• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.181-186
• /
• 2005

We demonstrate that the finite rate of dielectric relaxation in liquid crystals which has been ignored previously causes profound effects in the fast dielectric reorientation of the director. The phenomenon is relevant for submillisecond switching of the director when the switching rate approaches the rate of dielectric relaxation through the reorientation of the molecular dipoles. A submillisecond switching ($15-400\;{\mu}s$ for an optical retardation shift $0.3-2.2\;{\mu}m$ in $10-15\;{\mu}m$ thick cells) is demonstrated for dual frequency nematic cells with high pretilt that maximizes the dielectric torque acting on the director. We propose the theory of dielectric response in which the electric displacement depends not only on the present (as in the standard theory) but also on the past values of electric field and director. We design an experiment in which the standard "instantaneous" model and our model predict effects of opposite signs; the experimental data support the latter model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.10a
• /
• pp.285-288
• /
• 2009

The purpose of this study is to predict the forming limit diagram (FLD) of strain-rate sensitive materials on the basis of the Marciniak and Kuczynski (M-K) theory. The strain-rate effect is taken into consideration in such a way that the stress-strain curves for various strain-rates are inputted into the formulation as point data, not as curve-fitted models such as power function. Tensile tests and R-value tests were carried out at several levels of temperature and strain-rate from $25^{\circ}C$ to $300^{\circ}C$ and 0.16 to 0.00016/s, respectively to obtain the mechanical properties of AZ31B magnesium alloy sheet. The FLD of this material was experimentally obtained by limit dome height tests with the punch velocity of 0.1 and 1.0 mm/s at $250^{\circ}C$. The M-K theory-based FLD predicted using Yld2000-2d yield criterion was compared with the experimental results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.9
• /
• pp.878-887
• /
• 2001

Experimental investigation has been carried out to examine the operating characteristics of a bubble pump for diffusion absorption refrigerator. The effects of heat input and delivery height on generation rate of refrigerant vapor and circulation rate of solution have been investigated. as a result heat input and delivery height increase, circulation rate of solution increases. And the smaller the tube diameter, the larger the circulation rate of solution. Pumping ratio increases to a critical point and then decrease with the increase of heat input, and it increases with the increase in delivery height. In this paper, Marcus's analytical theory was also examined. It was found that the Marcus\`s analytical theory of a bubble pump was not appropriate for a bubble pump using ammonia aqueous solution as a working fluid.

• Health Policy and Management
• /
• v.3 no.1
• /
• pp.102-123
• /
• 1993

This study investigates effcts of HMO internal structural arrangements on performance, specially cost reduction measured by hospitalization rate. This study formulates formalization, centralization measured by decision-making participation, differentiation, and coordination as structural factors, considering coordination as an intermediate factor between the rest of structural factors and hospitalization rate. The commonly used HMO types is assumed not effective in explaining performance differences. For the empirical test, I use bootstrap regression analyses with 48 HMOs. The results of the analyses show that HMO types fail to explain differences in hospitalization rate. However, dicision-making participation and differention effectively reduce hospiatalization rate, while frmalization increases hospitalization rate and coordination has nonessential effect on hospitalization rate. And, formalization and decision-making participation positively contribute to achieve coordination in HMO. These findings suggest that the theoretical framework derived from rational-citingency theory of formal organization better explains performance differences of HMOs than HMO types.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.57.2-57.2
• /
• 2011

In this study, the effects of shear flows around a 2-dimensional airfoil, S809 on its aerodynamic characteristics were analyzed by CFD simulations. Various parameters including reference inflow velocity, shear rate, angle of attack, and cord length of the airfoil were examined. From the simulation results, several important characteristics were found. Shear rate in a flow makes some changes in the lift coefficient depending on its sign and magnitude but angle of attack does not have a distinguishable influence. Cord length and reference inflow also cause proportional and inversely proportional changes in lift coefficient, respectively. We adopted an analytic expression for the lift coefficient from the thin airfoil theory and proposed a modified form applicable to the traditional load analysis procedure based on the blade element momentum theory. Some preliminary results applied to an well known load simulation software, FAST, are presented.

• Structural Engineering and Mechanics
• /
• v.51 no.4
• /
• pp.627-641
• /
• 2014

Functionally graded steels (FGSs) are a family of functionally graded materials (FGMs) consisting of ferrite (${\alpha}$), austenite (${\gamma}$), bainite (${\beta}$) and martensite (M) phases placed on each other in different configurations and produced via electroslag remelting (ESR). In this research, the flow stress of dual layer austenitic-martensitic functionally graded steels under hot deformation loading has been modeled considering the constitutive equations which describe the continuous effect of temperature and strain rate on the flow stress. The mechanism-based strain gradient plasticity theory is used here to determine the position of each layer considering the relationship between the hardness of the layer and the composite dislocation density profile. Then, the released energy of each layer under a specified loading condition (temperature and strain rate) is related to the dislocation density utilizing the mechanism-based strain gradient plasticity theory. The flow stress of the considered FGS is obtained by using the appropriate coefficients in the constitutive equations of each layer. Finally, the theoretical model is compared with the experimental results measured in the temperature range $1000-1200^{\circ}C$ and strain rate 0.01-1 s-1 and a sound agreement is found.

