, False Alarm, Missing Probability and Mean Acquisition Time, PER Curve, etc. For fixed-point design, we propose an efficient methodology for optimized fixed-point design from floating-point At last, we design fixed-point of traffic channel, time and frequency synchronization, DFE block in uplink and downlink. The tradeoff between performance and complexity are optimized through computer simulations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.6
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• pp.67-81
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• 2011

In recently years, there are cyber-weapon aim to national infrastructure such as 'stuxnet'. Security experts of the world are paying attention to this phenomenon. The networks which controls traffic, subway, waterworks of the city are safe from threats such as computer virus, malware, because the networks were built on closed-networks. However, it's about time to develop countermeasure for the cyber-weapon. In this paper, we review status-quo of the control systems for metropolitan infrastructure and analyze the risk of industrial control system in SCADA(Supervisory Control And Data Acquisition) network. Finally, we propose a security model for control systems of metropolitan infrastructure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.153-160
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• 2016

In this paper, we propose a system that tracks the position of the passengers and sailors using a Bluetooth-based Beacon in the ship. The position of the tracking passengers, sometimes fatal emergencies of the rescue team, such as the sinking of the ship is utilized in order to efficiently and quickly rescue the passengers, and the collected data can be utilized additionally by grasping the flow of human traffic patterns. The system proposed in this paper, install MAC data acquisition called AP (Access Point) for each cabin, and in the installed AP retrieves Tag of the information provided to the passenger and collected. A Tag has only its own MAC Address to the privacy, no user information is not collected. All data communication by sending and receiving MAC Address was only to ensure anonymity.

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.303-310
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• 2002

Nowadays, the combined land navigation system using GPS(Global Positioning System) and DR(Deduced Reckoning), etc. has been used. Although GPS is popular with the land navigation system, this is not useful for the kinematic positioning of the vehicles in the urban canyon because of its few satellites. Thus, this study deals with the kinematic positioning of the vehicles with the combined GPS/GLONASS(GLObal Navigation Satellite System) to compliment the drawbacks of GPS. So the kinematic positioning of the vehicles can be performed constantly by the combined GPS/GLONASS based on the high acquisition rate of data with the help of GLONASS despite of many obstacles and few satellites tracked in the test sites. Consequently, the combined GPS/GLONASS can be applicable to the control of traffic flow and the effective management of read system.

• Convergence Security Journal
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• v.20 no.5
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• pp.11-17
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• 2020

With the increase in cases of using Bluetooth devices used in the electric vehicle charging systems, security issues are also raised. Although various technical efforts have beed made to enhance security of bluetooth technology, various attack methods exist. In this paper, we propose an intelligent Bluetooth intrusion detection system based on a well-known machine learning method, Hidden Markov Model, for the purpose of detecting intelligently representative Bluetooth attack methods. The proposed approach combines packet types of H4, which is bluetooth transport layer protocol, and the transport directions of the packet firstly to represent the behavior of current traffic, and uses the temporal deployment of these combined types as the final input features for detecting attacks in real time as well as accurate detection. We construct the experimental environment for the data acquisition and analysis the performance of the proposed system against obtained data set.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.1131-1142
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• 2018

The autonomous vehicles are being developed and operated widely because of the advantages of reducing the traffic accident and saving time and cost for driving. The vehicle localization is an essential component for autonomous vehicle operation. In this paper, localization algorithm based on sensor fusion is developed for cost-effective localization using in-vehicle sensors, GNSS, an image sensor and reference images that made in advance. Information of the reference images can overcome the limitation of the low positioning accuracy that occurs when only the sensor information is used. And it also can acquire estimated result of stable position even if the car is located in the satellite signal blockage area. The particle filter is used for sensor fusion that can reflect various probability density distributions of individual sensors. For evaluating the performance of the algorithm, a data acquisition system was built and the driving data and the reference image data were acquired. Finally, we can verify that the vehicle positioning can be performed with an accuracy of about 0.7 m when the route image and the reference image information are integrated with the route path having a relatively large error by the satellite sensor.