• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.97-99
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• 2002

Turbulent premixed flames were a subject of many researches for a number of decades. Especially, Borghi suggested a manificent diagram classifying turbulent combustion reasions and Lipatnikov and Chomiak modified this diagram. But this diagram has difficulties tn defining a flame thickness and velocity and measuring integral length scales In addition, recently experimental techniques are being developed, so we can accurately use PIV diagnostics measuring 2D velocity field instead of LDV and make good use of PLIF techniques for obtaining the flame information. In this study, according to developing techniques, suggest a new diagram replacing the existing Borghi diagram. Simultaneous PIV/OH PLIF measurements are used, which measure a shear strain rate and a location of flames, respectively. The shear strain rate represents turbulence and the OH signal indicates the flame information, but there is no geometric Information which is very important to flame quenching. Hence, to consider the geometric information, calculate fractal dimensions of the OH images. So the diagram suggested in this research has three axes which consist of strain rate, OH signal, and fractal dimension and can classify turbulent premixed flames.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.87-93
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• 2000

Recently Software Industry has tended to enhance the productivity and quality with using the software architecture in software development and administration. The research of software component technique and software development methodology are just doing and making many applications. The software architecture is considered as the essential element for analyzing and maintaining the entire structure with organizing the software into components and describing the relations with connectors. The software modeling methodology that we propose is generating Happy Work Language describing the software structure with the modeling tool as Happy Work. We can use System Context Diagram, Component Diagram, Component Sequence Diagram, and they are composed of four Elements as Users, Systems, Components, Connectors.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.1
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• pp.19-26
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• 2013

To improve the reliability and quality of software system, many studies of the testing based on state-transition diagram have been in progress. Existing studies tried to solve the complexity problem of state-transition diagram. But the development of test case demands the better way to derive and manage the state diagram with low complexity. In this paper, the STMT(State-Transition Mapping Tree) is proposed to decrease the complexity of state diagram without changing or loosing the original state or transition information. Comparing with other methods, the proposed method turns out to be less complex.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.3
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• pp.633-652
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• 2024

Software testing is an important phase as it ensures the software quality. The software testing process comprises of three steps: generation, execution, and evaluation of test cases. Literature claims the usage of single and multiple 'Unified Modeling Language' (UML) diagrams to generate test cases. Using multiple UML diagrams increases test case coverage. However, the existing approaches show limitations in test case generation from UML diagrams. Therefore, in this research study, we propose an approach to generate the test cases using UML State Chart Diagram (SCD), Activity Diagram (AD), and Sequence Diagram (SD). The proposed approach transforms UML diagrams into intermediate forms: SCD Graph, AD Graph, and SD Graph respectively. Furthermore, by integrating these three graphs, a System Testing Graph (STG) is formed. Finally, test cases are identified from STG by using a traversal algorithm such as Depth First Search (DFS) that is an optimization method. The results show that the proposed approach is better compared to existing approaches in terms of coverage and performance. Moreover, the generated test cases have the ability to detect faults at the unit level, integration, and system level testing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.2
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• pp.127-133
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• 2014

This paper proposes a determination method of waypoints to maximize the survivability of a UAV. Voronoi diagram which is used for the initial selection of waypoint candidates is the most widely used path planning technique to avoid the threat as far as possible when the location and strength of the threat are given. But if threat strength is different each other and flight path is constrained along with straight lines, Voronoi diagram has limitations in real applications. In this study, the initial waypoints obtained from Voronoi diagram are optimized considering the shape of each threat. Here, a waypoint is optimized while adjacent waypoints are fixed. By repeating this localized optimization until whole waypoints are converged, computation time for finding the best waypoints is greatly reduced.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.108-115
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• 2009

In metal forming technologies, the stamping process is one of the significant manufacturing processes to produce sheet metal components. It is important to design stamping process which can produce sound products without defect such as fracture and wrinkle. The objective of this study is to propose the feasible formability diagram which denotes the safe region without fracture and wrinkle for effective design of stamping process. To determine the feasible formability diagram, FE-analyses were firstly performed for the combinations of process parameters and then the characteristic values for fracture and wrinkle were estimated from the results of FE-analyses based on forming limit diagram. The characteristic values were extended through training of the artificial neural network. The feasible formability diagram was finally determined for various combinations of process parameters. The stamping process of turret suspension to support suspension module was taken as an example to verify the effectiveness of feasible formability diagram. The results of FE-analyses for process conditions within fracture and wrinkle as well as safe regions were in good agreement with experimental ones.

• Korean Journal of Construction Engineering and Management
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• v.20 no.5
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• pp.42-51
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• 2019

The train operation institution establishes a transportation plan based on the forecast of transport demand and the ability of train vehicles to transport, and establishes a train operation plan accordingly. The train operation plan adjusts the intervals between trains, creates a timetable (train diagram) for trains, and establishes a plan for the operation of train vehicles used for train operation. The train operation institution shall establish a crew schedule to determine and place the crew members of the trains arranged in the diagram in order to enhance the efficiency of the operation management of the trains. In this study, the authors apply the neighborhood search method that satisfies the constraints at the phase of generating the crew diagram. This suggests a methodology for efficient management of crew schedule plan. The crew diagram generated in this study compared with the existing crew diagram in accordance with the actual operating train timetable, and verified the effectiveness of the suggested method.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.1-9
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• 2022

UML class diagrams are used to visualize the static aspects of a software system and are involved from analysis and design to documentation and testing. Software modeling using class diagrams is essential for software development, but it may be not an easy activity for inexperienced modelers. The modeling productivity could be improved with a dataset of class diagrams which are classified by domain categories. To this end, this paper provides a classification method for a dataset of class diagram images. First, real class diagrams are selected from collected images. Then, class names are extracted from the real class diagram images and the class diagram images are classified according to domain categories. The proposed classification model has achieved 100.00%, 95.59%, 97.74%, and 97.77% in precision, recall, F1-score, and accuracy, respectively. The accuracy scores for the domain categorization are distributed between 81.1% and 95.2%. Although the number of class diagram images in the experiment is not large enough, the experimental results indicate that it is worth considering the proposed approach to class diagram image classification.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.17-32
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• 2022

This study explored an approach to estimate a flow-density diagram(FD) on a link in highway traffic environment by utilizing probe vehicles' time headway records. To study empirical flow-density diagram(EFD), the probe vehicles with vision sensors were recruited for collecting driving records for nine months and the vision sensor data pre-processing and GIS-based map matching were implemented. Then, we examined the new EFDs to evaluate validity with reference diagrams which is derived from loop detection traffic data. The probability distributions of time headway and distance headway as well as standard deviation of flow and density were utilized in examination. As a result, it turned out that the main factors for estimation errors are the limited number of probe vehicles and bias of flow status. We finally suggest a method to improve the accuracy of EFD model.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.629-633
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• 1990