• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.1-9
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• 2020

Acritical function of a nation is to protect its people's lives and properties from natural disasters such as a drought. A drought affects many aspects of human life, including social, economic, and industrial activities. Approximately 75.7% of reservoirs in Korea are over 50 years old.Sedimentation over the years may have caused a situation where storage capacity of the reservoirs is no longer sufficient and compliant with the original reservoir specifications. This study analyzes storage capacities for ten aged reservoirs using the autonomous navigation USV. It compares these capacities with sediment estimated by conventional empirical equations. Comparisons were made to the original specifications for the reservoirs.Storage capacity of six reservoirs decreased in a range between 16.2%-55.3% and storage capacity of 4 reservoirs increased in a range between 1.5%-380.2%. This data was compared to data derived from estimating sediment by empirical equations. Yoon's equation(1982) appeared more accurate than Sur's equation(1988) in Uhlinzi and Yongpo reservoirs, and Sur's equation(1988), however, appeared more accurate than Yoon's equation in Daegok, Ugok2 and Ochi reservoirs. The significant ranges of sedimentation shown in this study suggest that it is worth continuously surveying reservoirs to ensure their efficient management and operation.

• Spatial Information Research
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• v.20 no.3
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• pp.83-93
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• 2012

Recent environmental concerns have made interest in environment-friendly transportation means such as walking, biking, and public transportation. However, since it is difficult to move long distance by walking or biking, their scope of application is rather limited. On the other hand, public transportation can solve traffic congestion, a recent social issue, though its usability may depend on its time schedule. Currently available information services on public transportation in the Web do not reflect well such traits of the public transportation; thus, in some cases, they may provide wrong information to end users. To solve such problems and provide information based on timetable of public transportations, this paper proposes a STP(Space Time Point) data model. Unlike existing space-time data models, this model recognizes the bottommost element of an object as a point and structures these points in hierarchical way to define an object. In particular, It can make it possible to implement a variety of dynamic spatial objects changing object information according to time. An objective of this study is to design a STP model for bus and subway based on timetables of public transportation in Daejeon area and builds a system to provide path navigation. With the designed navigation function, a path from the Daejeon National Cemetery to Hannam University was searched by time slot. The result showed that the system provided different paths by time, as the system guided different paths when bus operation was limited in midnight. As existing data model could not provide such results, it is confirmed that the system can provide path navigation based on real-time traffic information. It is expected that based on such functionality, it is possible to provide additional functionalities by applying diverse data models such as real-time transport information or traffic history information.

• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.295-301
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• 2009

Recently, considerable number of bridges crossing over navigable waterways are under construction for the connection of coastal islands with mainland and the optimization of logistic system However, the most planned bridges have been initiated without paying much attention to ships safety aspects but with great emphasis on the economic factors, it has often been confronted with difficult social issues arising from opposing views and conflicts between building bodies and affected port users. The main reason for the conflicts is the lack of standards or specifications on the bridge design The proper location and scale of sea bridges are suggested in this paper considering fairway design criteria of both domestic and foreign countries, status analysis on the designs of existing and planned bridges, investigation findings of bridge-related marine accidents, the views of pilots and navigators collected through questionnaire. Since there is no general domestic or international design rules on bridge's scale, the design standards proposed in this paper may be useful at initial design stage of bridge.

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.33-41
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• 2021

In the last 5 years, a total of 567 accidents of operating vessels occurred under the influence of alcohol at sea, most of which occurred in fishing boats. Accidents caused by operating vessels under the influence of alcohol at sea are causing human and physical damages. There were 69 accidents caused by operating vessels under the influence of alcohol, leading to five deaths and one missing. The social damage due to operating vessels under the influence of alcohol is also increasing. Under the current law, punishment is given lightly compared to the seriousness of violation. In order to prevent the recurrence of accidents caused by operating vessels under the influence of alcohol, cases in Korea need to be analyzed. Regulations on the crackdown in foreign countries were compared to those in Korea and reviewed. In addition, risks of operating vessels under the influence of alcohol should be provided to ship workers while improving related laws and systems. In addition, efforts should be made to reduce the number of accidents due to operating vessels under the influence of alcohol by strengthening crackdowns on ships at sea so that accidents caused by operating vessels under the influence of alcohol could be prevented in advance in the future.

