• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1593-1608
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• 2009

If a certain relay node in multi-hop wireless networks might become a malicious node that does not cooperate with other nodes or a selfish node, network throughput will be dramatically decreased. Most of existing ad hoc routing protocols assuming that the nodes will fully cooperate with other nodes do not resolve the problem of network performance degradation due to malicious and selfish nodes. This paper presents the CARE (Cooperative Ad hoc routing protocol based REputation) scheme incorporating the reputation management that can achieve a multi-hop wireless network with high throughput performance. The proposed scheme provides the horizontal cross-layer approach which can identify misbehaving malicious, selfish nodes dropped out of the hop-by-hop based packet processing in the network and then set up an optimal packet routing path that will detour misbehaving nodes. And the vertical cross-layer approach contained in the CARE scheme attempts to improve the quality of routing paths by exploiting the quality of link information received from the MAC layer. Besides, it provides high TCP throughput by exploiting the reputation values of nodes acquired from the network layer into the transport layer. A case study on experiments and simulations shows that the CARE scheme incorporating vertical and horizontal cross-layer approaches yields better performance in terms of the low rate of packet loss, fast average packet delivery time, and high TCP throughput between end-to-end nodes.

• Journal of KIISE:Information Networking
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• v.35 no.3
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• pp.173-182
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• 2008

Promoting quality of streaming service in wireless networks has attracted intensive research over the years. Instable wireless channel condition causes high transmission delay and packet loss, due to fading and interference. Therefore, they lead to degrade quality of video streaming service. The IEEE 802.11 Working Group is currently working on a new standard called IEEE 802.11e to support quality of service in WLANs. And several schemes were proposed in order to guarantee QoS. However, they are not adaptable to network condition. Accordingly, they suffered video quality degradation, due to buffer overflow or packet loss. In this paper, to promote quality of video streaming service in WLANs, we propose a cross-layer architecture based on IEEE 802.11e EDCA model. Our cross-layer architecture provides differentiated transmission mechanism of IEEE 802.11e EDCA based on priority of MPEG-4 video frames and adaptively controls the transmission rate by dropping video frames through the efficient bandwidth estimation based on distinction of each AC. Through the simulation, proposed scheme is shown to be able to improve end-to-end qualify for video streaming service in WLANs.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.205-214
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• 1989

The present experiment was conducted to investigate effects of soil conditioner applied on continuous cropping fields of red pepper from 1985 to 1986 in Imsil, Chunbuk province. 1. The ratios of bacteria/fungi (B/F) and actinomycetes/fungi (A/F) in the soils of continuous cultivation were increased with application of phytotoxin decomposers such as deep tillage (De), compost (Co), magnesium lime (Mg), gypsum silicate, and De + Co + Mg. 2. Degradation of phytotoxin (p-hydrohylenyons aeid) in the continuous soils was promoted with application of De, Co, Mg, gypsum, silicate and De + Co + Mg resulting in yield increase. 3. The infection rate plant by phytophthora were decreased with deep tillage and application of compost and magnesium lime and caused the increase of yield (22%) due to the increase of fruit per hill.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1126-1135
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• 2012

In order to produce high-quality fermenting composts, bacteria strains with high activities of extracellular enzymes (cellulase, chitinase, amylase, protease and lipase) were isolated from the soils in 6 provinces of Korea, and characterized by 16S rRNA gene sequence analysis and properties. The selected 7 stains inoculated to livestock manure for 2' fermenting time, and experimental treatment divided into 3 groups, B1, B2 and B3, according to microbial activity and enzyme type. Our results showed that microbe applications (B1, B2 and B3) can increase (p<0.05) both rhizomes (17-38%) and enzyme activities (50-81%) in compost after fermenting time, respectively, compared to non-microbe treatment (control). The microbe application also decreased significantly (p<0.05) the $NH_3$ and $H_2S$ gas contents 13.4 and 27.3% compared with control, and the Propionic acid and Butyric acid gas contents 14.5 and 19.6%, respectively, as compared to the control. The microbial degradation rate (%) of pesticides and heavy metals increased significantly (p<0.05) after fermenting time, respectively, as compared to the control. Especially, microbe applications were more effective in total rhizomes yields and bioactivities than non-microbe treatment. Thus the results of this study could help in development of potential bioinoculants and composting techniques that maybe suitable for crop production, and protectable for earth environment under various conditions.

