• 해양환경안전학회지
• /
• 제24권3호
• /
• pp.319-324
• /
• 2018

The collision problem is one of the design factors that must be carefully considered for the risk of collision occurring during the operation of ships and offshore structures. This paper presents the main results of the ship collision study, and its main goal is to analyze potential crash scenarios that may occur in the FLNG (Floating Liquefied Natural Gas) considering the likelihood and outcome. Consideration being given to vessels visiting the FLNG and surrounding vessels navigating around, such as functionally supported vessels and offloading carriers. The scope includes vessels visiting the FLNG facility such as in-field support vessels and off-loading carriers, as well as third party passing vessels. In this study, based on QRA (quantitative risk assessment), basic research methods and information on collision are provided. Based on the assumptions and methodologies documented in this study, it has been possible to clarify the frequency of collision and the damage category according to the type of visiting ship. Based on these results, the risk assessment results related to the collision have been derived.

• 산업공학
• /
• 제24권4호
• /
• pp.379-386
• /
• 2011

The importance of renewable energy technology is discussed and next generation power transmission networks, which is called the smart grid, are constructed in developed countries. However for construction and operation of the smart grid, it is required not only to develop the electrical power generation technologies and transmission equipments but also to study systematic analysis and optimization for design and operation of the smart grid. In this paper we study electrical power trade in the smart grid using operations research models and simulation methods. We also consider future electrical power exchange markets in Korea and build four scenarios and the related optimization and simulation models, which reflect electrical power transaction pricing strategies of stake-holders. We can also simulate electrical power exchange market and analyze the results of electrical power trading, which can give us some insights for future electrical power exchange market.

• 방송공학회논문지
• /
• 제24권7호
• /
• pp.1259-1265
• /
• 2019

Maintaining timing relationships among packets in a single media stream or between packets from different media streams is an essential criterion in MMT system. It is the function of the synchronization and de-jittering algorithms to re-adjust timing relationship between the MMT packets to assure synchronized playback. Thus, delivery of time constrained MPEG media on time, according to their temporal requirements, is an important goal of MMT. For this purpose MMT needs to specify syntax and semantics of a timing model to be used by the delivery functions. In this paper, we propose a proper timestamp-related header format for MMT delivery timing model to support media synchronization in various delivery scenarios including hybrid delivery.

• 전기전자학회논문지
• /
• 제24권2호
• /
• pp.669-672
• /
• 2020

본 논문에서는 사이버물리시스템에 대한 사이버공격 경호위협 중 지능형건물관리시스템(IBS)을 중심으로 발생할 수 있는 사이버공격의 특성과 주요 위협 시나리오를 분석했다. 분석한 결과 일반적으로 예측이 가능한 위협에 대해 공격의 성공 가능성을 낮추는 것이 현실적인 공격의 대응방법이 되는 것으로 판단하였고, 구체적인 대응방안으로는 다계층 방어시스템의 적용과 보호대상 시스템에 대한 사이버안전진단 사전점검, 이동식 보안관제 시스템과 같은 방안들을 제시하였다.

• Journal of Information Technology Applications and Management
• /
• 제24권2호
• /
• pp.81-96
• /
• 2017

Forecasting long-term mobile service demand is inevitable to establish an effective frequency management policy despite the lack of reliability of forecast results. The statistical forecasting method has limitations in analyzing how the forecasting result changes when the scenario for various drivers such as consumer usage pattern or market structure for mobile communication service is changed. In this study, we propose a dynamic model of the mobile communication service market using system dynamics technique and forecast the future demand for long-term mobile communication subscriber based on the dynamic model, and also experiment on the change pattern of subscriber demand under various scenarios.

• 한국컴퓨터정보학회논문지
• /
• 제24권8호
• /
• pp.95-103
• /
• 2019

According to the Statistics Korea in 2017, the 10 leading causes of death contain a cardiac disorder disease, self-injury. In terms of these diseases, urgent assistance is highly required when people do not move for certain period of time. We propose an unusual event detection algorithm to identify abnormal user behaviors using dust, vision and activity sensors in their houses. Vision sensors can detect personalized activity behaviors within the CCTV range in the house in their lives. The pattern algorithm using the dust sensors classifies user movements or dust-generated daily behaviors in indoor areas. The accelerometer sensor in the smartphone is suitable to identify activity behaviors of the mobile users. We evaluated the proposed pattern algorithms and the fusion method in the scenarios.

• 한국컴퓨터정보학회논문지
• /
• 제24권6호
• /
• pp.67-72
• /
• 2019

This paper proposes a computer vision-based banknote recognition system intended to assist the blind. This system is robust and fast in recognizing banknotes on videos recorded with a smartphone on real-life scenarios. To reduce the computation time and enable a robust recognition in cluttered environments, this study segments the banknote candidate area from the background utilizing a technique called Pixel-Based Adaptive Segmenter (PBAS). The Speeded-Up Robust Features (SURF) interest point detector is used, and SURF feature vectors are computed only when sufficient interest points are found. The proposed algorithm achieves a recognition accuracy of 98%, a 100% true recognition rate and a 0% false recognition rate. Although Korean banknotes are used as a working example, the proposed system can be applied to recognize other countries' banknotes.

• 한국컴퓨터정보학회논문지
• /
• 제24권5호
• /
• pp.59-66
• /
• 2019

According to the KT telecommunication statistics, people stayed inside their houses on an average of 11.9 hours a day. As well as, according to NSC statistics in the united states, people regardless of age are injured for a variety of reasons in their houses. For purposes of this research, we have investigated an abnormal event detection algorithm to classify infrequently occurring behaviors as accidents, health emergencies, etc. in their daily lives. We propose a fusion method that combines three classification algorithms with vision pattern, audio pattern, and activity pattern to detect unusual user events. The vision pattern algorithm identifies people and objects based on video data collected through home CCTV. The audio and activity pattern algorithms classify user audio and activity behaviors using the data collected from built-in sensors on their smartphones in their houses. We evaluated the proposed individual pattern algorithm and fusion method based on multiple scenarios.

• 한국정보통신학회논문지
• /
• 제24권2호
• /
• pp.337-339
• /
• 2020

Speed-run is a gameplay style in what the player tries to finish the game as quickly as possible. The purpose of this study is to observe and analyze the difference between a normal player and a speed runner in a speed run to better understand their interaction with the game and to extrapolate the applications of the analyzed frameworks to scenarios that extent normal gameplay. For this purpose, MDA (Mechanic, Dynamic, Aesthetics) and DPE (Experience, Design, Play) were used. As a result, the average player was found to focus on aesthetics or affects while the speed runner focused on mechanics and gameplay.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제24권2호
• /
• pp.111-130
• /
• 2021

This exploratory study focuses on analyzing three mathematics textbooks in Germany, Singapore and South Korea to reveal similarities and differences in their introductions of fraction concepts. Findings reveal that all three countries' textbooks introduce fraction concepts predominantly by using pictorial representations such as area models, but the introductions of multiple fraction constructs vary. The Singaporean and South Korean textbooks predominantly used a part-whole construct to introduce fractional concepts while the German textbook introduced various constructs sequentially in the first pages using several scenarios from different real-life situations. The findings were represented using visual representations, which we called textbook signatures. The textbook signatures provided configurations of the textbook features across the three countries. At the end of paper, we share insights and limitations about the use of textbook signatures in the research on textbook analysis.