• Journal of applied mathematics & informatics
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• v.30 no.5_6
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• pp.925-934
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• 2012

In this work the sine-Gordon equation will be examined for multiple soliton solutions. The higher dimensional sine-Gordon equations will be studied for multiple soliton solutions as well. The simplified form of the Hirota's method will be employed to conduct this analytic study.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.847-858
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• 2011

We make use of the simplified Hirota's bilinear method with computer symbolic computation to study a variety of coupled potential KdV (pKdV) equations. Each coupled equation is completely integrable and gives multiple soliton solutions and multiple singular soliton solutions. The phase shifts for all coupled pKdV equations are identical whereas the coefficients of the obtained solitons are not identical. The four coupled pKdV equations are resonance free.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.65-67
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• 2007

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2019.05a
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• pp.393-394
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• 2019

• ALGAE
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• v.21 no.3
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• pp.323-332
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• 2006

Mitochondrial distribution and abundance were assessed during the growth of apical and subapical cells in the red algae Colaconema caespitosum (J. Agardh) Jackelman, Stegenga and Bolton and Antithamnion cruciatum (C. Agardh) Nägeli after staining with 3,3’-dihexyloxacarbocyanine iodide [DiOC6(3)] and 2,4’-dimethylaminostyryl-Nethylpyridinium iodide (DASPEI). In fully elongate apical cells of C. caespitosum there were 100-120 mitochondria. During apical cell enlargement and division there is a doubling and then halving of the mitochondrial numbers. Apical cells prior to cytokinesis in young filaments are smaller than in mature filaments (ca. 50 and 100 μm long, respectively) and have fewer mitochondria (ca. 100 and 120 mitochondria per cell, respectively). In older vegetative cells mitochondria tend to aggregate at opposite ends of the cells with some mitochondria associated with the central nucleus or at points of apparent branch initiation. There is a greater density of mitochondria in apical cells of smaller versus larger plants (one mitochondrion per 6.3 μm3 and 9.8 μm3, respectively), suggesting that apical cells of younger plants may be more metabolically active. Male and female gametophytic thalli of Antithamnion cruciatum had similar numbers of mitochondria in apical cells of indeterminate axes, as did gametophytic and sporophytic thalli. There were about 40-50 mitochondria in fully elongated apical cells with about half this number in newly divided apical and subapical cells. Apical cells of determinate branches had more mitochondria (60-77) than indeterminate branches (60-70 vs. 40-50). In both species and in all cell types mitochondrial numbers were highly correlated with cell size.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.73-84
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• 2020

As the Internet began to become popular, there have been hacking and attacks on networks including systems, and as the techniques evolved day by day, it put risks and burdens on companies and society. In order to alleviate that risk and burden, it is necessary to detect hacking and attacks early and respond appropriately. Prior to that, it is necessary to increase the reliability in detecting network intrusion. This study was conducted on applying weight initialization and weight optimization to the KDD'99 dataset to improve the accuracy of detecting network intrusion. As for the weight initialization, it was found through experiments that the initialization method related to the weight learning structure, like Xavier and He method, affects the accuracy. In addition, the weight optimization was confirmed through the experiment of the network intrusion detection dataset that the Adam algorithm, which combines the advantages of the Momentum reflecting the previous change and RMSProp, which allows the current weight to be reflected in the learning rate, stands out in terms of accuracy.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.4
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• pp.11-18
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• 2021

We propose a method that combines learning in a virtual environment and a real environment for indoor autonomous driving through reinforcement learning. In case of learning only in the real environment, it takes about 80 hours, but in case of learning in both the real and virtual environments, it takes 40 hours. There is an advantage in that it is possible to obtain optimized parameters through various experiments through fast learning while learning in a virtual environment and a real environment in parallel. After configuring a virtual environment using indoor hallway images, prior learning was carried out on the desktop, and learning in the real environment was conducted by connecting various sensors based on Jetson Xavier. In addition, in order to solve the accuracy problem according to the repeated texture of the indoor corridor environment, it was possible to determine the corridor wall object and increase the accuracy by learning the feature point detection that emphasizes the lower line of the corridor wall. As the learning progresses, the experimental vehicle drives based on the center of the corridor in an indoor corridor environment and moves through an average of 70 steering commands.

• Animal cells and systems
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• v.3 no.3
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• pp.243-246
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• 1999

A type of symbiosis was previously described from nature in which the gametophytes of Laminariales were endophytic in filamentous red algae. Here we reconstruct this symbiosis for the first time in laboratory culture using zoospores of the kelp, Undaria pinnatifida, and the red alga, Aglaothamnion oosumiense. Zoospores of U. pinnatifida readily attached to A. oosumiense. In 48 h these spores germinated and the initial germ tube penetrated into the host cell wall leaving only an empty zoospore wall outside the host. Within ten days, four to five-celled endophytic gametophytes were present. Zoospores of Laminaria religiosa which were also inoculated into cultures of A. oosumiense rarely attached to the red alga and never became endophytic. Within ten days the free-living gametophytes of L. religiosa on cover slips became fertile and produced young sporophytes. These observations demonstrate the ability of U. pinnatifida to become endophytic, and show differences in host specificity among kelp species.

• ALGAE
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• v.25 no.4
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• pp.155-171
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• 2010

The underlying physiology of algal antioxidant compounds is reviewed in the context of seaweed biology and utilization. The application of seaweed antioxidants in foods, food supplements, nutraceuticals and medicine is considered from the perspective of benefits to human health. We advocate that direct consumption of seaweed products for their antioxidant composition alone provides a useful alternative to non-natural substances, while simultaneously providing worthwhile nutritional benefits. Economic utilization of seaweeds for their antioxidant properties remains in its infancy. This review provides examples ranging from laboratory studies through to clinical trials where antioxidants derived from seaweeds may provide major health benefits that warrant subsequent investigative studies and possible utilization.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1150-1152
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• 2009

Geraniol (1) is the biogenetic precursor of a number of monoterpenes. We tested various marine-derived microorganisms to determine their ability to biotransform 1. Only Hypocrea sp. was capable of transforming 1 into its oxidized derivative, 1,7-dihydroxy-3,7-dimethyl-(E)-oct-2-ene (2). The structure of the metabolite obtained was assigned on the basis of detailed spectroscopic data analyses.