• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.388-395
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• 2018

Significant efforts have been applied toward fabricating three-dimensional (3D) scaffolds using 3D-bioprinting tissue engineering techniques. Gelatin has been used in 3D-bioprinting to produce designed 3D scaffolds; however, gelatin has a poor printability and is not useful for fabricating desired 3D scaffolds using 3D-bioprinting. In this study, we fabricated pore size controlled 3D gelatin scaffolds with two step 3D-bioprinting approach: a low-temperature ($-10^{\circ}C$) freezing step and a crosslinking process. The scaffold was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The pore sizes of the produced 3D gelatin scaffolds were approximately 30% smaller than the sizes of the designed pore sizes. The surface morphologies and pore sizes of the 3D gelatin scaffolds were confirmed and measured using scanning electron microscopy (SEM). Human dermal fibroblasts (HDFs) were cultured on a 3D gelatin scaffold to evaluate the effect of the 3D gelatin scaffold pore size on the cell proliferation. After 14 days of culture, HDFs proliferation throughout the 3D gelatin scaffolds prepared with more than $580{\mu}m$ pore size was approximately 14% higher than proliferation throughout the 3D gelatin scaffold prepared with a $435{\mu}m$ pore size. These results suggested that control over the 3D gelatin scaffold pore size is important for tissue engineering scaffolds.

• Korean Journal of Materials Research
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• v.31 no.11
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• pp.619-625
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• 2021

Cu₂ZnSn(S,Se)₄ (CZTSSe) based thin-film solar cells have attracted growing attention because of their earth-abundant and non-toxic elements. However, because of their large open-circuit voltage (V_oc)-deficit, CZTSSe solar cells exhibit poor device performance compared to well-established Cu(In,Ga)(S,Se)₂ (CIGS) and CdTe based solar cells. One of the main causes of this large V_oc-deficit is poor absorber properties for example, high band tailing properties, defects, secondary phases, carrier recombination, etc. In particular, the fabrication of absorbers using physical methods results in poor surface morphology, such as pin-holes and voids. To overcome this problem and form large and homogeneous CZTSSe grains, CZTSSe based absorber layers are prepared by a sputtering technique with different RTA conditions. The temperature is varied from 510 ℃ to 540 ℃ during the rapid thermal annealing (RTA) process. Further, CZTSSe thin films are examined with X-ray diffraction, X-ray fluorescence, Raman spectroscopy, IPCE, Energy dispersive spectroscopy and Scanning electron microscopy techniques. The present work shows that Cu-based secondary phase formation can be suppressed in the CZTSSe absorber layer at an optimum RTA condition.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.105-112
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• 2022

The development and spread of IT-technologies has raised interest in teaching programming pupils. The article deals with problems related to programming and ways to overcome them. The importance of programming skills is emphasized, as this process promotes the formation of algorithmic thinking of pupils. The authors determined the level of pupils' interest to programing learning depending on the age. The analysis has showed that the natural interest of younger pupils in programming is decreasing over the years and in the most productive period of its study is minimized. It is revealed that senior school pupils are characterized by low level of interest in the study of programming; lack of motivation; the presence of psychological blocks on their own abilities in the context of programming; law level of computer science understanding. To overcome these problems, we conducted the second stage of the experiment, which was based on a change in the approach to programing learning, which involved pupils of non-specialized classes of senior school (experimental group). During the study of programming, special attention was paid to the motivational and psychological component, as well as the use of game technologies and teamwork of pupils. The results of the pedagogical experiment on studying the effectiveness of teaching programming for pupils of nonspecialized classes are presented. Improvement of the results provided the use of social and cognitive motives; application of verbal and non-verbal, external and internal means; communicative attacks; stimulation and psychological setting; game techniques, independent work and reflection, teamwork. The positive effect of the implemented methods is shown by the results verified by the methods of mathematical statistics in the experimental and control groups of pupils.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.816-827
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• 2021

The purpose of this study is to understand the relationship between fear and anger emotions in the discourse produced by the media during the period of major emerging infectious diseases (SARS, Swine Flu, MERS, and COVID-19) that occurred since 2000 in Korea. The researcher collected editorial articles of the major daily newspaper after a significant epidemic of new infectious diseases and analyzed them using the Extended Parallel Processing Model (EPPM) and text mining techniques. In all epidemic times, fear appears stronger than anger, but the smaller the fear, the greater the risk control message is produced. In detail, fear emerges strongly in the discourse of the risk of infectious diseases or the economic crisis. Anger appears strong when the government's quarantine failures, groups where group infections occurred, and concealing information about infectious diseases. In this process, anger is strongly expressed against the factors that threaten the safety of society. Anger is also an emotion that can justify strong quarantine, but it can be the basis for discourse on minority hate. In this respect, anger is a two-sided emotion, so it must be handled carefully in the media.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.420-426
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• 2022

