• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.179-192
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• 2014

Keeping in line with the recent changes in the information technology environment, the online learning environment that supports multiple users' participation such as MOOC (Massive Open Online Courses) has become important. One of the largest professional associations in Information Technology, IEEE Computer Society, announced that "Supporting New Learning Styles" is a crucial trend in 2014. Popular MOOC services, CourseRa and edX, have continued to build active learning environment with a large number of lectures accessible anywhere using smart devices, and have been used by an increasing number of users. In addition, collaborative web services (e.g., blogs and Wikipedia) also support the creation of various user-uploaded learning materials, resulting in a vast amount of new lectures and learning materials being created every day in the online space. However, it is difficult for an online educational system to keep a learner' motivation as learning occurs remotely, with limited capability to share knowledge among the learners. Thus, it is essential to understand which materials are needed for each learner and how to motivate learners to actively participate in online learning system. To overcome these issues, leveraging the constructivism theory and collective intelligence, we have developed a social bookmarking system called WeStudy, which supports learning material sharing among the users and provides personalized learning material recommendations. Constructivism theory argues that knowledge is being constructed while learners interact with the world. Collective intelligence can be separated into two types: (1) collaborative collective intelligence, which can be built on the basis of direct collaboration among the participants (e.g., Wikipedia), and (2) integrative collective intelligence, which produces new forms of knowledge by combining independent and distributed information through highly advanced technologies and algorithms (e.g., Google PageRank, Recommender systems). Recommender system, one of the examples of integrative collective intelligence, is to utilize online activities of the users and recommend what users may be interested in. Our system included both collaborative collective intelligence functions and integrative collective intelligence functions. We analyzed well-known Web services based on collective intelligence such as Wikipedia, Slideshare, and Videolectures to identify main design factors that support collective intelligence. Based on this analysis, in addition to sharing online resources through social bookmarking, we selected three essential functions for our system: 1) multimodal visualization of learning materials through two forms (e.g., list and graph), 2) personalized recommendation of learning materials, and 3) explicit designation of learners of their interest. After developing web-based WeStudy system, we conducted usability testing through the heuristic evaluation method that included seven heuristic indices: features and functionality, cognitive page, navigation, search and filtering, control and feedback, forms, context and text. We recruited 10 experts who majored in Human Computer Interaction and worked in the same field, and requested both quantitative and qualitative evaluation of the system. The evaluation results show that, relative to the other functions evaluated, the list/graph page produced higher scores on all indices except for contexts & text. In case of contexts & text, learning material page produced the best score, compared with the other functions. In general, the explicit designation of learners of their interests, one of the distinctive functions, received lower scores on all usability indices because of its unfamiliar functionality to the users. In summary, the evaluation results show that our system has achieved high usability with good performance with some minor issues, which need to be fully addressed before the public release of the system to large-scale users. The study findings provide practical guidelines for the design and development of various systems that utilize collective intelligence.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.299-313
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• 2018

Inquiry-centered education is important in science education, but in the actual education field, scientific research is being done in a uniform manner due to realistic difficulties. In this study, we use RS (Reverse Science) as a secondary chemistry class to provide opportunities for students to engage in inquiry learning and scientific thinking through process-oriented activities. In this study, we developed and applied it to explore the effects on the scientific inquiry abilities of middle school students and checked the students' perception of it. For the application of the program, 128 students were selected from 6 classes of the 2nd grade in D district middle school, 64 from the experimental group and 64 from the comparative group. The experimental group taught RSP-based the chemistry inquiry programs and the comparative group taught instructor-led classes and verification experiments on the same topic over the seventh hour with three themes. In addition, we analyzed the results of the pre- and post-test by using the science inquiry ability test, and discussed the effects of the program based on the students' perceptions through class observation, student activity area, questionnaire and interview. As a result, the class using the program showed statistically significant changes in the science inquiry ability of secondary school students. Specifically, the experimental group was found to be significant in its prediction among the subcomponents of basic exploration ability compared to the comparative group. The differences have also been shown to be significant in terms of data translation, hypothesis setup and variable control, which are subcomponents of integrated exploration capabilities (p <. 05). In addition, students became interested in the process of creating the theory of science, and were highly interested in collaborating with their friends. It also provided students with opportunities to experience scientific thinking through process-oriented inquiry. Finally, based on the positive impact of the RSP-based chemistry inquiry program on students, we were able to identify the potential use of the program.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.196-202
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• 2007

