• Korean Journal of Food Science and Technology
• /
• v.51 no.2
• /
• pp.160-168
• /
• 2019

This study aimed to determine whether double-processed ginseng berry extract (PGBC) could improve learning and memory in an $A\hat{a}42$-induced Alzheimer's mouse model. Passive avoidance test (PAT) and Morris water-maze test (MWMT) were performed after mice were treated with PGBC, followed by acetylcholine (ACh) measurement and glial fibrillary acidic protein (GFAP) detection for brain damage. Furthermore, acetylcholinesterase (AChE) activity and choline acetyltransferase (ChAT) expression were analyzed using Ellman's and qPCR assays, respectively. Results demonstrated that PGBC contained a high amount of ginsenosides (Re, Rd, and Rg3), which are responsible for the clearance of $A{\hat{a}} 42$. They also helped to significantly improve PAT and MWMT performance in the $A{\hat{a}} 42-induced$ Alzheimer's mouse model when compared to the normal group. Interestingly, ACh and ChAT were remarkably upregulated and AChE activities were significantly inhibited, suggesting PGBC to be a palliative adjuvant for treating Alzheimer's disease. Altogether, PGBC was found to play a positive role in improving cognitive abilities. Thus, it could be a new alternative solution for alleviating Alzheimer's disease symptoms.

• Journal of Christian Education in Korea
• /
• v.64
• /
• pp.203-235
• /
• 2020

The purpose of this study is to identify the degree of social presence perceived by students and to explore the factors that have affected it after practicing Christian Education classes as synchronous distance course due to Covid-19. It is also to suggest effective ways in the aspects of the design and operation to improve social presence. In order to measure social presence and derive influencing factors, research related to synchronous distance class and social presence is summarized through literature review. The researchers also surveyed 58 students in three courses of Christian education major at a University in Gyeonggi-do and conducted in-depth interviews with 6 students. The main findings are as follows: First, the sense of social presence was moderate, the emotional bond was the lowest by sub-factor, the open communication, the sense of community was moderate, and the mutual support and concentration were the highest. Second, factors that had a positive impact on the sense of social reality were group activities, selfintroduction activities, active participation in classes, mutual communication such as Q & A or response to peer learners' opinions during lectures by professors, questions, feedback, etc, and having a smaller number of students. Factors that had a negative impact on the perception of social presence were lack of private conversations, poor participation in classes, lack of communication with each other, and difficulty concentrating. The causes of these negative factors were technical problems and limitations arising from zoom, inconvenience and distracting surroundings, lack of time, and psychological awkwardness. Reflecting the results of the study, orientation to effective synchronous distance course, guidance on smooth communication methods, strengthening the role of professors to promote learning, strengthening group activities and learner-centered activities, and proposing a smaller scale of students were ways that are offered to improve the sense of social presence in synchronous distance courses.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.11
• /
• pp.1552-1563
• /
• 2016

To examine the cognitive function of onion (Allium cepa L.) beverages (odourless and fortified), we analyzed in vitro neuronal cell protection against $H_2O_2$-induced cytotoxicity and performed in vivo tests on amyloid beta ($A{\beta}$)-induced cognitive dysfunction. Cellular oxidative stress and cell viability were evaluated by DCF-DA assay and MTT assay. These results show that fortified beverage resulted in better neuronal cell protection than odourless beverage at lower concentration ($0{\sim}100{\mu}g/mL$). Fortified beverage also showed more excellent acetylcholinesterase (AChE) inhibitory activity ($IC_{50}$: 4.20 mg/mL) than odourless beverage. The cognitive functions of odourless beverage and fortified beverage in $A{\beta}$-induced neurotoxicity were assessed by Y-maze, passive avoidance, and Morris water maze tests. The results show improved cognitive function in both groups treated with beverages. After in vivo tests, cholinergic activities were determined based on AChE inhibition and acetylcholine levels, and antioxidant activities were measured as SOD, oxidized glutathione (GSH)/total GSH ratio, and MDA levels in mouse brain tissue. In a Q-TOF UPLC/MS system, main compounds were analyzed as follows: odourless beverage (five types of sugars and three types of phenolics) and fortified beverages (six types of phenolics and two types of steroidal saponins).

