• Bulletin of the Korean Mathematical Society
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• v.50 no.3
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• pp.915-928
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• 2013

In this paper, we will provide an alternative proof to characterize the pointwise multipliers which maps a Sobolev space $\dot{H}^r(\mathb{R}^d)$ to its dual $\dot{H}^{-r}(\mathb{R}^d)$ in the case 0 < $r$ < $\frac{d}{2}$ by a simple application of the definition of fractional Sobolev space. The proof relies on a method introduced by Maz'ya-Verbitsky [9] to prove the same result.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.84-84
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• 2004

• East Asian mathematical journal
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• v.13 no.2
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• pp.245-251
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• 1997

• International Journal of Advanced Culture Technology
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• v.4 no.2
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• pp.38-42
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• 2016

In the growing data saturated world, the question of "whether data can be used" has shifted to "can it be utilized effectively?" More data is being generated and utilized than ever before. As the collection of data increases, data mining techniques also must become more and more accurate. Thus, to ensure this data is effectively utilized, the analysis of the data must be efficient. Interpretation of results from the analysis of the data set presented, have their own on the basis it is possible to obtain the desired data. In the data mining method a decision tree, clustering, there is such a relationship has not yet been fully developed algorithm actually still impact of various factors. In this experiment, the classification method of data mining techniques is used with easy decision tree. Also, it is used special technology of one R and J48 classification technique in the decision tree. After selecting a rule that a small error in the "one rule" in one R classification, to create one of the rules of the prediction data, it is simple and accurate classification algorithm. To create a rule for the prediction, we make up a frequency table of each prediction of the goal. This is then displayed by creating rules with one R, state-of-the-art, classification algorithm while creating a simple rule to be interpreted by the researcher. While the following can be correctly classified the pattern specified in the classification J48, using the concept of a simple decision tree information theory for configuring information theory. To compare the one R algorithm, it can be analyzed error rate and accuracy. One R and J48 are generally frequently used two classifications${\ldots}$

• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.514-536
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• 2018

GPI (Group Pollution Index) using 29 indicator groups of Korean benthic macroinvertebrates was proposed in 1992, a higher category taxa-level index developed for rapid field assessment of organic water pollution. This study was performed to revise the assessment scheme of GPI based on taxonomic performance and ecological information accumulated since 1992. The original GPI was renamed SBMI (Simple Benthic Macroinvertebrates Index), and SBMI was based on saprobic valency of 26 indicator groups composed of higher category taxa (mainly family ~ phylum) excluding some genus or species-level taxa. SBMI revealed highly significant correlation with concentration of 5-day biochemical oxygen demand ($BOD_5$) (correlation coefficient r = 0.78, n = 569 sites), total suspended solids (r = 0.69), and total phosphorus (r = 0.77). Also, SBMI revealed strong correlation with Shannon-Weaver's species diversity (r = -0.85), Margalef's species richness (r = -0.85), and McNaughton's dominance (r = 0.83). Determination coefficient of SBMI to concentration of water quality items and values of community indices such as species diversity was 3 ~ 8 % and approximately 11 ~ 14 % higher than that of GPI, respectively. Correlation between SBMI and water quality factors or community indices such as species diversity did not reveal much difference compared to that of species-level indices, such as BMI (Benthic Macroinvertebrates Index) and ESB (Ecological Score of Benthic Macroinvertebrates). SMBI is a simple-qualitative index with higher category taxa easily identified, and is applicable for rapid field assessment of water environment impairment.

• Bulletin of the Korean Mathematical Society
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• v.46 no.1
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• pp.71-78
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• 2009

An element of a ring R with identity is called strongly clean if it is the sum of an idempotent and a unit that commute, and R is called strongly clean if every element of R is strongly clean. Let R be a noncommutative local ring, a criterion in terms of solvability of a simple quadratic equation in R is obtained for $M_2$(R) to be strongly clean.

• Journal of IKEEE
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• v.13 no.2
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• pp.220-223
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• 2009

A simple measurement system is built to estimate the dual-antenna diversity gain at 2.4GHz easily in open lab environment. To obtain multipath fading propagation channel, the system consists of two transmission horn that placed on opposite direction and a rotating stage mechanically changing the position of test dual-antenna with time over distance greater than one wavelength. Estimated diversity is nearly same as theoretical value such that measured diversity gain of 30mm separated is about 6dB similar to theoretical value of 5.7dB and increases monotonically with the increasing separation distance as predicted by the theory. Proposed measurement system that is simple enough to fit in a small space can evaluate the performance of various dual-antennas with a reasonable accuracy with lower 5% difference between the ten sets of measured waveform distribution and theoretical Rayleigh cumulative distribution.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.145-150
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• 2003

To determine effectively the chitinolytic activity of rCHT1 from the hard tick H. longicornis expressed in baculovirus-mediated Spodoptera frugtperda (Sf) 9 cells, a simple and sensitive assay system was established in solid phase using agarose gel containing ethylene glycol chitin as substrate. The various factors affecting the efficacy of the assay were also investigated. The effects of various temperature, dosages of proteins, pH of media and time courses of reaction were examined to verify the sensitivity of assay for chitinolytic activity of rCHT1 protein. It was found that the optimal reactive conditions were $37^{\circ}C$ of temperature, 12 to 15 hours of reactive times, $0.1{\mu}g$ of protein concentration and pH 5 to 7 of media. Using the assay system designed, the functional activities of H. longicornis rCHT1l protein could be evaluated simply and sensitively.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.707-710
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• 2002

A 120kV/70A high voltage switch has been installed at Korea Atomic Energy Research Institute in Taejon to supply power with Korea Superconducting Tokamak Advanced Research (KSTAR) Neutral Beam Injection (NBI) system. NBI system requires fast cutoff of the power supply voltage for protection of the grid when arc detected and fast turn-on the voltage for sustaining the beam current. Therefore the high voltage switch and arc current detection circuit are important part of the NBI power supply and there are much need for high voltage solid state switches in NBI system and a broad area of applications. This switch consisted of 100 series connected MOSFETs and adopted the proposed simple and reliable gate drive circuit without bias supply, Various results taken during the commissioning phase with a 100kW resistive load and NBI source are shown. This paper presents the detailed design of 120kV/70A high voltage MOSFETs switch and simple gate drive circuit. Problems with the high voltage switch and gate driver and solutions are also presented.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2018.06a
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• pp.126-127
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• 2018