• Journal of Radiation Protection and Research
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• v.44 no.3
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• pp.118-126
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• 2019

Background: Government conducts environmental radioactivity surveillance for verification purpose around nuclear facilities based on the Nuclear Safety Law and issues a surveillance report every year. This study aims to evaluate the short and the long-term fluctuation of radionuclides detected above MDC and their origins using concentration ratios between these radionuclides. Materials and Methods: Sample media for verification surveillance are air, rainwater, groundwater, soil, and milk for terrestrial samples, and seawater, marine sediment, fish, and seaweed for marine samples. Gamma-emitting radionuclides including $^{137}Cs$, $^{90}Sr$, Pu, $^3H$, and $^{14}C$ are evaluated in these samples. Results and Discussion: According to the result of the environmental radioactivity verification surveillance in the vicinity of nuclear power facilities in 2017, the anthropogenic radionuclides were not detected in most of the environmental samples except for the detection of a trace level of $^{137}Cs$, $^{90}Sr$, Pu, and $^{131}I$ in some samples. Radioactivity concentration ratios between the anthropogenic radionuclides ($^{137}Cs/^{90}Sr$, $^{137}Cs/^{239+240}Pu$, $^{90}Sr/^{239+240}Pu$) were similar to those reported in the environmental samples, which were affected by the global fallout of the past nuclear weapon test, and Pu atomic ratios ($^{240}Pu/^{239}Pu$) in the terrestrial sample and marine sample showed significant differences due to the different input pathway and the Pu source. Radioactive iodine ($^{131}I$) was detected at the range of < $5.6-190mBq{\cdot}kg-fresh^{-1}$ in the gulfweed and sea trumpet collected from the area of Kori and Wolsong intake and discharge. A high level of $^3H$ was observed in the air (Sangbong: $0.688{\pm}0.841Bq{\cdot}m^{-3}$) and the precipitation (Meteorology Post: $199{\pm}126Bq{\cdot}L^{-1}$) samples of the Wolsong nuclear power plant (NPP). $^3H$ concentration in the precipitation and pine needle samples showed typical variation pattern with the distance and the wind direction from the stack due to the gaseous release of $^3H$ in Wolsong NPP. Conclusion: Except for the detection of a trace level of $^{137}Cs$, $^{90}Sr$, Pu, and $^{131}I$ in some samples, anthropogenic radionuclides were below MDC in most of the environmental samples. Overall, no unusual radionuclides and abnormal concentration were detected in the 2017's surveillance result for verification. This research will be available in the assessment of environment around nuclear facilities in the event of radioactive material release.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.41-45
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• 2006

From the 1978 Seasat synthetic aperture radar(SAR) to present systems, spaceborne SAR has demonstrated the capability to image the Earth's ocean and land features over broad areas, day and night, and under most weather conditions. The application of SAR for surveillance of commercial fishing grounds can did in the detection of illegal fishing activities and provides more efficient use cf limited aircraft or patron craft resources. In the area of vessel traffic monitoring for commercial vessels, Vessel Traffic Service (VTS) which uses the ground-based radar system has some difficulties in detecting moving ships due to the limited detection range cf about 10 miles. This paper introduces the field testing results of ship detection by RADARSAT SAR imagery, and proposes a new approach for a Vessel Monitoring System(VMS), including VTS, and SAR combination service.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.127-132
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• 2007

From the 1978 Seasat synthetic aperture radar(SAR) to present systems, spaceborne SAR has demonstrated the capability to image the Earth's ocean and land features over broad areas, day and night, and under most weather conditions. The application of SAR for surveillance of commercial fishing grounds can aid in the detection of illegal fishing activities and provides more efficient use of limited aircraft or patrol craft resources. In the area of vessel traffic monitoring for commercial vessels, Vessel Traffic Service (VTS) which uses the ground-based radar system has some difficulties in detecting moving ships due to the limited detection range of about 10 miles. This paper introduces the field testing results of ship detection by RADARSAT SAR imagery, and proposes a new approach for a Vessel Monitoring System(VMS), including VTS, and SAR combination service.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.90-95
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• 2015

This paper proposes the new adaptive gain control monitoring sensor for the marine IT system. The marine IT system sensors make it possible to conduct search missions, record climate changes, provide pollution control, study marine life, conduct survey missions, tactical surveillance, and predict natural disturbances in the ocean. In this paper, the adaptive gain control circuit which changes its parameters according to the ambient noise situation for obtaining the precise location information of marine IT system sensor is developed and analyzed. The performance characteristics for ensuring the precise location information of marine system sensor is presented and analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the monitoring of the marine system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.12
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• pp.84-89
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• 2014

