• Journal of Ginseng Research
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• v.21 no.1
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• pp.1-12
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• 1997

Ginseng, the root of Panax ginseng C.A. Meyer, is well-known oriental herbal medicine. The number of paper reporting the effects on its physiological, pharmacological, and behavioral effects has been increased every year, since ginsenosides isolated from ginseng are known to be biologically active components. This brief review summarizes some of new findings from recently published papers on ginsenosides or ginseng saponins. Therefore, this paper includes the various effects of ginsenosides on neuronal cell growths, on behavior of experimental animals, on enzyme activities, on the release and uptake of neurotransmitters, on neuronal cell excitability, on the motility of intestine, on antitumor activity, on cardiovascular system and metabolism. In spite of various effects of ginsenosides on various cells or organs, it is still to date impossible for one to clearly explain the exact mechanism on the action of ginsenosides. However, in this article I will discuss several papers providing possible explanations on the physiological and pharmacological actions including signal transudation pathway of ginsenosides. The elucidation of the exact mechanism of ginsenosides on cellular or molecular level will not only give us a chance to explain why people have used ginseng as an elixir of life for several thousands of year but also give us a crucial chance to apply ginseng to modern medicine.

• English Language & Literature Teaching
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• v.18 no.1
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• pp.23-43
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• 2012

This study investigates the effects of three different types of instruction, namely form-based, comprehension-based, and production-based on the development of Korean university students' (n=137) comprehension and production of English relative clauses (RCs). The extent of improvements was analyzed by administering pre-and post-tests consisting of two comprehension tests (selecting the right form of RCs and the right picture descriptions) and one production test (combining two sentences). Findings of this study suggest that all three types of instruction increased participants' comprehension and productions of RCs. However, there appeared differential effects by the instruction type. It was found production-based instruction was most effective in promoting comprehension, followed by comprehension-based instruction. Comprehension-based instruction worked best with the development of production, suggesting that the effects of comprehension training did not only work for increasing comprehension skills, but also transfer to production skills. The type or level of tasks employed for each instruction appeared to play an important role in causing such results. Form-based instruction displayed the lowest improvements in both comprehension and production of RCs. A sentence-combination task employed for form-based instruction appear to result in mere explicit rule explanations without chances to notice rules in context or use their knowledge in practice.

• Korean Circulation Journal
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• v.48 no.11
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• pp.974-988
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• 2018

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), which are collectively called pluripotent stem cells (PSCs), have emerged as a promising source for regenerative medicine. Particularly, human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have shown robust potential for regenerating injured heart. Over the past two decades, protocols to differentiate hPSCs into CMs at high efficiency have been developed, opening the door for clinical application. Studies further demonstrated therapeutic effects of hPSC-CMs in small and large animal models and the underlying mechanisms of cardiac repair. However, gaps remain in explanations of the therapeutic effects of engrafted hPSC-CMs. In addition, bioengineering technologies improved survival and therapeutic effects of hPSC-CMs in vivo. While most of the original concerns associated with the use of hPSCs have been addressed, several issues remain to be resolved such as immaturity of transplanted cells, lack of electrical integration leading to arrhythmogenic risk, and tumorigenicity. Cell therapy with hPSC-CMs has shown great potential for biological therapy of injured heart; however, more studies are needed to ensure the therapeutic effects, underlying mechanisms, and safety, before this technology can be applied clinically.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.34-50
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• 2012

This study conducted the empirical analysis of the influence that are quality attributes, and strengths, weaknesses, low ranking and excess of Korean restaurants menu on revisit intention based on differences between importance and satisfaction by surveying Korean students in Paris, and also conducting IPA analysis based on survey result. The result of IPA analysis showed weaknesses that are the visual elements of foods; in contrast it showed strengths that are the price, temperature, taste, quantity, cleanliness, freshness, and flavor of dishes. Also it showed low ranking that are seasonal items, authenticity, originality, sizes, colors, texture, explanations, ingredients, recipes of menu, classification of healthy food, suitability of bowls, creativity of existing food. Therefore, it is found that the higher recognition of attributes, organic functions, properties, and explanations of menu, the higher revisit intention. It showed that explanations, sensibility, characters, quality of menu influenced on revisit intention according priority by analysis of quality attributes of menu on revisit intention. This study is significant in that it provides useful data services for marketing strategies and operational suggestions to globalization of Korean food by analysis local menu of Korean food service industry.

• Journal of Korean Elementary Science Education
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• v.31 no.1
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• pp.109-124
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• 2012

Developing pedagogical content knowledge (PCK) has been emphasized for teacher's professionalism and it should be done from systematic teacher training courses. In this study, we investigated changes of elementary pre-service teachers' PCK of science teaching and motivational strategies before and after a training course. For the analysis of pre-service teachers' PCK, their lesson plans, surveys, and interviews were collected. According to the results, in the beginning of the semester, pre-service teachers in the experimental group usually used didactic or combination of didactic and inquiry teaching strategies and a few pre-service teachers used inquiry or discovery teaching strategies when making lesson plans. However, at the end of the semester many pre-service teachers used inquiry teaching strategies in their lessons which included activities of asking students' prior knowledge, conducing experiments, finding conclusion, and comparing teachers' explanations with students' explanations. Regarding motivational strategies, in the beginning of the semester they focused using activities to create student's emotional interest in science lesson but at the end they used other strategies to create positive atmosphere for learning, capture intellectual interest in science, and connect science to students' everyday lives. The changes in pre-service teachers' PCK in the experimental group was meaningful because there was less change in pre-service teachers' PCK in the control group. This study implies the need for effective professional development programs for developing pre-service teachers' PCK.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.1-8
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• 2014

