• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.569-582
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• 2010

The following "Periodic Jacobi Procrustes" problem is studied: find the Periodic Jacobi matrix X which minimizes the Frobenius (or Euclidean) norm of AX - B, with A and B as given rectangular matrices. The class of Procrustes problems has many application in the biological, physical and social sciences just as in the investigation of elastic structures. The different problems are obtained varying the structure of the matrices belonging to the feasible set. Higham has solved the orthogonal, the symmetric and the positive definite cases. Andersson and Elfving have studied the symmetric positive semidefinite case and the (symmetric) elementwise nonnegative case. In this contribution, we extend and develop these research, however, in a relatively simple way. Numerical difficulties are discussed and illustrated by examples.

• The Journal of Asian Finance, Economics and Business
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• 제3권2호
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• pp.33-39
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• 2016

This study empirically evaluates the impact of exchange rate volatility, foreign direct investment, terms of trade, inflation, and industrial production and foreign exchange reserves on Pakistani trade volume over the period of 1975-2010 using quarterly data set. The study employs financial econometrics methods such as Augmented Dickey Fuller (ADF) test GARCH (1, 1) technique and Almon Polynomial Distributed Lag (APDL) models to estimate the relationship of variables. Findings of the study are in accordance with theoretical relationships presented by Clark, Tamirisa, Wei, Sadikov, & Zeng (2004), McKenzie (1999), Dellas & Zilberfarb (1993) and Côté (1994). These findings are also in accordance with the empirical studies which support positive relationship of exchange rate volatility and exports presented by Hsu & Chiang (2011), Chit (2008), Feenstra & Kendall (1991), Esquivel & Larraín (2002) and Onafowora & Owoye (2008). Findings of the study in terms of imports are supported by the studies such as Lee (1999), Alam & Ahmad (2011) and Arize (1998). The study also recommends some very important policy prescriptions.

• Journal of the Korean Statistical Society
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• 제26권4호
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• pp.493-505
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• 1997

The analysis of binary data appears to many areas such as statistics, biometrics and econometrics. In many cases, data are often collected in which some observations are incomplete. Assume that the missing covariates are missing at random and the responses are completely observed. A method to Bayesian analysis of the binary regression model with incomplete data is presented. In particular, the desired marginal posterior moments of regression parameter are obtained using Meterpolis algorithm (Metropolis et al. 1953) within Gibbs sampler (Gelfand and Smith, 1990). Also, we compare logit model with probit model using Bayes factor which is approximated by importance sampling method. One example is presented.

• East Asian Economic Review
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• 제18권2호
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• pp.187-212
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• 2014

The purpose of this paper is to examine the equity market crisis contagion in major Asian economic markets. A comparative assessment of Asian markets during the Asian Financial Crisis and Global Financial crisis may clearly identify the changing nature of long term integration of major Asian markets. The selection criteria of specific Asian markets of different peripheries depend particularly on the roles and structure of these markets. The impact of the global financial contagion and the lingering financial linkage in the aftermath of crisis will explain the reaction of the majority of Asian markets to global linkage. While majority of the studies focused on dynamic short term association in European and MENA contagions in the post global financial crisis period; after the global financial crisis, attention paid to long term Asian contagion adds new perspective to hitherto disorganized theories.

• 대한수학회지
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• 제46권5호
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• pp.1071-1085
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• 2009

This paper considers the problem of existence and exponential stability of almost periodic solution for shunting inhibitory cellular neural networks with distributed delays and large impulses. Based on the contraction principle and Gronwall-Bellman's inequality, some sufficient conditions are obtained. The results of this paper are new and they complement previously known results.

• 대한수학회지
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• 제53권6호
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• pp.1371-1389
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• 2016

In this paper, we propose a new rank two quasi-Newton method based on adjoint Broyden updates for solving symmetric nonlinear equations, which can be seen as a class of adjoint BFGS method. The new rank two quasi-Newton update not only can guarantee that $B_{k+1}$ approximates Jacobian $F^{\prime}(x_{k+1})$ along direction $s_k$ exactly, but also shares some nice properties such as positive deniteness and least change property with BFGS method. Under suitable conditions, the proposed method converges globally and superlinearly. Some preliminary numerical results are reported to show that the proposed method is effective and competitive.

