• Journal of Digital Convergence
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• v.20 no.4
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• pp.565-573
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• 2022

This study aims to analyze the preference factors of the Korean MZ generation with regards to the online programs developed by museums abroad during the COVID-19 pandemic. World renown museums such as the British Museum, the National Gallery of London, Van Gogh Museum, J. Paul Getty Museum, Hasting Contemporary, Uffizi Gallery, and the Guggenheim Museum tackled the social-distancing situation with various creative online programs and events to continue their role as socially relevant institutions. Ten acclaimed programs conducted by these museums were shown to the Korean MZ generation, the most digitally savvy and frequent visitors to museums, to extract their responses to the various types of programs. The study showed that the Korean MZ generation prefer online programs which most closely reflect the onsite experience of a museum, and online contents with educational elements.

• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.525-533
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• 2022

We propose an effective method for suppressing both side and grating lobes by applying 2-dimensional Fourier Transform to the received channel data during the receive focusing process of an ultrasound imaging system. When the signal from the image point is focused, the channel signals have the same DC value across the channels. However, even after echoes from outside an imaging point are focused, they are manifested as having different spatial frequencies depending on their incident angles. Therefore, after the receive focusing delay time is applied, 2-D Fourier Transform is performed on the time-channel data to separate the DC component and other frequency components in the spectral domain, and the weighting value is defined using the ratio of the two values. The side lobe and grating lobe were suppressed by multiplying the ultrasound image by a weighting value. Ultrasound images with a frequency of 5 MHz were simulated in a 64-channel linear array. The grating lobe appearing in the ultrasound image was completely removed by applying the proposed method. In addition, the side lobe was reduced and the lateral resolution was greatly increased. Results of computer simulation on a human organ mimicking image show that the proposed method can aid in better lesion diagnosis by increasing the image contrast.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.2
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• pp.51-77
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• 2023

This study analyzed the respective teaching and learning-related services offered by the Centers for Teaching and Learning and the academic libraries to find the proper roles of libraries regarding this type of service. We interviewed librarians to collect the data. The content analysis of the qualitative interview data enabled us to identify the librarians' perceptions of teaching and learning support, service provision method, strengthening relationships with other academic units, recognition of libraries' roles within the universities, and generating more investment for the libraries. Finally, the analysis led to six suggestions for libraries' teaching and learning support functions, such as advertising the availability of specific academic discipline or unit-oriented library services, strengthening librarian's capabilities as educators, bolstering digital information literacy of the faculty members and students, injecting libraries' views into the development and maintaining fundamental knowledge-related programs, emphasizing the notion of human-centered libraries, and finding new ways to utilize library space.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.15-25
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• 2006

Using kinematic wave equation, the influence of moving storms to runoff was analysised with a focus on watersheds. Watershed shapes used are the oblong, square and elongated shape, and the distribution types of moving storms used are uniform, advanced and intermediate type. The runoff hydrographs according to the rainfall distribution types were simulated and the characteristics were explored for the storms moving down, up and cross the watershed with various velocity. The shape, peak time and peak runoff of a runoff hydrograph are significantly influenced by spatial and temporal variability in rainfall and watershed shapes. A rain storm moving in the cross direction of channel flow produces a higher peak runoff than in the downstream direction and upstream direction. A peak runoff from a storm moving downstream exceeds that from a storm moving upstream. For storms moving downstream peak time was more delayed than for other storm direction in the case of elongated watershed. The runoff volume and time base of the hydrograph decreased with the increasing storm speed.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.5
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• pp.69-80
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• 2023

Carbon neutrality in agriculture can be derived from systematic GHG reduction policies based on quantitative environmental impact analysis of GHG-emitting activities. This study is to explore how to advance the calculation of carbon emissions from agricultural activities to the detailed spatial level to a spatial Tier 3 level (Tier 2.5 level), methodologically beyond the Tier 2 approach. To estimate the GHG emissions beyond the Tier 2.5 level by region for detailed spatial units, we constructed available activity data on carbon emission impact factors such as rice cultivation, agricultural land use, and livestock. We also built and verified detailed data on emission activities at the field level through field surveys. The GHG emissions were estimated by applying the latest national emission factors and regional emission factors according to the IPCC 2019 GL based on the field-level activity data. This study has significance that it explored ways to build activity data and calculate GHG emissions through statistical data and field surveys based on parcels, one of the smallest spatial units for regional carbon reduction strategies. It is expected that by utilizing the activity data surveyed for each field and the emission factor considering the activity characteristics, it will be possible to improve the accuracy of GHG emission calculation and quantitatively evaluate the effect of applying reduction policies.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1331-1339
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• 2023

