• Journal of the Korea Society for Simulation
• /
• v.29 no.2
• /
• pp.63-72
• /
• 2020

Tank, which is a representative ground weapon system, is one of the most important weapon systems in each country. For the cost-effective acquisition of a tank based on scientific analysis, the operational concept and effectiveness should be studied based on engagement simulation technology. Besides physical capabilities including maneuver and communication, logical models including decision-making of a tank commander should be developed systematically. This paper describes a method to model a tank for engagement simulation based on Base System Model(BSM), which is the standard architecture of the weapon system model in AddSIM, an integrated engagement simulation software. In particular, a method is proposed to develop logical models by hierarchical and modular approach based on human decision-making model. The proposed method applies a mathematical formalism called DEVS(Discrete EVent system Specification) formalism. It is expected that the proposed method is widely used to study the operational concept and analyze the effectiveness of tanks in the Korean military in the future.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.9
• /
• pp.91-103
• /
• 2004

A series of shaking table model tests were performed to verify the validity of similitude law, which is suggested by lai (1989) to simulate the dynamic behavior of soil-fluid-structure system for is shaking table tests. In the tests, the similitude law suggested by lai was applied to determine the length and the time scaling factors. Also, the steady state concept was used in determining the density of model backfill soil, which is a key factor in simulating the development of excess pore pressure during shaking. The similitude law was verified by checking whether three different sizes of quay walls show the identical behavior or not. The similar responses of acceleration, excess pore pressure and horizontal displacement of walls were obtained far the small and large models. However, the medium model showed larger responses than those of the small and large models because of the resonance between the frequency of input acceleration and the natural frequency of the wall system. In addition, the vertical displacement and rotational angle of the walls became larger with the increase of model size.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.3
• /
• pp.1-7
• /
• 2019

In this paper, we propose an approach to design a practical filter and a mathematical modeling for images. In the areas of signal processing, including high-dimensional image processing, the filtering process has been fundamental and crucial in diverse practical applications such as image processing, computer vision, and pattern recognition. In general, the ideal filter is modeled as circular-shaped in the 2D frequency domain as the rectangular shape is ideal for the 1D frequency domain. This paper proposes an approach to modeling practical and efficient image filter in the 2D frequency domain. Instead of employing a circular-shaped filter, this study proposes a polygon-shaped filter inspired by the concept of a hexagon cellular system for frequency reuse in wireless communication systems. By employing the concept of frequency reuse, bandwidth efficiency is also achieved in the frequency domain. To substantiate the proposed approach, quantitative evaluation is performed using PSNR.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.1
• /
• pp.15-21
• /
• 2020

In this paper, the observation performance of the electro-optical telescope system which surveils the unknown space objects, is analyzed by the Modeling & Simulation(M&S). The operation concept for the observation of the unknown space objects using two telescope systems is considered and the M&S models are constructed. Based on the operation concept for observing the unknown space objects, the estimated orbit is generated by Initial Orbit Determination(IOD) and the observation performance is analyzed according to the offset compensation cycle for the estimated orbit. The result of the M&S based analysis in this paper shows that the observation performance increases with the shorter offset compensation cycle, and decreases with the longer offset compensation cycle. Therefore, to improve the performance of the telescope system which surveils the unknown space objects, the observation system with accurate initial orbit determination or shorter offset compensation cycle should be designed and constructed.

• Geomechanics and Engineering
• /
• v.33 no.1
• /
• pp.11-18
• /
• 2023

This study explores a new energy partitioning approach to determine the fracture toughness of 3-D printed pristine/recycled high density polyethylene (HDPE) blends employing the essential work of fracture (EWF) concept. The traditional EWF approach conducts a uniaxial tensile test with double-edge notched tensile (DENT) specimens and measures the total energy defined by the area under a load-displacement curve until failure. The approach assumes that the entire total energy contributes to the fracture process only. This assumption is generally true for extruded polymers that fracture occurs in a material body. In contrast to the traditional extrusion manufacturing process, the current 3-D printing technique employs fused deposition modeling (FDM) that produces layer-by-layer structured specimens. This type of specimen tends to include separation energy even after the complete failure of specimens when the fracture test is conducted. The separation is not relevant to the fracture process, and the raw experimental data are likely to possess random variation or noise during fracture testing. Therefore, the current EWF approach may not be suitable for the fracture characterization of 3-D printed specimens. This paper proposed a new energy partitioning approach to exclude the irrelevant energy of the specimens caused by their intrinsic structural issues. The approach determined the energy partitioning location based on experimental data and observations. Results prove that the new approach provided more consistent results with a higher coefficient of correlation.

