• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.309-316
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• 2024

Facial recognition technology is widely used in various fields but faces challenges due to its vulnerability to fraudulent activities such as photo spoofing. Extensive research has been conducted to overcome this challenge. Most of them, however, require the use of specialized equipment like multi-modal cameras or operation in high-performance environments. In this paper, we introduce LH-FAS v2 (: Lightweight Head-pose-based Face Anti-Spoofing v2), a system designed to operate on a commercial webcam without any specialized equipment, to address the issue of facial recognition spoofing. LH-FAS v2 utilizes FSA-Net for head pose estimation and ArcFace for facial recognition, effectively assessing changes in head pose and verifying facial identity. We developed the VD4PS dataset, incorporating photo spoofing scenarios to evaluate the model's performance. The experimental results show the model's balanced accuracy and speed, indicating that head pose estimation-based facial anti-spoofing technology can be effectively used to counteract photo spoofing.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.1
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• pp.71-82
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• 2024

With the advancement of information and communication technology (ICT), the use of electronic document types such as PDF, MS Office, and HWP files has increased. Such trend has led the cyber attackers increasingly try to spread malicious documents through e-mails and messengers. To counter such attacks, AI-based methodologies have been actively employed in order to detect malicious document files. The main challenge in detecting malicious HWP(Hangul Word Processor) files is the lack of quality dataset due to its usage is limited in Korea, compared to PDF and MS-Office files that are highly being utilized worldwide. To address this limitation, data augmentation have been proposed to diversify training data by transforming existing dataset, but as the usefulness of the augmented data is not evaluated, augmented data could end up harming model's performance. In this paper, we propose an effective semi-supervised learning technique in detecting malicious HWP document files, which improves overall AI model performance via quantifying the utility of augmented data and filtering out useless training data.

• IMMUNE NETWORK
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• v.16 no.4
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• pp.242-248
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• 2016

Thymic atrophy is a complication that results from exposure to many environmental stressors, disease treatments, and microbial challenges. Such acute stress-associated thymic loss can have a dramatic impact on the host's ability to replenish the necessary naïve T cell output to reconstitute the peripheral T cell numbers and repertoire to respond to new antigenic challenges. We have previously reported that treatment with the orexigenic hormone ghrelin results in an increase in the number and proliferation of thymocytes after dexamethasone challenge, suggesting a role for ghrelin in restraint stress-induced thymic involution and cell apoptosis and its potential use as a thymostimulatory agent. In an effort to understand how ghrelin suppresses thymic T cell apoptosis, we have examined the various signaling pathways induced by receptor-specific ghrelin stimulation using a restraint stress mouse model. In this model, stress-induced apoptosis in thymocytes was effectively blocked by ghrelin. Western blot analysis demonstrated that ghrelin prevents the cleavage of pro-apoptotic proteins such as Bim, Caspase-3, and PARP. In addition, ghrelin stimulation activates the Akt and Mitogen-activated protein kinases (MAPK) signaling pathways in a time/dose-dependent manner. Moreover, we also revealed the involvement of the FoxO3a pathway in the phosphorylation of Akt and ERK1/2. Together, these findings suggest that ghrelin inhibits apoptosis by modulating the stress-induced apoptotic signal pathway in the restraint-induced thymic apoptosis.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.209-218
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• 2015

This study aims to look into whether market merchant college education in Convergence to has any influence to the educational performance. For the purpose, 300 surveys were distributed to the ones who completed the course at ** city and in total 275 replies were selected out of 300. The age as of the subjects of this study suggests many of the most common are 91 people with more than 60 121 people 50s. This suggests that the age of a person engaged in the business owners have a lot of seniors. Dependant variable of this study, educational performance resulted in sales increase, help in self development with 82.4%, stronger confidence in success of business startup, overall satisfaction with the market merchant college education. Advanced studies regarding market merchant college and series of domestic and overseas documents were referred to for this study. As trait elements for market merchant college education, educational service, change intention, challenge spirit, decisive factors for customer communication were derived. Along with these elements, research model and hypothesis verifying the relationship with operational fund were established and empirical analysis and investigation was set as study objective.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.6
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• pp.1393-1403
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• 2003