This paper proposes the new multiple signal processing monitoring sensor for the marine installation. The recent marine technology is focused on underwater sensors and underwater sensor networks in order to measure, monitor, surveillance of and control of underwater environments. For these marine applications to be available, however, the provision of precise location information using monitoring sensor is essential. In this paper, the multiple signal processing circuit for obtaining the precise location information of marine installation sensor is developed and analyzed. The performance characteristics for obtaining the location information of marine installation sensor is analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the monitoring for the marine installation.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.4
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• pp.350-357
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• 2015

Many countries have been developing and operating an underwater surveillance system in order to protect their oceanic environment from infiltrating hostile marine forces which intend to lay mines, conduct reconnaissance and destroy friendly ships anchored at the harbor. One of the most efficient methods to detect unidentified submarine approaching harbor is sensing variation of magnetism of target by magnetic sensors. This measurement system has an advantage of high possibility of detection and low probability of false alarm, compared to acoustic sensors, although it has relatively decreased detection range. The contents of this paper mainly cover the analysis of possible effectiveness of magnetic sensors. First of all, environmental characteristics of surveillance area and magnetic information of simulated targets has been analyzed. Subsequently, a signal processing method of separating target from geomagnetic field and methods of estimating target location has been proposed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.2 s.21
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• pp.55-60
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• 2004

As GNP increases, many peoples need the seafood with high quality. In Korea, aquaculture is one of major incomes for fishing households and records $50.6\%$ of total incomes for domestic fishery. The loss of aquaculture farm due to thievery at sea increases every year. In this research, we propose the system model for development of radar surveillance system, which protects aquaculture farms. For the proposed system, general requirements are described Our system is cost-effective when it is applied to domestic fishing households.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.7
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• pp.1026-1031
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• 2002

In this Paper, We analysed the technical characteristics of a automatic identification system that will introduce in aviation and marine radio stations. IMO's Marine Safety Committee approved revision of chapter V of the Safety of Life at Sea(SOLAS) Convention in 73rd meeting. According to this, AIS will become a mandatory carriage requirement by 01 July 2002. AIS as a surveillance system continuously receives its own position from the GNSS and then repeatedly broadcasts it on a W:.u data link for avoiding traffic conflicts and possible disasters. VHF data link is organized so that a specified number of time slots make up a repeatable frame. Each radio station can autonomously allocate and deallocate slots within the frame using selection algorithm which is called SOTDMA(Self-Organized Time Division Multiple Access). The results can be an aid in the continued of understanding technical characteristics for AIS as a broad surveillance system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.187-191
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• 2002

In this paper, We analysed the technical characteristics of a automatic identification system that will introduce in aviation and marine radio stations. IMO's Marine Safety Committee approved revision of chapter V of the Safety of Life at Sea(SOLAS) Convention in 73rd meeting. According to this, AIS will become a mandatory carriage requirement by 01 July 2002. AIS as a surveillance system continuously receives its own position from the GNSS and then repeatedly broadcasts it on a VHF data link for avoiding traffic conflicts and possible disasters. VHF data link is organized so that a specified number of time slots make up a repeatable frame. Each radio station can autonomously allocate and deallocate slots within the frame using selection algorithm which is called SOTDMA(Self-Organized Time Division Multiple Access). The results can be an aid in the continued of understanding technical characteristics for AIS as a broad surveillance system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.1-8
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• 2013

This study focuses on a ship detection and tracking method using Frequency Modulated Continuous Wave (FMCW) radar used for horizontal surveillance. In general, FMCW radar can play an important role in maritime surveillance, because it has many advantages such as low warm-up time, low power consumption, and its all weather performance. In this paper, we introduce an effective method for data and signal processing of ship's detecting and tracking using the X-band radar. Ships information was extracted using an image-based processing method such as the land masking and morphological filtering with a threshold for a cycle data merged from raw data (spoke data). After that, ships was tracked using search-window that is ship's expected rectangle area in the next frame considering expected maximum speed (19 kts) and interval time (5 sec). By using this method, the tracking results for most of the moving object tracking was successful and those results were compared with AIS (Automatic Identification System) for ships position. Therefore, it can be said that the practical application of this detection and tracking method using FMCW radar improve the maritime safety as well as expand the surveillance coverage cost-effectively. Algorithm improvements are required for an enhancement of small ship detection and tracking technique in the future.