• Biomolecules & Therapeutics
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• v.10 no.2
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• pp.71-77
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• 2002

Heme oxygenase-1 (HO-1) is the inducible from of the rate-limiting enzyme of heme degradation; it regulates the cellular contents of heme. HO-1 is up-regulated by various stimuli including oxidative stress so that it is thought to participate in general cellular defense mechanisms against oxidative stress in mammalian cells. To investigate the role of the cAMP-dependent protein kinase A (PKA) signaling pathway on nitrogen oxidative stress-induced HO-1 gene expression, RAW 264.7 cell cultures were treated with sodium nitroprusside (SNP). SNP increased the expression of HO-1 mRNA and protein, time- and concentration-dependently. Treatment with H89, PKA inhibitor, but not LY83583, guanylate cyclase inhibitor, significantly diminished the HO-1 expression by SNP, indicating that cAMP plays a crucial role in the induction of HO-1. Incubation with cAMP-elevating agents, such as forskolin or isoproterenol resulted in up-regulation of the expression of HO-1. Forskolin-induced expression of HO-1 was inhibited by H89. Furthermore, propranolol, $\beta$-adrenoceptor blocker, inhibited the isoproterenol-induced HO-1 expression, supporting the importance of cAMP in the induction of HO-1 expression. Higenamine-S, but not higenamineR, enhanced the HO-1 expression induced by SNP. Furthermore, cellular toxicity induced by hydrogen peroxide was attenuated by the presence of SNP, which was further increased by the presence of ZnPPIX, HO-1 inhibitor. Collectively, these results strongly suggest that up-regulation of HO-1 expression in RAW 264.7 cells involves PKA signal pathway.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.23-32
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• 2006

Total suspended solids (TSS), five-day biochemical oxygen demand ($BOD_5$), total nitrogen (T-N), and total phosphorous (T-P) concentrations around and under a floating island were examined from October 2002 to September 2003. The island was installed in July 2002 on the surface of an agricultural irrigation reservoir located in the southern part of the Korean Peninsula. It was composed of six polyethylene panels. Each panel was 2 m (length) ${\times}$ 1 m (width) ${\times}$ 0.02 m (thick) and had about thirty-two holes each with a diameter of eight centimeters, through which plant roots grew down into the water. Coconut fibers of nine-centimeters in height were placed on the panel, which sustained plants rhizomes and roots. Both the fibers and the panel were raped with polyethylene wire mashes. About thirty irises (Iris pseudoacorus) were planted into the fibers of each panel. The concentrations of TSS, $BOD_5$, T-N and T-P below the island during the iris-growing season averaged 9.70, 2.59, 3.61 and 0.14 mg/L, respectively and those around it averaged 9.99, 2.83, 4.07 and 0.16 mg/L, respectively. The average concentrations of TSS, $BOD_5$, T-N and T-P below it during the iris non-growing season were 8.68, 2.37, 3.25 and 0.14 mg/L, respectively and those near it were 8.76, 2.43, 3.34 and 0.15 mg/L, respectively. At a significance level of ${\alpha}$=0.05, $BOD_5$, T-N and T-P concentrations under the island during the iris-growing season were significantly low when compared with those around it except TSS. No differences in TSS, $BOD_5$, T-N and T-P concentrations between around and near it were found at a significance level of ${\alpha}$=0.05 during the iris non-growing season. The removal of $BOD_5$, T-N, and T-P during the growing season were significantly high when compared with those during the non-growing season. TSS abatement of the floating island was very low during both the growing and non-growing seasons. The island's reductions of $BOD_5$, T-N and T-P were good during the growing season, especially T-N and T-P, which have been considered as primary pollutant sources causing the water quality degradation of reservoirs. The removal of T-N and T-P was primarily attributed to the absorption of nitrogen and phosphorous by the irises during the growing season.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.276-286
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• 2013

The goal of this study was to investigate change of thermal decomposition feature of miscanthus (Miscanthus sacchariflorus) after removal of inorganic constituents using distilled water (D.I-w; 30, 60 and $90^{\circ}C$). The carbon content was increased whereas the oxygen content was decreased with the temperature of D.I-w treatment. Moreover, ash content was slightly decreased from 4.6% of control to 3.2% of $90^{\circ}C$ D.I-w treated sample. Results of total monomeric sugar contents and X-ray diffraction (XRD) analysis showed that structural changes of cellulose/hemicellulose regions did not occurr during D.I-w treatment. Results of inductively coupled plasma emission spectrometer (ICP-ES) showed that miscanthus has the largest amount of inorganic constituents such as potassium (5,644 ppm), phosphorus (3,995 ppm), magnesium (1,403 ppm) and calcium (711 ppm). Thermogravimetric analysis (TGA) confirmed that the yield of char slightly decreased whereas the yield of volatiles increased with increasing D.I-w treatment temperature. In addition, differential thermogravimetric analysis (DTGA) indicated that the maximum decomposition rate ($V_M$) and temperature ($T_M$) corresponding to VM were varied from $0.82%/^{\circ}C$, $360.60^{\circ}C$ of control to $1.17%/^{\circ}C$, $362.62^{\circ}C$ of $90^{\circ}C$-D.I-w treated sample.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.197-205
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• 2017