• Journal of Korean Library and Information Science Society
• /
• v.46 no.4
• /
• pp.245-269
• /
• 2015

This study suggested that the concept of creative zone raised by the national interest of the 'Creation' should be extended in public libraries. The concept of creative zone in public libraries was analyzed on the basis of 'Con-creative structure ontology' by Rombach. As we understand a creator and creation as the relation of 'subject'-'object', The current concept of 'Creation' dilutes the possibility of 'Autogenese' that all beings as a subject possess. But 'Con-creative Structure' describes the process of 'Autogenese' through sharing and mutual communication of all beings. The formation process of Con-creative Structure corresponds to the philosophy of the library that supports the self-growth through communication and sharing. 'Co-working Space' is more suitable for the substantive image of Con-creativity than 'Makerspace'. Therefore, this study analyzed circumstances of creative zone in public libraries and Co-working Space in business areas and provided the conceptive and substantive modeling for Co-working Space in public libraries.

• The KIPS Transactions:PartD
• /
• v.9D no.1
• /
• pp.31-42
• /
• 2002

In this paper, we propose a new spatio-temporal representation scheme which can model moving objets trajectories effectively in video data and a new signature-based access method for moving objects trajectories which can support efficient retrieval on user query based on moving objects trajectories. The proposed spatio-temporal representation scheme supports content-based retrieval based on moving objects trajectories and concept-based retrieval based on concepts(semantics) which are acquired through the location information of moving objects trajectories. Also, compared with the sequential search, our signature-based access method can improve retrieval performance by reducing a large number of disk accesses because it access disk using only retrieved candidate signatures after it first scans all signatures and performs filtering before accessing the data file. Finally, we show the experimental results that proposed scheme is superior to the Li and Shan's scheme in terns of both retrieval effectiveness and efficiency.

• Journal of The Korean Association For Science Education
• /
• v.36 no.3
• /
• pp.361-369
• /
• 2016

In this study, we investigated the characteristics of group discussion and classroom discussion in the scientific modeling of the particulate model of matter. 7th graders in Seoul participated in this study. We implemented science instructions based on the GEM cycle of scientific modeling. We analyzed the differences between group discussion and classroom discussion in three steps: exploring thoughts, comparing thoughts, and drawing conclusions. We also looked into the level of argumentations of the students in the modeling activities. The analysis of the results indicated that students generated a group model by extracting commonalities from each model of their group members, and then they evaluated and modified the group model by comparing the differences among the models in classroom discussion. The main step involved in group discussion was 'exploring thoughts', whereas in classroom discussion it was 'comparing thoughts'. Although the levels of argumentation among the students were generally low, most students participated with enthusiasm, as they expressed their interest and had positive perception in the modeling activities. As a result, the modeling activities were found to have positive influences on concept development. Some suggestions to implement the modeling activities in science teaching effectively were discussed.

• The Journal of the Korea Contents Association
• /
• v.14 no.4
• /
• pp.513-521
• /
• 2014

The purpose of this research is to develope and implement a convergent educational contents based on theoretical background of integrated education using agent based modeling in the ubiquitous learning environment. The structure of this contents consists of three modules that were designed by trans-disciplinary concept and situated learning theory. These three modules are: convergent problem presenting module, resource of knowledge module and learning of agent based modeling and IT tools module. After the satisfaction survey of the implemented content, out of 5 total value, the average value was 3.86 for effectiveness, 4.13 for convenience and 3.86 for design. The result of the survey shows that the users are generally satisfied. By using this u-learning contents, learners can experience and learn how to solve the convergent problem by utilizing IT tools without any limitation of device, time and space. At the same time, the proposal of structural design of contents can be a good guideline to the researchers to develop the convergent educational contents in the future.

• Journal of the Korea Computer Graphics Society
• /
• v.15 no.1
• /
• pp.25-34
• /
• 2009

Sound is very important element to enhance and reinforce reality and immersion of users in virtual reality and computer animation. Recently, significant researches about sound modeling are presented in computer graphics community. In this article, main subjects are explained and major researches are reviewed based on the sound papers presented in computer graphics community. Specially, several papers about following two subjects are reviewed in this paper: 1) synthesing sound using physically-based laws and generating sound synchronized with graphics. 2) spatializing sound and modeling sonic environment. Many research about sound modeling have been focused on more efficient modeling of real physical law and generate realistic sound with limited resources. Based on this concept, various papers are introduced and the relationship between researches about sound and graphics is discussed.