• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.65-70
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• 2019

In recently, ship trajectory data consisting of ship position, speed, course, and so on can be obtained from the Automatic Identification System device with which all ships should be equipped. These data are gathered more than 2GB every day at a crowed sea port and used for analysis of ship traffic statistic and patterns. In this study, we propose a method to process ship trajectory data efficiently with distributed computing resources using MapReduce algorithm. In data preprocessing phase, ship dynamic and static data are integrated into target dataset and filtered out ship trajectory that is not of interest. In mapping phase, we convert ship's position to Geohash code, and assign Geohash and ship MMSI to key and value. In reducing phase, key-value pairs are sorted according to the same key value and counted the ship traffic number in a grid cell. To evaluate the proposed method, we implemented it and compared it with IALA waterway risk assessment program(IWRAP) in their performance. The data processing performance improve 1 to 4 times that of the existing ship trajectory analysis program.

• Journal of Aerospace System Engineering
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• v.13 no.5
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• pp.87-93
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• 2019

This study suggests the development of the ALE (Automatic Link Establishment) system for the long-range communication with a helicopter at the lands or marines by HF (High Frequency) radios. In the condition of LOS or more than 35 NM, the communication success rate is significantly lowered when the frequency is manually selected because of the reduced transmission power and various strong RF environment noise signals. In this paper, we make an effort to overcome the difficulties of choosing the optimal frequency when the operating frequency selection is manually operated in long-distance communication or LOS uncertain environment. The ALE system is designed based on the frequency analysis propagation software and is verified that the communication success rate is increased by applying the proposed system. The ALE system was applied to the helicopter system and the ground/flight test was conducted. As a result, the superiority and efficiency of the proposed system were verified.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.1011-1017
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• 2006

It is so sensitive that the wetland ecosystem very weak in artificial interference and environment change. wetlands are a transitional zone between aquatic and terrestrial ecosystems. This natural property is important to people and life. It is necessary to preservation and protection of the wetland with a countermeasure. we really need to Environment-GIS (E-GIS) and digital map which is included correct position, attribute data and range of the wetland. In this study, we take priority of making a database of wetland management. Moreover, we standardize a digital map production of wetland in our research and we improve accuracy of control survey using GPS surveying. The main purpose of this study is to suggest a pre-estimated wetland that have not yet been discovered. by analysing terrain, geological feature, a geographical distribution of plants and animals using GIS.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.617-636
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• 2015

The Mokpo coastal waters receive discharges from three artificial lakes(Youngsan, Youngam, Geumho) and other terrigenous freshwater inflows(streams, sewage treatment effluent, fresh groundwater), which exhibit very high concentrations of nutrients and/or organic matters. To understand spatial distributions of nutrients(DIN, DIP, DSi) and other water quality parameters(Chl-a, water temperature, salinity, DO, COD, SS), field surveys were conducted at 10 stations in the Mokpo harbor and adjacent estuaries on May, July, September, and November 2008 within 10 days following discharge events from artificial lakes. In this study, the freshwater flow rate influxed by the operation of sea dike sluice had significant influence on water qualities of the Mokpo coastal waters, although nutrient concentrations in other freshwater sources such as streams, sewage treatment effluent, and fresh groundwater were much higher. As a result of statistical analysis, DIN, COD, and Chl-a had a negative correlation with salinity. Therefore it was shown that discharge extents, time, and nutrients from the Youngsan lake were major impact factors dominating the spatial characteristics of nutrients and other water quality parameters in the Mokpo harbor and adjacent waters. However, despite non-discharge from the Youngsan Lake on September of this investigated period, it was observed that the nutrient addition was taking place in the lower layer of the estuary suggesting nutrient supply through different pathways. This result has emphasized the need to implement the combined assessment about the cumulative impacts on the Youngsan Estuary environment and ecosystem due to freshwater inputs derived from the artificial lakes as well as other terrigenous inflows, or benthic releases.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.3
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• pp.205-212
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• 2009

With an entry into force of OPRC-HNS on June 14th 2007, response system against any large scale accidents related to HNS is required to respond rapidly and effectively in a national scale, US national response system and national contingency plan for any chemicals in operation were analyzed to understand the characteristics of management system and response system for any HNS driven accidents in the Us. Main characteristics of the US system were well described as an unified information window and an integrated incident command system supported by response facilities, manpower and technical support from other response organizations through good cooperation. In general, response activities are conducted by private sectors, however, the government will take over response activities in case large scale accidents occur in the Us. Expected expenses for response activities are covered by a type of Superfund in the Us. Several applicable ways are proposed to enable NGO to participate in and reorganize response system in ROK, and are feasible in collaboration with other response organizations and private sectors in the aspects of equipment, technology and manpower, Based upon the above activities, it is desirable to reorganize domestic rules and/or regulations related to response measures in ROK.