The genetic effects of restraint stress challenge on HPA axis and the therapeutic effect of Boshimgeonbi-Tang on the stress were studied with cDNA microarray analyses on hypothalamus using an immobilization-stress mouse as stress model. Male CD-1 mice were restrained in a tightly fitted and ventilated vinyl holder for 2hours once a day, and this challenge was repeated for seven consecutive days. The body weights of the immobilization-stress mice were diminished about 25 percent degree as compared to normal ones. Seven days later, total RNA was extracted from the organs of the mouse, body-labeled with CyDye/sup TM/ fluorescence dyes (Amersham Bioscience Co., NJ), and then hybridized to cDNA microarray chip. Scanning and analyzing the array slides were carried out using GenePix 4000 series scanner and GenePix Pro/sup TM/ analyzing program, respectively. The expression profiles of 109 genes out of 6000 genes on the chip were significantly modulated in hypothalamus by the immobilization stress. Energy metabolism-, lipid metabolism-, apoptosis- and signal transduction-related genes were transcriptionally activated whereas DNA repair-, protein biosynthesis-, and structure integrity-related genes were down-regulated in hypothalamus. The 58 genes were up-regulated by the mRNA expression folds of 1.5 to 7.9. and the 51 genes were down-regulated by 1.5 - 3.5 fold. The 20 genes among them were selected to confirm the expression profiles by RT-PCR. The mRNA expression levels of Tnfrsf1a (apoptosis), Calm2 (cell cycle), Bag3 (apoptosis), Hspe1 (protein folding), Aatk (apoptosis), Dffa (apoptosis), Itgb1 (cell adhesion), Vcam1 (cell adhesion), Fkbp5 (protein folding), BDNF (neuron survival) were restored to the normal one by the treatment of Boshimgeonbi-Tang.

• Information Systems Review
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• v.12 no.3
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• pp.117-139
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• 2010

Online games are not only tools for enjoyment, they are also the linking pins connecting between the online and the offline worlds. The effects affecting other domains can be termed 'spillover'. With the process behaving as forward and reverse spillovers, there are interaction effects on online and offline behavior. However, there is little research dealing with the spillover effects from the offline to the online domain. This study concentrates on the individual behavior of online garners centering on offline dependence. With the purpose of finding the factors affecting both flow and immersion, I am interested in the moderator effect of offline dependence influencing both flow and immersion from social interaction. A research model is developed and a survey research is conducted from one of universities in Korea. The results show that flow is strongly influenced by skills, challenge, and social interaction, but immersion is only influenced by skills and social interaction and not challenge. The findings reveal that the moderating effect of offline dependence affects only the relationship from social interaction to the immersion on the lower offline dependence group.

• Journal of Korean Academy of Nursing
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• v.27 no.3
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• pp.541-549
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• 1997

This study was done to describe health promoting lifestyle and determine affecting factors in elderly based on the Heath Promotion Model by Pender. Cognitive-perceptual factors that were included in this study were self-efficacy and hardiness. Modifying factors were demographic characteristics (sex, age, partner, previous illness, education level. income and religion). The specific purpose of this study was to examine the relationships of self-efficacy, hardiness and the demographic chasteristics to health promoting lifestyle and to determine causal factors affecting the elderly. The subjects were a volunteer sample of 98 elderly in one city in? The instruments for this study were Health Promoting Lifestyle Profile(47items, 4scale), Health Related Hardiness Scale(22i1ems, 6scale), general Self-Efficacy Scale(13i1ems, 5scale). Frequency, percentage, t-test, ANOVA, Pearson's correlation coefficient and Stepwise Multiple regression technique with SAS program were used to analyse the data. The Results of the study are as follows : 1) The average item score for the health promoting lifestyle was 2.63, the highest score on the subscales was interpersonal support (M=3.3), followed by self-actulization(M=2.9), nutrition(M=2.8), stress management(M=2.7), health responsibility(M=2.1) with the lowest bring exercise(M=2.0) 2) A significant difference between education level, income, religion and health promoting lifestyle were found. 3) All of the subscales on health promoting lifestyle were positively related to total hardiness (r=0.330, p<0.001). The hardiness subscale of control was positively related to self-actulization(r=0.276, p<0.01), and commitment was positively related to self-actualization(r=0.315, p<0.001), exercise /nutrition(r=0.245, p<0.01), interpersonal support(r=0.278, p<0.01), stress management(r=0.250, p<0.01). Challenge was positively related to self-actualization(r=0.315, p<0.001), exercise /nutrition(r=0.245, p<0.01). There was no significant correlation between self-efficacy and all of the subscales of health promoting lifestyle. Self-efficacy showed a significant correlation only with control(r=0.469, p<0.001), comittment(r=0.507, p<0.001), challenge (r=0.489, p< 0.001). 4) Comittment, self-efficacy and income explained 25.01% of the variance for the total health promoting lifestyle. The results of this study show that commitment, self efficacy and income predicted the health promoting lifestyle of the elderly. So health promoting programs that increase commitement and self-efficacy should be developed to promote a healthy lifestyle of the elderly, especially those who have low income.

