• The Journal of the Korea Contents Association
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• v.7 no.1
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• pp.131-138
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• 2007

In wired networks, packet losses mostly occur due to congestion. TCP reacts to the congestion by decreasing its congestion window, thus to reduce network utilization. In wireless networks, however, losses may occur due to the high bit-error rate of the transmission medium or due to fading and mobility. Nevertheless, TCP still reacts to packet losses according to its congestion control scheme, thus to reduce the network utilization unnecessarily. This reduction of network utilization causes the performance of TCP to decrease. In this paper, we predict packet loss by using RSS(Received Signal Strengths) on the wireless and suggest adding RSS flag bit in ACK packet of MH. By using RSS flag bit in ACK, the FH(Fixed Host) decides whether it adopt congestion control scheme or not for the maximum throughput. The result of the simulation by NS-2 shows that the proposed mechanism significantly increases sending amount and receiving amount by 40% at maximum.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2153-2159
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• 2015

Mycoplasma hyopneumoniae is known to cause porcine enzootic pneumonia (EP), an important disease in swine production. The objective of this study was to examine the effects of sonicated protein fractions of M. hyopneumoniae on inflammatory response and gene expression in the murine alveolar macrophage MH-S cell line. The effects of sonicated protein fractions and intact M. hyopneumoniae on the gene expression of cytokines and iNOS were assessed using RT-PCR. The Annealing Control Primer (ACP)-based PCR method was used to screen differentially expressed genes. Increased transcription of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, COX-2, and iNOS mRNA was observed after exposure to the supernatant (SPT), precipitant (PPT), and intact M. hyopneumoniae protein. A time-dependent analysis of the mRNA expression revealed an upregulation after 4 h for IL-6 and iNOS and after 12 h for IL-1β and TNF-α, for both SPT and PPT; the fold change in COX-2 expression was less. A dose- and time-dependent correlation was observed in nitrite (NO) production for both protein fractions; however, there was no significant difference between the effects of the two protein fractions. In a differential gene analysis, PCR revealed differential expression for nine gene bands after 3 h of stimulation — only one gene was downregulated, while the remaining eight were upregulated. The results of this study provide insights that help improve our understanding of the mechanisms underlying the pathogenesis of and macrophage defenses against M. hyopneumoniae assault, and suggest targets for future studies on therapeutic interventions for M. hyopneumoniae infections.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.149-156
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• 2013

Interstitial cells of Cajal (ICCs) are the pacemaker cells in the gastrointestinal tract, and histamine is known to regulate neuronal activity, control vascular tone, alter endothelial permeability, and modulate gastric acid secretion. However, the action mechanisms of histamine in mouse small intestinal ICCs have not been previously investigated, and thus, in the present study, we investigated the effects of histamine on mouse small intestinal ICCs, and sought to identify the receptors involved. Enzymatic digestions were used to dissociate ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record potentials (in current clamp mode) from cultured ICCs. Histamine was found to depolarize resting membrane potentials concentration dependently, and whereas 2-PEA (a selective H1 receptor agonist) induced membrane depolarizations, Dimaprit (a selective H2-agonist), R-alpha-methylhistamine (R-alpha-MeHa; a selective H3-agonist), and 4-methylhistamine (4-MH; a selective H4-agonist) did not. Pretreatment with $Ca^{2+}$-free solution or thapsigargin (a $Ca^{2+}$-ATPase inhibitor in endoplasmic reticulum) abolished the generation of pacemaker potentials and suppressed histamine-induced membrane depolarization. Furthermore, treatments with U-73122 (a phospholipase C inhibitor) or 5-fluoro-2-indolyl des-chlorohalopemide (FIPI; a phospholipase D inhibitor) blocked histamine-induced membrane depolarizations in ICCs. On the other hand, KT5720 (a protein kinase A inhibitor) did not block histamine-induced membrane depolarization. These results suggest that histamine modulates pacemaker potentials through H1 receptor-mediated pathways via external $Ca^{2+}$ influx and $Ca^{2+}$ release from internal stores in a PLC and PLD dependent manner.

• Advances in Traditional Medicine
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• v.6 no.4
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• pp.349-354
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• 2006

In the present study, three Malaysian Channa spp. fish Channa striatus, Channa micropeltes and Channa lucius were assessed for their analgesic activity. Distilled water and mixture of chloroform: methanol were used for extraction. The analgesic or antinociceptive activity was investigated by abdominal writhing and hot plate test. The water extract of Channa striatus and the chloroform: methanol extract Channa lucius produced potent antinociceptive effect when assessed with the abdominal writhing test. The activity was compared to morphine where the activity of the extracts was less potent than the opioid. In the hote plate test, water extract of Channa striatus revealed significant activity and chloroform:methanol extract of Channa micropeltes had moderate activity. However, these activities were statistically lower than morphine. Collectively, this study also showed that Channa striatus extract was more potent analgesic agent when compared to the other closely related snakehead Channa micropeltes and Channa lucius.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.4
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• pp.17-25
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• 1991

Slotted coaxial cables are used for a wide variety of radio communications and control applications within buildings, subways, tunnels and outdoors. They function as continuous antennas to solve RF coverage problems in difficult or confined areas. In this paper the electric and magnetic field distributions inside and outside of axially slotted coaxial cables are analyzed numerically. This paper gets the fields from the equivalent potentials which are obtained by grid relaxation method. The slot electric field configurations are consistent with Essam E. Hassan's results. The field distributions in the slotted coaxial cables show that the TEM mode doesn't propagate any longer in them. But the fields don't variate with the frequencies that are under the first higher order mode cutoff frequency of shielded coaxial cable of the same dimension The fields inside of the tunnel ($3\times4$) including the slotted coaxial cable axially are similar to those of $TE_{10}$ mode at 38.75 MHz. This method offers the basis for theoretical analysis of coaxial cables with nonuniform slots as well as coaxial cables in tunnels and buildings.

