• KIISE Transactions on Computing Practices
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• v.23 no.1
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• pp.74-79
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• 2017

The Geostationary Ocean Color Imager (GOCI), the world's first ocean color sensor operated in a geostationary orbit, can be utilized to mitigate damages by monitoring marine disasters in real time such as red tides, green algae, sargassum, cold pools, typhoons, and so on. In this paper, we described a methodology and procedure for processing GOCI data in order to maximize its utilization potential. The GOCI data processing procedure is divided into data reception, data processing, and data distribution. The kinds of GOCI data are classified as raw, level 1, and level 2. "Raw" refers to an unstructured data type immediately generated after reception by satellite communications. Level 1 is defined as a radiance data type of two dimensions, generated after radiometric and geometric corrections for raw data. Level 2 indicates an ocean color data type from level-1 data using ocean color algorithms.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.4
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• pp.93-99
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• 2010

Since the facility management for various facilities in urban area are conducted by general managers who have poor knowledge for surveying technology, it is not easy to trace the exact location of the facility in a short time with the GIS map only by themselves in the field. In order to improve it, VRS-RTK or SBAS DGPS system integrated with UMPC and PDA which is uploaded GIS field software are being used recently however lot of difficulties are still existed with the GPS positioning in urban area due to the lack of visible satellites, no reception of correction data and multipath error by the interruption of the high buildings and houses etc. Therefore, in this study, we applied with Network DGPS system which allows better reception of satellite signal and correction data even in dense housing areas with the use of GNSS receiver and CDMA mobile phone. Based on the analysis of field data, it was confirmed that standard deviations of the Network DGPS positioning are 0.3 to 0.84m with a very high positioning rate even in dense housing areas. Therefore, it was concluded that the Network DGPS system could be used widely to fast and accurate positioning for various facilities management works in dense housing areas in the future.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.4
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• pp.9-21
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• 2008

In this paper, we propose a GNSS-based RF receiver, A high precision localization architecture, and a high sensitivity localization architecture in order to solve the satellite navigation system's problem mentioned above. The GNSS-based RF receiver model should have the structure to simultaneously receive both the conventional GPS and navigation information data of future-usable Galileo. As a result, it is constructed as the multi-band which can receive at the same time Ll band (1575.42MHz) of GPS and El band (1575.42MHz), E5A band (1207.1MHz), and E4B band (1176.45MHz) of Galileo This high precision localization architecture proposes a delay lock loop with the structure of Early_early code, Early_late code, Prompt code, Late_early code, and Late_late code other than Early code, Prompt code, and Late code which a previous delay lock loop structure has. As we suggest the delay lock loop structure of 1/4chips spacing, we successfully deal with the synchronization problem with the C/A code derived from inaccuracy of the signal received from the satellite navigation system. The synchronization problem with the C/A code causes an acquisition delay time problem of the vehicle navigation system and leads to performance reduction of the receiver. In addition, as this high sensitivity localization architecture is designed as an asymmetry structure using 20 correlators, maximizes reception amplification factor, and minimizes noise, it improves a reception rate. Satellite navigation system repeatedly transmits the same C/A code 20 times. Consequently, we propose a structure which can use all of the same C/A code. Since this has an adaptive structure and can limit(offer) the number of the correlator according to the nearby environment, it can reduce unnecessary delay time of the system. With the use of this structure, we can lower the acquisition delay time and guarantee the continuity of tracking.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.17-27
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• 2006

Car following model is a theory that examines changes of condition and interrelationship of acceleration deceleration. headway, velocity and so on closely based on the hypothesis that the Posterior vehicle always follows the preceding vehicle. Car following mode) which is one of the research fields of microscopic traffic flow was first introduced in 1950s and was in active progress in 1960s. However, due to the limitation of data gathering the research depression was prominent for quite a while and then soon was able to tune back on track with development in global positioning system using satellite and generalization of computer use. Recently, there has been many research studies using reception materials of global Positioning system(GPS). Introducing GPS technology to traffic has made real time tracking of a vehicle position possible. Position information is sequential in terms of time and simultaneous measurement of several vehicles in continuous driving is also practicable. Above research was focused on judging whether it is feasible to overcome the following model research by adopting the GPS reception device that was restrictively proceeded due to the limitation of data gathering. For practical judgment, we measured the accuracy and confidence level of the GPS reception devices material by carrying out a practical experiment. Car following model is also being applied in simulations of traffic flow analysis, but due to the difficulty of estimating parameters the basis of the above result. it is our goal to produce an accurate calibration of car following model's parameters that is suitable in this domestic actuality.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.613-621
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• 2016

