• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.574-584
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• 2006

Bi-directional loading test data are available to evaluate the design parameters which reflect the characteristics of a construction method and the variations of ground at the site where drilled shafts are installed. The method to obtain the design parameters of a real bridge by hi-directional loading test was introduced. The plans of multi-level testing and installation of measuring instruments should be made according to the rough estimation of axial bearing capacity, the length of pile, and the construction method. While the relationship between end bearing resistance and displacement was obtained directly from the hi-directional loading test, the relationship between unit side resistance and displacement was calculated through the measuring values. 1% displacement of pile diameter was adopted as the criteria of failure for ultimate resistance. As the settlement of pile head at the total ultimate bearing capacity obtained from these method was less than 1.5 % of pile diameter, this method was conservative to use in the field.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.561-571
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• 2014

The standards of ventilation system for bi-directional tunnel have not been established now. For this reason, with regard to the bi-directional tunnel below 1km, some problems have been appeared in ventilation capacity designing and in determining whether the mechanical ventilation system is needed or not for each case. In this study, we examine the characteristics of natural ventilations, analyze ongoing ventilation design cases for bi-directional tunnels and classify those cases into two groups. This study is carried out about the capability of using natural ventilating system by calculation of reasonable ventilation capacity in bi-directional tunnel and review of relationship between natural wind speed ($Vr^*$) and required speed(Vreq). This paper aims at providing a basis data for bi-directional tunnel ventilation design standards.

• Journal of Technology Innovation
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• v.10 no.1
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• pp.65-82
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• 2002

This paper inquires into the causal relationship between R&D investment and GDP (Gross Domestic Product) in Korea. We apply the method of unit-root test, co-integration test, and Hsiao version of the Granger causality test to find the evidence of bi-directional causality between R&D and GDP. However, it is interesting to observe no significant directional effect between government funded R&D and GDP while private sector funded R&D turns out to affect GDP significantly. Utilizing the previous study results on bi-directional relationship between government and private sector funded R&D, we draw the following conclusion: In order to increase GDP, government funded R&D needs to induce private sector to fund more R&D in an effective manner. In this way, government is expected to indirectly participate in the development for better economy in Korea.

• East Asian Economic Review
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• v.16 no.1
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• pp.97-115
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• 2012

This paper investigates the relationship between financial markets and output growth for a panel of 27 Asian countries over 1960-2009. It utilizes the recently-developed panel cointegration techniques to test and estimate the long-run equilibrium relationship between real GDP and financial development proxies. Real GDP and financial development variables are found to have unit roots and to be cointegrated, based on various panel unit root tests and panel cointegration tests. We find that there is a statistically significant positive bi-directional cointegrating relationship between financial development and output growth by three distinct methods of panel cointegration estimation. Empirical findings suggest that financial market development promotes output growth and in turn output growth stimulates further financial development.

• Smart Structures and Systems
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• v.32 no.5
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• pp.297-308
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• 2023

Dynamic deflection is important for evaluating the performance of a long-span cable-stayed bridge, and its continuous measurement is still cumbersome. This study proposes a dynamic deflection monitoring method for cable-stayed bridge based on Bi-directional Long Short-term Memory (BiLSTM) neural network taking advantages of the characteristics of spatial variation of cable acceleration response (CAR) and main girder deflection response (MGDR). Firstly, the relationship between the spatial and temporal variation of the CAR and the MGDR is described based on the geometric deformation of the bridge. Then a data-driven relational model based on BiLSTM neural network is established using CAR and MGDR data, and it is further used to monitor the MGDR via measuring the CAR. Finally, numerical simulations and field test are conducted to verify the proposed method. The root mean squared error (RMSE) of the numerical simulations are less than 4 while the RMSE of the field test is 1.5782, which indicate that it provides a cost-effective and convenient method for real-time deflection monitoring of cable-stayed bridges.

• East Asian Economic Review
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• v.19 no.1
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• pp.39-70
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• 2015

This paper examines the effects of foreign direct investment (FDI) on South Asian economies' output growth, utilizing recent panel cointegration testing and estimation techniques. Annual panel data on eight SAARC (South Asian Association for Regional Cooperation) member countries' macroeconomic variables over the period 1960- 2013 are employed in empirical analysis. Using various heterogeneous panel cointegration and panel causality tests, a bi-directional relationship between FDI and growth is found. We find evidence for both FDI-led growth and growth-induced FDI hypotheses for the South Asian economies over the sample period. Individual member countries exhibit heterogeneity in terms of the direction or existence of causality subject to their idiosyncratic economic conditions. Among various regressors, FDI, financial development, human capital, and government consumption show the most significant positive effects on output growth. As determinants of FDI, GDP, financial development, human capital, and government consumption are found significant in the region. The bi-directional causality between FDI and growth is found robust to the inclusion of other control variables and using different estimation techniques.