• Journal of Acupuncture Research
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• v.23 no.1
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• pp.63-70
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• 2006

Objectives : This study was designed to evaluated the effect of electroacupuncture on Quality of life of patients with urinary incontinence Methods : Subjects were voluntarily recruited by newspapers and internet. Electroacupuncture was performed three times a week for 3 weeks. Acupuncture point for EA group was B32, Electrical stimulation frequency was 2Hz, duration 20 minutes, and intensity was up to pain threshold according to patients. The patients's symptoms were assessed before, after 3 weeks of treatment by QOL item of International Prostate Symptom Score(IPSS), Medical Outcomes Study(MOS) 36-Item Short-Form Health Survey(SF-36). Results : QOL score of IPSS were significantly improved after 3 weeks(p<0.05) compared to the pre-treatment. There were significant changes in Social functioning(SF), role-physical(RP), role emotional(RE), mental health(MH), bodily pain(BP) score of SF-36 after 3 weeks(p<0.05), but there were no significant changes in physical functioning(PF), vitality(VT), general health(GH) score of SF-36. Conclusion : This study suggests that electroacupuncture treatments can be applicable to improve symptoms in patients with urinary incontinence.

• Journal of Acupuncture Research
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• v.23 no.6
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• pp.145-152
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• 2006

Objectives : The aim of this study is to investigate the effect of Acupuncture and Bee-venom acupuncture for patients with chronic whiplash injury. Methods : Subjects were voluntarily recruited by newspapers and internet. Acupuncture(Eo-Hyeol Bang) and Bee-Venom Acupuncture were performed two times a week for 4 weeks. The patients' symptoms were assessed before, after 4 weeks of treatment by Visual Analogue Scale(VAS), Medical Outcome Study(MOS) 36-Item Short-Form Health Survey(SF-36) Results : VAS score was significantly improved after 4 weeks(p<0.05) compared to the pre-treatment. There were significant changes in physical functioning(PF), Social functioning(SF), role-physical(RP), role emotional(RE), mental health(MH), bodily pain(BP) score of SF-36 after 4 weeks(p<0.05), but there were no significant changes in vitality(VT), general health(GH) score of SF-36. Conclusion: This study suggests that Acupuncture(Eo-Hyeol Bang) and Bee-Venom Acupuncture can be applicable to improve symptoms in patients with chronic whiplash injury.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1365-1374
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• 2010

The maritime traffic is more complex these days. It is more hard for the small fishing ships to navigated in shores. The requirements for the navigate information system to protect the sea environments and support the small fishing ships are more increased. However, the Inmarsat communication system is too burden to the fishermen with the expensive terminal and call fees. We propose the wireless digital fishing information network which use the existing MF/HF SSB communications system by connecting I-PHONE, PDA, NetBook, Notebook, PC, etc with the PSK31 method and AIS(Automatic Identification System) on the MF/HF radio Band.

• Advances in Traditional Medicine
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• v.7 no.1
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• pp.34-40
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• 2007

The present study was carried out to elucidate the potential of Muntingia (M.) calabura leaves chloroform extract (MCCE) as antinociceptive, anti-inflammatory and antipyretic agents using various animal models. The dried powdered leaves of M. calabura (20 g) were soaked in chloroform for 72 h and the supernatant obtained was then evaporated to dryness. The crude dried extract (0.912 g), dissolved in dimethyl sulfoxide (1:20; w/v) and considered as a stock solution (100% concentration/strength), was then diluted to the concentrations of 10 and 50% and used together in all experimental models. The MCCE was found to show significant (P < 0.05) antinociceptive and antipyretic activities, but less remarkable anti-inflammatory activity. Only the antinociceptive activity of MCCE measured using the abdominal constriction test and in the first phase of the formalin test occurred in a concentration-dependent manner. The anti-inflammatory activity of 50 and 100% concentrations MCCE was observed only at the range of time interval of 60 - 120 and 60 min, respectively. Based on the results, we conclude that the M. calabura leaves chloroform extract possessed remarkable antinociceptive and antipyretic, but less effective anti-inflammatory, activities and thus justifies the Peruvian folklore claims of its medicinal values.

• The Korean Journal of Rehabilitation Nursing
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• v.10 no.2
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• pp.90-98
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• 2007

ression and quality of life of family caregivers of patients with Parkinson's disease(PD). Methods: A cross-sectional descriptive study was conducted in one neurology outpatient clinic in Seoul, Korea from March to June, 2006. Sixty eight family caregivers of PD patients were participated to the study, using CES-D and SF-36. Results: Mean scores of depression were $16.18{\pm}8.39$ (range: 0-48) and it was a little lower than caregiver's who took care of Dementia patients and were higher than primary caregivers of the patients with Stroke. Time for caregiving, perceived severity, duration of PD were significantly related with depression respectively. Higher ADL scores which mean greater motor disabilities were related to higher caregiver depression. Lower income and greater medical expenditure were closely related with the depression of family caregivers respectively. The mean scores of total QOL were $435.5{\pm}96.5$ and the mean scores of PF, SF, RE and MH were lower than general population. Time for caregiving, depression, patients' ADL scores were significantly associated with QOL respectively. People who were older and had lower educational background showed lower QOL scores respectively. Conclusion: Healthcare professionals should pay more attention to emotional aspects of caregivers who take care of PD patients, and develop comprehensive management strategies both for patients and their caregivers.