• Journal of Surface Science and Engineering
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• v.55 no.4
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• pp.187-195
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• 2022

WO₃ thin films were synthesized by electrodeposition, and their electrochromic properties were investigated. The application of static voltage produced WO₃ films with a smooth, compact surface morphology, and the film thickness linearly increased with the application time. The thicker film showed a strong color contrast but a slow color-switching speed. High-temperature heat treatment exceeding 300 ℃ induced a phase transformation from an amorphous to a monoclinic structure and resulted in degraded electrochromic performance. Furthermore, the optimized WO₃ thin films demonstrated their potential application as electrochromic boards for writing and erasing letters using a simple modified 3D printer in a rapid, accurate process

• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.251-258
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• 2022

Silk fibroin microparticles were fabricated using a phase separation technique between silk fibroin solution and polyvinyl alcohol. We found that the concentration of polyvinyl alcohol determines the size of microparticles. The mean diameter of the silk fibroin microparticles varied from 3.48 ㎛ to 4.05 ㎛. The silk fibroin microparticle size increased as a function of the concentration of PVA in aqueous silk solution. The resulting silk fibroin microparticles have narrow size distribution (i.e. monodisperse) and smooth/spherical surface. Also, we studied the effects of mouse serum, sodium phosphate buffer (PBS), and pH on the stability of the silk fibroin microparticles. Overall, we demonstrated the simple method to fabricate and to control the silk fibroin microparticles that makes our silk microparticles to be usable for a potential drug delivery carrier.

• International Journal of Computer Science & Network Security
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• v.23 no.2
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• pp.210-226
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• 2023

It is difficult to transform a blockchain initiative from the feasibility stage to the fully commercialized the technology's products or services, especially considering the significant investment required and the lack of studies on the benefits and barriers from deployment perspective. Whereas some organizations have come up with their own solutions to moving beyond the feasibility stage, commercial applications do not yet exist and few organizations are willing to invest beyond the prototype phase and fill in the gap between the expected and actual business value of these types of projects. This study aims to develop a blockchain model using a survey to gather qualitative data on experts' opinions on the deployment of blockchain technology. Our model will measure how business professionals could take advantage of blockchain's disruptive technology to develop business opportunities. This study's contribution is to show blockchain technology's potential strategic business value. The findings from this exploration include the prospective for delivering comprehensions to businesses for different creating investment choices on the embracing of the blockchain technology.

• Annual Conference of KIPS
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• 2009.11a
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• pp.243-244
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• 2009

So far, many researches have been conducted in the area of audio based context recognition. Nevertheless, most of them are based on existing feature extraction techniques derived from linear signal processing such as Fourier transform, wavelet transform, linear prediction... Meanwhile, environmental audio signal may potentially contains non-linear dynamic properties. Therefore, it is a big potential to utilize non-linear dynamic signal processing techniques in audio based context recognition.

• Progress in Superconductivity and Cryogenics
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• v.12 no.1
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• pp.66-70
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• 2010

The operational temperature range of thermosiphon is generally limited from the critical point to the triple point of the working fluid to maintain two-phase state. Thermosiphon with mixed working fluid has a potential to widen the operational temperature range. In this study, the physical behavior of mixed working fluid during the transient operation of thermosiphon was analyzed with temperature-mole fraction diagram. The condenser and the evaporator temperature variations were explained by the dew line and the bubble line of the mixture. It is encouraging that the thermosiphon operation commences early with larger fraction of high boiling point component, but the temperature gap between the condenser and the evaporator due to the separation of two components has a negative effect on the officient cool down process.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.485-496
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• 2023

Precise construction cost estimation is paramount to determining the total construction expense of a project prior to the initiation of the construction phase. Despite this, manual quantification and cost estimation methods, which continue to be widely used, may result in imprecise estimation and subsequent financial loss. Given the fast-paced and efficiency-demanding nature of the construction industry, trustworthy quantity and cost estimation is essential. To mitigate these obstacles, this research is focused on establishing an automated quantity estimation algorithm, particularly designed for the main rebar of beams which are recognized for their complicated reinforcement configurations. The exact quantity derived from the proposed algorithm is compared to the manually approximated quantity, reflecting a variance of 10.27%. As a result, significant errors and impending financial loss can be averted. The implementation of the findings from this research holds the potential to significantly assist construction firms in quickly and accurately estimating rebar quantities while adhering strictly to applicable specifications and regulatory requirements.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.493-502
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• 2020

Traditionally, road projects are initiated based on an assessment of their economic benefit, after which the environmental, social and governance effects are addressed discretely for the project according to a set of predetermined alternatives. Sustainable road infrastructure planning is vital as issues like diminishing access to road construction supplies, water scarcity, Greenhouse Gas emissions, road-related fatalities and congestion pricing etc., have imposed severe economic, social, and environmental damages to the society. In the process of addressing these sustainability factors in the operational phase of the project, the dynamics of these factors are generally ignored. This paper argues that effective delivery of sustainable roads should consider such dynamics and highlights how different aspects of sustainability have the potential to affect project sustainability. The paper initially presents the different sustainability-assessment tools that have been developed to determine the sustainability performance of road projects and discuss the inability of these tools to model the interrelationships among sustainability-related factors. The paper then argues the need for a new assessment framework that facilitates modelling these dynamics at the macro-level (system level) and helping policymakers for sustainable infrastructure planning through evaluating regulatory policies.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.59.1-59.1
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• 2021

The Korean spacecraft for the exploration of Apophis will be equipped with an optical navigation camera with a wide-angle lens. The major purpose of the wide-angle camera is to capture imagery during the rendezvous phase in order to determine the spacecraft's position and the pointing direction relative to the asteroid Apophis. Two potential sciences, however, can be achieved by the wide-angle camera: (1) to measure the high-order gravity terms, and (2) to capture possible ejecting small particles. In this presentation, we will discuss instrument specification and operation scenario required to accomplish the given science objectives.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.239-240
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• 2023

Construction site management involves overseeing tasks from the construction phase to the maintenance stage, and digitalization of construction sites is necessary for digital construction site management. In this study, we aim to conduct research on object recognition at construction sites using drones. Images of construction sites captured by drones are reconstructed into BIM (Building Information Modeling) models, and objects are recognized after partially rendering the models using artificial intelligence. For the photorealistic rendering of the BIM models, both traditional filtering techniques and the generative adversarial network (GAN) model were used, while the YOLO (You Only Look Once) model was employed for object recognition. This study is expected to provide insights into the research direction of digital construction site management and help assess the potential and future value of introducing artificial intelligence in the construction industry.

• Molecular Medicine Reports
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• v.19 no.3
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• pp.1911-1918
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• 2019

Traditional herbal medicines are being increasingly used worldwide to treat cancer. Radix Sophorae Flavescentis (RSF) is a Chinese herb, which has numerous pharmacological properties, including anti-tumour effects. In this study, we investigated the mechanisms underlying RSF-induced apoptosis in human gastric cancer cells (AGS cells). We found that RSF treatment (20-200 ㎍/ml) inhibited the proliferation of AGS cells and increased the sub-G1 phase ratio. RSF-induced cell death was associated with the downregulation of BCl-2 and upregulation of Bax. In addition to increasing the expression levels of apoptosis-mediating surface antigen FAS and Fas ligand, RSF also activated caspase-3; however, mitogen-activated protein kinase appeared to inhibit RSF-induced cell death. RSF also led to an increased production of reactive oxygen species. Based on these results, we propose that RSF could be a potential therapeutic agent for gastric cancer.