• Fire Science and Engineering
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• v.8 no.1
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• pp.47-52
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• 1994

이 논문은 설계상의 안전 및 완전한 정량적 위험성 평가에 의해 맞추는 것이 가능한 여러가지 방법(QRA: Quantitative risk analysis)에 촛점을 두면서, 위험성 평가의 방법론의 간략한 개요를 소개하고 있다. QRA의 결과는 단독 위험 및 그룹 혹은 사회적 위험으로써 보통 소개된다. 계산된 단독 risk는 자주 단독 위험 graph(IRG : Individual risk graph)와 단독 위험등고선(IRC : Individual risk contours)의 형으로 나타낸다. IRG와 IRC는 예를 들면 다음과 같은 사고의 시나리오로 계산된다. : 여러가지 기상조건 하에서 2kg/s의 암모니아의 유출을 1800s로 한다. 이 예는 그래프가 곡선의 상승을 나타내는 것이 확실하다. 마지막으로, QRA는 예를 들어서 토지이용계획 등에 유용한 수단으로 될 수 있다고 할 수 있다. 한편 화학플랜트의 안전에 대해서는, 위험성 평가를 위해 다른 방법이 유효하며, 불가피하다.

• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.196-202
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• 2024

The ability to understand given environments and plan a sequence of actions leading to goal state is crucial for personal service robots. With recent advancements in deep learning, numerous studies have proposed methods for state representation in planning. However, previous works lack explicit information about relationships between objects when the state observation is converted to a single visual embedding containing all state information. In this paper, we introduce graph-based state representation that incorporates both object and relationship features. To leverage these advantages in addressing the task planning problem, we propose a Graph Neural Network (GNN)-based subgoal prediction model. This model can extract rich information about object and their interconnected relationships from given state graph. Moreover, a search-based algorithm is integrated with pre-trained subgoal prediction model and state transition module to explore diverse states and find proper sequence of subgoals. The proposed method is trained with synthetic task dataset collected in simulation environment, demonstrating a higher success rate with fewer additional searches compared to baseline methods.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.413-421
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• 2005

Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristics method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.447-455
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• 2005

Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristic method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.143-149
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• 2021

This paper proposes length rate measurement for relative efficiency that is a core of data envelopment analysis(DEA). It has been said that the linear programming(LP) is a unique method to get the relative efficiency. This method has drawback that applies fractional LP focusing on each DMU in turn. This paper draws bi-dimensional input-output relational graph and distinguishes between efficient and inefficient DMU. The relative efficiency of inefficient DUM is solve using length rate measurement. As a result of various experimental data, the LP shows mistake of application, but this method gets the correct relative efficiency at all times. Also, this method only gets the relative efficiency for only inefficient DMUs without efficient DUMs that already achieved 100% efficiency. This method solves the relative efficiency of inefficient DUM draws the line to efficient frontier and decides the reference set easily.

• Journal of The Korean Association For Science Education
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• v.43 no.3
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• pp.225-236
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• 2023

This study investigated the characteristics of pre-service elementary teachers' TPACK in science lesson planning using VR/AR content based on epistemic network analysis (ENA). Seven TPACK coding elements were derived inductively based on the existing TPACK framework. Then, the pre-service elementary teachers' discourse in science lesson planning was coded according to the seven TPACK coding elements and analyzed using the ENA Web Tool. The discourses of the two groups were analyzed and compared, and the differences between the two groups, which the researchers analyzed qualitatively, were clearly shown on the ENA graph. Based on these findings, the researchers argued that the ENA method is a useful research tool for analyzing the complex interactions of technology knowledge (TK), content knowledge (CK), and pedagogical knowledge (PK), which is different from previous TPACK research. Also, the researchers discussed the implications for the TPACK competency development of pre-service teachers by comparing the characteristics of the two groups' discourse.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1189-1194
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• 2016

While increasing the convenience of life is a high population BMI (Body Mass Index) is increasing rapidly. Accordingly, the development of the monitoring system to manage and prevent obesity is the time that is required. But most of the monitoring system, the less information it receives management and show to have only simple information calculated this was a low efficiency problem. Also Users with normal and disease Management accuracy is low. In this paper shows the user in a graph of Body Mass Index, BMR (Basal metabolic rate) divided by grade increased accuracy for users to manage their own. Also represented by recovery with exercise machines you used, select a balanced movement mechanism, expressed as a Kcal consumption. If the graph recent data show only increased the visibility. We developed an efficient web-based monitoring system for design a exercise plan.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.335-341
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• 2017

This paper proposes an image-processing algorithm for inspecting double-cut defects in the motor shaft manufacturing process. The algorithm consists of extracting the outline using the brightness of the image, obtaining a binarized boundary graph using the extracted outline, and determining the defects from the graph. Defects in which two cut surfaces are separated are considered type 1 defects, and those in which two cut surfaces are connected are defined as type 2 defects. In an actual manufacturing process, 112 good samples and 44 defective samples (34 type 1 defects and 10 type 2 defects) were collected and used to verify the algorithm. The samples were judged with 100% accuracy for both type 1 and type 2 defects. The algorithm will be used in the field after securing reliability for various samples.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.615-620
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• 2016

Improved quality of life has increased in a population with a high BMI (Body Mass Index). Accordingly, the development of a system for prevention of obesity management is required. Because a requirement for the prevention of obesity management system. This system has been developed to solve this problem and it is done by measuring the user information of the individual's body. The purpose of this paper is to understand the changes in your own BMI over the course of usage of this application and store the BMI in the database. This BMI data is expressed as a graph to the user and based on the BMI graph, the user is suggested to the type of exercise required by his body. The most appropriate exercise equipment's are shown to the user based on the BMI and also recommendations based on the historical data of other users with similar BMI. This system also recommends chronic diseases depending on blood sugar, blood pressure.

• Spatial Information Research
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• v.19 no.3
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• pp.43-52
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• 2011

Recently, interest in location-based service (LBS) which utilizes a DBMS in mobile system environment has been increasing, and it is expected to overcome the existing file-based system's limitation in advanced in-vehicle system by utilizing DBMS's advantages such as efficient storage, transaction management, modelling and spatial queries etc. In particular, the road network data corresponds to the most essential domain in a route planning system, which needs efficient management and maintenance. Accordingly, this study aims to develop an efficient graph-based geodata model for topological network data and to support dynamic path computation algorithm based on heuristic approach in mobile LBS system. To achieve this goal, we design a data model for supporting the hierarchy of network, and implement a path planning system to evaluate its performance in mobile LBS system. Last but not least, we find out that the designed path computation algorithm with hierarchical graph model reduced the number of nodes used for finding and improved the efficiency of memory.