• Journal of Communications and Networks
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• v.17 no.4
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• pp.406-418
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• 2015

Cognitive radio networks (CRNs) have emerged as a promising solution to the problem of spectrum under utilization and artificial radio spectrum scarcity. The paradigm of dynamic spectrum access allows a secondary network comprising of secondary users (SUs) to coexist with a primary network comprising of licensed primary users (PUs) subject to the condition that SUs do not cause any interference to the primary network. Since it is necessary for SUs to avoid any interference to the primary network, PU activity precludes attempts of SUs to access the licensed spectrum and forces frequent channel switching for SUs. This dynamic nature of CRNs, coupled with the possibility that an SU may not share a common channel with all its neighbors, makes the task of multicast routing especially challenging. In this work, we have proposed a novel multipath on-demand multicast routing protocol for CRNs. The approach of multipath routing, although commonly used in unicast routing, has not been explored for multicasting earlier. Motivated by the fact that CRNs have highly dynamic conditions, whose parameters are often unknown, the multicast routing problem is modeled in the reinforcement learning based framework of learning automata. Simulation results demonstrate that the approach of multipath multicasting is feasible, with our proposed protocol showing a superior performance to a baseline state-of-the-art CRN multicasting protocol.

• Applied Biological Chemistry
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• v.9
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• pp.1-7
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• 1968

The action Spectra for violaxanthin de-epoxidation and zeaxanthin expoxidation in New Zealand spinach leaf segments Tetragonia expansa, were determined at equal incident quanta of $2.0{\times}10^{15}$ quanta $cm^{-2}$ $second^{-1}$. The action spectrum for de-epoxidation had major peaks at approximately 180 and 648 nm. Blue light was slightly more effective than red light and little activity was observed beyond 700 nm. The action spectrum for epoxidation showed major peaks at around 441 and 670 nm. Blue light was more effective than red light and light beyond 700 nm showed definite activity. The net result of de-epoxidation and epoxidation is a cyclic scheme, the violaxanthin cycle, which consumes $O_2$ and photoproducts. The action spectra indicate that the violaxanthin cycle is more active m clue than in red light and therefore could accout for $O_2$ uptake stimulated by blue light. The differences between the action spectra for de-epoxidation suggest that possibly two photosynthetic systems are involved. It was suggested that the violaxanthin cycle may functional a pathway for the consumption of excess photoproducts generated in blue light or the conversion of these photoproducts to other forms of energy.

• Journal of Nutrition and Health
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• v.28 no.11
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• pp.1073-1077
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• 1995

The volatile components of Eutrema wasabi were prepared by distillation and ether extraction. The extracts were similar in the color, the odor, and the antimicrobial activity to allylisothiocyanate, the main ingredient of wasabi essential oil. The antimicdrobial activity of the extracts was evaluated and it was found that these had the antibacterial effect against a broad spectrum of pathogenic bacterial such as Staphylococcus, Escherichia, Pseudomonas and Salmonella.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.308-313
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• 1991

The synthesis of 1-[(2-phenyl-1, 3-benzodioxol-2-yl)methyl]-1H-imidazole derivatives is described starting with 2-bromoacetophenones and catechols. 1-[(2-Phenyl-1, 3-benzodioxol-2-yl)methyl]-1H-imidazole (9-$_{12}$) showed potent broad-spectrum activity, not only against Candida species but also Cr. neofortnans, S. cerevisiae and T. mentagrophytes.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.131-131
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• 2002

PCBs are wide spread persistent environmental pollutants that exert a broad spectrum of toxic effects. PCBs includes 209 possible congeners differing in extent and position of chlorination of their aromatic rings. In order to understand the toxic mechanism of PCBs, we have tested the effect of PCB on the EROD activity in vivo.(omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.171.1-171.1
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• 2003

·The potent antitumor activities of 3-arylisoquinolines promoted us to explore the structure-activity relationship of these compounds. A series of 3-arylisoquinoline derivatives were evaluated for antitumor cytotoxicity against human lung tumor cell (A 549). For the next stage, we decided to prepare the constrained form of 3-arylisoquinolines as indeno[1,2-c]isoquinolines. As a result, diverse spectrum against human tumor cell lines was obtained. In order to study structure-activity relationship (SAT) of these compounds the comparative molecular field analysis (CoMFA) was carried out. (omitted)