This research connected network equipment, including CCTV, PAGA, IP-PBX, and Legacy, in order to enable the operation and configuration of internal IP-based network equipment in maritime plants and vessels, both in the field and from remote places, and to allow for the support of remotely controlling such equipment. It also realized an operating program for the integrated network equipment management system to enable the monitoring and control of equipment status, operation condition, and notifications from distant places. By applying the operating program to satellite stations and vessels sailing on the sea, a performance test was conducted to evaluate data loss and transmission/reception delay in the communication section between the land and vessels. As a result, this research verified the normal operation of CCTV control and of real-time monitoring and control of the network equipment, including PAGA, IP-PBX, and Legacy under the FBB and MVSAT environments. It was observed that the transmission of CCTV video images with a large volume of data as well as the transmission and reception of voice data were found to be slightly delayed, indicating the need to develop technology to compress and convert data for real-time transmission and reception.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.7
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• pp.1258-1270
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• 2000

A synthetic aperture radar (SAR) system is able to provide all-weather, day-and-night, high resolution imaging capability in the wide area of interest, and thus is extremely useful in surveillance for both civil and military applications. In this paper, the X-band high-resolution spaceborne SAR system design is described with the key design parameters for the mission and system requirement characterized by the small satellite platform. The SAR imaging mode design technique is presented, and the standard imaging mode design results are analyzed with respect to image quality performance. In line with the system requirement, X-band SAR payload and ground reception/processing subsystems are designed and the key design results are demonstrated with the outstanding performance characteristics. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance systems in the light weight, high performance and cost-effective points of view.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.57-62
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• 2011

The VLC (visible light communication) system is communication technology using visible rays (RGB) that come out in LED device. It is energy curtailment effect and possible in ubiquitous network service applications. Also, VLC system has the above advantage about that the communication throughout the whole room is enabled by high power lighting and lighting equipment with white colored LED which are easy to install and have good outward appearance. However, the signal detection performance for the receiver near the network of transmitter boundary is severely degraded and the transmission efficiency decreased due to the influence of the interference signal from the adjacent networks. In this paper, we propose an interference mitigation method with optical beamforming in VLC systems, and evaluate the reception performance. For the system BER, the proposed optical beamforming transmission demonstrates the performance enhancement compared to the not using the optical beamforming scheme, and up to about 5~6dB SNR performance gain is achieved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.7
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• pp.1529-1536
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• 2010

In this paper, we propose a Axially displaced ellipse gregorian antenna with conical feed horn operating in Ku-band. For fast searching satellite position, it is designed the sub-reflector rotates about $1.5^{\circ}$ tilted by the central axis. the curvature and feed center of the main-reflector and sub-reflector are optimized to achieve maximum antenna efficiency. The designed reflector antenna shows the gain of 33dB and the cross polarization level of less than -21dB and the side-lobe level of less than －14 dB at 12.2 GHz. and C/N ratio of 19dB is proved by reception experiment of Koreasat with fabricated antenna.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.6-12
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• 2014

The traditional broadcasting service has advanced into a smart media service with the help of communication network. in In the smart media ecosystem, a variety of innovative media services have been provided by new players. However, terrestrial broadcasting service companies seem to lag comparatively behind new players in spite of their powerful contents production capacity and stable terrestrial media delivery networks. In this paper, we design a proposed media platform based on a set-to-box (STB) with various new function for terrestrial ultra-high definition(UHD) broadcasting service. Also we suggest specific transmission network architecture and platform components for UHD broadcasting service. The proposed media platform is expected to increase the number of direct home reception and to enhance the right of the free-viewers which is one of the natural mission of terrestrial broadcasting company. Also it can provide some profit model of UHD terrestrial broadcasting service with new value-added services.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.63-68
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• 2012

The VLC (visible light communication) system is communication technology using visible rays (RGB) that come out in LED device. It is energy curtailment effect and possible in ubiquitous network service applications. Also, VLC system has the above advantage about that the communication throughout the whole room is enabled by high power lighting and lighting equipment with white colored LED which are easy to install and have good outward appearance. However, the signal detection performance for the receiver near the network of transmitter boundary is severely degraded and the transmission efficiency decreased due to the influence of the interference signal from the adjacent networks. In this paper, we propose an interference mitigation method with optical relay and optical beamforming scheme in VLC systems, and evaluate the reception performance. For the system BER, the proposed system demonstrates the performance enhancement compared to the not using the optical relay and optical beamforming scheme, and SNR performance gain and higher channel capacity is achieved.