• Journal of Korea Water Resources Association
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• v.56 no.spc1
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• pp.1007-1014
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• 2023

Two-dimensional flow analysis, a fundamental component of hydrodynamics, plays a pivotal role in numerically simulating fluid behavior in rivers and waterways. This modeling approach heavily relies on parameters such as eddy viscosity and roughness coefficient to accurately represent flow characteristics. Therefore, combination of appropriate parameters is very important to accurately simulate flow characteristics. In this study, an automation algorithm was developed and applied to find the optimal combination of parameters. Previously, when applying a two-dimensional flow analysis model, former researchers usually depend on the empirical approach, which causes many difficulties in finding optimal variable values. Using the experimental data, we tracked errors according to the combination of various parameters and applied the algorithm that can determine the optimal combination of parameters with the Python language. The automation algorithm can easily determine the most accurate combination by comparing the flow velocity error values among the two-dimensional flow analysis results among the combinations of 121 (11×11) parameters. In the perspective of utilizing automation algorithm, there is an expected high utility in promptly and straightforwardly determining the optimal combination of parameters with the smallest error.

• Information Systems Review
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• v.23 no.3
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• pp.127-158
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• 2021

Many online travel agencies (OTAs) provide average ratings and time-relevant information or the most recently posted reviews regarding hotels to satisfy customers. To identify these two factors' relative influence on behavioral decision-making processes, we conducted two studies: (1) an experimental research design to explore the relative influence of the two on online review consumption and (2) an empirical approach to examine their relative impact on online review generation. The results show that when review posters observe an inconsistency between average ratings and recent reviews, they tend to deviate from the recent reviews regardless of the overall direction (reactance behavior). Meanwhile, review consumers tend to conform to the opinions presented in recent reviews (herding behavior). Additionally, in both cases, the effects are amplified in case of a negative aberration. Based on the findings, this study provides theoretical and practical implications regarding the relative influences of average rating and recently posted reviews and their different impacts on online review consumption and generation.

• The Transactions of the Korea Information Processing Society
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• v.13 no.6
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• pp.243-250
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• 2024

Biomimetic robots, which emulate characteristics of biological entities such as birds or insects, have the potential to offer a tactical advantage in surveillance and reconnaissance in future battlefields. To effectively utilize these robots, it is essential to develop technologies that emulate the wing flapping of birds or the movements of cockroaches. However, this effort is complicated by the challenges associated with securing the necessary hardware and the complexities involved in software development and validation processes. In this paper, we presents the design and implementation of a multi-HILS based biomimic robot software validation testbed using modeling and simulation (M&S). By employing this testbed, developers can overcome the absence of hardware, simulate future battlefield scenarios, and conduct software development and testing. However, the multi-HILS based testbed may experience inter-device communication delays as the number of test robots increases, significantly affecting the reliability of simulation results. To address this issue, we propose the data distribution service priority (DDSP), a priority-based middleware. DDSP demonstrates an average delay reduction of 1.95 ms compared to the existing DDS, ensuring the required data transmission quality for the testbed.

• Journal of The Korean Association For Science Education
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• v.26 no.6
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• pp.691-702
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• 2006

The purposes of the study are to portray Korean beginning secondary science teachers' ways of arranging science content, sense-making strategy, and factors contributing to the tensions between teachers' intentions and actual practice. Six beginning secondary science teachers participated in this study. Science classes taught by the participating teachers were observed and videotaped. Semi-structured interviews were conducted for science teachers participated in this study after science classes were observed. Instructional materials were also collected for each science class. Video- and audio-taped data were transcribed and analyzed using conceptual framework developed by the Michigan State University. The findings of this study produce the following conclusions: (1) beginning teachers' science classes are arranged in ways compatible to traditional school science, (2) frequently used sense-making strategies are procedural display and narrative reasoning, (3) tensions between beginning teachers' intentions and practice arise from two factors such as assessment and differences in educational views with peer teachers, and (4) learning experiences, lack of perceptions and preparations on reform science teaching, and the absence of systematic program for professional development programs for beginning science teachers are major obstacles to reform science teaching for beginning teachers.

• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.592-608
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• 2007

This study explored the types of conceptual change of 'force' within middle school students' conceptual ecologies. This qualitative study was implemented with the use of classroom observations and two interviews with the participants. 11 middle school students (7 females and 4 males) joined in this study. The interviews with the participants were conducted individually before and after the 'force' unit. The collected data were all transcribed and analyzed interpretively. The results of this study consisted of two parts. First, the participants' conceptual ecologies of 'force' were categorized into 4: epistemological commitments (fixed or interactional explanatory consistency), analogy (attribute, working), metaphysical beliefs (people-oriented ontology, animism, causationism, mixed), and past experiences. Second, two representative cases including 'stable' and 'transitional' states were explained based on the interactions within their own conceptual ecologies. We can see students' conceptions with the integrated perspective in the sense that this results tried to get contextual and interactional understandings of the status of the conception and the possibilities of conceptual change. In addition, it implied that conceptual change research should have the perspective of conceptual ecology evolution in the future.

