• Journal of Haehwa Medicine
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• v.17 no.1
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• pp.67-74
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• 2008

Objective: The purpose of this research is to examine the effects of Mahaenggamseok-tang-gagambang (MGTG) on CD3+ T cells, CD4+ T cells and CD8+ T cells in ovalbumin (OVA)-induced asthmatic mice. Methods: C57BL/6 mice were injected, inhaled and sprayed with OVA for 12 weeks (four a week) for asthma induction. Two experimental groups were treated with different concentrations of MGTG (400 mg/kg and 200 mg/kg) extract and cyclosporin A (10 mg/kg) for the later 8 weeks. At the end of the experiment, the mice lung was removed and analyzed CD3+ T cells, CD4+ T cells and CD8+ T cells by flow cytometer. Results: Numbers of CD3+ T cells in lung of the MGTG groups (200, 400 mg/kg) were significantly decreased compared with that of control group. Numbers of CD4+ T cells in lung of the MGTG groups (200, 400 mg/kg) were significantly decreased compared with that of control group. Numbers of CD8+ T cells in lung of the MGTG groups (200, 400 mg/kg) were significantly decreased compared with that of control group. Conclusion: The results of this study suggest that MGTG alleviated asthmatic hyperreactiviry through CD4+ and CD8+ T cells. Further study of relative cytokines is expected.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1272-1280
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• 2001

An experimental study has been conducted to elucidate the resonance of natural convection in a side-heated square enclosure having a mechanically oscillating bottom wall. Under consideration is the impact of the imposed oscillating frequency, amplitude and the system Rayleigh number on the fluctuation of air temperatures. The experimental results show that the magnitude of the fluctuation of air temperature is substantially augmented at a specific forcing frequency of the oscillating bottom wall. The resonant frequency is increased with the increase of the Rayleigh number and it is little affected by the amplitude of the oscillating wall. It is also found that the resonant frequency is relevant to the Brunt- V$\"{a}$iS$\"{a}$l$\"{a}$ frequency which represents the stratification degree of the system.

• Herbal Formula Science
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• v.14 no.1
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• pp.105-119
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• 2006

Objectives & Methods : This present study was performed to investigate the effect of Hwadamtongrak-Tang extract (HTT) on the regulation of cerebral hemodynamics in terms of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. Also the effects of HTT on changes in local blood flow, inhibition of LD H activity in neuronal cells, and levels of cytokine production in the serum were determined in the ischemic rat model. The major findings are summarized below. Results : 1. HTT significantly increased rCBF in a dose-dependent manner, but MABP was not changed by HTT treatment. These results suggest that HTT may increase rCBF by dilating cerebral arterial diameter. 2. HTT-induced increase in rCBF was blocked by pretreatment with cyclooxygenase inhibitor indomethacin (IDN, 1 mg/kg, i.p.) and MABP was significantly increased by ID N. 3. Pretreatment of methylene blue $(MTB,\;10\;{\mu}g/kg,\;i.p.)$, an inhibitor of guanylate cyclase, significantly decreased both rCBP and MABP in HTT-treated rats. 4. HTT treatment significantly increased rCBP to a stable level during the period of cerebral reperfusion. 5. HTT significantly inhibited LD H activity in neuronal cells, suggesting a neuroprotection by HTT. 6. Serum interleukin $(IL)-1{\beta}$ and tumor necrosis factor $(TNF)-{\alpha}$ levels were significantly decreased in the femoral artery 1 hr after middle cerebral arterial occlusion in HTT-treated rats. IL-10 levels in the serum were significantly increased by HTT treatment whereas transforming growth factor $(TGF)-{\beta}$ levels were similar between HTT-treated and control groups. 7. Serum interleukin $(IL)-1{\beta}$ and tumor necrosis factor $(TNF)-{\alpha}$ levels were significantly decreased in the femoral artery 1 hr after reperfusion in HTT-treated rats. Serum IL-10 levels were significantly decreased in HTT-treated rats compared with the control group, and no significant changes in $(TGF)-{\beta}$ in the serum were observed by HTT treatment. Conclusions: The present data suggest that HTT may have an anti-ischemic effect via the improvement of cerebral hemodynamics and thus protect the brain from ischemic damage.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.18-24
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• 2015

In this study, a $CO_2$ air-conditioning system was investigated with different types of electrically driven compressors, parallel flow type gas cooler, four-pass type evaporator, internal heat exchanger integrated with accumulator, and electric expansion valve. The experimental study was conducted under various operating conditions (ie., different rotational compressor speeds, air inlet temperatures and air velocity coming into heat exchangers). The experimental results showed the cooling capacity was 3.5kW at $35^{\circ}C$ ambient temperature when the vehicle was idle (ie., the worst condition for cooling off the gas cooler). In terms of performance effect of the compressor, the e-RP model had a slightly better cooling capacity and coefficient of performance than the e-GR model under the same test conditions. An experimental equation for optimum cooling-performance control was also suggested based on the results. A high-pressure control algorithm for the super critical cycle was determined to achieve both maximum cooling performance and efficient energy consumption. The results from the experimental equation coincided with those of previous experimental studies.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.446-451
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• 2005

This experiment was designed to investigate the effect of Mominis Placenta herbal acupuncture solution(HP-HAS) on immune cells and cytokines in murine asthma model. In vivo C57BL/6 mice were sensitized and challenged with OVA for 12 weeks. The experimental group was treated with Hominis Placenta herbal acupuncture solution(HP-HAS) at P'yesu(BL13) for the later 8 weeks(3 times a week) and analyzed by ELISA, flow cytometer. The results were obtained as follows Eosinophils in BALF(bronchoalveolar lavage fluid) of HP-HAS group decreased significantly compared with that of control group. IL-4, IL-5, IL-13, IgE in BALF of HP-HAS group decreased significantly compared with that of control group. Number of $CD3e^-/CCR3^+$, $CD69^+/CD3e^+$, $CD11b^+/Gr-1^+$ cells in the HP-HAS group decreased compared with that of control group.