• Journal of rehabilitation welfare engineering & assistive technology
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• v.12 no.1
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• pp.38-45
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• 2018

The purpose of this study was to investigate the effects of an increase in self - determination experience on the behavior of young children with autism spectrum disorder by telepresence robot. As for research method, the study used AB design, two selected children engaged in activities with a telepresence robot in free play time in the morning. The activities were conducted in 19 sessions, twice a week, 15 to 40 minutes each. To investigate the effect of the activity on the child's behavior was observed using the behaviors of free play time and work time in the afternoon. All the process was recorded by a camera and then analyzed by frequency recording. The results of the study are as follows. First, the participation of young children with autism spectrum disorder in free play time increased. Second, choice-making or preference behavior of young children with autistic spectrum disorder were increased. This study suggests that increasing the self-determination experience of young children with autism spectrum disorders using telepresence robots increases their participation and increases their choice-making or preference behavior.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.885-892
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• 2004

Due to the rapidly growing number of resistant strains of bacteria, the search for antibacterial agents with new modes of action will always remain an important and challenging task. Thus, the reaction of 2-substituted or. unsubstituted-4-(4-acetylanilino)-5,6,7,8-terahydrobenzo［b］ thieno［2,3-d］pyrimidine derivatives 1-3 with the hydrazine derivatives, semi and / or thiosemi-carbazides, provided the corresponding hydrazones 4-6 and semi and/or thiosemicarbazones 7-9. Claisen-Schmidt condensation of compounds 1 or 2 with the appropriate aldehyde yielded the chalcones 10, 11 which, when treated with hydroxylamine hydrochloride gave rise to the isoxazoline-containing compounds 12, 13. Furthermore, reacting the respective chalcones 10, 11 with different hydrazines, urea and/or thiourea, furnished compounds 14, 15, 16, and 17 respectively. Representative compounds were tested for their antimicrobial activity against Candida Albicans and certain gram-positive and gram-negative bacteria. Their MICs were then determined. Compound 15e, showed a broad spectrum of activity while most of the other com-pounds showed varying antimicrobial activity.

• Advances in Traditional Medicine
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• v.7 no.4
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• pp.385-389
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• 2007

We undertook the present study to evaluate different pharmacological as antioxidant, antibacterial and cytotoxic activities of the crude ethanolic extract of Momordica charantia (Family: Cucurbitaceae) leaves. The antioxidant property of the extract was assessed by 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging assay. The extract showed antioxidant activity where $IC_{50}$ was about ${\sim}500{\mu}g/ml\;and\;IC_{50}$ was about ${\sim}10{\mu}g/ml$ for standard drug ascorbic acid. The extract showed a broad spectrum of antibacterial activity against all the tested gram positive and gram-negative bacteria where Staphylococcus epidermidis, Staphylococcus aureus, Salmonella typhi and Shigella dysenteriae were prominent. And the zones of inhibition were ranging from 8-15 mm for all the tested bacteria. Its cytotoxic property was evaluated by brine shrimp lethality bioassay. The extract showed significant lethality and the $LC_{50}$ value was $20{\mu}g/ml$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.441-445
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• 2005

Tripterygium regelii has been used as an oriental medicine, especially antiparasitic, anti-inflammatory and detoxifying agents in East asia. During our research to develop new antitumor agents from natural products, MeOH ext. and CH2Cl2 ext. of Tripterygium regelii showed the potent antitumor activity. In order to purify active compounds from Tripterygium regelii, activity-guided fractionation was carried out. Silica gel and RP-18 column chromatography for the active fraction led to the isolation of two compounds and their antitumor activities were studied. Those two compounds didn't show potent antitumor activity against human tumor cell lines. The structure of two compounds were determined by $^1H-NMR$, $^{13}C-NMR$, DEPT, $^1H-^{13}C$ COSY and IR spectrum. Compound I and Compound II were turned out to be Celastrol, and ${\beta}-sitosteryl-3-o-{\beta}-D-glucopyranoside$ respectively.