• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.367-377
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• 2015

Atmospheric drag force is an important source of perturbation of Low Earth Orbit (LEO) orbit satellites, and solar activity is a major factor for changes in atmospheric density. In particular, the orbital lifetime of a satellite varies with changes in solar activity, so care must be taken in predicting the remaining orbital lifetime during preparation for post-mission disposal. In this paper, the System Tool Kit (STK$^{(R)}$) Long-term Orbit Propagator is used to analyze the changes in orbital lifetime predictions with respect to solar activity. In addition, the STK$^{(R)}$ Lifetime tool is used to analyze the change in orbital lifetime with respect to solar flux data generation, which is needed for the orbital lifetime calculation, and its control on the drag coefficient control. Analysis showed that the application of the most recent solar flux file within the Lifetime tool gives a predicted trend that is closest to the actual orbit. We also examine the effect of the drag coefficient, by performing a comparative analysis between varying and constant coefficients in terms of solar activity intensities.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.472-477
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• 2011

The Forsythiae Fructus is an oriental medicine containing various lignans. In this study, the Forsythiae Fructus were extracted by hot water (Sample 1), hot water after bio-conversion using Lactobacillus strain (Sample 2-LP2, 2-LA, 2-LC, 2-LL, 2-BL and 2-LM) and 70% ethanol (Sample 3). Total polyphenol and flavonoid contents were improved by bio-conversion process using Lactobacillus strain, compared to water extract. Especially, sample 2-LL and 2-LA which had shown the high total polyphenol and flavonoid content in antioxidant activity. Also, sample 2-LL and 2-LA showed higher melanin generation inhibitory activity as of 55%, 53% in maximum extract concentration of $100{\mu}g/m{\ell}$. In the anti-inflammation test of the Forsythiae Fructus extracts, nitric oxide (NO) synthesis was inhibited. Specially, both 70% Forsythiae Fructus ethanol extract and sample 2-BL which have shown the relatively higher 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD) like activities. In conclusion, the Forsythiae Fructus extracts with bio-conversion process has effect of skin whitening and anti-inflammation activity than other extracts. It could be used as a valuable materials for functional cosmetics.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.312-316
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• 2006

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced $H_2O_2$-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in $H_2O_2$-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

• BMB Reports
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• v.49 no.5
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• pp.282-287
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• 2016

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a homo-trimeric cytotoxic ligand. Several studies have demonstrated that incorporation of artificial trimerization motifs into the TRAIL protein leads to the enhancement of biological activity. Here, we show that linkage of the isoleucine zipper hexamerization motif to the N-terminus of TRAIL, referred as ILz(6):TRAIL, leads to multimerization of its trimeric form, which has higher cytotoxic activity compared to its native state. Size exclusion chromatography of ILz(6):TRAIL revealed possible existence of various forms such as trimeric, hexameric, and multimeric (possibly containing one-, two-, and multi-units of trimeric TRAIL, respectively). Increased number of multimerized ILz(6):TRAIL units corresponded with enhanced cytotoxic activity. Further, a high degree of ILz(6):TRAIL multimerization triggered rapid signaling events such as activation of caspases, tBid generation, and chromatin condensation. Taken together, these results indicate that multimerization of TRAIL significantly enhances its cytotoxic activity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.321-344
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• 2017

Smart homes are the new generation of homes where pervasive computing is employed to make the lives of the residents more convenient. Human activity recognition (HAR) is a fundamental task in these environments. Since critical decisions will be made based on HAR results, accurate recognition of human activities with low uncertainty is of crucial importance. In this paper, a novel HAR method based on a difference of convex programming (DCP) problem is represented, which manages to handle uncertainty. For this purpose, given an input sensor data stream, a primary belief in each activity is calculated for the sensor events. Since the primary beliefs are calculated based on some abstractions, they naturally bear an amount of uncertainty. To mitigate the effect of the uncertainty, a DCP problem is defined and solved to yield secondary beliefs. In this procedure, the uncertainty stemming from a sensor event is alleviated by its neighboring sensor events in the input stream. The final activity inference is based on the secondary beliefs. The proposed method is evaluated using a well-known and publicly available dataset. It is compared to four HAR schemes, which are based on temporal probabilistic graphical models, and a convex optimization-based HAR procedure, as benchmarks. The proposed method outperforms the benchmarks, having an acceptable accuracy of 82.61%, and an average F-measure of 82.3%.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.158-164
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• 2002

In the course of searching immunomodulators from natural sources, the protein-bound polysaccharide, CM-Ala, has been isolated from the water extract of Chelidonium majus L. (Papaveraceae). The immunostimulatory characteristics have been investigated in several experiments such as generation of activated killer (AK) cells, proliferation of splenocytes, activation of macrophages and granulocyte macrophage-colony forming cell (GM-CFC) assay. Of the fractions obtained using Sephacryl S200 column chromatography, CM-Ala was the most effective fraction that augmented the cytotoxicity against Yac-1 tumor cells from 0.88% to 34.18% by culturing with splenocytes for 5 days. CM-Ala also enhanced nitric oxide production by two fold in peritoneal macrophages and exhibited antitumor activity. It showed mitogenic activity on both spleen cells and bone marrow cells. CM-Ala induced proliferation of splenocytes by 84 fold and increased GM-CFC numbers by 1.48 fold over than the non-treated. On the contrary, CM-Ala had cytotoxic activity to a diverse group of tumor cells. From the above results, we proposed that CM-Ala has a possibility of an effective antitumor immunostimulator.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.247-249
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• 2003

