• Journal of Microbiology
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• 제34권4호
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• pp.300-304
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• 1996

To define the effects of zooplankton and phytoplankton to bacteria, bacterial numbers, frequency of dividing cells (FDC) and size distribution were performed with image analysis in the surface layer of Lake Soyang. In August 1992, when Anabaena was blooming, the bacterial number increased at daytime. Bacterial numbers and FDC value had a negative correlation (r = 0.83, P < 0.01). Bacterial size spectrums were dynamically changed during the day and night, especially the small bacteria less than $0.5\;{\mu}m^3$. Meanwhile, in October, after the bloom, the bacterial number was only one third of that in August, even though the FDC was higher than that in August. The bacterial numbers of small size class dropped at 13:00. But the size spectrums were relatively constant during the night time. These results suggest that the bacterial growth was tightly coupled with phytoplankton during Anabaena bloom. And after the bloom, the bacterial number was controlled grazing activity of zooplankton at daytime.

• Journal of the Korean Society of Earth Science Education
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• 제8권2호
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• pp.152-163
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• 2015

In this study, to raise the interest and curiosity of students and at the same time to learn science concepts meaningfully for students, the teaching and learning program was developed by applying the Frayer model. The purpose of this study was to find out the Effect of Elementary Science Teaching Program with Frayer model on Learning Motive and Learning Achievement. To this end, the 6th grade classroom of A-elementary school located in Seogwipo-city was selected the experimental group (26 patients). And the other 6th grade classroom in the same school was selected to the comparative group (27 patients). The experimental group was conducted applying the Frayer model. Comparison group has been conducted lesson program in accordance with the general science class teacher guide. Was through a pre-test of science learning motivation and academic achievement level can be assumed in the same group. After completing the experimental treatment by conducting a post-mortem examination was statistically validated. In this study, the following conclusions were obtained. First, elementary science class which applied Frayer model had the effect of to improve the scientific motivation. In particular, attention (p <.01), association (p <.01), confidence (p <.01) in the experimental group were higher than the scores of the comparative group, the difference was significant. Second, the Frayer model applied to elementary science class had a significant effect on improving science achievement. The experimental group which applied Frayer model was higher than the comparative group in science achievement post-test comparison. Between the groups showed a significant difference between the two groups (p <.01). The above findings, Elementary science class which applied Frayer model can be concluded to be effective in science and science achievement motivation. Therefore, applying the Frayer model of elementary science class could be useful in science teaching and learning methods. In addition, when it is determined through the previous study, applying the Frayer model classes will be able to derive a meaningful learning also subjected to a number of fields and areas.

• Journal of the korean academy of Pediatric Dentistry
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• 제29권4호
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• pp.568-573
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• 2002

The purpose of study was to investigate the caries activity factors of children during orthodontic treatment. Fifty children with fixed or removable intraoral orthodontic appliances were examined for their Cariostat caries activity test scores, gender, age, duration of treatment, appliance type, treatment site, Angle's classification of malocclusion, and the number of teeth with caries experience. The mean age of the high caries activity group was significantly higher than that of the low caries activity group(P<0.01). The duration of treatment of the high caries activity group was longer than that of the low caries activity group, but the difference was not significant(P>0.05). The fixed appliance group showed higher caries activity than the removable appliance group(P<0.01). The caries activity of Angle Class III group was lower than that of Angle Class I group, not significant statistically(P>0.05). The number of teeth with caries experience in the high caries activity group was lower than that in the low caries activity group, not significant statistically(P>0.05).

• Kyungpook Mathematical Journal
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• 제43권4호
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• pp.489-494
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• 2003

In this paper, we first establish an interesting theorem involving the $\bar{H}$-function introduced by Inayat-Hussain ([7], [8]). The convergence and existence condition, basic properties of this function were given by Buschman and Srivastava ([2]). Next, we obtain certain new integrals and an expansion formula by the application of our theorem. On account of the most general nature of the functions involved herein, our main findings are capable of yielding a large number of new, interesting and useful integrals, expansion formulae involving simple special functions and polynomials as their special cases. A known special case of our main theorem in also given ([11]).

• The Pure and Applied Mathematics
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• 제16권2호
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• pp.199-212
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• 2009

We investigate the multiplicity of the nontrivial periodic solutions for a class of the system of the nonlinear suspension bridge equations with Dirichlet boundary condition and periodic condition. We show that the system has at least two nontrivial periodic solutions by the abstract version of the critical point theory on the manifold with boundary. We investigate the geometry of the sublevel sets of the corresponding functional of the system and the topology of the sublevel sets. Since the functional is strongly indefinite, we use the notion of the suitable version of the Palais-Smale condition.

