• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.585-593
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• 1996

According to the considerable increase of the length of belt conveyors, the dynamic analysis of systme becomes necessary to consider the variation of tensions and transient motion of components during starting and stopping of conveyor. The mathematical model of system is derived using the lumped parameter method. The input driving force is represented with two functions of time and pulley speed to count the characteristics of motor and fluid coupling. An example system was studied with 14 km in the distance of carrying. At head, it has two drivers and one gravity take-up and at tail ond driver and one power winch take-up. In the example, the transient tensions and responses, calculated using two cases of driving force, are mutually compared in starting mode. Also, the position of maximum tension and the braking force of take-up are obtained in stopping mode.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.388-393
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• 2005

Private peering, public peering and transit are three common types of interconnection agreements between providers in the Internet. An important decision that an Internet service provider (ISP) has to make is which private peering/transit ISPs and Internet exchanges (IXs) to connect with to transfer traffic at a minimal cost. In this paper, we deal with the problem to find the minimum cost set of private peering/transit ISPs and IXs for a single ISP. There are given a set of destinations with traffic demands, and a set of potential private peering/transit ISPs and IXs with routing information (routes per destination, the average AS-hop count to each destination, etc.), cost functions and capacities. Our study first considers all the three interconnection types commonly used in real world practices. We show that the problem is NP-hard, and propose a heuristic algorithm for it. We then evaluate the quality of the heuristic solutions for a set of test instances via comparison with the optimal ones obtained by solving a mixed integer programming formulation of the problem. Computational results show that the proposed algorithm provides near-optimal solutions in a fast time.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.934-939
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• 2001

The growth inhibition of Campylobacter jejuni ATCC 33291 in the presence of $1\%$ acetic acid at 4, 25, and $42^{\circ}C$, followed by $25^{\circ}C$ and $4^{\circ}C$, at pH 5.5 and pH 6.5, and by the addition of $1\%$ acetic acid aat 4, 25, and $42^{\circ}C$ were determined to be 22, 8.5, and 1.4 min, respectively, in an FBP-SBB medium. The D values of C. jejuni were increased by the addition of chicken and did not follow the linear relationship observed in the FBP-SBB media without chicken. When using distilled water instead of FBP-SBB in the model system, the death rate of C. jejuni was dramatically accelerated. The injured or low cell numbers that were impossible to enumerate using the plate count method, were detected by a polymerase chain reaction and enrichment culture procedure. These results suggested that acetic acid is reliable and effective as a disinfectant, however, it is necessary to take additional care at refrigeration temperatures due to the potential of injred cells during poultry processing.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.444-450
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• 2003

In order to develop an effective means to treat P. aeruginosa infections, we have purified P. aeruginosa outer membrane proteins (OMPs)-specific human IgG antibody. In this study, we investigated the protective activity of the purified anti-OMPs IgC against P. aeruginosa infection in a rabbit endophthalmitis model. Rabbits were inoculated by an intravitreal injection with P. aeruginosa, and treated with a single dose of 1 mg anti-P. aeruginosa OMPs IgG. All the control rabbits predominantly developed edematous responses and opacity in the eyes, but the rabbits treated with the antibody showed only very limited degree of edema. Aliquots of the vitreous humor were extracted and analyzed for the number of viable bacteria and endotoxin level. The results showed that the anti-OMPs IgC significantly reduced the bacterial count compared with the control group, and that the endotoxin level of the vitreous from the IgG-treated rabbits was more than 70-fold lower 6 h after the administration than the control animals. These data suggested that the anti-P. aeruginosa OMPs IgG is effective in inhibiting the bacterial growth and thereby in reducing endotoxin levels in the vitreous, warranting further development of the anti-P. aeruginosa OMPs IgG as a therapeutic means for treating Pseudomonas endophthalmitis.

• Proceedings of the KSRS Conference
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• v.2
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• pp.525-528
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• 2006

The remote sensing data can be used to calculate the water depth especially in the clear and shallow water area. In this study, the SPOT data was used for bathymetric mapping in Dong-Sha atoll, located in northern South China Sea. The in situ sea depth was collected by echo sounder as well. A global positioning system was employed to locate the accurate sampling points for sea depth. An empirical model between measurement sea depth and band digital count was determined and based on least squares regression analysis. Both non-classification and unsupervised classification were used in this study. The results show that the standard error is less than 0.9m for non-classification. Besides, the 10% error related to the measurement water depth can be satisfied for more than 85% in situ data points. Otherwise, the 10% relative error can reach more than 97%, 69%, and 51% data points at class 4, 5, and 6 respectively if supervised classification is applied. Meanwhile, we also find that the unsupervised classification can get more accuracy to estimate water depth with standard error less than 0.63, 0.93, and 0.68m at class 4, 5, and 6 respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8119-8126
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• 2016