Breast cancer is among the cancers that may be healed as the disease diagnosed at early times before it is distributed through all the areas of the body. The Automatic Analysis of Diagnostic Tests (AAT) is an automated assistance for physicians that can deliver reliable findings to analyze the critically endangered diseases. Deep learning, a family of machine learning methods, has grown at an astonishing pace in recent years. It is used to search and render diagnoses in fields from banking to medicine to machine learning. We attempt to create a deep learning algorithm that can reliably diagnose the breast cancer in the mammogram. We want the algorithm to identify it as cancer, or this image is not cancer, allowing use of a full testing dataset of either strong clinical annotations in training data or the cancer status only, in which a few images of either cancers or noncancer were annotated. Even with this technique, the photographs would be annotated with the condition; an optional portion of the annotated image will then act as the mark. The final stage of the suggested system doesn't need any based labels to be accessible during model training. Furthermore, the results of the review process suggest that deep learning approaches have surpassed the extent of the level of state-of-of-the-the-the-art in tumor identification, feature extraction, and classification. in these three ways, the paper explains why learning algorithms were applied: train the network from scratch, transplanting certain deep learning concepts and constraints into a network, and (another way) reducing the amount of parameters in the trained nets, are two functions that help expand the scope of the networks. Researchers in economically developing countries have applied deep learning imaging devices to cancer detection; on the other hand, cancer chances have gone through the roof in Africa. Convolutional Neural Network (CNN) is a sort of deep learning that can aid you with a variety of other activities, such as speech recognition, image recognition, and classification. To accomplish this goal in this article, we will use CNN to categorize and identify breast cancer photographs from the available databases from the US Centers for Disease Control and Prevention.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.146-160
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• 2023

Purpose: The construction industry is a complex mechanism in which multiple processes are carried out at the same time, and the frequency and severity of accidents account for a higher proportion than other industries, and the accident fatality rate also accounts for more than 50% of all industries. In order to reduce such accidents, the government's disaster investigation method analyzes the limitations from the system safety point of view and proposes improvement plans. Method: The main contents of the government's serious accident investigation were identified, and the effectiveness/adequacy was analyzed from the system safety point of view. Result: Disaster investigation and analysis techniques tailored to violations and compliance were limited in providing fundamental solutions, and alternatives for accident prevention were possible for each component of the system when safety constraints, controls, and hierarchical interactions were combined. Conclusion: When combining the disaster investigation and analysis method from the current accident analysis method from the perspective of system safety, it is possible to identify the problems of interaction by class and communication process, so it is possible to suggest alternatives to prevent accidents from an integrated perspective.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.437-444
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• 2008

In the paper, a methodology is verified to integrate IKONOS-2 satellite imagery and ALS dataset by compensating biases of RPC models. To achieve this, conjugate features from both data should be extracted in advance. For this purpose, linear features are chosen as conjugate features because they can be accurately extracted from man-made structures in urban area and more easily extracted than point features from ALS data. Then, observation equations are established from similarity measurements of the extracted features. During the process, several kinds of transformation functions were selected and used to register them. In addition, it was also analyzed how the number of linear features used as control features affects the accuracy of registration results. Finally, the results were evaluated by using check-points obtained from DGPS surveying techniques and it was clearly demonstrated that the proposed algorithms are appropriate to integrate these data.

• Smart Media Journal
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• v.12 no.5
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• pp.46-57
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• 2023

As the COVID-19 pandemic and the development of IT technology have led to the gradual popularization of remote and telecommuting, cloud computing technology is advancing, and cyber attack techniques are becoming more sophisticated and advanced. In response to these trends, companies are increasingly moving away from traditional perimeter-based security and adopting Zero Trust to strengthen their security. Zero Trust, based on the core principle of doubting and not trusting everything, identifies all traffic and grants access permissions through a strict authentication process to enhance security. In this paper, we analyze the background of Zero Trust adoption and the adoption policies and trends of countries that are proactively promoting its implementation. Additionally, we propose necessary efforts from governments and organizations to strengthen corporate security and considerations for companies when applying Zero Trust.

• 한국노년학
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• v.31 no.2
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• pp.401-417
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• 2011

The life review means a process of appraising life of oneself and it is essential for finding the meaning of life in old age. The memoir writing is a kind of method of life review. The memoir writing program used in this study focused especially on enhancing the cognitive skills by providing priming and retrieval support for memory performance in reminiscing past experiences. All fourteen participants were healthy and normal community dwellers and attended four-month long programof memoir writing classes which are consisted of different themes for each week. The aim of this study was to examine if the memoir writing program would render the positive effect on mental health and cognitive ability of the elderly. The results were that quality of life, life satisfaction, ego integrity of the participants showed positive change and the level of depression was significantly reduced compared to that of the control group. The findings in the present study suggest that the memoir writing can serve as one of the community initiative program to the growing population of the elderly for their emotional and cognitive challenges that they face everyday. To warrant the validity of the program, further study is needed for other sectors of elderly population, such as elderly living alone or those with both physical and/or cognitive disadvantages.

• Molecules and Cells
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• v.46 no.9
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• pp.538-544
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• 2023

The formation of uniform vitreous ice is a crucial step in the preparation of samples for cryogenic electron microscopy (cryo-EM). Despite the rapid technological progress in EM, controlling the thickness of vitreous ice on sample grids with reproducibility remains a major obstacle to obtaining high-quality data in cryo-EM imaging. The commonly employed classical blotting process faces the problem of excess water that cannot be absorbed by the filter paper, resulting in the formation of thick and heterogeneous ice. In this study, we propose a novel approach that combines the recently developed nanowire self-wicking technique with the classical blotting method to effectively control the thickness and homogeneity of vitrified ice. With simple procedures, we generated a copper oxide spike (COS) grid by inducing COSs on commercially available copper grids, which can effectively remove excess water during the blotting procedure without damaging the holey carbon membrane. The ice thickness could be controlled with good reproducibility compared to non-oxidized grids. Incorporated into other EM techniques, our new modification method is an effective option for obtaining high-quality data during cryo-EM imaging.