• Development and Reproduction
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• v.5 no.1
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• pp.1-8
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• 2001

Golden hamsters show the reproductive activity that is determined by the photoperiod (length of light per day). Photoperiod is an environmental factor that is predictable through an entire year. The hamsters are sexually active in summer during which day length exceeds night time. The critical length is at least 12.5 hours of light in a day where reproductive function is maintained. The information of photoperiod is mediated by the pineal gland because removal of pineal gland blocks the influence of photoperiod on reproductive activity. The hamsters without pineal gland maintain sexual activity and promote it in a situation that suppresses gonadal activity. The pineal gland secretes melatonin that reflects the photoperiod. The appropriate administrations of melatonin into both pineal intact and pinealectomized hamsters lead to a gonadal reression. The results suggest that melatonin constitutes a part of control mechanism whereby environmental information is transduced to neuroendocrine signal respensible for the functional integrity of the reproductive system. Despite of the intense studies, the action site of melatonin is on the whole unknown. It is mainly due to the lack of acute efffct of melatonin on the secretion of reproductive hormones. However, sexually regressed animals display the low levelsof gonadotropins and the augmentation of the hypothalamic gonadotropin-releasing hormone (GnRH) content, implying that the antigonadotropic effects either by photoperiod and/or by the treatment of melatonin are mediated by the GnRH neuronal system. The action mechanism by which melatonin exerts its effect on GnRH neuron needs to be investigated. Recent cloning of melatonin receptor will contribute to examine various and putative potencies of melatonin via its anatomical identification and the action mechanism of melatonin on target tissues at the molecular level.

• Journal of Internet Computing and Services
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• v.19 no.4
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• pp.135-150
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• 2018

The biological resources research data around the world are not only very critical themselves but should be shared and utilized. Up to now, the biological resources have been compiled and managed individually depending on the purpose and characteristics of the study without any clear standard. So, in this study, the data reference model would be suggested which is applicable in the phase ranging from the start of the construction of the information system and which can be commonly used. For this purpose, the data model of the related information system would be expanded based on the domestic and foreign standards and data control policy so that the data reference model which can be commonly applicable to individual information system would be developed and its application procedure would be suggested. In addition, for the purpose of proving the excellence of the suggested data reference model, the quality level would be verified by applying the Korgstie's data model evaluation model and its level of data sharing with the domestic and foreign standards would be compared. The test results of this model showed that this model is better than the conventional data model in classifying the data into 4 levels of resources, target, activities and performances and that it has higher quality and sharing level of data in the data reference model which defines the derivation and relation of entity.

• Journal of Life Science
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• v.26 no.1
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• pp.91-100
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• 2016

Angiogenesis is essential for the pathophysiological processes of embryogenesis, tissue growth, diabetic retinopathy, psoriasis, wound healing, rheumatoid arthritis, cardiovascular diseases, and tumor growth. Inhibition of angiogenesis represents an attractive therapeutic approach for the treatment of angiogenic diseases such as cancer. However, uncontrolled angiogenesis is also necessary for tumor development and metastasis. Inhibition of vascular endothelial growth factor (VEGF) signaling, a critical factor in the induction of angiogenesis, cause robust and rapid changes in blood vessels of tumors and therefore VEGF constitutes a target for such anti-angiogenic therapy. Recently, since natural compounds pose significantly less risk of deleterious side effects than synthetic compounds, a great many natural resources have been assessed for useful substance for anti-angiogenic treatment. Here we evaluated the anti-angiogenic effects of a hot water extract of Scutellaria baicalensis (SBHWE) using in vitro assays and ex vivo animal experiments. Our results show that SBHWE dose-dependently abrogated vascular endothelial responses by inhibiting VEGF-stimulated migration and invasion as well as tube formation in a human umbilical vein endothelial cell (HUVEC) model, without cytotoxicity, as determined by a cell viability assay. Further study revealed that SBHWE prevented VEGF-induced neo-vascularization in a rat aortic ring sprouting model. Taken together, our findings reveal an anti-angiogenic activity of Scutellaria baicalensis and suggest that SBHWE is a novel candidate inhibitor of VEGF-induced angiogenesis.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.317-328
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• 1996

