Decomposition of network of queues with self-similar traffic

Jackson's network of queues model greatly simplifies the performance analysis of telecommunication networks with Poisson traffic arrivals and exponential service times. It reduces the analysis of a network into the analysis of individual communication links, each of which may be modeled as an M/M/m queue. Motivated by the growing significance of self-similar traffic in modeling broadband network traffic, we propose a new network of queues model for telecommunication networks. Our model resembles Jackson's model except that the arrival is self-similar and the service time is deterministic. It captures the characteristics of modern high speed cell-based networks. We hypothesize a result analogous to Jackson's Theorem, that each mode of this network model behaves as a G/D/1 queue with self-similar arrival. Based on this hypothesis, many network-wide performance measures, such as the end-to-end delay, can be evaluated in a simple fashion. Our hypothesis is strongly supported by three facts, namely, the sum of independent self-similar processes, the random splitting of self-similar processes, and the output process of a deterministic service time queue with self-similar input are all self-similar.published_or_final_versio

Decomposition of network of queues with self-similar traffic

Jackson's network of queues model greatly simplifies the performance analysis of telecommunication networks with Poisson traffic arrivals and exponential service times. It reduces the analysis of a network into the analysis of individual communication links, each of which may be modeled as an M/M/m queue. Motivated by the growing significance of self-similar traffic in modeling broadband network traffic, we propose a new network of queues model for telecommunication networks. Our model resembles Jackson's model except that the arrival is self-similar and the service time is deterministic. It captures the characteristics of modern high speed cell-based networks. We hypothesize a result analogous to Jackson's Theorem, that each mode of this network model behaves as a G/D/1 queue with self-similar arrival. Based on this hypothesis, many network-wide performance measures, such as the end-to-end delay, can be evaluated in a simple fashion. Our hypothesis is strongly supported by three facts, namely, the sum of independent self-similar processes, the random splitting of self-similar processes, and the output process of a deterministic service time queue with self-similar input are all self-similar.published_or_final_versio

Antinociceptive and Anti-Inflammatory Effects of Ethanolic Extracts of Glycine max (L.) Merr and Rhynchosia nulubilis Seeds

The aim of this study was to assess the in vivo potential of ethanolic extracts of Glycine max (L.) Merr. (SoRiTae) and Rhynchosia nulubilis (Yak-Kong) seeds as natural anti-nociceptive and anti-inflammatory agents. To assess the anti-nociceptive and anti-inflammatory potential, the ethanolic extracts of SoRiTae and Yak-Kong seeds were tested in arachidonic acid-induced ear edema, carrageenan induced paw edema, formalin-induced licking time, acetic acid induced writhing and hot plate-induced thermal stimulation in mice. The administration of ethanolic extracts of SoRiTae and Yak-Kong seeds evoked a significant effect of anti-nociceptive and anti-inflammatory activities as compared to standards aminopyrine and indomethacin. The ear edema, paw edema, paw licking time, pain and writhes in mice were significantly reduced (p < 0.05) as compared to the control. The results obtained in this study indicate that both SoRiTae and Yak-Kong soybeans possesses potential anti-nociceptive and anti-inflammatory activities

Serum cytokine profiles in healthy young and elderly population assessed using multiplexed bead-based immunoassays

<p>Abstract</p> <p>Background</p> <p>Lipid metabolites and cytokines, including chemokines and growth factors, are the key regulators of immune cell function and differentiation, and thus, dysregulation of these regulators is associated with various human diseases. However, previous studies demonstrating a positive correlation of cytokine levels with aging may have been influenced by various environmental factors and underlying diseases. Also, data regarding cytokine profiling in the elderly are limited to a small subset of cytokines.</p> <p>Methods</p> <p>We compared the profiles of 22 cytokines, including chemokines and growth factors, in a case-controlled study group of a gender-matched, healthy cohort of 55 patients over the age of 65 and 55 patients under the age of 45. Assessment of serum cytokine concentrations was performed using commercially-available multiplex bead-based sandwich immunoassays.</p> <p>Results</p> <p>Soluble CD40 ligand (sCD40L) and transforming growth factor alpha (TGF-α) levels were significantly higher in the elderly patients, whereas granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein-1 (MCP-1) levels were significantly lower in the elderly patients. The partial correlation analysis demonstrating the correlation between cytokine levels when controlled for gender, systolic blood pressure, total cholesterol, HDL cholesterol, triglyceride, and serum creatinine levels further demonstrated that G-CSF, GM-CSF, and MCP-1 had significant negative correlations with age, whereas sCD40L and TGF-α had significant positive correlations.</p> <p>Conclusions</p> <p>Future studies will focus on examining the significance of these age-related changes in circulating cytokines and other biological markers and their potential contribution to the development of different age-associated diseases.</p

The Acute and Chronic Effect of Korea Ginseng Supplement on Exercise Performance, Cognitive Function, and Fatigue Recovery

