• Biomedical Science Letters
• /
• v.23 no.1
• /
• pp.34-38
• /
• 2017

To investigate the efficacy of extract of Tartary buckwheat (F. tataricum Gaertn.) in high fat diet (HFD) in mice, the F. tataricum Gaertn. extract (FTE) was orally administered to mice with a HFD at 300 mg/kg/day for 4 weeks. Our results show that FTE significantly inhibited fat accumulation. Moreover, FTE markedly reduced the final body weight with a decrease in epididymal adipose tissue mass and adipocyte size compared with the untreated HFD-induced group. Additionally, FTE ameliorated serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels. The results show that Tartary buckwheat possesses hypocholesterolemic effect through downregulating lipid metabolism. Further studies are required in this area to strengthen the anti-obesity effects of FTE with active component, and it can be used a pro-drug instead of whole extract.

• Journal of Korean Elementary Science Education
• /
• v.23 no.1
• /
• pp.50-60
• /
• 2004

The purpose of this study was to define teachers' learning motivation strategies and students' responses by analyzing science classes and interviews. The subjects were first grade and sixth grade teachers and students of an elementary school. The analysis tools are based on Keller's ARCS theory. The differences of teachers' motivation strategies were analyzed by grades and teachers' and students' backgrounds. The interviewers were composed of three teachers and three students of first grade, and three teachers and three students of sixth grade. The data were collected by recording of the classes using tape recorders, video cameras, and notebooks written by researchers. The results are as follows. First, teachers had their own styles of teaching strategies in their classes. Especially teachers' teaching backgrounds affected on the teachers' instructional strategies. The teachers who had long teaching experiences of lower grade students used to show a lot of attention strategies. While the teachers with long teaching experiences of higher grade students used to show few learning motivation strategies. Especially, sixth grade teachers used to show fewer confidence strategies than first grade teachers. Second, all of the teachers used to show few satisfaction strategies commonly in all the classes observed. Third, the students' recognition of the motivation strategies were not different according to their conceptions or activities of the classes. Commonly first grade students focused on the attention strategies, while sixth grade students focused on negative motivation strategies. Fourth, the teachers who believed that students need detail guidance and control recognized the needs of satisfaction strategies by students' autonomous activities after observing video tapes of other teachers' classes.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2007.11a
• /
• pp.32-32
• /
• 2007

• Journal of Korean Elementary Science Education
• /
• v.28 no.1
• /
• pp.1-8
• /
• 2009

This study was to analyze the effect of 'mobile science-lab' through the survey of students' perception. 'Mobile science-lab' is the one of the most distinguished public science programs and has been made in order to promote the students' understanding of science by providing students an opportunity to be engaged in several activities of science and high-technology. To fulfill the purpose of this study, we analyzed the opinions of 3,643 students who participated in 'mobile science-lab'. As the results, 'mobile science-lab' is very effective on improving the students' interest and concern of science. Most students recognized that the best advantage of 'mobile science-lab' is the participation in experiments. To overcome the mobile science-lab's some limits, more researches including development of the training program of science show coordinators should be done.

• Management Science and Financial Engineering
• /
• v.4 no.2
• /
• pp.59-75
• /
• 1998

This paper presents an incentive system to reduce response time from a supplier. The incentive system is expressed as a contract between an assembler and a supplier who have a long-term relationship. We produce the optimal payment scheme and expected total cost, when the assembler is farsighted. We show that the farsighted assembler obtains higher effort level from the supplier than the myopic assembler. We also show that the expected total cost of the farsighted assembler is smaller in the long run, although it is initially higher than that of the myopic assembler.

• Management Science and Financial Engineering
• /
• v.13 no.1
• /
• pp.1-24
• /
• 2007

I propose new combined randomized methods for global optimization problems. These methods are based on the Nested Partitions(NP) method, a useful method for simulation optimization which guarantees global optimal solution but has several shortcomings. To overcome these shortcomings I hired various statistical selection methods and combined with NP method. I first explain the NP method and statistical selection method. And after that I present a detail description of proposed new combined methods and show the results of an application. As well as, I show how these combined methods can be considered in case of computing budget limit problem.

• East Asian mathematical journal
• /
• v.29 no.5
• /
• pp.503-510
• /
• 2013

A quadratic B-spline finite element method for the spatial variable combined with a Newton method for the time variable is proposed to approximate a solution of Benjamin-Bona-Mahony-Burgers (BBMB) equation. Two examples were considered to show the efficiency of the proposed scheme. The numerical solutions obtained for various viscosity were compared with the exact solutions. The numerical results show that the scheme is efficient and feasible.

• Journal of the Korean Data and Information Science Society
• /
• v.19 no.4
• /
• pp.1345-1352
• /
• 2008

An inventory with constant demand is studied. We adopt a renewal argument to obtain the transient and stationary distribution of the level of the inventory. We show that the stationary distribution can be also derived by making use of either the level crossing technique or the renewal reward theorem. After assigning several managing costs to the inventory, we calculate the long-run average cost per unit time. A numerical example is illustrated to show how we optimize the inventory.

• Journal of applied mathematics & informatics
• /
• v.28 no.5_6
• /
• pp.1409-1418
• /
• 2010

In this paper, we present a preconditioned iterative method for solving linear systems Ax = b, where A is a Z-matrix. We give some comparison theorems to show that the rate of convergence of the new preconditioned iterative method is faster than the rate of convergence of the previous preconditioned iterative method. Finally, we give one numerical example to show that our results are true.

• Journal of the Korean Data and Information Science Society
• /
• v.17 no.3
• /
• pp.687-705
• /
• 2006

In this paper we consider GPH distribution that is defined as a distribution for sum of random number of random variables following exponential distribution. We establish approximation process of general distributions to GPH distributions and offer numerical results for various cases to show the accuracy of the approximation. We also propose analysis method of delay distribution of queueing systems using approximation to GPH distributions and offer numerical results for various queueing systems to show applicability of GPH approximation.