• Korean Journal of Biological Psychiatry
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• v.18 no.1
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• pp.36-45
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• 2011

Objectives : Though a proportion of Alzheimer's disease(AD) patients treated with donepezil have shown positive response on cognition, but the responders' characteristics are still uncertain. This study attempts to identify whether a single oral dose of donepezil(5mg) can change cognition and the relationship between single dose responder items and long-term responder are examined. Methods : Twenty-three AD patients for single donepezil challenge study group and eleven AD patients for controls were participated in the study. Seven days after baseline study for neuropsychological test and EEG, same studies were rechecked after donepezil medication in study group. In donepezil study groups, 12 weeks after donepezil medication, neuropsychological test and EEG were rechecked. Results : After single donepezil challenge, forward digit span, Rey-Osterrieth Complex Figure Test copy, SVLT delayed recall were significantly improved, and beta spectra power in anterior, theta spectra power in posterior field were significantly decreased. According to linear regression analysis, forward digit span after single donepezil challenge was significantly positive correlated with long-term responders. Conclusions : This study suggests that single donepezil medication can significantly change cognitive functions and EEG in AD patients. Among these responsive items, forward digit span was significantly correlated with long-term responder.

• Nutritional Sciences
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• v.2 no.2
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• pp.119-124
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• 1999

Food allergies play an important role in Atopic Dermatitis (AD). Dietary manipulation is essential in the management of AD. However, there has been a paucity of data reporting the prevalence of food allergies in AD patients in Korea. In this study, the Food Open Challenge Tests (FOCT) were conducted to investigate food allergies in AD patients. The skin-prick test and the detection of specific IgE, as well as allergy history of patient were used to detect food allergies in all AD patients. Elimination diet was conducted for two weeks prior to FOCTs. The prevalence of food allergies by FOCT is as follows: milk (67.3%); chicken (64.2%); pork (62.8%); eggs (61.0%); beef(55.4%) ; wheat (52.0%) and soybean (45.2%). Allergenic food items in Korean AD patients were different from people in other foreign countries. The seven major foods those tested positively by FOCTs were completely eliminated from the replaced diets for two weeks, and were subsequently reintroduced one at a time. Results from FOCTs were not comparable with allergy history or skin-prick tests or specific IgE detection. The sensitivity and specificity of skin-prick tests and specific IgE detection were lower than FOCTs. Allergy history, skin-prick tests, and specific IgE detection are useful for the identification of food allergen but its clinical significance differed according to food items. Therefore, we conclude that even though a 10-day delay was necessary after food challenge, FOCT is a useful and valid method to confirm food allergies and may be essential for the effective control of food allergies for treatment of AD.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.1
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• pp.26-37
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• 2009

Recently rapid environmental changes due to desertification and industrialization in China make a threat to Korea, especially during Asian Dust Event (ADE). This study was aimed to compare symptoms and behaviors related to ADE between Korea and China. We conducted questionnaires on self-reported symptoms and behaviors before and during ADE. Korean and Chinese subjects were grouped into children, adults, and elderly by nation (n=791). Statistical analyses were performed by $X^2$-test, Fisher's exact test, t-test and chow's test for comparing differences between Korean and Chinese. We estimated the odds ratio for perceived symptoms during ADE by preventive behavior, using Generalized Estimation Equation (GEE). The study indicated that there were significant differences between symptoms in Korea and those in China such as cold, cough, and sore throat, especially in elderly. Preventive behaviors such as avoiding outdoor activity and wearing sunglasses were more often performed in China than Korea. However wearing mask was more often performed in Korea than China. After adjusting for age, sex, educational level, and smoking status, the odds ratio (OR) of dry cough symptom in Korea was significantly decreased by closing the windows and wearing a mask during ADE. In China, the OR of dry cough symptom was decreased by wearing a mask and avoiding outdoor activity. We found that China which had higher performance of preventive behavior showed lower prevalence of symptoms during ADE than Korea. Also preventive behaviors could affects prevalence of symptoms during ADE. This results suggest that preventive behavior. could reduce symptoms during ADE and there are needed for. more attentions to reduce a threat of ADE.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.1-5
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• 2014