• Journal of The Korean Astronomical Society
• /
• v.12 no.1
• /
• pp.7-9
• /
• 1979

The rate of gravitational quadrupole radiation is derived in the formalism of source theory. It is also shown that gravitational superradiance is theoretically possible.

• Journal of Sasang Constitutional Medicine
• /
• v.4 no.1
• /
• pp.107-148
• /
• 1992

The definitions of Four Constitution (Tae-Yang-In, So-Yang-In, Tae-Eum-In, So-Eum-In) in Four-Beginning-Theory (四端論) and Distribution-Theory (擴充論) were morphologically diagrammatized. the method of measuring the five parts came from the diagrams. The five parts are the followings; Top-Line is the distance between Rt. & Lt.Shoulders. Bosom-Line is the horizontal distance passing through the Rt. & Lt.nipples. Stomach-Line is the horizontal distance passing through the Rt. & Lt. acupuncture point Bool-Yong (不容穴). Navel-Line is the horizontal distance passing through the navel. Bottom-Line is the distance between the Rt.& Lt. anterior superior iliac spines. According to it, 311 people were measured in the clinic. Through the measured numerical values, to find out the objective propriety of the morphological diagrammings and the discriminating ability of Four Constitutions by the method of measuring the five, the author tried this study and got the following results. 1. On the ground of the Internal Organs-Theory (臟腑論), the definitions of Four Constitutions were classified and diagrammatized step by step and it was possible to draw the morphological graphs satisfying the reasonable condition objectively. 2. It was found that the graphings by Mean, Standard Deviation and 95% Confidence Interval for mean of the numerical values of five measured parts and the morphological diagrammings of the definitions in Four-Beginning Theory and Distribution-Theory drove to the same figures. 3. Through the method of the Analysis of variance and the Discriminant Analysis, it was discovered that the measured numerical values of five parts could distinguish the Four Constitutions. 4. Tae-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of Confidence Interval from Top to Bottom is downwardly decreased at the rate of 3.7, 1.5, 1.8, 3.4. 5. So-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of confidence Interval from Top to Bottom is downwardly decreased at the rate of 2.3, 1.5, 1.5, 1.1. 6. Tae-Eum-In has the longest Navel-Line. The Mean head of Confidence Interval from Navel to Top is upwardly decreased at the rate of 0.5, 0.4, 2.5 and downwardly decreased at the rate of 2.7 between Navel and Bottom. 7. So-Eum-In has the longest Bottom-Line. The Mean head of Confidence Interval from Bottom to Top is upwardly decreased at the rate of 1.1, 1.1, 1.8, 2.3. From the above findings, it was possible to draw the morphological graphings satisfying the objectively reasonable conditions in the definitions of Four-Beginning-Theory and Distribution-Theory and it was proved that the results of the Positive Analysis, carried with the measured numerical values of five parts from the diagramming, could show the objective propriety of the morphological graphings and the discerning ability of Four Constitutions by the method of measuring the five parts.

• International Commerce and Information Review
• /
• v.8 no.4
• /
• pp.159-175
• /
• 2006

This paper that explain exchange rate determination using Korea's economy data moment investigate whether each theory cause effect that is some on exchange rate showdown analyzing actual proof relation between foreign exchange fluctuation and financing part variance examine wish to. Because korea economic enters in the 1990s and the 2000s and the change is notable, foreign exchange fluctuation by such change is real condition that is changing. In this paper, I wish to enforce actual proof analysis if change such as him is grasped by form that is some about foreign exchange fluctuation. First, the second chapter investigates exchange rate decision theory that is used on actual proof interpretation, and executes actual proof Test in reply in subsequent the third chapter. And finally, the fourth chapter wishes to drive conclusion of this paper.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.1
• /
• pp.153-166
• /
• 2022

The study estimates the Structured VAR and the Dynamic Stochastic General Equilibrium Model for the Vietnamese economy based on the new Keynesian model for small and open economies, with the output gap, inflation, policy interest rate, the Vietnamese exchange rate, and the inflation and interest rate in the United States. The paper aims to clarify the impulse response of the macro variables through their shocks. It offers to model the SVAR and DSGE processes, as well as describe why and how interest rate policy is important in the impulse response of macro variables like the output gap and inflation process. The study supports the central role of monetary policy by giving empirical evidence for the new Keynesian theory, according to which an interest rate shock causes the output gap to widen and inflation to decrease. Finally, the application of the DSGE model is becoming more and more popular in the State Bank of Viet Nam to improve its policy planning, analyzing, and forecasting policy towards sustainable and stable growth.