The purpose of this study was to determine the acute and chronic effects of Korean ginseng supplements on exercise performance, cognitive function, and fatigue recovery. The study used double-blind, placebo-controlled, crossover design. Twelve healthy adult males (age = 31 ± 6.86 yrs) were randomly assigned to either KGD or placebo trials. All subjects conducted the exercise consisted with 30 minutes cycling at 70-75% of VO2 max followed by 16 km time trial with 30 minutes resting periods. All subjects were tested for muscular power, strength, endurance, cognitive function, and fatigue. The subjects took KGD (280 ml containing 5.88 mg of ginsenosides) or placebo 90 mins before exercise trials and following 7 days. The blood sample was drawn for IL-6, myoglobin, and total antioxidant capacity immediately after time trial, as well as 2, 24, 48, and 72 hours. After 2 weeks of wash-out period, the subjects were crossed over into the opposite trial and performed the same test. Repeated measures ANOVAs were used to examine the effect of acute and chronic intake of ginseng on exercise performance and blood variables. An alpha of .05 was used, and the Greenhouse-Geisser (G-G) adjusted F and degrees of freedom were reported. In a placebo trial, peak power and mean power levels were significantly decreased across time, F (1.47, 13.24) = 4.63, G-G p = .039, h2p = .340 and F (1.46, 13.13) = 5.31, G-G p = .028, h2p = .371 while no differences were found in a ginseng trial. In a placebo trial, average reaction time (ART) was significantly increased across time, F (1.29, 11.63) = 10.81, G-G p = .005, h2p = .546, but in a ginseng trial, no difference in ART was found across time, F (1.54, 13.86) = 4.02, G-G p = .051, h2p = .309. There was a significant increase in TAC across time in a ginseng trial, F (1.42, 11.37) = 5.07, G-G p = .035, h2p = .388 while no difference was found in a placebo trial. No significant differences were found in other variables from placebo and ginseng trails. The 7 days of KRG supplementation significantly reduced the serum myoglobin concentration across time in the KGD trial, F (1.88, 13.17) = 5.18, G-G p = .023, while no difference was found in the placebo trial, F (2.21, 17.66) = .88, G-G p = .443. No significant differences were observed in serum total antioxidant activity and IL-6 between KGD and placebo trials. The study shows that Korean ginseng supplement before stating the exercise improve anaerobic capacity, cognitive function in particular psychomotor vigilance task, and fatigue recovery during cycling exercise. And 7 days of Korean ginseng supplement reduces muscle damage and fatigue after cycling exercise

Effect of a multi-layer infection control barrier on the micro-hardness of a composite resin

OBJECTIVE: The aim of this study was to evaluate the effect of multiple layers of an infection control barrier on the micro-hardness of a composite resin. MATERIAL AND METHODS: One, two, four, and eight layers of an infection control barrier were used to cover the light guides of a high-power light emitting diode (LeD) light curing unit (LCU) and a low-power halogen LCU. The composite specimens were photopolymerized with the LCUs and the barriers, and the micro-hardness of the upper and lower surfaces was measured (n=10). The hardness ratio was calculated by dividing the bottom surface hardness of the experimental groups by the irradiated surface hardness of the control groups. The data was analyzed by two-way ANOVA and Tukey's HSD test. RESULTS: The micro-hardness of the composite specimens photopolymerized with the LED LCU decreased significantly in the four- and eight-layer groups of the upper surface and in the two-, four-, and eight-layer groups of the lower surface. The hardness ratio of the composite specimens wa

Replication of the genetic effects of IFN regulatory factor 5 (IRF5) on systemic lupus erythematosus in a Korean population

Recently, two studies provided convincing evidence that IFN regulatory factor 5 (IRF5) gene polymorphisms are significantly associated with systemic lupus erythematosus (SLE) in several white populations. To replicate the association with SLE in an Asian population, we examined the genetic effects in our SLE cohort from a Korean population. A total of 1,565 subjects, composed of 593 cases and 972 controls, were genotyped using the TaqMan® (Applied Biosystems, Foster City, CA, USA) method. The genetic effects of polymorphisms on the risk of SLE were evaluated using χ2 tests and a Mantel–Haenszel meta-analysis. Statistical analysis revealed results in the Korean population were similar to the previous reports from white populations. The rs2004640 T allele had a higher frequency in SLE cases (0.385) than controls (0.321; odds ratio (OR) = 1.32, P = 0.0003). In combined analysis, including all seven independent cohorts from the three studies so far, robust and consistent associations of the rs2004640 T allele with SLE were observed. The estimate of risk was OR = 1.44 (range, 1.34–1.55), with an overall P = 1.85 × 10-23 for the rs2004640 T allele. The haplotype (rs2004640T–rs2280714T) involved in both the alternative splice donor site and the elevated expression of IRF5 also had a highly significant association with SLE (pooled, P = 2.11 × 10-16). Our results indicate that the genetic effect on the risk of SLE mediated by IRF5 variants can be generally accepted in both white and Asian populations

Promoting Public Participation and Environmental Education in the Republic of Korea

The industrialization in the Republic of Korea began only in early 1960's. The economic development has been based mainly on the export-oriented heavy-chemical industries. The development has been quite successful. But at the same time it brought severe environmental pollution problems, especially in industrial areas. There have been continual disputes between industrial firms and inhabitants over damages on agricultural and fishery products and on human health. In some areas it was hard to find solution so that the disputes ended up as removing the whole population from the problem areas such as in Ulsan, Onsan, and Yeocheon. Tens of thousand natives had to give up their hometown and occupation, which caused a serious social problem. The Government began to realize the seriousness of the environmental problems, and the Office of Environment was established in 1980 which was raised to the Ministry of Environment in 1990. However, the quality of the environment has not been improved much in spite of the Governmental intervention. It is probably because the Governmental policies have not been strong enough to keep up with the rapid industrialization while the public were not allowed to protest against or participate in governmental policies until democratization in 1987