The purpose of this paper is to review the trend of research in geographical education since the launching of the Korean Geographical Society in 1945 and to suggest the areas and directions for future oriented research in geographical education. 422 articles (including 12 books) were reviewed and analized for this paper. The outputs of research in geographical education contributed in developing and improving the geographical education in primary and secondary school geography. But to achieve stable and desirable status as a subject in the school curriculum, research in geographical education has to be changed in its target areas and methods. The results and the suggestions of this study are summarized as follows: First, research in geographical education in diverse areas, especially in the areas of significance, aims and objectives, and psychology of geographical education should be preceded the revision of the school curriclum so that the results could be used as the basis information and evidences in decision making about the curriculum. Second, research in geographical education for affective domain and skill development should be implemented more actively in accordance to the trend of integration centering around the dicipline-inquiry skill and citizenship skill. More close relationship between the circles of geographical education and geography would be one of the ways to satisfy the social needs. Third, the linkage between primary and secondary school geography is crucial to the research in geographical education. Considering the sequence in human development research in geographical education for two levels of school should be conducted in more wide school-year span. Fourth, critical and prescriptive research in geographical education focusing on the individual, diciplinary, and social relevancy of the content of geographical education may be recommended. Finally, the outputs of the research in geographical education should be publicized more widely so that the rationale for justification of subject geography and geographical education may be shared with among the researchers, educational administrators, and practioners.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.52-58
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• 2010

Human histamine H1 receptor (HHR1) is a G protein-coupled receptor and a primary target for antiallergic therapy. Here, the ligand-based three-dimensional pharmacophore models were built from a set of known HHR1 inverse agonists using HypoGen module of CATALYST software. All ten generated pharmacophore models consist of five essential features: hydrogen bond acceptor, ring aromatic, positive ionizable and two hydrophobic functions. Best model had a correlation coefficient of 0.854 for training set compounds and it was validated with an external test set with a high correlation value of 0.925. Using this model Maybridge database containing 60,000 compounds was screened for potential leads. A rigorous screening for drug-like compounds unveiled RH01692 and SPB00834, two novel molecules for HHR1 with good CATALYST fit and estimated activity values. The new lead molecules were docked into the active site of constructed HHR1 homology model based on recently crystallized squid rhodopsin as template. Both the hit compounds were found to have critical interactions with Glu177, Phe432 and other important amino acids. The interpretations of this study may effectively be deployed in designing of novel HHR1 inverse agonists.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.704-716
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• 2012

This paper provides a detailed account of pilot testing conducted at South Lake Tahoe (California), the Ddukdo (Seoul) water treatment plant (WTP) and the Bokjung (Seongnam) WTP between February, 2010, and February, 2012. The objectives were first, to characterize the reactions of ozone with hydrogen peroxide (Peroxone) for Han River water following sand filtration, second to determine empirical ozone and hydrogen peroxide doses to remove a taste-and-odor surrogate 2-methylisoborneol (MIB) using an advanced oxidation process (AOP) configuration and third, to determine the optimum dosing configuration to reduce residual ozone to a safe level at the exit of the process. The testing was performed in a real-time plant environment at both low- and high seasonal water temperatures. Experimental results including ozone decomposition rates were dependent on temperature and pH, consistent with data reported by other researchers. MIB in post-sand-filtration water was spiked to 40-50 ng/L, and in all cases, it was reduced to below the specified target level (7 ng/liter) and typically non-detect (ND). It was demonstrated that Peroxone could achieve both MIB removal and low effluent ozone residual at ozone+hydrogen peroxide doses less than those for ozone alone. An empirical predictive model, suitable for use by design engineers and operating personnel and for incorporation in plant control systems was developed. Due to a significant reduction in the ozone reaction/decomposition at low winter temperatures, results demonstrate the hydrogen peroxide can be "pre-conditioned" in order to increase initial reaction rates and achieve lower ozone residuals. Results also indicate the method, location and composition of hydrogen peroxide injection is critical to successful implementation of Peroxone without using excessive chemicals or degrading performance.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.686-692
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• 2001

The effects of extrusion on solubilization of brown rice, glutinuous rice, barley and job's tear were analyzed by response surface methodology (RSM). Solubilization of whole grains by extrusion was characterized in terms of water solubility index (WSI), concentration of water soluble polysaccharides (C) and intrinsic viscosity $([\eta])$. Considering both concentration and intrinsic viscosity, a dimensionless target parameter $([\eta])$ was also included for analysing the extrusion effects on cereal extrusion. Response surface methodology analysis showed that the moisture content was the most significant contributor among screw speed, temperature and moisture content affecting the solubilizing phenomena of cereals processed with extrusion. Brown rice was not showed the significant relationship on $([\eta])$ because $([\eta])$ was more affected by intrinsic viscosity. The critical point of whole grains extrusion except brown rice was corresponded to screw speed of 300 rpm, moisture content of 20% and temperature of $120^{\circ}C$.

