• East Asian Economic Review
• /
• v.22 no.3
• /
• pp.337-370
• /
• 2018

This paper discusses the design of monetary policy in a New Keynesian small open economy framework by introducing nominal wage rigidities and incomplete exchange rate pass-through on import prices. Three main findings are summarized. First, with the existence of an incomplete exchange rate pass-through and nominal wage rigidities, the optimal policy is to seek to minimize the output gap, the variance of domestic price and wage inflation, as well as deviations from the law of one price. Second, the CPI inflation targeting Taylor rule is welfare enhancing when there is a technological shock to the economy. The exception occurs when there is a foreign income shock, which minimizes welfare losses under the domestic inflation targeting Taylor rule. Last, two stylized Taylor rules turn out to be a bad approximation, but the modified Taylor rules that respond to the unemployment gap rather than the output gap are a closer approximation to the optimal policy.

• East Asian Economic Review
• /
• v.18 no.3
• /
• pp.301-335
• /
• 2014

In this paper, we consider a small open economy under the New Keynesian model with unemployment of Gal$\acute{i}$ (2011a, b) to discuss the design of the monetary policy. Our findings can be summarized in three parts. First, even with the existence of unemployment, the optimal policy is to minimize variance of domestic price inflation, wage inflation, and the output gap when both domestic price and wage are sticky. Second, stabilizing unemployment rate is important in reducing the welfare loss incurred by both technology and labor supply shocks. Therefore, introducing the unemployment rate as an another argument into the Taylor-rule type interest rate rule will be welfare-enhancing. Lastly, controlling CPI inflation is the best option when the policy is not allowed to respond to unemployment rate. Once the unemployment rate is controlled, however, stabilizing power of CPI inflation-based Taylor rule is diminished.

• Journal of applied mathematics & informatics
• /
• v.24 no.1_2
• /
• pp.31-48
• /
• 2007

The paper deals with the solution of some fractional partial differential equations obtained by substituting modified Riemann-Liouville derivatives for the customary derivatives. This derivative is introduced to avoid using the so-called Caputo fractional derivative which, at the extreme, says that, if you want to get the first derivative of a function you must before have at hand its second derivative. Firstly, one gives a brief background on the fractional Taylor series of nondifferentiable functions and its consequence on the derivative chain rule. Then one considers linear fractional partial differential equations with constant coefficients, and one shows how, in some instances, one can obtain their solutions on bypassing the use of Fourier transform and/or Laplace transform. Later one develops a Lagrange method via characteristics for some linear fractional differential equations with nonconstant coefficients, and involving fractional derivatives of only one order. The key is the fractional Taylor series of non differentiable function $f(x+h)=E_{\alpha}(h^{\alpha}{D_x^{\alpha})f(x)$.

• Kyungpook Mathematical Journal
• /
• v.56 no.4
• /
• pp.1179-1189
• /
• 2016

We provide a combination of the forward Euler method and the trapezoidal quadrature rule leads to a two-step conservative numerical method which possesses TV-stable property together with consistency.

• Communications for Statistical Applications and Methods
• /
• v.2 no.2
• /
• pp.146-154
• /
• 1995

By using simple Taylor expansion, we derive an easy bias-correction rule for the apparent prodiction error of the predictor defined by the general M-estimators with respect to an arbitrary measure of prediction error. Our method has a considerable computational advantage over the previous methods based on the resampling thchnique such as Cross-validaton and Boothtrap. Connections with AIC, Cross-Validation and Boothtrap are discussed too.

• KDI Journal of Economic Policy
• /
• v.36 no.2
• /
• pp.1-64
• /
• 2014

This paper attempts to search the driving forces of the Korean economy after 2000 by analyzing an estimated DSGE model and observing the degree of implementation regarding non-systematic parts of both the monetary and fiscal policy during the global financial crisis. Two types of trends, various cyclical factors and frictions are introduced in the model for an empirical analysis in which historical decompositions of key macro variables are quantitatively assessed after 2000. While the monetary policy during the global financial crisis have reacted systematically in accordance with the estimated Taylor rule relatively, the fiscal policy which was aggressively expansionary is not fully explained by the estimated fiscal rule but more by the large magnitude of non-systematic reaction.