• Biomedical Science Letters
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• v.3 no.2
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• pp.77-82
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• 1997

One of the most important prerequisites of the industrial microorganism is that it should not be virulent to humans or economically important animals or plants. In this investigation, the microbiological characterization of T. madida N-5-3 strain was performed. And then, the virulence of the test strain in mouse model was examined systematically. The microbiological characteristics of the test strain were found to be fully consistent with those of typical T. madida. The i.p. lethal dose(LD)$_{50}$ of the test strain was greater than 1$\times$10$^8$, because there was no dead animal with the challenge doses upto the level of 1$\times$10$^8$. When 1$\times$10$^8$ yeast cells were challenged to the laboratory mice, T. madida N-5-3 strain was completely cleared from the liver and spleen in 4 days after challenge. And no pathological changes in the histological examination of the internal organs from challenged mice was observed. Above results can provide the predictability of the safety of T. madida N-5-3 strain for the industrial use in the view point of the public health aspect.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.1
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• pp.62-67
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• 2002

Purpose: The aim of this study was to investigate the age of onset and the prevalence of lactose malabsorption in early childhood in Korea. Methods: We conducted a study of lactose malabsorption by breath hydrogen test in healthy children aged between 25~96 months old. Standard lactose loading (2 g lactose/kg, maximum 40g) test was done in 129 children and cow's milk (10 mL/kg) loading in 126 children followed by breath sampling of 60 and 120 minutes after the loading. An increase above baseline of 20 ppm or more was used as a criteria for positive responses. Results: The prevalence of lactose malabsorption was 7% in 25~36 months old, 19% in 37~48 months old, 35% in 49~60 months old, 55% in 61~72 months old, 82% in 72~84 months old, 80% in 85~96 months old children. Only 1% of the children showed positive result in breath hydrogen test after the cow's milk challenge. Conclusion: The prevalence of lactose malabsorption was increased between 37 months and 60 months of age, reached to adult level of prevalence after 72 months of age. When physiological dose of lactose was used as the challenge, the number of lactose malabsorbers become clinically insignificant.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.203-211
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• 2020

Objective: Staphylococcus aureus (S. aureus) is one of the major microorganisms responsible for subclinical mastitis in dairy cattle. The present study was designed with the aim to explore the DNA methylation patterns using the Fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) techniques in a S. aureus-infected mouse model. Methods: A total of 12 out-bred Institute of Cancer Research female mice ranging from 12 to 13 weeks-old were selected to construct a mastitis model. F-MSAP analysis was carried out to detect fluctuations of DNA methylation between control group and S. aureus mastitis group. Results: Visible changes were observed in white cell counts in milk, percentage of granulocytes, percentage of lymphocytes, CD⁴⁺/CD⁸⁺ ratio (CD⁴⁺/CD⁸⁺), and histopathology of mice pre- and post-challenge with S. aureus. These findings showed the suitability of the S. aureus-infected mouse model. A total of 369 fragments was amplified from udder tissue samples from the two groups (S. aureus-infected mastitis group and control group) using eight pairs of selective primers. Results indicated that the methylation level of mastitis mouse group was higher than that in the control group. In addition, NCK-associated protein 5 (Nckap5) and transposon MTD were identified to be differentially methylated through secondary polymerase chain reaction and sequencing in the mastitis group. These observations might play an important role in the development of S. aureus mastitis. Conclusion: Collectively, our study suggests that the methylation modification in Nckap5 and transposon MTD might be considered as epigenetic markers in resistance to S. aureus-infected mastitis and provided a new insight into S. aureus mastitis research in dairy industry and public health.