Skin wrinkles are associated with collagen synthesis and matrix metalloproteinase-I (MMP-1) activity. This study was carried out to select optimum ratio of 3 herbs in skin health food for anti-wrinkle. Human dermal fibroblast cell was incubated with experimental samples, which were Korean red ginseng ethanol extracts (ER), Torilis fructus water extracts (WT), Corni fructus water extracts (WC) and their mixtures (WM1, WM3). And then we determined effects on collagen biosynthesis, MMP-1 activity and SOD activity in human dermal fibroblast cell. In control group, collagen biosynthesis was amounted at 474.8 ng/ml and 533.9 ng/ml, 539.3 ng/ml, 514.1 ng/ml in ER, WT and WC respectively. Furthermore, WM3 (KTNG0345) was increased to 561.45 ng/ml. MMP-1 activity of ER, WT, WC, WM1 were determined to 31.9 ng/ml, 32.85 ng/ml, 32.0 ng/ml, 31.3 ng/ml and WM3 (KTNG0345) was decreased to 28.85 ng/ml. In addition, the experimental samples showed a antioxidative activities. From this results, we conclude that Korean red ginseng ethanol extracts, Torilis fructus water extracts, Corni fructus water extracts and their mixtures have a anti-wrinkle effect and WM3 (KTNG0345) may be regarded as an optimum composition for synergic effect producing. The standardized components of KTNG0345, ginsenoside-$Rb_1$, torilin and loganin were identified at 10.85 mg/g, 0.128 mg/g and 3.92 mg/g respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.211-219
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• 2004

Yew (Taxus cuspidata Sieb.) chose that grow as medicine, food, decorative plant in Korea's Kyong-Gi province surroundings. Extracts of yew extracted leaf of 250g and stems of 300g with 1,3-butylene glycol (l,3-BG), propylene glycol (PG) and water. As results, external appearance of leaf extract of yew was slightly brown clear extract. The pH was 5.3${\pm}$0.5, and specific gravity was 1.012${\pm}$0.05, and refractive index was l.375${\pm}$0.05. Also, appearance of stem's extract was slightly brown clear extract, and the pH was 5.4${\pm}$0.5, and specific gravity was 1.016${\pm}$0.05, and refractive index was 1.358${\pm}$0.05. Oil of yew separated from seeds, and extracted polysaccharide high purity from fruits. As a result, specific gravity of oil was 0.987, and obtained 40.0% of yield. Total polyphenols amount of yew extract is detected 0.563% in leaves, 0.325% in stems, whereas total tannins amount contained 0.054% and 0.037% each in leaves and stems. As effect in cosmetics, the anti-oxidative effect by DPPH method is 75.0% in leaves, and stems was 64.0%. Collagen synthesis rate was shown high activity by 54.16% in stem's extract, 33.18% in leaves' extract. Also, PPE-inhibitory activities were 13.7% and 23.5% each in leaves and stems. Anti-inflammatory effect of yew seed oil displayed superior effect of 41% than control. Polysaccharide's molecular weight that is gotten from fruits was 5${\times}$10$^4$-3${\times}$10$\^$5/ dalton, and got 20.0${\pm}$5% of yield.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

• Food Science and Preservation
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• v.20 no.2
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• pp.234-241
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• 2013

The phenolic compounds of water extracts from Prunella vulgaris were highest at 9.25 mg/g, respectively, when various extraction solvents were used. The optimum condition for extracting phenolic compounds from Prunella vulgaris was extraction in water for 18hr. The DPPH-scavenging activities of Prunella vulgaris were highest at the water extracts. The ABTS radical cation decolorization was higher than 40% in the range of 0~100% ethanol extract section. The antioxidant protection factor on the lipophilic phenolic metabolites was shown to be 1.1 PF in the water extracts from Prunella vulgaris. The TBARS was lower than the control ($0.53{\mu}M$) in all the sections. The tyrosinase inhibitory effect, which is related to skin whitening, was above 40%, and for the anti-wrinkle effect, the elastase inhibition activity was above 40% at 0.2 mg/mL. The astringent effect of the Prunella vulgaris 40% ethanol extracts was 98.1% at 1 mg/mL. As a result, it can be concluded that Prunella vulgaris has the potential to be used as a cosmetic material.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.441-446
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• 2012

We investigated the chemical properties and antioxidant activities of sword bean (SWB) and compared it to soybean (SB) and black soybean (seoritae, BSB). The value of vitamin C, vitamin A, crude fat, and crude protein in SWB was 25.5, 0.37 mg/kg, 1.2, and 25.6%, respectively. The crude fat content (1.2%) in SWB was very low in comparison with those of SB (16.5%) and BSB (16.1%). In 16 free amino acids investigated, the histidine content (9.2%) was high in SWB, followed by SB (3.0%) and BSB (2.9%). Total flavonoid content of SWB (493.2 mg/100 g) was significantly higher than those of SB (71.8 mg/100 g) and BSB (97.5 mg/100 g). Total polyphenol content of SWB (1,152.0 mg/100 g) was not significantly different from that of SB (1,165.7 mg/100 g) but lower than that of BSB (1,298.6 mg/100 g). DPPH radical scavenging activity ($SC_{50}$, 50% scavenging concentration) of SWB was 13.1 ${\mu}g/mL$, whereas that of positive control (${\alpha}$-tocopherol) was 8.3 ${\mu}g/mL$.