• Structural Engineering and Mechanics
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• v.73 no.4
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• pp.407-426
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• 2020

In this present paper, a semi-analytical mesh-free method is employed for the three-dimensional free vibration analysis of a bi-directional functionally graded piezoelectric circular structure. The dependent variables have been expanded by Fourier series with respect to the circumferential direction and have been discretized through radial and axial directions based on the mesh-free shape function. The current approach has a distinct advantage. The nonlinear Green-Lagrange strain is employed as the relationship between strain and displacement fields to observe thermal impacts in stiffness matrices. Nevertheless, high order terms have been neglected at the final steps of equations driving. The material properties are assumed to vary continuously in both radial and axial directions simultaneously in accordance with a power law distribution. The convergence and validation studies are conducted by comparing our proposed solution with available published results to investigate the accuracy and efficiency of our approach. After the validation study, a parametric study is undertaken to investigate the temperature effects, different types of polarization, mechanical and electric boundary conditions and geometry parameters of structures on the natural frequencies of functionally graded piezoelectric circular structures.

• Korean Journal of Social Welfare Studies
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• v.40 no.2
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• pp.59-87
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• 2009

The purpose of this study is to empirically test some hypotheses derived from the alliance model of the family, which focuses on theorizing situations in which family members simultaneously compete with other members within a family and rivals in society to maximize their statuses in the family and in society. Specifically, associations between wives' level of income relative to that of their husbands and each spouse's satisfaction with family relationships were examined, using the first wave of Korea Welfare Panel Study having been conducted in 2006 by the Korea Institute for Health and Social Affairs. The results of the analyses showed that three ones among four research hypotheses were supported. Wives' satisfaction with family relationships was negatively associated with their relative level of income. This pattern strongly appeared among wives from lower class families rather than among wives from middle/upper class families. Relationship between wives' relative level of income and husbands' satisfaction with family relationships was likely to be bi-directional among husbands from middle/upper class families. Unlike the author's expectation, however, this bi-directional relationship was not observed among husbands from lower class families.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.665-675
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• 2020

The aim of this article is to investigate the relationship between insurance and economic growth at aggregate and disaggregate level for the period 1982-2018. Very few studies have been carried out in this field, with contradictory results and using an aggregate data while, according to different authors, an aggregate data might provide spurious results. The author used Ordinary Least Squares Regressions (OLS) and Granger Causality tests to explore the strength and direction of the relationship between insurance and economic growth at an aggregate level. To check the relationship at disaggregate level life insurance, marine insurance, and property insurance are regressed on trade openness and investment, respectively. Non-life insurance at an aggregate level plays a positive and significant role in promoting economic growth, but life insurance has an insignificant impact on the Pakistan economy. On the other hand, non-life insurances at a disaggregated level such as marine insurance negatively affect a vital part of economic growth, i.e., trade. At the same time, property insurance has a significant and positive role in boosting investment. Life, marine, and property insurance Granger cause economic growth, trade, and investment in a single direction. Nevertheless, is a bi-directional relationship between economic growth and non-life insurance.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.31-38
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• 2021

This study contributes to the existing literature and tries to analyze the validity of the Fisher hypothesis in the Philippines. Using monthly data from January 1995 to December 2020, the empirical analysis used the Engle-Granger and Johansen cointegration testing technique. The correlation coefficient suggests a strong positive association. All things being equal, a rise in inflation leads to a rise in the nominal interest rate. The unit-root tests show that inflation and the nominal interest rate are both stationary. Based on both Engle-Granger and cointegrating regression Durbin-Watson tests, the nominal interest rate and inflation are cointegrated. Likewise, the results from Johansen cointegration indicate that there exists a long-run relationship between the variables. However, we rejected a one-to-one relationship between nominal interest rate and inflation. The error correction term coefficient (ECM) shows that it is statistically significant suggesting that the nominal interest rate adjusts to the inflation rate with a lag. The Pair-wise Granger Causality test reported a bi-directional causal relationship between nominal interest rate and inflation. Inflation targeting has been the monetary policy framework of choice for most central banks. In essence, the conclusions of this study are useful to central banks because they help them better comprehend the long-run equilibrium relationship between the nominal interest rate and inflation.