• Coupled systems mechanics
• /
• v.6 no.2
• /
• pp.207-227
• /
• 2017

In this paper Timoshenko beam theory is employed to investigate the vibration characteristics of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) Beams with a stiff core in thermal environment. The material characteristic of carbon nanotubes (CNT) are supposed to change in the thickness direction in a functionally graded form. They can also be calculated through a micromechanical model where the CNT efficiency parameter is determined by matching the elastic modulus of CNTRCs calculated from the rule of mixture with those gained from the molecular dynamics simulations. The differential transform method (DTM) which is established upon the Taylor series expansion is one of the effective mathematical techniques employed to the differential governing equations of sandwich beams. Effects of carbon nanotube volume fraction, slenderness ratio, core-to-face sheet thickness ratio, different thermal environment and various boundary conditions on the free vibration characteristics of FG-CNTRC sandwich beams are studied. It is observed that vibration response of FG-CNTRC sandwich beams is prominently influenced by these parameters.

• Clinics in Shoulder and Elbow
• /
• v.25 no.3
• /
• pp.244-254
• /
• 2022

Radiographic osteolysis after total shoulder arthroplasty (TSA) remains a challenging clinical entity, as it may not initially manifest clinically apparent symptoms but can lead to clinically important complications, such as aseptic loosening. A thorough consideration of medical history and physical examination is essential to rule out other causes of symptomatic TSA-namely, periprosthetic joint infection-as symptoms often progress to vague pain or discomfort due to subtle component loosening. Once confirmed, nonoperative treatment of osteolysis should first be pursued given the potential to avoid surgery-associated risks. If needed, the current surgical options include glenoid polyethylene revision and conversion to reverse shoulder arthroplasty. The current article provides a comprehensive review of the evaluation and management of osteolysis after TSA through an evidence-based discussion of current concepts.

• KDI Journal of Economic Policy
• /
• v.29 no.2
• /
• pp.135-157
• /
• 2007

The goal of this paper is to examine the validity of nonlinear Taylor rules in Korea. To perform our tests, we utilize new IV ECM threshold cointegration tests that are invariant to nuisance parameters. The new tests have a standard chi-square distribution and the same critical values can be used throughout. This is in contrast to OLS ECM threshold cointegration tests, which depend on nuisance parameters and have nonstandard distributions. After finding significant support for nonlinear cointegration, we find that the Bank of Korea raises the call rate of interest only when inflation is above a threshold rate. We additionally find that the Bank of Korea increases the call rate of interest to possibly counter domestic currency deprecation only when the rate of currency deprecation exceeds a threshold.

• Structural Engineering and Mechanics
• /
• v.74 no.6
• /
• pp.809-819
• /
• 2020

For the first time, the influence of in-plane magnetic field on wave propagation of Graphene Nano-Platelets (GNPs) polymer composite nanoplates is investigated here. The impact of three- parameter Kerr foundation is also considered. There are two different reinforcement distribution patterns (i.e. uniformly and non-uniformly) while the material properties of the nanoplate are estimated through the Halpin-Tsai model and a rule of mixture. To consider the size-dependent behavior of the structure, Eringen Nonlocal Differential Model (ENDM) is utilized. The equations of wave motion derived based on a higher-order shear deformation refined theory through Hamilton's principle and an analytical technique depending on Taylor series utilized to find the wave frequency as well as phase velocity of the GNPs reinforced nanoplates. A parametric investigation is performed to determine the influence of essential phenomena, such as the nonlocality, GNPs conditions, Kerr foundation parameters, and wave number on the both longitudinal and flexural wave characteristics of GNPs reinforced nanoplates.