• The Korean Journal of Ecology
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• 제14권3호
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• pp.305-316
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• 1991

Growth hadit and demograph in a mature population of polygonatum and polygonatum humile in kanghwa island were studied for two growing seasons. Shoots of two species emerged early spring from the growing apices of the underdground rhizomes which had persisted for up to 1~5 year.after flowering, the ramets produced two rhizome buds at the shoot base. Bacause of the apical dominance in the rhizome system, a new rhizome was developed from only one bud, an actual bud,and the other latent buds were suppressed sothat remained dormant. The latent dud produced a new rhizome only when the actual dud was severed by the herbivores or by the physical obstacles. Therefore, the ramet number is not increased by the new rhizome from the latent bud. however, new ramets dould sometimes grow from latent buds which had been produced more than a year ago. Production of these ramets was main means increasing the ramet numbew and widening the potential zone of exploitation. Changes in size class of each ramet were noyiceable after a tear in small size-classes. Small ramets replaced themselves with larger-sized ramet, while large ramets with similar-sized or smallar-sized ramets. ramet numbers were average 0.82and 1.14 times of those fromthe previous year inp. involucratum and p. humile, though there was between-site variation. Almost all the ramets in the quadrats were alive during the growing season. when the entire rhizome systems were excavater next spring, there were many rhizomesegments without shoots, especially in p. involucratum. therefore, the drcrease of ramet number in p. involucratum in probably due to the climatic factors of winter.

• The Korean Journal of Applied Statistics
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• 제15권2호
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• pp.367-379
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• 2002

In this paper, the method of constructing incomplete block designs for comparing general combining abilities of p inbred lines for partial diallel crosses is proposed. These partial diallel crosses block designs are constructed by using m-associate class partially balanced incomplete block designs with block size 2 and balanced incomplete block designs. Also, the efficiencies of block designs obtained through this method are tabulated for number of lines 24 or less.

• ETRI Journal
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• 제28권6호
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• pp.745-760
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• 2006

In this paper, we particularly deal with no $F_p$-rational two-torsion elliptic curves, where $F_p$ is the prime field of the characteristic p. First we introduce a shift product-based polynomial transform. Then, we show that the parities of (#E - 1)/2 and (#E' - 1)/2 are reciprocal to each other, where #E and #E' are the orders of the two candidate curves obtained at the last step of complex multiplication (CM)-based algorithm. Based on this property, we propose a method to check the parity by using the shift product-based polynomial transform. For a 160 bits prime number as the characteristic, the proposed method carries out the parity check 25 or more times faster than the conventional checking method when 4 divides the characteristic minus 1. Finally, this paper shows that the proposed method can make CM-based algorithm that looks up a table of precomputed class polynomials more than 10 percent faster.

• Journal of the Institute of Electronics Engineers of Korea CI
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• 제47권6호
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• pp.28-39
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• 2010

The study aims at offering a solution to the problems of transmission delay and data throughput decrease as the number of contending On-Board Units (OBU) increases by applying CSMA medium access control protocol based upon IEEE 802.11p. In a competition-based medium, contention probability becomes high as OBU increases. In order to improve the performance of this medium access layer, the author proposes EDCA which a adaptive adjustment of the Contention Windows (CW) considering traffic density and data type. EDCA applies fixed values of Minimum Contention Window (CWmin) and Maximum Contention Window (CWmax) for each of four kinds of Access Categories (AC) for channel-specific service differentiation. EDCA does not guarantee the channel-specific features and network state whereas it guarantees inter-AC differentiation by classifying into traffic features. Thus it is not possible to actively respond to a contention caused by network congestion occurring in a short moment in channel. As a solution, CWminAS(CWmin Adaptation Scheme) and ACATICT(Adaptive Contention window Adjustment Technique based on Individual Class Traffic) are proposed as active CW control techniques. In previous researches, the contention probabilities for each value of AC were not examined or a single channel based AC value was considered. And the channel-specific demands of IEEE 802.11p and the corresponding contention probabilities were not reflected in the studies. The study considers the collision number of a previous service section and the current network congestion proposes a dynamic control technique ACCW(Adaptive Control of Contention windows in considering the WAVE situation) for CW of the next channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제27권1A호
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• pp.42-50
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• 2002

In this paper, for a prime number p, a construction method to genarate p-ary d-from sequences with ideal autocorrelation property is proposed and using the ternary sequences with ideal autocorrelation found by Helleseth, Kumar and Martinsen, ternary d-form sequences with ideal autocorrelation introduced. By combining the methods for generation the p-ary extended sequence (a special case of geometric sequences) and the p-ary d-from sequences, a construction method of p-ary unified (extended d-form) sequences which also have ideal autocorrelation property is proposed, which is very general class of p-ary sequences including the binary and nonbinary extended sequences and d-form seuqences. Form the ternary sequences with ideal autocorrelation by Helleseth, Kumar and Martinesen, ternary unified sequences with ideal autocorrelation property are also generated.