• The Journal of the Korea Contents Association
• /
• v.14 no.1
• /
• pp.30-39
• /
• 2014

The purpose of this study is to suggest the feasible strategies to vitalize e-learning through investigating the characteristics of e-learning and the evaluations of distance learners on online courses in the domestic universities in Korea. First, in order to accomplish this, 10 Universities and 17 Cyber Universities were selected to explore their characteristics and main projects of e-learning for the administration level investigation. Secondly, content analysis of the bulletin board systems(BBS) and in-depth interviews on distance learners in Cyber Universities were conducted for the user level investigation. The results revealed that Universities in Korea were focused on establishing mobile or smart campuses, diversifying online educational contents, enhancing online interactive systems, and educating e-learning system and smart device utilization. However, distance learners reported that mobile e-learning lacked stability when taking online courses despite its convenience for purpose of academic administration. In addition, distance learners requested the social application workshops to improve on their learning experience as well as the interactions among peers. Therefore, it is important to focus more on how to establish the education-oriented e-learning environment rather than how to implement the administrative projects to animate e-learning in the domestic universities in Korea.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.5B
• /
• pp.405-414
• /
• 2011

The adaptive network-based fuzzy inference system (ANFIS) which had a success for time series prediction and system control was applied for modeling the hourly runoff in the Gapcheon watershed. The ANFIS used the antecedent rainfall and runoff as the input. The ANFIS was trained by varying the various simulation factors such as mean areal rainfall estimation, the number of input variables, the type of membership function and the number of membership function. The root mean square error (RMSE), mean peak runoff error (PE), and mean peak time error (TE) were used for validating the ANFIS simulation. The ANFIS predicted runoff was in good agreement with the measured runoff and the applicability of ANFIS for modelling the hourly runoff appeared to be good. The forecasting ability of ANFIS up to the maximum 8 lead hour was investigated by applying the different input structure to ANFIS model. The accuracy of ANFIS for predicting the hourly runoff was reduced as the forecasting lead hours increased. The long-term predictability of ANFIS for forecasting the hourly runoff at longer lead hours appeared to be limited. The ANFIS might be useful for modeling the hourly runoff and has an advantage over the physically based models because the model construction of ANFIS based on only input and output data is relatively simple.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.5
• /
• pp.738-742
• /
• 2005

This study was designed to investigate the anti-dementia effects of acorn (Quercus acutissima CARR.) in brain of the mouse. Dementia model was induced by administration of scopolamin (30 mg/kg BW) Male ICR mouse $(30{\pm}2g\;BW)$ were fed basal diet (control group), and experimental diets (AP-5 and AP-10 groups) added $5\%\;and\;10\%$ of dried acorn powder to basal diet for 8 months. Acetylcholine content significantly increase in AP-5 and AP-10 groups ($4.2\%\;and\;11.3\%$, respectively) compared with control group. Acetylcholinesterase activities were significantly inhibited ($13.5\%\;and\;17.6\%$, respectively) in brain of AP-5 and AP-10 groups. Monoamine oxidase-B (MAO-B) activities were significantly inhibited ($10.0\%\;and\;12.7\%$, respectively) in brain of AP-S and AP-10 groups. These results suggest that acorn (Q. acutissima CARR.) may play an effective role in an attenuating various age-related changes such as dementia including learning and memory impairments in brain.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.41 no.1
• /
• pp.44-50
• /
• 2013

The persons in charge of management request diagnosis and prescription to tree hospitals in order to get consultation about the problems like blight that occur in landscape tree management. This study aims to analyze what the main problems and questions raised by landscape gardeners are and those concerned in landscape tree management. This is done by investigating landscape tree-related questions and answers uploaded on the online consultation boards of the plant diagnostic centers approved in Korea including the Seoul National University Plant Clinic, the Chungbuk National University Plant Hospital, and the Kangwon Diagnostic Center. As a result, those concerned in landscape occupied the most as 81.4% among the questioners. However, only 11.5% did explain the plant management history or surrounding environment, which is essential for landscape tree diagnosis when asking questions. This shows that those concerned in landscape lack basic knowledge or interest about plant diagnosis. Among 263 questions about landscape trees, questions about physiological damage included 94 cases that were the most taking up 35.8%. Moreover, the next were damage by insects and damage by disease in order. It is thought that due to the characteristics of physiological problems that occur by various sorts of stress and with no signs, they tend to request diagnosis or prescription the most. The most frequent reasons for physiological damage are water stress and temperature stress. About damage by disease, there exist many types of diseases, and there are many complex damages accompanied by physiological causes. About damage by insects, the most common include damage by moths. In consideration of this result, universities or technician training centers should provide education for landscape tree management so that landscape technicians and students can acquire essential knowledge and information about landscape tree management and increase their interest in it. In particular, it is necessary to provide profound learning opportunities for plant physiology, and the technicians should make efforts themselves. In addition, it is needed to build organizations to which they can ask technical questions about landscape planting and management in order to understand landscape industry in general and the actual status of landscape planting technique and the actual field. Moreover, to elevate systemicity and expertise in the area of landscape tree management not yet equipped with the foundation, it is needed to cultivate the technicians intensively and conduct research by those concerned both in academic and industrial circles.