The diagnosis and treatment of cow's milk protein allergy (CMPA) is still a challenge. A systematic literature search was performed using Embase, Medline, The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials for the diagnosis and treatment of cow's milk allergy (CMA). Since none of the symptoms of CMPA is specific and since there is no sensitive diagnostic test (except a challenge test), the diagnosis of CMPA remains difficult. A "symptom-based score" is useful in children with symptoms involving different organ systems. The recommended dietary treatment is an extensive cow milk based hydrolysate. Amino acid based formula is recommended in the most severe cases. However, soy infant formula and hydrolysates from other protein sources (rice) are gaining popularity, as they taste better and are cheaper than the extensive cow's milk based hydrolysates. Recent meta-analyses confirmed the safety of soy and estimate that not more than 10-15% of CMPA-infants become allergic to soy. An accurate diagnosis of CMA is still difficult. The revival of soy and the development of rice hydrolysates challenge the extensive cow's milk based extensive hydrolysates as first option and amino acid formula.

• Biomolecules & Therapeutics
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• v.2 no.4
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• pp.331-335
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• 1994

As a part of the safety evaluation of Pseudomonas vaccine(CFC-101), antigenicity tests were carried out in guinea pigs and mice. In active systemic anaphylaxis(ASA) test, guinea pigs showed no sign or only moderate sign(1/5) when sensitized and challenged with up to 200 $\mu\textrm{g}$/kg. In homologous passive cutaneous anaphylaxis(PCA) test using guinea pigs, inoculation of CFC-101 alone did not produce CFC-101-specific antibody. When inoculated with 200 $\mu\textrm{g}$/kg plus adjuvant, challenge of 200 $\mu\textrm{g}$/kg produced PCA titer of 32(5/5) but challenge of 20 $\mu\textrm{g}$/kg did not produce CFC-101-specific antibody. In heterologous PCA test using mice, CFC-101-specific antibody was not detected when sensitized with CFC-101 alone. Some animals(3/12) showed positive PCA response when inoculated with 200 $\mu\textrm{g}$/kg plus alum. In passive hemagglutination (PHA) test, although no antibody was detected at 20 $\mu\textrm{g}$/kg, inoculation of 200 $\mu\textrm{g}$/kg alone or with alum produced positive response in all animals. This result has already been predicted because CFC-101 is a vaccine developed for the purpose of immunization. From the above results, it can be concluded that there is no adverse antigenic potential up to 10 times clinical dose of 200 $\mu\textrm{g}$/kg.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4742-4770
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• 2019

Cloud computing provides a broad range of services like operating systems, hardware, software and resources. Availability of these services encourages data owners to outsource their intensive computations and massive data to the cloud. However, considering the untrusted nature of cloud server, it is essential to encrypt the data before outsourcing it to the cloud. Unfortunately, this leads to a challenge when it comes to providing search functionality for encrypted data located in the cloud. To address this challenge, this paper presents a public key encryption with equality test for heterogeneous systems (PKE-ET-HS). The PKE-ET-HS scheme simulates certificateless public encryption with equality test (CLE-ET) with the identity-based encryption with equality test (IBE-ET). This scheme provides the authorized cloud server the right to actuate the equivalence of two messages having their encryptions performed under heterogeneous systems. Basing on the random oracle model, we construct the security of our proposed scheme under the bilinear Diffie-Hellman (BDH) assumption. Eventually, we evaluate the size of storage, computation complexities, and properties with other related works and illustrations indicate good performance from our scheme.

• International Journal of Contents
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• v.18 no.3
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• pp.58-65
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• 2022

This study proposed a soft skill integration activity for online EFL classrooms and investigated student responses. Toward this end, this study recruited 54 college students taking an English Presentation and Discussion class in South Korea. Participants were assigned into high and low-proficiency groups based on the Test of English for International Communication. This study employed questionnaire, class video recordings, and interview to obtain responses. Moreover, problem-based learning with challenge questions was applied to develop soft skills in online synchronous classes. Responses were examined in terms of whether a difference existed according to English proficiency. Major findings of this study were as follows. Regardless of proficiency levels, participants reported improvements in their IT and problem-solving skills and exhibited positive attitudes toward live online presentations via Zoom. However, this study observed significant differences in communication and teamwork skills, perceived learning, and confidence. Interviews with students with low English proficiency levels revealed that they were negatively affected by the lack of non-verbal cues, mechanical skills, and socialization time provided by online classes. Based on these results, pedagogical implications and directions for future studies are discussed.