Exposure of Jurkat T cell clone (J/Neo cells) to acacetin (5,7-dihydroxy-4'-methoxyflavone), which is present in barnyard millet (Echinochloa esculenta (A. Braun)) grains, caused cytotoxicity, enhancement of apoptotic $sub-G_1$ rate, Bak activation, loss of mitochondrial membrane potential (${\Delta}{\Psi}m$), activation of caspase-9 and caspase-3, degradation of poly(ADP-ribose) polymerase, and FITC-Annexin V-stainable phosphatidylserine exposure on the external surface of the cytoplasmic membrane without accompanying necrosis. These apoptotic responses were abrogated in Jurkat T cell clone (J/Bcl-xL) overexpressing Bcl-xL. Under the same conditions, cellular autophagic responses, including suppression of the Akt-mTOR pathway and p62/SQSTM1 down-regulation, were commonly detected in J/Neo and J/Bcl-xL cells; however, formation of acridine orange-stainable acidic vascular organelles, LC3-I/II conversion, and Beclin-1 phosphorylation (Ser-15) were detected only in J/Neo cells. Correspondingly, concomitant treatment with the autophagy inhibitor (3-methyladenine or LY294002) appeared to enhance acacetin-induced apoptotic responses, such as Bak activation, ${\Delta}{\Psi}m$ loss, activation of caspase-9 and caspase-3, and apoptotic $sub-G_1$ accumulation. This indicated that acacetin could induce apoptosis and cytoprotective autophagy in Jurkat T cells simultaneously. Together, these results demonstrate that acacetin induces not only apoptotic cell death via activation of Bak, loss of ${\Delta}{\Psi}m$, and activation of the mitochondrial caspase cascade, but also cytoprotective autophagy resulting from suppression of the Akt-mTOR pathway. Furthermore, pharmacologic inhibition of the autophagy pathway augments the activation of Bak and resultant mitochondrial damage-mediated apoptosis in Jurkat T cells.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.197-205
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• 2010

This study was conducted to investigate the optimum conditions for efficient methane production through anaerobic digestion of pig waste slurry. The examined parameters were organic matter content of the pig slurry, the ratio of seed sludge to pig slurry, and stirring intensity of the digestion reactor. The effects of types of slurry produced from different purpose-based pigs fed with different feeds were also tested. The methane concentration in the produced biogas was 45% when the ratio of seed sludge to pig slurry was 50% and total solid (TS) concentration was 1%, and it increased in proportional to TS concentration increases from 3 to 7%. At 3 and 5% of TS concentration, increasing mixing velocity from 80 to 160 rpm resulted in higher biogas production amount. However, mixing amount of seed sludge did not cause any significant effect on biogas production. Overall, the most efficient biogas production was achieved at 3-5% TS concentration in combination with 50% seed sludge inoculation and mixing velocity at 120 rpm. Among pig slurry types, gestating sow waste slurry showed the highest biogas production probably due to higher the degradation rate than other types of pig waste slurry being affected by the feeds components.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.351-356
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• 2008

This study was carried out to assess adoptability and environment impacts of ultra low volume (ULV) pesticide spray solutions aerially sprayed by manned-helicopter. Uniformity of the deposited amount in paddy fields was uneven, showing $3.1{\sim}4.7$ times differences among surveyed sites. Drifting distance of aerially sprayed droplets from the target area was within 30 m in the wind direction and 20 m in the opposite direction. Most of the aerially sprayed pesticides were deposited in/on rice plants, while those in submerged paddy water and soil were relatively small. The degradation rate of the deposited pesticides was in the decreasing order of rice plants, paddy water and soil. Soil residues of pesticides in the aerially sprayed rice paddy fields after harvest ranged from non-detected to 0.201 mg/kg. However, no pesticides were detected in brown rice and rice straw. No phytotoxic symtoms were observed in rice plants and nearby non-target crops by the sprayed pesticides.