In support of the National ATM Reformation and Enhancement Plan (NARAE), a trajectory-based aviation weather service is under development through the NARAE-Weather project. Specifically, weather data presented in a standardized digital format facilitates the seamless integration of digital weather data with air traffic information. Thus, this paper introduces an approach that entails structuring numerical model data to integrate aviation weather information and flight trajectory data. The extraction results using structurally transformed data showed superior performance compared to the results extracted from the original data in terms of performance, and this research is poised to enhance the safety and efficiency of airline operations.

• Journal of the Korea Society of Computer and Information
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• v.29 no.6
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• pp.1-12
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• 2024

Deep learning with faster and more accurate results requires large amounts of storage space and large computations. Accordingly, many studies are using hardware accelerators for quick and accurate calculations. However, the performance bottleneck is due to data movement between the hardware accelerators and the CPU. In this paper, we propose a data prefetch strategy that can efficiently reduce such operational bottlenecks. The core idea of the data prefetch strategy is to predict the data needed for the next task and upload it to local memory while the hardware accelerator (Matrix Multiplication Unit, MMU) performs a task. This strategy can be enhanced by using a dual buffer to perform read and write operations simultaneously. This reduces latency and execution time of data transfer. Through simulations, we demonstrate a 24% improvement in the performance of hardware accelerators by maximizing parallel processing with dual buffers and bottlenecks between memories with data prefetch.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.213-218
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• 2020

Coronary artery aneurysm is a rare disease. It occurs in the epicardial space, mostly along the course of major coronary arteries. Here, we report a case of a giant incidental aneurysm embedded in the basal posterior wall of the left ventricle. A 43-year-old woman was referred to our institution for the evaluation of cardiac palpitations that had been present from the previous 2 months. She reported no medical history (such as Kawasaki's disease or hypertension) or previous operative history. Echocardiogram and subsequent cardiac CT revealed a giant aneurysm in the left ventricle, with a direct fistulous connection to a dilated and tortuous left circumflex artery, which showed direct communication with the straight right coronary artery.

• Clean Technology
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• v.30 no.1
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• pp.62-67
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• 2024

In this study, an alkali metal Na was introduced into iron-based catalysts used in the carbon dioxide-based Fischer-Tropsch process by wet impregnation and physical mixing methods to compare their performance. The as-prepared catalysts were evaluated for reactivity at 3.5 MPa, 330 ℃, feed ratio of H₂/CO₂ = 3 with a space velocity of 4,000 mL h^-1 g_cat^-1. Comparing the two catalysts, it was found that Na was uniformly distributed throughout the catalyst when wet-impregnated, but Na for physically mixed catalyst was relatively located on the surface of the catalyst. In addition, the wet-impregnated catalyst showed higher liquid hydrocarbon (C₅₊) yield and lower CO selectivity. In conclusion, the effect of Na distribution in the catalyst on the reaction was identified and can be controlled by the introduction method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.3 s.55
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• pp.93-100
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• 2009

This study forms part of a research project that was carried out on the development and application of high-strength concrete for large underground spaces. In order to develop 50MPa high-strength concrete, eight optimal mixtures with different portions of fly ash and ground granulated blast furnace slag were selected. For assessments of shrinkage characteristics, free shrinkage tests with prismatic specimens and shrinkage crack tests were performed. The compressive strength was more than 30MPa at 7days, and stable design strength was acquired at 28days. High-strength concrete containing blast furnace slag shows large autogenous shrinkage, while large shrinkage deformations and cracks will occur when mixtures are replaced with large volumes of cementitious materials. Hence, for these high-strength concrete mixtures, the curing conditions of initial ages that affect the reaction of hydration and drying effects need to be checked.