• Journal of The Korean Association of Information Education
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• v.23 no.1
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• pp.65-72
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• 2019

As the importance of SW education grows, researches are actively being conducted to improve students' thinking skills. We conducted the group III tasks, which are experiencing and challenging in Beaver Challenge 2018, on 55 students of 5th grade in elementary school. Based on the result, we analyzed their average scores and defined whether each test has a correlation with possession of smartphone, computer familiarity, patience, concentration, and academic ability. The result indicated challenging task boosted the average score, the percentage of correct answers, and the percentage of correct answers for each level of difficulty. Moreover, the challenge task scores were higher as they higher computer familiarity, patience and concentration level. However, possession of smartphones and academic ability did not affect the score. Lastly, the scores were affected by different factors in different level of difficulty that patience factor in advanced level, computer familiarity factor in intermediate level, and concentration factor in beginner level. Thus, further researches are necessary to be conducted to expand the scope of the analysis through the diversification of test subject group and expansion of an evaluation area.

• Journal of Global Scholars of Marketing Science
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• v.17 no.2
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• pp.1-29
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• 2007

The flow theory becomes one of the most important frameworks in the internet research arena. Hoffman and Novak proposed a hierarchical flow model showing the antecedents and outcomes of flow and the relationship among these variables in the hyper-media computer circumstances (Hoffman and Novak 1996). This model was further tested after their initial research (Novak, Hoffman, and Yung 2000). At their paper, Hoffman and Novak explained that the balance of challenge and skill leads to flow which means the positive optimal state of mind (Hoffman and Novak 1996). An imbalance between challenge and skill, leads to negative states of mind like anxiety, boredom, apathy (Csikszentmihalyi and Csikszentmihalyi 1988). Almost all research on the flow 4-channel model have been focusingon flow, the positive state of mind (Ellis, Voelkl, and Morris 1994 Mathwick and Rigdon 2004). However, it also needs to examine the formation of the negative states of minds and their outcomes. Flow researchers explain play or playfulness as antecedents or the early state of flow. However, play has been regarded as a distinct concept from flow in the flow literatures (Hoffman and Novak 1996; Novak, Hoffman, and Yung 2000). Mathwick and Rigdon discovered the influences of challenge and skill on play; they also observed the influence of play on web-loyalty and brand loyalty (Mathwick and Rigdon 2004). Unfortunately, they did not go so far as to test the influences of play on state of mind. This study focuses on the relationships between state of mind in the flow 4-channel model and play. Early research has attempted to hypothetically explain state of mind in flow theory, but has not been tested except flow until now. Also the importance of play has been emphasized in the flow theory, but has not been tested in the flow 4-channel model context. This researcher attempts to analyze the relationships among state of mind, skill of play, challenge, state of mind and web loyalty. For this objective, I developed a measure for state of mind and defined the concept of play as a trait. Then, the influences of challenge and skill on the state of mind and play under on-line shopping conditions were tested. Also the influences of play on state of mind were tested and those of flow and play on web loyalty were highlighted. 294 undergraduate students participated in this research survey. They were asked to respond about their perceptions of challenge, skill, state of mind, play, and web-loyalty to on-line shopping mall. Respondents were restricted to students who bought products on-line in a month. In case of buying products at two or more on-line shopping malls, they asked to respond about the shopping mall where they bought the most important one. Construct validity, discriminant validity, and convergent validity were used to check the measurement validations. Also, Cronbach's alpha was used to check scale reliability. A series of exploratory factor analyses was conducted. This researcher conducted confirmatory factor analyses to assess the validity of measurements. All items loaded significantly on their respective constructs. Also, all reliabilities were greater than.70. Chi-square difference tests and goodness of fit tests supported discriminant and convergent validity. The results of clustering and ANOVA showed that high challenge