Time filter

Source Type

Hoengseong gun, South Korea

Baek W.M.,Kongju National University | Yoon J.H.,Korean Minjok Leadership Academy | Kim C.,Sangji University
Scientific World Journal | Year: 2014

Many strategies have been proposed to reduce the mobility management cost in mobile communication networks. This paper studies the zone-based registration methods that have been adopted by most mobile communication networks. We focus on two special zone-based registration methods, called two-zone registration (2Z) and two-zone registration with implicit registration by outgoing calls (2Zi). We provide a new mathematical model to analyze the exact performance of 2Z and 2Zi. We also present various numerical results, to compare the performance of 2Zi with those of 2Z and one-zone registration (1Z), and show that 2Zi is superior to 2Z as well as 1Z in most cases. © 2014 Woon Min Baek et al. Source

Ju J.W.,Korean Minjok Leadership Academy
Applied Mechanics and Materials | Year: 2014

Sunlight generation in the schoolyard and geothermal generation are typical examples. However, from someday, sunlight generation is not doing its function enough. Many schools are trying to utilize renewable energy. But, in most of the cases, unlike preliminary plans, schools are not substantially utilizing renewable energy efficiently. In order to maximize the energy efficiency of school’s renewable energy, multiple renewable energy needs to be comprehensively combined and applied. The current method of solar energy is used in the rooftops of schools. Geothermal energy is installed using the large area of the schoolyard. Acupressure energy device using piezoelectric element is installed in the school gate, the 1st floor stairway, and the school building’s main entrance. Also, in the school’s streetlamps, noiseless, small wind energy generator is installed to generate wind energy. In conclusion, efficiently applying solar energy, geothermal energy, acupressure energy, wind energy will increase the school’s renewable energy effect. © (2014) Trans Tech Publications, Switzerland. Source

Yu J.-Y.,Chonbuk National University | Zheng Z.-H.,Chonbuk National University | Son Y.-O.,University of Kentucky | Shi X.,University of Kentucky | And 2 more authors.
Toxicology in Vitro | Year: 2011

Zearalenone (ZEN) is commonly found in many food commodities and is known to cause reproductive disorders and genotoxic effects. However, the mode of ZEN-induced cell death of macrophages and the mechanisms by which ZEN causes cytotoxicity remain unclear. The present study shows that ZEN treatment reduces viability of RAW264.7 cells in a dose-dependent manner. ZEN causes predominantly necrotic and late apoptotic cell death. ZEN treatment also results in the loss of mitochondrial membrane potential (MMP), mitochondrial changes in Bcl-2 and Bax proteins, and cytoplasmic release of cytochrome c and apoptosis-inducing factor (AIF). Pre-treatment of the cells with either z-VAD-fmk or z-IETD-fmk does not attenuate ZEN-mediated cell death, whereas catalase suppresses the ZEN-induced decrease in viability in RAW264.7 cells. Treating the cells with c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), or p53 inhibitor prevented ZEN-mediated changes, such as MMP loss, cellular reactive oxygen species (ROS) increase, and cell death. JNK or p38 MAPK inhibitor inhibited mitochondrial alterations of Bcl-2 and Bax proteins with attendant decreases in cellular ROS levels. Knockdown of AIF via siRNA transfection also diminished ZEN-induced cell death. Further, adenosine triphosphate was markedly depleted in the ZEN-exposed cells. Collectively, these results suggest that ZEN induces cytotoxicity in RAW264.7 cells via AIF- and ROS-mediated signaling, in which the activations of p53 and JNK/p38 play a key role. © 2011 Elsevier Ltd. Source

Shin H.D.,SNP Genetics Inc. | Shin H.D.,Sogang University | Park B.L.,SNP Genetics Inc. | Shin H.J.,SNP Genetics Inc. | And 4 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2010

Context: Similar genetic factors may play role in the pathogenesis of gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM). However, genetic studies on GDM are relatively scarce as compared with T2DM. Objective: A recent genome-wide association (GWA) study has proved that three KCNQ1 polymorphisms were significantly associated with the risk of T2DM in various ethnic groups. This study aimed to examine possible genetic effects of these KCNQ1 polymorphisms on the risk of GDM. Design: Three KCNQ1 polymorphisms (rs2074196, rs2237892, and rs2237895) were genotyped using TaqMan assay. The genotype distributions between GDM patients and normal controls were analyzed using logistic regression models. In addition, GDM-related phenotypes were analyzed using multiple regression models. Setting: All GDM patients recruited from Cheil General Hospital in Seoul, Korea, between 2003 and 2008. Participants: Participants included 930 Korean females with GDM and the data of healthy controls from the previous GWA study. Results: KCNQ1 polymorphisms of rs2237892 and rs2237895 were significantly associated with the risk ofGDM(P=0.003 and 0.005, respectively). In the analyses of the GDM-related phenotype, only the risk allele of KCNQ1 rs2237895 was significantly associated with a high-level insulin sensitivity oral glucose tolerance test among patients with GDM(P=0.0003, 0.004, and 0.05 for codominant, dominant, and recessive models, respectively). Conclusion: KCNQ1 polymorphisms shown to be associated with increased risk for T2DM in the recent GWA study might also represent genetic factors contributing to the development of GDM in Koreans. Copyright © 2010 by The Endocrine Society. Source

Lee S.,Korean Minjok Leadership Academy
World Academy of Science, Engineering and Technology | Year: 2011

Since the advent of the information era, the Internet has brought various positive effects in everyday life. Nevertheless, recently, problems and side-effects have been noted. Internet witch-trials and spread of pornography are only a few of these problems.In this study, problems and causes of malicious replies on internet boards were analyzed, using the key ideas of game theory. The study provides a mathematical model for the internet reply game to devise three possible plans that could efficiently counteract malicious replies. Furthermore, seven specific measures that comply with one of the three plans were proposed and evaluated according to the importance and utility of each measure using the orthogonal array survey and SPSS conjoint analysis.The conclusion was that the most effective measure would be forbidding unsigned user access to malicious replies. Also notable was that some analytically proposed measures, when implemented, could backfire and encourage malicious replies. Source

Discover hidden collaborations