• Science of Emotion and Sensibility
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• v.26 no.4
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• pp.51-70
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• 2023

This study employed driving simulation to examine how takeover request (TOR) information modalities (visual, auditory, and visual + auditory) in Level-3 automated vehicles, and road types (straight and curved) influence the driver's control takeover time (TOT) and mental workload, assessed through subjective workload and heart rate variations. The findings reveal several key points. First, visual TOR resulted in the quickest TOT, while auditory TOR led to the longest. Second, TOT was considerably slower on curved roads compared to straight roads, with the greatest difference observed under the auditory TOR condition. Third, the auditory TOR condition generally induced lower subjective workload and heart rate variability than the visual or visual + auditory conditions. Finally, significant heart rate changes were predominantly observed in curved road conditions. These outcomes indicate that TOT and mental workload levels in drivers are influenced by both the TOR modality and road geometry. Notably, a faster TOT is associated with increased mental workload.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.103-113
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• 2024

This study is based on the design project of 'Sun-Garden' within the Solaseado Solar Power Plant located in Solaseado, which is a New City being developed in Haenam, Jeollanam-do. The purpose of this study is to create an integrated and sustainable energyscape that harmonizes energy infrastructure with the natural environment, while supporting the city's carbon neutrality agenda. To achieve this, design principles were established by considering three key aspects. The first aspect is economic, which seeks to create multifunctional spaces that integrate nature and technology, pursuing long-term sustainability while generating additional economic value. The second aspect is natural, emphasizing the creation of planting environments that conserve and enhance ecosystems, introduce region-specific species, and maintain ecosystem services and sustainable resource use. The third aspect is landscape, offering sensory and educational experiences to visitors and functioning as a landmark that symbolizes the carbon-neutral garden city of Solaseado through the aesthetic harmony of nature and technology. Through the creation of the 'Sun-Garden,' the Solaseado Solar Power Plant exemplifies a sustainable energyscape development model that merges economic, environmental, and landscape aspects beyond the conventional energy production facility. This project is expected to provide guidelines and implications for future energy infrastructure design, contributing to global energy transition efforts.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.157-165
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• 2020

Purpose To evaluate the optimal measurement location, cut-off value, and diagnostic performance of S-Shearwave in differential diagnosis of breast masses seen on ultrasonography (US). Materials and Methods During the study period, 225 breast masses in 197 women were included. S-Shearwave measurements were made by applying a square region-of-interest automatically generated by the US machine. Shearwave elasticity was measured three times at four different locations of the mass, and the highest shearwave elasticity was used for calculating the optimal cut-off value. Diagnostic performance was evaluated by using the area under the receiving operator characteristic curve (AUC). Results Of the 225 breast masses, 156 (69.3%) were benign and 69 (30.7%) were malignant. Mean S-Shearwave values were significantly higher for malignant masses (108.0 ± 70.0 kPa vs. 43.4 ± 38.3 kPa; p < 0.001). No significant differences were seen among AUC values at different measurement locations. With a cut-off value of 41.9 kPa, S-Shearwave showed 85.7% sensitivity, 63.9% specificity, 70.7% accuracy, and positive and negative predictive values of 51.7% and 90.8%, respectively. The AUCs for US and S-Shearwave did not show significant differences (p = 0.179). Conclusion S-Shearwave shows comparable diagnostic performance to that of grayscale US that can be applied for differential diagnosis of breast masses seen on US.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.4
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• pp.244-252
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• 2023

The timeliness and accuracy of test results are crucial factors for clinicians to decide and promptly administer effective and targeted antimicrobial therapy, especially in life-threatening infections or when vital organs and functions, such as sight, are at risk. Further research is needed to refine and optimize matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based assays to obtain accurate and reliable results in the shortest time possible. MALDI-TOF MS-based bacterial identification focuses primarily on techniques for isolating and purifying pathogens from clinical samples, the expansion of spectral libraries, and the upgrading of software. As technology advances, many MALDI-based microbial identification databases and systems have been licensed and put into clinical use. Nevertheless, it is still necessary to develop MALDI-TOF MS-based antimicrobial-resistance analysis for comprehensive clinical microbiology characterization. The important applications of MALDI-TOF MS in clinical research include specific application categories, common analytes, main methods, limitations, and solutions. In order to utilize clinical microbiology laboratories, it is essential to secure expertise through education and training of clinical laboratory scientists, and database construction and experience must be maximized. In the future, MALDI-TOF mass spectrometry is expected to be applied in various fields through the use of more powerful databases.

• Information Systems Review
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• v.20 no.4
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• pp.59-78
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• 2018

With the advent of the various device types and marketing communication, customer's search and purchase behavior have become more complex and segmented. However, extant research on multichannel marketing effects of the purchase funnel has not reflected the specific features of device User Interface (UI) and User Experience (UX). In this study, we analyzed the marketing channel effects of multi-device shoppers using a unique click stream dataset from global online retailers. We examined device types that activate online shopping and compared the differences between marketing channels that promote visits. In addition, we estimated the direct and indirect effects on visits and purchase revenue through customer's accumulated experience and channel conversions. The findings indicate that the same customer selects a different marketing channel according to the device selection. These results can help retailers gain a better understanding of customers' decision-making process in multi-marketing channel environment and devise the optimal strategy taking into account various device types. Our empirical analyses yield business implications based on the significant results from global big data analytics and contribute academically meaningful theoretical framework using an economic model. We also provide strategic insights attributed to the practical value of an online marketing manager.