and high skill leaded to flow, low challenge and high skill leaded to boredom, and low challenge and low skill leaded to apathy. But, it was different from my expectation that high challenge and low skill didnot lead to anxiety but leaded to apathy. The results also showed that high challenge and high skill, and high challenge and low skill leaded to the highest play. Low challenge leaded to low play. 4 Structural Equation Models were built by flow, anxiety, boredom, apathy for analyzing not only the impact of play on state of mind and web-loyalty, but also that of state of mind on web-loyalty. According the analyses results of these models, play impacted flow and web-loyalty positively, but impacted anxiety, boredom, and apathy negatively. Results also showed that flow impacted web-loyalty positively, but anxiety, boredom, and apathy impacted web-loyalty negatively. The interpretations and implications of the test results of the hypotheses are as follows. First, respondents belonging to different clusters based on challenge and skill level experienced different states of mind such as flow, anxiety, boredom, apathy. The low challenge and low skill group felt the highest anxiety and apathy. It could be interpreted that this group feeling high anxiety or fear, then avoided attempts to shop on-line. Second, it was found that higher challenge leads to higher levels of play. Test results show that the play level of the high challenge and low skill group (anxiety group) was higher than that of the high challenge and high skill group (flow group). However, this was not significant. Third, play positively impacted flow and negatively impacted boredom. The negative impacts on anxiety and apathy were not significant. This means that the combination of challenge and skill creates different results. Forth, play and flow positively impacted web-loyalty, but anxiety, boredom, apathy had negative impacts. The effect of play on web-loyalty was stronger in case of anxiety, boredom, apathy group than fl ow group. These results show that challenge and skill influences state of mind and play. Results also demonstrate how play and flow influence web-loyalty. It implies that state of mind and play should be the core marketing variables in internet marketing. The flow theory has been focusing on flow and on the positive outcomes of flow experiences. But, this research shows that lots of consumers experience the negative state of mind rather than flow state in the internet shopping circumstance. Results show that the negative state of mind leads to low or negative web-loyalty. Play can have an important role with the web-loyalty when consumers have the negative state of mind. Results of structural equation model analyses show that play influences web-loyalty positively, even though consumers may be in the negative state of mind. This research found the impacts of challenge and skill on state of mind in the flow 4-channel model, not only flow but also anxiety, boredom, apathy. Also, it highlighted the role of play in the flow 4-channel model context and impacts on web-loyalty. However, tests show a few different results from hypothetical expectations such as the highest anxiety level of apathy group and insignificant impacts of play on anxiety and apathy. Further research needs to replicate this research and/or to compare 3-channel model with 4-channel model.

• Journal of Food Hygiene and Safety
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• v.20 no.1
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• pp.13-17
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• 2005

The purpose of the present study was to investigate differences in the sensitizing potential of Rhus Veniciflua(Rhus-II), when tested by the guinea pig maximization test(GPMT) and Freund's complete adjuvant test(FCAT) with an identical, intradermal induction concentration. A new grading classification of the sensitization potential is proposed. The GPMT was conducted according to OECD guideline $\#406$, using a multiple-dose design and test results were analysed with logistic regression analysis. During the induction stage, we injected intradermally each three site 0.1 ml(l mg/animal) test material, 0.1 ml complete Freund's adjuvant and 0.lml the test agent emulsified in the adjuvant. 7 days later, we induced weak sensitization with $10\%$ sodium lauryl sulfate(SLS) and applide 1ml(l0mg/animal) test agent topically on the same site and made a tight occlusion. 14 days later we challenged with 1 ml(l 0mg/animal) of test material on the flank and observed ant 24 hours and 48 hours later. The results were also observed $0\%$ at 24 hours challenge. The results observed 48 hours after challenge were the identical. These data indicated that, although Rhus-II is a no contact allergen. It was reported that the skin sensitization by Rhus-II was not detected the skin sensitization in the guinea pig maximization test (GPMT). Consequently, it was confirmed that Rhus-II had no contact allergic sensitization in guinea pig maximization test.