• Journal of Astronomy and Space Sciences
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• v.34 no.4
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• pp.271-280
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• 2017

This study presents the application of satellite laser ranging (SLR) to orbit determination (OD) of high-Earth-orbit (HEO) satellites. Two HEO satellites are considered: the Quasi-Zenith Satellite-1 (QZS-1), a Japanese elliptical-inclinedgeosynchronous-orbit (EIGSO) satellite, and the Compass-G1, a Chinese geostationary-orbit (GEO) satellite. One week of normal point (NP) data were collected for each satellite to perform the OD based on the batch least-square process. Five SLR tracking stations successfully obtained 374 NPs for QZS-1 in eight days, whereas only two ground tracking stations could track Compass-G1, yielding 68 NPs in ten days. Two types of station bias estimation and a station data weighting strategy were utilized for the OD of QZS-1. The post-fit root-mean-square (RMS) residuals of the two week-long arcs were 11.98 cm and 10.77 cm when estimating the biases once in an arc (MBIAS). These residuals were decreased significantly to 2.40 cm and 3.60 cm by estimating the biases every pass (PBIAS). Then, the resultant OD precision was evaluated by the orbit overlap method, yielding three-dimensional errors of 55.013 m with MBIAS and 1.962 m with PBIAS for the overlap period of six days. For the OD of Compass-G1, no station weighting strategy was applied, and only MBIAS was utilized due to the lack of NPs. The post-fit RMS residuals of OD were 8.81 cm and 12.00 cm with 49 NPs and 47 NPs, respectively, and the corresponding threedimensional orbit overlap error for four days was 160.564 m. These results indicate that the amount of SLR tracking data is critical for obtaining precise OD of HEO satellites using SLR because additional parameters, such as station bias, are available for estimation with sufficient tracking data. Furthermore, the stand-alone SLR-based orbit solution is consistently attainable for HEO satellites if a target satellite is continuously trackable for a specific period.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.3
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• pp.11-21
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• 2010

To aim at improving performance and reflecting user's needs of retrieval, the number of researches has been actively conducted in recent year as the quantity of information and generation of the web pages exceedingly increase. One of alternative approaches can be a tagging system. It makes users be able to provide a representation of metadata including writings, pictures, and movies etc. called tag and be convenient in use of retrieval of internet resources. Tags similar to keywords play a critical role in maintaining target pages. However, they still needs time consuming labors to annotate tags, which sometimes are found to be a hinderance caused by overuse of tagging. In this paper, we present an automatic tagging scheme for a solution of current tagging system conveying drawbacks and inconveniences. To realize the approach, face recognition-based tagging system on SNS is proposed by building a face area detection procedure, linear-based classification and boosting algorithm. The proposed novel approach of tagging service can increase possibilities that utilized SNS more efficiently. Experimental results and performance analysis are shown as well.

• Journal of Environmental Policy
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• v.8 no.4
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• pp.1-24
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• 2009

As commercial use of genetic resources increases in modern society, calls for fair and equitable sharing of the benefits thereof have become increasingly prominent, particularly from developing countries. As a result, negotiations have been ongoing for the "International Regime on Access and Benefit Sharing (ABS)" for genetic resources as a successor to the non-binding Bonn Guideline. 2010 has been set as the target date for the Agreement. As South Korea is more likely to be a user country of genetic resources, it will be necessary for it to take part in the negotiating process and contribute to creating the International Regime on ABS, to ensure both appropriate access to genetic resources and fair and equitable sharing of the benefits arising there from. To develop appropriate response strategies for South Korea, it is critical not only to closely examine the negotiations within the framework of the CBD but also to engage in discussions within thescope of related international organizations and domestic legislation. To achieve this goal, it is imperative for South Korea to form a comprehensive Government Response System, composed of relevant governmental bodies including the Ministry of Foreign Affairs and Trade, and the Ministry of Environment, etc.