• 한방안이비인후피부과학회지
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• 제21권1호
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• pp.38-54
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• 2008

Objective : This study was designed to investigated effects of Pinelliae Rizoma (PR) on asthma Methods : Detecting antigen specific antibody isotypes, cytokines in serum and bronchoalveolar lavage fluid (BALF). In addition, the present author also investigated changes in weight of spleen and proliferation rates of splenocytes. Finally, histopathological observation of the lung tissue was also investigated. Results : Oral administration of PR lowered OVA specific IgE levels in serum, IgG1 levels in serum and BALF. PR also decreased production levels of IL-4 in BALF. In addition, total cells in BALF were decreased by oral administration of PR effectively. In histapathological observation, PR group showed downward tendency of inflammatory cell infiltration around small vessels. Conclusion : PR is useful to treat patients with asthma and the mechanisms are related in suppression of Th2 skewing reactions.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권3호
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• pp.123-130
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• 2006

This paper presents characteristics analysis of skewed Synchronous Reluctance Motor using equivalent magnetic circuit and compares with the result of Finite Element Method. Torque ripple must be reduced, because it is producing noise and vibration. There is many kinds of method to reduce torque ripple, but generally we apply skewing stator or rotor. The 2D Finite Element Method(FEM) or 3D FEM is used to analyze the motor, since skew influence the average torque in the motor. However, the FEM takes much time in spite of the advanced computer and numerical technique. This paper will analyze characteristics of skewed synchronous reluctance motor using equivalent magnetic circuit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.749-751
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• 2004

This paper analyzed the characteristics of the claw pole PM step motor by using 3D FEM. In case of analysing this type of motor, 3 dimensional analysis is necessary for an accurate analysis due to the magnetizing component of the z-axis direction. As a main design variable, the magnetization, width and the effects of skewing was selected. The variation of the detent torque and the back EMF depending on the shape of the pole is also shown.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.921-923
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• 2003

This paper introduces Flux-Reversal Machine(FRM) and presents the design of a FRM to reduce the cogging torque. The effect of the design parameters on the characteristic and cogging torque is analyzed by finite Element Method(FEM). The considered design parameters are bifurcated teeth, chamfered magnet poles, chamfered rotor tooth tips and rotor skewing. As a result, we can find the optimum model reduced cogging torque and torque ripple in 6/8 FRM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1180-1182
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• 2005

In this paper, the design and field analysis of the novel axial flux type permanent magnet(AFPM) motor with double stator and single rotor are investigated. The various design schemes of AFPM based on 3D finite element method are proposed. The effects of slot shapes, various magnetization of PM, and skewing on the cogging torque and average torque have been investigated in detail. From the results, we can improve the cogging torque and average torque characteristics.

• 한국광학회지
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• 제12권5호
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• pp.414-417
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• 2001

Experimentally, the aligned direction of AFLCs in electro-optic cells having both the substrates rubbed along the same direction is skewed by a few degrees from the rebbing direction. To explain why, we proposed "Torsional Rigid Body Model" and interpreted their skewing angle as the action of short pitch with the large shear stress. That is, the azimuthal an anchoring strength (about 35 dyn/cm) in the cell is much larger than the maximum shear stress (about 10$^{-6}$ dyn/cm) for the original pitch and so forbids the optic axis to skew. On the side hand, the strength is smaller than the maximum shear stress (about 42 dyn/cm) for short pitch and then allows the optic axis to skew.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.718-725
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• 2017

The method of stator segmentation is generally taken to enhance the electromagnetic performance of surface-mounted permanent magnet (SPM) machine and reduce its production cost. Based on the model with single slot, the expressions of cogging torque in machine with uniform or non-uniform segmentations are deduced and the optimal combination is given. Moreover, this paper discusses a structured skewing method and put forward a novel stator structure model to reduce the cogging torque in segmented permanent magnet machine. The model can reduce the cogging torque amplitude by shifting a proper angle of slot-opening. The shifting angle formula for analysis can also be suitable for other permanent machine with segmented stator. Finally the results of finite element simulation are given to prove that the method is effective and feasible.

• Advances in aircraft and spacecraft science
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• 제3권4호
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• pp.367-378
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• 2016

Thrust Vectoring is a dynamic feature that offers many benefits in terms of maneuverability and control effectiveness. Thrust vectoring capabilities make the satisfaction of take-off and landing requirements easier. Moreover, it can be a valuable control effector at low dynamic pressures, where traditional aerodynamic controls are less effective. A numerical investigation of Fluidic Thrust Vectoring (FTV) is completed to evaluate the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The methodology presented is general and can be used to study different techniques of fluidic thrust vectoring like shock-vector control, sonic-plane skewing and counterflow methods. For validation purposes the method will focus on the dual-throat nozzle concept. Internal nozzle performances and thrust vector angles were computed for several range of nozzle pressure ratios and fluidic injection flow rate. The numerical results obtained are compared with the analogues experimental data reported in the scientific literature. The model is integrated using a finite volume discretization of the compressible URANS equations coupled with a Spalart-Allmaras turbulence model. Second order accuracy in space and time is achieved using an ENO scheme.

• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.16-22
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• 2010

Cast austenitic stainless steel(CASS) is used in the primary cooling piping system of nuclear power plant for it's relative low cost, corrosion resistance and easy of welding. However, the coarse-grain structure of cast austenitic stainless steel can strongly affect the inspectability of ultrasonic testing. The major problems encountered during inspection are beam skewing, high attenuation and high background noise of CASS component. So far, the best inspection performance involving CASS components have been achieved using low frequency TRL(Transmitter/Receiver side-by-side L wave) angle beam probe. But TRL technique could not detect shallow defect and it contains an uncertainty for sizing capability. Currently, most of researchers are studying to overcome these challenge issue. In this study, low-frequency phased array TRL technique used to detect and sizing the flaws in CF8A cast austenitic stainless steel.As conclusion, we could detect and size not only axial flaw but also circumferential flaw using low frequency phased array technique.

• 대한본초학회지
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• 제22권2호
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• pp.175-180
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• 2007

Objective : The application of Sam So Eum (蔘蘇飮, SSE) as a herbal medicine to treat asthma in mice has been studied and the mechanism of cytokine production in asthmatic mice was discussed. Recently, SSE was known to have anti-allergic activity. However, its therapeutic mechanisms are unclear. Methods : So, we investigated the effects of SSE on levels of several cytokines in bronchoalveolar lavage fluid (BALF) using flow cytometric analysis in allergen-induced asthma. Results : In this experiment, SSE decreased levels of IL-la, IL-17 and GM-CSF respectively. Contrary, SSE restored level of IFN-g toward naive level in BALF. Conclusion : In conclusion, we demonstrate that SSE is useful to treat asthma and it's therapeutic mechanisms are involved in Thl skewing reaction.