• Journal of Life Science
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• v.22 no.12
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• pp.1658-1664
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• 2012

Conjugated linoleic acid (CLA) exhibits several beneficial biological activities including anticarcinogenesis and body-fat reduction. Now, we report that CLA ameliorated the oxidative stress in rat cardiomyoblast cells, H9c2, treated with hydrogen peroxide ($H_2O_2$). Cells were cultured in DMEM/F-12 media at $37^{\circ}C$ with humidified atmosphere of 5% $CO_2$. The cells, cultured for 48 hrs, were seeded at a density $3.5{\times}10^3$ cell/well in a 24 well-plate and incubated for 24 hr. Using these cells, two experiments were performed: the cytotoxicity test of CLA (10, 20, 30, 40, and $50{\mu}Ms$), and the oxidative stress amelioration test of CLA (20 and $50{\mu}Ms$) against cells treated with $H_2O_2$ (10 and 50 ${\mu}Ms$) for 1 and 2 hrs. CLA enhanced the growth of H9c2 cells at any concentrations of CLA and at any incubation times (up to 6 days), indicating that CLA acts as a growth stimulant. No protective effect of CLA (20 and $50{\mu}Ms$) was seen in cells treated $50{\mu}M$ $H_2O_2$ for 1 and 2 hr, but these CLA concentrations ameliorated (p<0.05) the adverse effect of $10{\mu}M$ $H_2O_2$ in cells treated for 1 hr. These CLA concentrations significantly (p<0.05) reduced the proportion of apoptotic cells, relative to control cells. These results suggest that CLA protected H9c2 cells from the oxidative stress of $H_2O_2$ through the suppression of cell apoptosis and could be a useful compound for the prevention of cardiac diseases caused by oxidative stress.

• Journal of Life Science
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• v.19 no.7
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• pp.956-962
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• 2009

The aim of this study was to assess the effects of dentifrice-contatning grapefruit seed extract (GSE) and processed sulfur solution (PSS) on antimicrobial effects against oral pathogens. We first evaluated the antimicrobial effects of GSE and PSS against oral microbes: Streptococcus mutans (Sm), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) and Candida albicans (Ca). When antimicrobial activity against Sm, Pi, Pg and Ca was tested, at 40 $\mu$l/disk, the inhibition zones of GSE were 11.0, 9.5, 8.0 and 9.0 mm, respectively. With the same method, the inhibition zones of PSS were 2.0, 3.5, 0.0 and 1.5 mm, respectively. In the micro broth dilution method, the MIC values of GSE against Sm, Pi, Pg and Ca were 0.24, 0.06, 0.10 and 15.63 $\mu$l/rnl, respectively. The MIC values of PSS were 0.12, 3.91,>125 and 7.81 $\mu$l/ml, respectively. When pH, refractive index, viscosity and color value of dentifrice-containing GSE and PSS were measured, there were no significant changes in these physical properties compared to the control samples. Antimicrobial activities of dentifrice products containing 0.5% GSE and 0.5% PSS against oral pathogens were 7.3, 4.3, 2.2 and 1.5 mm, respectively. According to these results, we conclude that there may be a role for GSE and PSS in the development of new oral supplies.

• Journal of Life Science
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• v.19 no.7
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• pp.983-993
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• 2009

The effects of Monascus-fermented Korean red ginseng (MFRG) on the contents of serum lipids and tissues lipid peroxidation was investigated in alcohol feeding rats (AC group). Serum contents of total lipid and free fatty acid in alcohol feeding rats were significantly increased, but these increases tended to decrease in the AMFRG group. Serum triglyceride content was also significantly decreased in the AMFRG group compared to other groups. Serum content of total-cholesterol was significantly increased in AC group compared to normal control (NC) group, whereas there was no significant difference between the AC and AMFRG groups. Content of HDL-cholesterol in serum was slightly increased in the AC group compared to the NC group, but this increase in the AC group was more significantly increased in the AMFRG group. At the same time, atherogenic index (AI) was also significantly decreased in the AMFRG group compared to the AC group. Contents of thiobarbituric acid reactive substances (TBARS) in the liver, heart, spleen and testes were significantly increased in the AC group compared to the NC group, but these increases were significantly less in the AMFRG group. Contents of liver nonheme ion was increased in the AC group and was significantly decreased in the AMFRG group, which suggested that lipid peroxidation contents are inversely correlated with liver nonheme ion content. Hepatic glutathione concentration was significantly decreased in the AC group, but this content was significantly increased in the AMFRG group and it showed the antioxidant abilities of glutathione. These results suggested that Monascus-fermented Korea red ginseng has anti-atherogenic index (AI) effects as well as antioxidative activities through reduced tissue oxidative stress in alcohol feeding rats.