• Spatial Information Research
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• v.18 no.4
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• pp.65-73
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• 2010

Recently, the importance of the ocean has been increasing internationally as the new source for mineral resources following the exhausted land resources that arc becoming scarce. On a long-term aspect, growth of nations by gaining competitiveness on marine resources was considered a paradigm. Because dominating the development right of marine resources came up as the main concern. South Korea has also been interested in marine resources and this is the reason why massive amounts of marine exploration data arc annually created through surveying and drilling around the Korean Peninsula. but the data has not been systematically managed very well because of its economic costs. Therefore, this research is mainly focused on systematical data managing methods. For Systematical data management. the exploration data is integrated and organized by using XML tables. This can be a systematical data management. because the methods release dependency between data and system, and it also enables to update existing data and renew the data. In the future, the constructed database from this study could definitely contribute to enhancing data management. As well, the developed system in this research can provide various spatial analysis and searching techniques to enable easier data provision of various exploration areas. Furthermore. this will be very useful to extend functions of the system and to adopt other types of DBMS. In addition, the spatial analysis and search function of location based service can be utilized through GIS. and it can support sustainable and systematic management in a long term.

• Spatial Information Research
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• v.11 no.2
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• pp.101-117
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• 2003

High resolution satellite image analysis has been recognized as an effective technique for monitoring local land-cover and atmospheric changes. In this study, a new high resolution map for land-cover was generated using both high-resolution IKONOS image and conventional land-use mapping. Fuzzy classification method was applied to classify land-cover, with minimum operator used as a tool for joint membership functions. In separateness analysis, the values were not great for all bands due to discrepancies in spectral reflectance by seasonal variation. The land-cover map generated in this study revealed that conifer forests and farm land in the ground and tidal flat and beach in the ocean were highly changeable. The kappa coefficient was 0.94% and the overall accuracy of classification was 95.0%, thus suggesting a overall high classification accuracy. Accuracy of classification in each class was generally over 90%, whereas low classification accuracy was obtained for classes of mixed forest, river and reservoir. This may be a result of the changes in classification, e.g. reclassification of paddy field as water area after water storage or mixed use of several classification class due to similar spectral patterns. Seasonal factors should be considered to achieve higher accuracy in classification class. In conclusion, firstly, IKONOS image are used to generated a new improved high resolution land-cover map. Secondly, IKONOS image could serve as useful complementary data for decision making when combined with GIS spatial data to produce land-use map.

• Spatial Information Research
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• v.21 no.6
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• pp.23-32
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• 2013

Recently, there has been much interest in the converged platform that enables the harmonized collection, integration, exchange, presentation and analysis of various kinds of marine information by using the ICT means. Regarding such the converged platform, S-100 standards including the international hydrographic data model are being announced and various studies have been published based on the S-100 standards. However, the existing studies have presented simple solutions for only given problems on the converged service of the maritime information. They could not propose the design concept of the converged platform which makes it possible to provide the standardized and integrated services among the geospatial data, the real-time maritime data, and the next ENC. Therefore, we propose design and implementation details of the converged service platform for the geospatial and the maritime data based on the S-100, WMS, WMTS, WPS, SOS standards. The proposed platform has advantages of supporting both the S-57 and the S-101, supporting the converged services of heterogeneous geospatial data and ENC data, supporting the real-time services of sensor data such as weather, AIS, and CCTV, and supporting the development of various kinds of maritime systems such as ECDIS, ECS, VTS based on the WebApp service. Finally, we proved the effectiveness of our proposed platform through the actual implementation of the converged service of geospatial data, S-101 data, and KWeather data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.7
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• pp.1021-1029
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• 2018

The marine buoys are operated in various domains, which are navigation route and danger maker, weather and environment monitoring, military strategical element, etc. If the marine buoy is damaged, there consumes many cost and time for recovery or replacement, because of severe environmental condition, and causes a risk possibility of secondary accident. In this paper, we developed an active monitoring and approach alarm providing system using trail cameras and AIS for protection for the marine buoys. To do this, we analyzed existing researches and similar systems, extracted requirements for enhancement, and designed the system architecture that applied the enhanced elements. The main considerations of system enhancement are: integration of AIS and trail cameras, adopting of phased alarm technique by approaching ships, applying of selective communication module, conducting the image processing of ships for providing alarm, and applying thermal cameras. After that, we developed the system using designed architecture and verified effectiveness of the system based on laboratory or field-level tests.

• Journal of Korea Port Economic Association
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• v.39 no.3
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• pp.33-46
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• 2023

The Autonomous ships are equipped with a function to judge and navigate the sea conditions on their own, so the job of the ship officer who operates it changes. The educational curriculum to nurture ship officer with the ability to operate and manage autonomous ships must also be changed. This study aimed to develop the curriculum for training autonomous ship officer by using the Delphi survey method suitable for predicting the uncertain future. Among the current 61 subjects for training ship officer identified in the Delphi survey, 32 subjects with high importance should be maintained in the training for autonomous ship officer, and subjects with low importance should be abolished or integrated into other subjects. These subjects were collectively referred to as 'general courses'. The expert panel of the Delphi survey suggested 42 items as new subjects, with 18 items of 'high', 14 items of 'middle', and 10 items of 'low'. Through in-depth analysis of these items by experts, 27 subjects were adjusted and three courses were proposed : 1)'Basic course(10 courses)' for developing basic capabilities such as basic theories for understanding advanced technology and information applied to autonomous ships, 2)'Job course(10 courses)' for practical competency directly related to autonomous ship operation, 3)'Intensive course(7 subjects)' for fostering land remote operators of autonomous ships. Since the introduction and spread of autonomous ships will progress rapidly, research to develop and supplement autonomous ship pilot training courses should be continued by reflecting the level of autonomous navigation of autonomous ships.