The positions, attitudes, and internal orientation parameters of three line scanners are critical factors in order to acquire the accurate location of objects on the ground. Based on the assumption that positions and attitudes of the sensors are derived either from direct geo-referencing which of using Global Positioning Systems (GPS) and Inertial Navigation Systems (INS), or from indirect geo-referencing which of using Ground Control Points (GCPs), this paper describes on biased effects of Internal Orientation Parameter (IOP) on the ground. The research concentrated on geometrical explanations of effects from different focal length biases on the ground. The Synthetic data was collected by reasonable flight trajectories and attitudes of three line scanners. The result of experiments demonstrated that the focal length bias in case of indirect geo-referencing does not have critical influences on the quality of reconstructed ground space. Also, the relationships between IO parameters and EO parameters were found by the correlation analysis. In fact, the focal length bias in case of the direct geo-referencing caused significant errors on coordinates of reconstructed objects. The RMSE values along the vertical direction and the amount of focal length bias turned out to be almost perfect linear relationship.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.523-528
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• 2005

The commercial interests in functional foods containing probiotics are gaining significance in view of increasing studies on their role in digestive tract. Probiotic dairy foods containing health-promoting bacteria are important segment of functional food market. Various health benefits have been attributed to specific strains of lactic acid bacteria or food containing these probiotic cultures. Probiotic-containing foods are considered to improve general gut health and natural defenses of body, and lower blood cholesterol level. Specific probiotic microbes can alleviate or prevent diverse intestinal diarrhea-inducing disorders, cause prophylaxis of intestinal and urogenital infections, inhibit mutagenicity of intestinal contents, and reduce incidence of intestinal tumors. Recent increasing evidences on health effects of probiotics have triggered consumer interest in this category of functional foods. Rational approach needs to be applied in selection of strains for probiotic preparation to achieve required functionality. Present article focuses on some prominent probiotic candidates and criteria for their inclusion in functional food sector. Various health claims of probiotics on gastrointestinal disorders, anticarcinogenic effects, and anti-cholestrimic effects, and possible mechanistic explanations for their functionality are highlighted.

• Korean Journal of Child Studies
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• v.35 no.1
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• pp.119-133
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• 2014

The purpose of this study is to examine the effects of time perspective, self-control and cellular phone addiction on academic procrastination, and to cellular phone addiction has any mediating effects in relation to the effects of adolescents' time perspective and self-control on academic procrastination. For this study, a survey was conducted with total 651 students in middle and high schools. Those who omitted responses or answered in ways which were otherwise invalid were excluded and finally, questionnaires responded to by 558 students were analyzed. Employing SPSS Win 12.0, average value, standard deviation, frequency analysis, Pearson's correlation analysis, stepwise multiple regression analysis, and simple linear regression analysis were used for the purposes of statistical analysis. In conclusion, first, explanations were made in order of future-oriented time perspective which is subordinate domain of view of time perspective, self-control, and cellular phone addiction. Second, it was found that cellular phone addiction has partially mediating effect on the relationships between future-oriented time perspective which is a subordinate area of adolescents' time perspective, and academic procrastination. Third, it was found that cellular phone addiction has partially mediating effect on the relationships between adolescents' self-control and academic procrastination.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.8
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• pp.1165-1173
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• 2003

The effects of (1) phonon dispersion on thermal conductivity model and (2) differentiation of group velocity and phase velocity are examined for germanium. The results show drastic change of thermal conductivity regardless of the same relaxation time model. Also the contribution of transverse acoustic (TA) phonon and longitudinal acoustic (LA) phonon on the thermal conductivity at high temperatures is reassessed by considering more rigorous dispersion model. Holland model, which is commonly used for modeling thermal conductivity, underestimates the scattering rate for TA phonon at high frequency. This leads the conclusion that TA is dominant heat transfer mode at high temperatures. But according to the rigorous consideration of phonon dispersion, the reduction of thermal conductivity is much larger than the estimation of Holland model, thus the TA at high frequency is expected to be no more dominant heat transfer mode. Another heat transfer mechanism may exist at high temperatures. Two possible explanations we the roles of (1) Umklapp scattering of LA phonon at high frequency and (2) optical phonon.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.38.3-38.3
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• 2008

In There are inventoried 308 eclipsing systems among 1,158 multiple systems listed in Tokovinin (1997, 2007)'s multiple system catalog. Their characteristics of (O-C) variations for 83 systems among the 308 systems, which have timings of minimum lights enough to see the trends of their period changes, were investigated with the Kreiner, Kim and Nha (2001)'s recent database of times of minimum lights of eclipsing binaries. It is found that the (O-C) variations for 39 systems, corresponding to 47% of the investigated 83 systems, does not show any anticipated light-time effects (hereafter LITE) at all. Among the rest 44 systems 7 systems with apsidal motion also have a single LITE. Only 6 systems have a single LITE or double LITEs. The rest 31 systems show a secular variation superposed on a single or double or more LITEs or very complicated variation patterns. Some possible explanations for their diverse differentiation of variation are discussed.