• 무역학회지
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• 제44권2호
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• pp.51-62
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• 2019

This study predicts the future world seaborne trade volume with econometrics methods using 23-year time series data provided by Clarksons. For this purpose, this study uses simple regression analysis, exponential smoothing method and seemingly unrelated regression model (SUR Model). This study is meaningful in that it predicts worldwide total seaborne trade volume and seaborne traffic in four major items (container, bulk, crude oil, and LNG) from 2019 to 2023 as there are few prior studies that predict future seaborne traffic using recent data. It is expected that more useful references can be provided to trade related workers if the analysis period was increased and additional variables could be included in future studies.

• East Asian Economic Review
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• 제25권1호
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• pp.3-31
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• 2021

This paper estimates the effects of transport (road and rail) & energy and ICT infrastructure (telephone, mobile, and broadband) on GDP growths in neighboring countries as well as own countries. We confirm positive direct contributions of infrastructure, access to Internet, and human capital on economic growth. The spatial panel regression models indicate that there exist positive externalities of the broadband infrastructure and human capital, and these results are robust regardless of the choice of spatial weight matrices. Our findings on spillover effects of infrastructure suggest the key role of neighboring countries' infrastructure on own country's economic growth.

• Communications for Statistical Applications and Methods
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• 제28권4호
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• pp.315-327
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• 2021

The Spatial Autoregressive (SAR) models have drawn considerable attention in recent econometrics literature because of their capability to model the spatial spill overs in a feasible way. While considering the Bayesian analysis of these models, one may face the problem of lack of robustness with respect to underlying prior assumptions. The generalized Bayes estimators provide a viable alternative to incorporate prior belief and are more robust with respect to underlying prior assumptions. The present paper considers the SAR model with a set of linear restrictions binding the regression coefficients and derives restricted generalized Bayes estimator for the coefficients vector. The minimaxity of the restricted generalized Bayes estimator has been established. Using a simulation study, it has been demonstrated that the estimator dominates the restricted least squares as well as restricted Stein rule estimators.

• 대한교통학회지
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• 제31권1호
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• pp.65-76
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• 2013

사고발생의 주요지점인 신호교차로 교통사고 발생건수는 해마다 증가하고 있어 교통사고를 감소시키기 위한 원인 규명이 매우 필요하다. 국내에서 연구되어진 기존의 교통사고예측 모형들은 대부분 Poisson 모형 등의 비선형 회귀분석을 이용한 사고원인분석이 주를 이루고 있다. 비선형 Econometrics 분석기법들이 사고의 성격을 분석하는데 가장 중요한 통계적 기법이기는 하지만, 도로에서 발생하는 교통사고의 원인분석적 차원에서 접근하면 이런 사고예측 모형들만 가지고 사고발생의 설명변수들을 규명하는데 구조적인 한계가 발생한다. 이는 이러한 통계적 방법들이 사고의 예측력을 높이는데 중점을 두고, 이를 위해 소수의 유효한 설명변수들만을 모형식에 포함시키기 때문이다. 따라서 사고에 대해 보다 구체적인 원인규명을 위해서는 비선형회귀분석모형의 개발과 동시에 비선형 Econometrics 분석기법의 단점을 보완하는 또 다른 통계적 노력이 필요하다. 이에 본 연구에서는 Poisson기법을 이용하여 지방부 4지 신호교차로의 사고예측모형을 개발하였고, 동시에 복합적인 인과관계를 증명하는데 다중변수관계를 포괄적으로 측정하여 탐색하는 구조방정식을 이용하여 사고모형을 개발하여 Poisson 모형의 결과값과 비교 분석하였다.