Currently there are a variety of different tools may be used to analyze, model, describe and document a business process. However, it is difficult to exchange the information of a business process created in different tools because of the distinct information formats used in different tools. The XML Process Definition Language (XPDL) of the Workflow Management Coalition (WfMC) forms a common interchange standard that enables products to continue to support arbitrary internal representations of process definitions with an import/export function to map to/from the standard at the product boundary. Generally a business process model can be represented by the UML activity diagram, but there is a difficult task to directly generate an XPDL document from a business process model represented by the standard activity diagram. In the paper we will propose an approach to generate an XPDL document from a business process model represented by the extended UML activity diagram.

• Archives of Pharmacal Research
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• v.22 no.2
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• pp.213-218
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• 1999

The antioxidant activity of Eriobotrya japonica was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and lipid peroxidation produced when mouse liver homogenate was exposed to the air at $37^{\circ}C$, using 2-thiobarbituric acid (TBA). The methanol extract and its factions of Eriobotrya japonica leaves showed strong antioxidant activity. The antioxidant activity of EtOAc and n-BuOH soluble fractions were stronger than the others, and were further purified by repeated silica gel, MCl gel CHP-20P, and Sephadex LH-20 column chromatography. Antioxidant chlorogenic acid, quercetin-3-sambubioside from n-BuOH fraction and methyl chlorogenate, kaempferol- and quercetin-3-rhamnosides, together with the inactive ursolic acid and$ 2{\alpha}$-hydroxyursolic acid from EtOAc fraction were isolated. Antioxidant flavonoids and chlorogenic acid also showed prominent inhibitory activity against free radical generation in dichlorofluorescein (DCF) method.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.62-62
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• 2019

Natural substances have various physiological activities. Substances isolated from natural substances are known to be safer and more potent than pharmaceuticals. Potatoes not only act as energy sources but also contain active ingredients such as vitamins and minerals. In particular, the potato contains a large amount of polar compounds, including the saponin in the polar compounds, and the physiological activity of the saponins, such as immunity enhancement, antioxidant and anti-inflammatory is known. In this study, the antioxidative activity of polar compounds from five potatoes was examined by chemical base anti-oxidation assay and cell based anti-oxidation assay. In the chemical base anti-oxidation assay, DPPH experiment showed activity in the order of Hongyoung, Haryung, Seohong, Sumi, and Jayoung. In the LPA experiment, IC50 was lower in the order of Jayoung, Seohong, Sumi, Hongyoung, and Haryung. In the cell based anti-oxidation assay, the smallest amount of ROS was generated when the compound was derived from Haryung and hongyoung, and strong SOD activity was observed in Sumi and Jayoung. The results of this study reveal the antioxidative effect of polar compounds extracted from various kind of potatoes, which will enable the acquisition of new bioactive candidates and the establishment of new profit generation models for farmers.

• Journal of Photoscience
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• v.3 no.1
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• pp.1-7
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• 1996

When cucumber (Cucumis sativus L.) cotyledon discs were floated on $\delta$-aminolevulinic acid, oxyfluorfen, or rose bengal solution under light condition following 20 h dark incubation, rapid electrolyte leakage from the tissues occurred. The electrolyte leakage from the tissues was dependent on the compounds treated, their concentrations, and the duration of light exposure to the tissues. Dark incubation before exposure to continuous white light enhanced electrolyte leakage from the tissues treated with the compounds and reduced lag period for the activity of the compounds. Electrolyte leakage from the treated tissues was greatly influenced by the light intensity to which they were exposed. Higher light intensities stimulated electrolyte leakage and reduced lag period. Porphyrin biosynthesis inhibitors, gabaculine and 4,6-dioxoheptanoic acid, completely inhibited electrolyte leakage from the oxyfluorfen-treated tissues. Protection against the activity of $\delta$-aminolevulinic acid from electrolyte leakage was complete with 4,6-dioxoheptanoic acid, but not with gabaculine. However, gabaculine and 4,6-dioxoheptanoic acid gave no such protection against rose bengal activity. In summary, our results indicate that $\delta$--aminolevulinic acid, oxyfluorfen, and rose bengal exert their effects by causing electrolyte leakage from the treated tissues in a similar manner, except that oxyfluorfen has an apparent lag period for its action on electrolyte leakage increase. All above compounds require preincubation of treated tissues in darkness and subsequent light exposure with a high intensity for their maximal activities. Our results also support that in the presence of light, $\delta$-aminolevulinic acid and oxyfluorfen cause cellular damage through the indirect generation of singlet oxygen from accumulated tetrapyrroles of porphyrin pathway, whereas rose bengal causes cellular damage through the direct generation of singlet oxygen.