• Journal of Nutrition and Health
• /
• v.52 no.4
• /
• pp.383-398
• /
• 2019

Purpose: This study investigated an association between dietary quality and use of convenience foods at convenience stores among high school students. Methods: A total of 474 high school students (225 boys and 249 girls) residing in Incheon participated in this questionnaire survey in June 2018. The subjects were divided into three groups according to the frequency of consumption of convenience foods at convenience stores; less than once a week, 1 ~ 2 times a week, and more than 3 times a week. Dietary quality was assessed using a nutrient quotient for adolescents (NA-Q). Logistic regression was used to investigate an association between dietary quality and use of convenience foods at convenience stores among high school students. Results: For boys and girls, higher monthly allowance was significantly associated with the higher frequency of consumption of convenience foods at convenience stores, whereas school grade, mother's occupational status, family size, extracurricular study, and eating speed were not significantly associated with the frequency of consumption of convenience foods. Higher intake frequency of cookies or sweet and greasy bread, processed beverage, Ramyon, night-time snack, and street food was significantly associated with the higher frequency of consumption of convenience foods for boys or girls. Boys and girls, who had a higher frequency of consumption of convenience foods at convenience stores had significantly greater odds for being in the low grade of dietary quality, especially in the moderation factor. Conclusion: The students who used convenience stores more often appeared to have more monthly allowance and to consume undesirable foods more often. Higher frequency of using convenience foods at convenience stores among high school students was associated with lower dietary quality. These study results can support efforts to provide nutrition education programs and guidelines to students who frequently use convenience foods at convenience stores.

• Journal of Intelligence and Information Systems
• /
• v.25 no.2
• /
• pp.39-55
• /
• 2019

Recently banks and large financial institutions have introduced lots of Robo-Advisor products. Robo-Advisor is a Robot to produce the optimal asset allocation portfolio for investors by using the financial engineering algorithms without any human intervention. Since the first introduction in Wall Street in 2008, the market size has grown to 60 billion dollars and is expected to expand to 2,000 billion dollars by 2020. Since Robo-Advisor algorithms suggest asset allocation output to investors, mathematical or statistical asset allocation strategies are applied. Mean variance optimization model developed by Markowitz is the typical asset allocation model. The model is a simple but quite intuitive portfolio strategy. For example, assets are allocated in order to minimize the risk on the portfolio while maximizing the expected return on the portfolio using optimization techniques. Despite its theoretical background, both academics and practitioners find that the standard mean variance optimization portfolio is very sensitive to the expected returns calculated by past price data. Corner solutions are often found to be allocated only to a few assets. The Black-Litterman Optimization model overcomes these problems by choosing a neutral Capital Asset Pricing Model equilibrium point. Implied equilibrium returns of each asset are derived from equilibrium market portfolio through reverse optimization. The Black-Litterman model uses a Bayesian approach to combine the subjective views on the price forecast of one or more assets with implied equilibrium returns, resulting a new estimates of risk and expected returns. These new estimates can produce optimal portfolio by the well-known Markowitz mean-variance optimization algorithm. If the investor does not have any views on his asset classes, the Black-Litterman optimization model produce the same portfolio as the market portfolio. What if the subjective views are incorrect? A survey on reports of stocks performance recommended by securities analysts show very poor results. Therefore the incorrect views combined with implied equilibrium returns may produce very poor portfolio output to the Black-Litterman model users. This paper suggests an objective investor views model based on Support Vector Machines(SVM), which have showed good performance results in stock price forecasting. SVM is a discriminative classifier defined by a separating hyper plane. The linear, radial basis and polynomial kernel functions are used to learn the hyper planes. Input variables for the SVM are returns, standard deviations, Stochastics %K and price parity degree for each asset class. SVM output returns expected stock price movements and their probabilities, which are used as input variables in the intelligent views model. The stock price movements are categorized by three phases; down, neutral and up. The expected stock returns make P matrix and their probability results are used in Q matrix. Implied equilibrium returns vector is combined with the intelligent views matrix, resulting the Black-Litterman optimal portfolio. For comparisons, Markowitz mean-variance optimization model and risk parity model are used. The value weighted market portfolio and equal weighted market portfolio are used as benchmark indexes. We collect the 8 KOSPI 200 sector indexes from January 2008 to December 2018 including 132 monthly index values. Training period is from 2008 to 2015 and testing period is from 2016 to 2018. Our suggested intelligent view model combined with implied equilibrium returns produced the optimal Black-Litterman portfolio. The out of sample period portfolio showed better performance compared with the well-known Markowitz mean-variance optimization portfolio, risk parity portfolio and market portfolio. The total return from 3 year-period Black-Litterman portfolio records 6.4%, which is the highest value. The maximum draw down is -20.8%, which is also the lowest value. Sharpe Ratio shows the highest value, 0.17. It measures the return to risk ratio. Overall, our suggested view model shows the possibility of replacing subjective analysts's views with objective view model for practitioners to apply the Robo-Advisor asset allocation algorithms in the real trading fields.