• The Journal of Korean Association of Computer Education
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• v.9 no.1
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• pp.19-28
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• 2006

In this paper, we have developed electronic textbooks for social studies centering on contents of a public educational process so that primary schools can use them as a text book. Also, we conducted a survey to find out how teachers perceived electronic textbooks in respect to site accessibility and utility, instructional design, progress of lesson, validity and accuracy of learning content, interface design, and web-based multimedia. In this paper, we presented a new model for electronic textbooks development, which is expected to be useful in developing electronic textbooks as a main text book, unlike other existing models. We applied the navigation utilizing book metaphors to the user interface, on the basis of the results from the analysis of the existing electronic textbooks. In addition, we provided affluent multi-media materials as well as hyperlink, a strong point of on-lines. Experimental results show that the academic achievement was high in knowledge-understanding areas and functional areas in the perspective of academic achievements of the learners.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.806-816
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• 2011

Interest about social security has recently increased in favor of safety for infrastructure. In addition, advances in computer vision and pattern recognition research are leading to video-based surveillance systems with improved scene analysis capabilities. However, such video surveillance systems, which are controlled by human operators, cannot actively cope with dynamic and anomalous events, such as having an invader in the corporate, commercial, or public sectors. For this reason, intelligent surveillance systems are increasingly needed to provide active social security services. In this study, we propose a core technique for intelligent surveillance system that is based on swarm robot technology. We present techniques for invader enclosing using swarm robots based on multiple distributed object environment. The proposed methods are composed of three main stages: location estimation of the object, specified object tracking, and decision of the cooperative behavior of the swarm robots. By using particle filter, object tracking and location estimation procedures are performed and a specified enclosing point for the swarm robots is located on the interactive positions in their coordinate system. Furthermore, the cooperative behaviors of the swarm robots are determined via the result of path navigation based on the combination of potential field and wall-following methods. The results of each stage are combined into the swarm robot-based invader-enclosing technique on multiple distributed object environments. Finally, several simulation results are provided to further discuss and verify the accuracy and effectiveness of the proposed techniques.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.337-339
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• 2015

As much interest recently location based service, a study to analyze the movement patterns of the users from getting a lot of large amounts of data collected from a GPS installed in the smart device. Also it is recorded in the log file in the form of day-to-day personal computer, the development of a variety of a smart phone, a black box, and navigation. This data is collected by the user have been developed a variety of personalized services. In this paper, using the black box camera, such as the vehicle to form a social network platform that broadcasts real-time traffic utilization real-time video information.

• Journal of Digital Convergence
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• v.16 no.2
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• pp.139-149
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• 2018

Since the 17th century, international trade has increased as a result of the development in the navigation skills. Recently, maritime transport, compared to other modes, is used more than 70% worldwide by shippers and ports, and it also has become essential in international trade. Most researchers focused only on port development, in topics like ensuring depth of water, port competition and port governance, but have left some topics undone, such as environment, ecosystem and balanced development. Therefore, this study provides insight to the academic world in port research using SNA (Social Network Analysis). The result of the SNA study shows that Baltic Sea ports researchers have focused on "Shipping", "Marine ecosystem"and "Pollution". The implications of this study are: first, the environment has become a main issue in the research field; second, the results suggest focusing on the main keywords from the keyword network. This study has some limitations such as excluding domestic journals and focusing in the recent 10 years.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.5
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• pp.179-186
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• 2014

Current networks such as social network, web page link, traffic network are big data which have the large numbers of nodes and edges. Many applications such as social network services and navigation systems use these networks. Since big networks are not fit into the memory, existing in-memory based analysis techniques cannot provide high performance. Frontier-Expansion-Merge (FEM) framework for graph search operations using three corresponding operators in the relational database (RDB) context. FEM exploits an index table that stores pre-computed partial paths for efficient shortest path discovery. However, the index table of FEM has low hit ratio because the indices are determined by distances of indices rather than the possibility of containing a shortest path. In this paper, we propose an method that construct index table using high degree nodes having high hit ratio for efficient shortest path discovery. We experimentally verify that our index technique can support shortest path discovery efficiently in real-world datasets.

• Journal of Multimedia Information System
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• v.4 no.3
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• pp.123-144
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• 2017

Personalized media includes user-targeted and user-generated content (UGC) exchanged through social media and interactive applications. The increased consumption of UGC presents challenges and opportunities to multimedia information systems. We work towards modeling a deep structure for content networks. To gain insights, a hybrid practice with Media Framework (MF) is presented for network creation of personalized media, which leverages the authoring methodology with user-generated semantics. The system's vertical integration allows users to audition their personalized media networks in the context of a global system network. A navigation scheme with dynamic GUI shifts the interaction paradigm for content query and sharing. MF adopts a multimodal architecture anticipating emerging use cases and genres. To model diversification of platforms, information processing is robust across multiple technology configurations. Physical and virtual networks are integrated with distributed services and transactions, IoT, and semantic networks representing media content. MF applies spatiotemporal and semantic signal processing to differentiate action responsiveness and information responsiveness. The extension of multimedia information processing into authoring enables generating interactive and impermanent media on computationally enabled devices. The outcome of this integrated approach with presented methodologies demonstrates a paradigmatic shift of the concept of UGC as personalized media network, which is dynamical and evolvable.