Cancer is a leading cause of death worldwide. Due to the toxic side effects of the commonly used chemotherapeutic drug cyclophosphamide (CTX), the use of herbal medicines with fewer side effects but having potential use as inducing anti-cancer outcomes in situ has become increasingly popular. The present study sought to investigate the effects of a methanolic extract of Bauhinia tomentosa against Dalton's ascites lymphoma (DAL) induced ascites as well as solid tumors in BALB/c mice. Specifically, B. tomentosa extract was administered intraperitonealy (IP) at 10 mg/kg. BW body weight starting just after tumor cell implantation and thereafter for 10 consecutive days. In the ascites tumor model hosts, administration of extract resulted in a 52% increase in the life span. In solid tumor models, co-administration of extract and CTX significantly reduced tumor volume (relative to in untreated hosts) by 73% compared to just by 52% when the extract alone was provided. Co-administration of the extract also mitigated CTX-induced toxicity, including decreases in WBC count, and in bone marrow cellularity and ${\alpha}$-esterase activity. Extract treatment also attenuated any increases in serum levels of $TNF{\alpha}$, iNOS, IL-$1{\beta}$, IL-6, GM-CSF, and VEGF seen in tumor-bearing hosts. This study confirmed that, the potent antitumor activity of B.tomentosa extract may be associated with immune modulatory effects by regulating anti-oxidants and cytokine levels.

• Journal of The Korean Association For Science Education
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• v.13 no.2
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• pp.219-229
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• 1993

The purpose of this study is to investigate college science students' and science teachers' understanding of chromosomal behavior in the context of cell division. The research problems were as follows: 1. What is the level of college science students' understandings of chromosomal behaviors? 2. What is the level of science teachers' understandings of chromosomal behaviors? 3. What is the level of understanding by grade and major area? The sample consisted of 28 sophomore, 17 junior and 23 senior biology students; and 23 middle school science teachers and 14 high school biology teachers. The instrument of the study was a short answer required paper and pencil test. The results of the study were as follows: 1) About 15 percent of the sample could not count the number of chromosome in a cell in appropriate. 2) Seventy percent of the students, and 80 percent of the teachers identified homologous chromosomes as ones with the similar shape and size, and 30 percent of the whole sample could not pair two homologous chromosomes. 3) About 70 percent of the students and 30 percent of the teachers could not mark corresponding allele on chromosome. 4) Biology major students showed higher understanding of overall chromosomal behaviors than non Biology students. Based upon the results, some implications were made. The major one was a development of a teaching model in which students can improve the ability to connect chromosome theory to mendelian genetics.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3989-3995
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• 2012

The aim of the present investigation was to evaluate the effect of A.nilotica extract against Dalton's ascitic lymphoma (DAL) induced solid and ascitic tumors in BALB/c mice. Experimental animals received A.nilotica extract (10 mg/kg.bw) intraperitoneally for 10 and 14 consecutive days before induction of solid and ascitic tumors, respectively. Treatment with A.nilotica extract significantly decreased the development of tumor and percentage increase in body weight when compared to DAL induced solid tumor control group, also increasing the life span, restoring the total white blood cell count and hemoglobin content and significantly decreasing the levels of serum aspartate transaminase (SGPT), alanine transaminase (SGOT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT) and nitric oxide (NO) when compared to DAL induced ascitic tumor controls. The treatment also reduced significantly the cellular glutathione (GSH) and nitric oxide levels in treated animals. Histopathological studies also confirmed protective influence. The outcome of the present work indicates that A.nilotica extract could be used as natural anticancer agent for human health.

• Korean Journal of Pharmacognosy
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• v.26 no.4
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• pp.385-389
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• 1995

MeOH extract of Gastrodia elata was fractionated to five solvent fractions, hexane fr (fr I), 90% MeOH fr (fr II), EtOAc fr (fr III), BuOH fr (fr IV) and $H_2O$ fr (fr V). Among the five fractions, fr II, III and IV showed platelet anti-aggregating effects against ADP or collagen induced rat platelet aggregation in vitro. Fr II , III and IV were also tested in vivo, in the mouse and rat models of thrombosis. Oral administration of fr II, III or IV enhanced the recovery from the thrombotic shock in the mouse model of thrombosis to 32-40% from 17% of recovery with the control group of mice. Treatment with fr II, III or IV also attenuated the sudden reduction in the blood platelet count following intravenous collagen injection to rat. The above results were indicative of the presence of anti-platelet and anti-thrombotic components in this plant.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1547-1555
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• 2017

This paper studies Bayesian test of homogeneity in contingency tables made by discretizing a continuous variable. Sometimes when we are considering events of interest in small area setup, we can think of discretization approaches about the continuous variable. If we properly discretize the continuous variable, we can find invisible relationships between areas (groups) and a continuous variable of interest. The proper discretization of the continuous variable can support the alternative hypothesis of the homogeneity test in contingency tables even if the null hypothesis was not rejected through k-sample tests involving one-way ANOVA. In other words, the proportions of variables with a particular level can vary from group to group by the discretization. If we discretize the the continuous variable, it can be treated as an analysis of the contingency table. In this case, the chi-squared test is the most commonly employed method. However, further discretization gives rise to more cells in the table. As a result, the count in the cells becomes smaller and the accuracy of the test becomes lower. To prevent this, we can consider the Bayesian approach and apply it to the setup of the homogeneity test.