• ETRI Journal
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• v.33 no.3
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• pp.470-473
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• 2011

In this letter, we propose blackbox and scenario-based testing of multiplayer online games as well as simple load testing. Game testing is done from outside the source code, and the access to the source code is not required to testers because the game logic is described with a game description language and virtual game map. Instead of using a subset of the main game client for the test client, only game packet protocols and the sequence of packets are analyzed for new game testing. In addition, complex and various scenarios can be tested through combining defined actions. Scenario-based testing helps testers mimic real testing environments instead of doing simple load testing and improves the productivity of game testing.

• International Journal of Railway
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• v.3 no.1
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• pp.28-33
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• 2010

The research is to develop cost methodology to support railway managers for identifying principles, tools and methods of activity based management correctly and precisely, and can be useful and effective for managers for realizing their goals. The research result a ministry can be suitable guideline in terms of how to execute activity based management. Since in this research, main and secondary activities are studied completely in the Railway organization, it can be an explanatory research. The research population is headquarter managers and experts of railway organization and the sampling procedure is goal-oriented and judgmental. 74 people were selected by using a formula. All hypotheses were tested in 95% significance level. Meanwhile a proposed process of applying. activity based management was offered.

• ETRI Journal
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• v.41 no.3
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• pp.277-288
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• 2019

VWorld is run by the Ministry of Land, Infrastructure, and Transport of South Korea and provides national spatial information, such as aerial images, digital elevation models, and 3D structural models. We propose herein an open platform for 3D spatial information based on WebGL using spatial information from VWorld. WebGL is a web-based graphics library and has the advantage of being compatible with various web browsers. Our open platform is also compatible with various web browsers. Accordingly, it is easily accessible via the VWorld site and uses the three-dimensional (3D) map program. In this study, we describe the proposed platform configuration, and the requests, management, and visualization approaches for VWorld spatial information data. Our aim is to establish an approach that will provide a stable rendering speed even on a low-end personal computer without a graphics processing unit based on a quadtree structure. We expect that users will be able to visualize 3D spatial information through the VWorld open platform, and that the proposed platform will become the basis for various applications.

• ETRI Journal
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• v.45 no.6
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• pp.929-938
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• 2023

The detection of all the symbols transmitted simultaneously in multiuser systems using limited wireless resources is challenging. Traditional model-based methods show high performance with perfect channel state information (CSI); however, severe performance degradation will occur if perfect CSI cannot be acquired. In contrast, data-driven methods perform slightly worse than model-based methods in terms of symbol error ratio performance in perfect CSI states; however, they are also able to overcome extreme performance degradation in imperfect CSI states. This study proposes a novel deep learning-based method by improving a state-of-the-art data-driven technique called deep soft interference cancellation (DSIC). The enhanced DSIC (EDSIC) method detects multiuser symbols in a fully sequential manner and uses an efficient neural network structure to ensure high performance. Additionally, error-propagation mitigation techniques are used to ensure robustness against channel uncertainty. The EDSIC guarantees a performance that is very close to the optimal performance of the existing model-based methods in perfect CSI environments and the best performance in imperfect CSI environments.

• ETRI Journal
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• v.46 no.3
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• pp.367-378
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• 2024

We propose a number-theory-based quantized mathematical optimization scheme for various NP-hard and similar problems. Conventional global optimization schemes, such as simulated and quantum annealing, assume stochastic properties that require multiple attempts. Although our quantization-based optimization proposal also depends on stochastic features (i.e., the white-noise hypothesis), it provides a more reliable optimization performance. Our numerical analysis equates quantization-based optimization to quantum annealing, and its quantization property effectively provides global optimization by decreasing the measure of the level sets associated with the objective function. Consequently, the proposed combinatorial optimization method allows the removal of the acceptance probability used in conventional heuristic algorithms to provide a more effective optimization. Numerical experiments show that the proposed algorithm determines the global optimum in less operational time than conventional schemes.

• Korean Journal of Radiology
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• v.20 no.6
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• pp.909-915
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• 2019

The Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency developed a primary imaging test for suspected traumatic thoracolumbar spine injury. This guideline was developed using an adaptation process involving collaboration between the development committee and the working group. The development committee, consisting of research methodology experts, established the overall plan and provided support on research methodology. The working group, composed of radiologists with expertise in musculoskeletal imaging, wrote the recommendation. The guidelines recommend that thoracolumbar spine computed tomography without intravenous contrast enhancement be the first-line imaging modality for diagnosing traumatic thoracolumbar spine injury in adults.

• Toxicological Research
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• v.34 no.1
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• pp.23-29
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• 2018

Ethanol-induced fat accumulation, the earliest and most common response of the liver to ethanol exposure, may be involved in the pathogenesis of liver diseases. Isoliquiritigenin (ISL), an important constituent of Glycyrrhizae Radix, is a chalcone derivative that exhibits antioxidant, anti-inflammatory, and phytoestrogenic activities. However, the effect of ISL treatment on lipid accumulation in hepatocytes and alcoholic hepatitis remains unclear. Therefore, we evaluated the effect and underlying mechanism of ISL on ethanol-induced hepatic steatosis by treating AML-12 cells with 200 mM ethanol and/or ISL ($0{\sim}50{\mu}M$) for 72 hr. Lipid accumulation was assayed by oil red O staining, and the expression of sirtuin1 (SIRT1), sterol regulatory element-binding protein-1c (SREBP-1c), AMP-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor alpha ($PPAR{\alpha}$) was studied by western blotting. Our results indicated that ISL treatment upregulated SIRT1 expression and downregulated SREBP-1c expression in ethanol-treated cells. Similarly, oil red O staining revealed a decrease in ethanol-induced fat accumulation upon co-treatment of ethanol-treated cells with 10, 20, and $50{\mu}M$ of ISL. These findings suggest that ISL can reduce ethanol induced-hepatic lipogenesis by activating the SIRT1-AMPK pathway and thus improve lipid metabolism in alcoholic fatty livers.

• Research in Mathematical Education
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• v.9 no.2 s.22
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• pp.125-133
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• 2005

This paper investigates student conceptual understanding and application on algebra using problem-based curricula. Seven principles which National Research Council announced were considered because these seven principles all involved in the development of a deep conceptual understanding. A problem-based curriculum itself provides a significant contribution to improving student learning. A problem-based curriculum encourages students to obtain a more conceptual understanding in algebra. From the results the national curriculum developers in Korea consider the problem-based curriculum.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.49-49
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• 2002

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1026-1033
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• 2022

This study presents a novel DNA part characterization technique that increases throughput by combinatorial DNA part assembly, solid plate-based quantitative fluorescence assay for phenotyping, and barcode tagging-based long-read sequencing for genotyping. We confirmed that the fluorescence intensities of colonies on plates were comparable to fluorescence at the single-cell level from a high-end, flow-cytometry device and developed a high-throughput image analysis pipeline. The barcode tagging-based long-read sequencing technique enabled rapid identification of all DNA parts and their combinations with a single sequencing experiment. Using our techniques, forty-four DNA parts (21 promoters and 23 RBSs) were successfully characterized in 72 h without any automated equipment. We anticipate that this high-throughput and easy-to-use part characterization technique will contribute to increasing part diversity and be useful for building genetic circuits and metabolic pathways in synthetic biology.