• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.462-469
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• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.170-172
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• 2019

최근 우리나라에서는 해양사고의 효과적인 예방을 위하여 구축 중인 한국형 e-Navigation SV20-선내시스템 원격모니터링 서비스에서는 복원성, 화재, 침수, 과도경사, 항해장비의 이상과 같이 선박의 안전 운항과 직접적으로 관련이 있는 선박의 센서들을 수집, 분석하여 이상 상태와 긴급상황을 자동으로 식별하여 안전운항을 지원하는 기능이 있다. IMO 선박안전관리 시스템의 경우 선원의 인적 과실에 의한 해상에서 안전 및 해양환경 보호를 위한 핵심 요소로서 우리나라는 SOLAS 협약 제9장(선박의 안전운항을 위한 관리)및 ISM CODE를 1999년 2월 해사안전법에 수용하여 2002. 7. 1.부터 단계적으로 시행하고 있다. 이 연구에서는 이 둘의 융합 개념의 기술적 결합을 통한 체계적이고 자동화적으로 선박에서의 안전관리 능력을 제고하여 안전 사고 발생을 최소화 할 수 있는 여러 가지 시스템과 더불어 사고 발생시 효율적으로 대응할 수 있는 표준 토폴로지 기반 UI 및 항차 기반 위기대응 가이던스를 개발 하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.605-606
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• 2016

Recently utilizing various wearable device has been going research to provide new services. Conventional wearable devices provide a service to a user by measuring the biological information. However, by measuring the biometric information such a situation the value of the algorithm, the user state and insufficient technology. In this paper, by utilizing an acceleration sensor and the rate sensor set a threshold for measuring the biological information, and heart rate and movement in order to solve this problem. And it proposes an algorithm to cope with the user's status and identifying emergency situations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1771-1776
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• 2017

Recently, IoT(Internet of Things) has been utilized in various fields provide a service to users by configuring a smart environment in a particular place. However, since the existing system does not change the operation and the task of the device according to the change of the surrounding environment, the user must operate passively every time the environment and the situation change. In this paper, we propose Situation-specific Task Control System based on real-time data classification. Sensor data is sent to the server and classified into real-time and non-real-time data, and then inserted into the decision tree to identify tasks according to the situation. In addition, the danger situation is divided into two stages, such as gas leakage and fire, and a warning message is sent. Therefore, it is possible to reduce the waste of electric power and the occurrence of malfunction, and it can be expected that the service with increased work efficiency will be provided.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.25-40
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• 2019

Many companies are executing big data analysis and utilization projects to legitimize the development of new business areas or conversion of management or technical strategies. In Korea and abroad, however, such projects are failing because they are not completed within specified deadlines, which is not unrelated to the current situation in which the knowledge base for big data project risk management from an engineering perspective is grossly lacking. As such, the current study analyzes the risk factors of big data implementation and utilization projects, in addition to finding risk factors that are highly important. To achieve this end, the study extracts project risk factors via literature review, after which they are grouped using affinity methodology and sifted through expert surveys. The deduced risk factors are structuralize using factor analysis to develop a table that categorizes various types of big data project risk factors. The current study is significant that in it provides a basis for developing basic control indicators related to risk identification, risk assessment, and risk analysis. The findings from the study contribute greatly to the success of big data projects, by providing theoretical basis regarding efficient big data project risk management.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.604-611
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• 2016

Drone, which refers to unmanned aerial vehicles (UAV), industries are improving rapidly and exceeding existing level of remote controlled aircraft models. Also, they are applying automation and cloud network technology. Recently, the ability of drones can bring serious threats to public safety such as explosives and unmanned aircraft carrying hazardous materials. On the purpose of reducing these kinds of threats, it is necessary to detect these illegal drones, using acoustic feature extraction and classifying technology. In this paper, we introduce sound feature vector extraction method by harmonic feature extraction method (HLA). Feature vector extraction method based on HLA make it possible to distinguish drone sound, extracting features of sound data. In order to assess the performance of distinguishing sounds which exists in outdoor environment, we analyzed various sounds of things and real drones, and classified sounds of drone and others as simulation of each sound source.

• Korean Journal of Construction Engineering and Management
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• v.12 no.4
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• pp.139-148
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• 2011

u-City projects are different with the existing urban development projects progress via convergence with IT technology. Therefore, it inheres many risk factors more than the existing development projects as including more complexity and variety. The risk management system to systematically manage those risks which get identified and quantified is required. Especially, the planning phase that is appeared the various forms has a large effect on the success of the business. However, the management of risk factors remains in the passive form. So the problems on u-City project in the planning phase and risk factors of existing development business were analyzed for the continuous growth and the successful performance of u-City project, and those risk factors was identified and quantified by using statistical technique. In the results of it, the core risk factors were obtained through which way and the basis for the effective risk management in u-City business is provided.

• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.277-282
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• 2018

Recently, the Vessel Traffic Service (VTS) coverage has expanded to include coastal areas following the increased attention on vessel traffic safety. However, it has increased the workload on the VTS operators. In some cases, when the traffic volume increases sharply during the rush hour, the VTS operator may not be aware of the risks. Therefore, in this paper, we proposed a new method to recognize ship movement anomalies automatically to support the VTS operator's decision-making. The proposed method generated traffic pattern model without any category information using the unsupervised learning algorithm.. The anomaly score can be calculated by classification and comparison of the trained model. Finally, we reviewed the experimental results using a ship-handling simulator and the actual trajectory data to verify the feasibility of the proposed method.

• Journal of Advanced Navigation Technology
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• v.20 no.2
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• pp.148-154
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• 2016

Safety assessment is necessary to develop safety related CNS/ATM system. It includes functional hazard assessment (FHA), effects eliciting system safety requirement that mitigates system's hazardous event. This paper performs a case study for functional hazard assessment of A-SMGCS. To do this, related A-SMGCS studies from Eurocontrol and EMMA are surveyed, and assessment schemes of functional hazard from Eurocontrol and EMMA are combined. Not only FHA scope but also several assumptions for FHA are defined for Incheon airport. 29 hazards are identified and their severities are assessed. And exposures and safety objectives from hazards are analyzed using event tree analysis method. Differences between result of this study and result of EMMA are analysed, and assessment results in this study are also reviewed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.268-277
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• 2019

Flight test systems should monitor various conditions in real time during flight tests and take safety measures in an emergency. The importance of ensuring test safety increases in more complicated and wider test environments. Also, due to the transition of wartime operational authority, many guided missile systems must be developed simultaneously. Early deployment and budget reduction by shortening the development and T&E periods are also necessary. Consequently, the risk of flight tests under the circumstance of inefficient test resources is increasing. To address this deficiency, a flight test system model using SysML was proposed in this study. The method of designing and verifying the test system is based on the agile shift left testing methodology of advanced T&E labs and utilizing a system reference model in the aerospace field. Through modeling and simulation analysis, early identification and correction of faults resulting from inconsistent test requirements can mitigate the risk of delays during the T&E phase of flight tests. Also, because the flight test system model was constructed using SysML, it can be applied to test various guided missile systems.