• Korean Journal of Acupuncture
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• v.24 no.4
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• pp.163-180
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• 2007

Objective : Oriental medicines have been applied to Membranous nephropathy(MN) for the purpose on increasing renal blood flow and modulating immune activity in according to Oriental medicine theories. Magsungsinyeom-bang (MSSYB) is one of the prescription which is known to show positive results in clinic with lack of laboratorial evidence. Thus, this study was aimed to evaluate the effects of MSSYB and partially investigate the mechanisms of it. Methods : The effect of MSSYB was evaluated by the morphology for the GBM thickening, protein excretion in urine and biochemical parameters in serum using cBSA-induced MN mice model. Mice were administered with MSSYB(250 or 500 mg/kg) or PBS for control group from experimental week 3 for 4 weeks. Results : 24 hrs proteinuria and the concentrations BUN was significantly decreased in the MS groups compared to the control group while the concentrations of serum albumin was higher in the MS groups than control group. MSSYB didn't affect the ratio of CD3e+/CD or 19CD4+/CD8 in the spleen and kidney, but inhibit the expression of IL-1${\beta}$, TNF-${\alpha}$, IL-6, and production of IgG and IgM. In histological analysis of kidney tissue, thickening of GBM was significantly decreased in the MS group compared to control group. Conclusions : MSSYB showed the positive results on the cBSA-induced membranous nephropathy in mice, thus, it could be a useful candidate for oriental drug for treating the membranous nephropathy in clinic.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.125-131
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• 2006

Recently air pollution has become an important issue. So, as tile number of vehicles increases, the noise pollution has become one of the most serious social issues nowadays. It is a muffler, which is one of the vehicle components. that has the hugest impact on the noise from the vehicle. And it also has a direct influence on the engine performance. So lately the research is proceeding on tile semi-active muffler which can control the back pressure variably by setting up the exhaust variable valve in the baffle to improve its internal structure. The inner parts of muffler which consist of a baffle, pipes and etc. appear to have the complicated turbulence phenomena by the pulsational wave of an unsteady state in the engine and by the structural characteristics of the inner parts. To analyze these phenomena, it is required to have an analysis of its constant quantity and quality. Therefore this study is to analyze with PIV measurement which can analyze the time and space variables, not with the point measurement method like former multi-point anemometer. It is to suggest proper design variables which need to make internal structure of the muffler improve though comparison between the passive type muffler and the semi-active muffler by fabricating a muffler which can be visualized.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.697-704
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• 2007

Recently, a variable valve timing system has been widely adopted in internal combustion engine in order to improve the fuel economy and torque at low engine speed. In addition, it is known that varying valve timing according to the various engine operations could reduce exhaust gas, especially NOx, because of residual gas by valve overlap. In this study, to improve the low exhaust gas and fuel economy at part load condition, the residual gas and back flow of exhaust gas due to valve overlap were calculated computationally. Moreover, the characteristics of engine performances and NOx formations were investigated with the experiment of combination of intake and exhaust valve timing condition. Under these various valve operating conditions, the effects of both the positive valve overlap and negative valve overlap(valve underlap) were examined simultaneously. Finally, the characteristics of cyclic THC emission were analyzed by using Fast Response FID(FR-FID) in the cylinder, intake port and exhaust port positions. Besides, the effect of the different gradients of the valve timing change on engine performance was investigated and an optimum control strategy was suggested.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.117-128
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• 2005

Printing inks are basically dispersions of solid pigment particles in a vehicle. Pigment flocculation and/or colloidal aggregates created by thixotrope additives form a three- dimensional network in the inks. This structure complicates the flow behaviour of inks. However, if the internal structure is formed under control, the printing process will benefit from it because the ink must satify rheological requirements over a very wide range of shear conditions. The presence of internal structure results in the following prominent non-Newtonian rheological properties: viscoelasticity, yield stress, shear thinning and thixotropy. If the components of printing inks were changed, the rheological characteristics such as viscosity, yield stress, viscoelasticity and tack value were considerably varied. Thus, in this paper, the effects of changing the content of rosin modified phenolic resin on rheological properties of the vehicle will be studied. For that, the rheological properties were found by flow, yield stress, creep and oscillation measurements using Bohlin C-VOR Rotational Rheometer. And Emulsion rheology and its microstructure will be investigated.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.2
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• pp.44-50
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• 1999

This paper presents a set of techniques to automatically find rate optimal or near rate optimal implementation of shift-invariant flow graphs on pipelined processor, in which pipeline processor has multiple accumulators and internal datapaths. In such case, the problem to be addressed is the scheduling of multiple instruction streams which control all of the pipeline stages. The goal of an automatic scheduler in this context is to rearrange the order of instructions such that they are executed with minimum iteration period between successive iteration of defining flow graphs. The scheduling algorithm described in this paper also focuses on the problem of removing the hazards due to inter-instruction dependencies.