• Title/Summary/Keyword: Generalized Methods of Moments

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Parameter Estimation and Analysis of Extreme Highest Tide Level in Marginal Seas around Korea (한국 연안 최극 고조위의 매개변수 추정 및 분석)

  • Jeong, Shin-Taek;Kim, Jeong-Dae;Ko, Dong-Hui;Yoon, Gil-Lim
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.5
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    • pp.482-490
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    • 2008
  • For a coastal or harbor structure design, one of the most important environmental factors is the appropriate extreme highest tide level condition. Especially, the information of extreme highest tide level distribution is essential for reliability design. In this paper, 23 set of extreme highest tide level data obtained from National Oceanographic Research Institute(NORI) were analyzed for extreme highest tide levels. The probability distributions considered in this research were Generalized Extreme Value(GEV), Gumbel, and Weibull distribution. For each of these distributions, three parameter estimation methods, i.e. the method of moments, maximum likelihood and probability weighted moments, were applied. Chi-square and Kolmogorov-Smirnov goodness-offit tests were performed, and the assumed distribution was accepted at the confidence level 95%. Gumbel distribution which best fits to the 22 tidal station was selected as the most probable parent distribution, and optimally estimated parameters and extreme highest tide level with various return periods were presented. The extreme values of Incheon, Cheju, Yeosu, Pusan, and Mukho, which estimated by Shim et al.(1992) are lower than that of this result.

Derivation of Probability Plot Correlation Coefficient Test Statistics and Regression Equation for the GEV Model based on L-moments (L-모멘트 법 기반의 GEV 모형을 위한 확률도시 상관계수 검정 통계량 유도 및 회귀식 산정)

  • Ahn, Hyunjun;Jeong, Changsam;Heo, Jun-Haeng
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.1
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    • pp.1-11
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    • 2020
  • One of the important problem in statistical hydrology is to estimate the appropriated probability distribution for a given sample data. For the problem, a goodness-of-fit test is conducted based on the similarity between estimated probability distribution and assumed theoretical probability distribution. Probability plot correlation coefficient test (PPCC) is one of the goodness-of-fit test method. PPCC has high rejection power and its application is simple. In this study, test statistics of PPCC were derived for generalized extreme value distribution (GEV) models based on L-moments and these statistics were suggested by the multiple and nonlinear regression equations for its usability. To review the rejection power of the newly proposed method in this study, Monte Carlo simulation was performed with other goodness-of-fit tests including the existing PPCC test. The results showed that PPCC-A test which is proposed in this study demonstrated better rejection power than other methods, including the existing PPCC test. It is expected that the new method will be helpful to estimate the appropriate probability distribution model.

Determinants of Foreign Direct Investment: Evidence from Vietnam

  • NGO, Minh Ngoc;CAO, Huy Hoang;NGUYEN, Long Ngoc;NGUYEN, Thuc Ngoc
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.173-183
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    • 2020
  • The paper investigates the determinants of foreign direct investment (FDI) in Vietnam in 2000-2019 period. This study uses difference Generalized Methods of Moments (GMM) and Pooled Mean Group (PMG) to analyse panel data officially provided by General Statistical Office of Vietnam. The results show that market size impacts positively significant on FDI attraction: 1% -1.45% (PMG) and 1% -1.25% (GMM). Besides, some other factors have positive influences as labor force, macroeconomic policy, macroeconomic stability and skilled labor. Meantime, the trade openness negatively affects FDI inflows in the short-term, while not being statistically significant in the long-term. Moreover, economic shocks often have a negative impact on FDI inflows. The findings of this study lead to the following recommendations. First, authorities should pay special attention to encourage economic growth rate in Vietnam to expand market size because this is the first priority of foreign investors. Second, authorities need to continue increasing the rate of skilled labor, especially highly qualified management force, engineers and well-skilled workers. Third, the authorities should adjust trade openness to boost the role of its determinant in attracting FDI inflows. Fourth, macroeconomic stability needs to be governed by international standards in order to secure the belief of foreign investors in the long-term.

Counter-Cyclical Capital Buffer and Regional Development Bank Profitability: An Empirical Study in Indonesia

  • ANDAIYANI, Sri;HIDAYAT, Ariodillah;DJAMBAK, Syaipan;HAMIDI, Ichsan
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.829-837
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    • 2021
  • The study investigates the impact of the Counter-Cyclical Buffer Policy (CCB) on regional development bank profitability in Sumatra, Indonesia. CCB requires banks to hold capital at times when credit is growing rapidly so that the buffer can be reduced if the financial cycle turns down or the economic and financial environment becomes substantially worse. This study employs time series data of regional development banks (RDBs) in Sumatra Island, Indonesia. The methodology applied in this study is a panel dynamic model with Generalized Methods of Moments (GMM). The results show that increasing capital through the implementation of CCB did not have a significant effect on RDBs' profitability. The findings of this study suggest that the activation and implementation of CCB lead to an increase in the amount and cost of loans to companies but do not affect the profitability of RDBs. The value of a Non-Performing Loan (NPL) proved to have a negative and significant effect on bank profitability. The CCB policy aims to overcome the pro-cyclicality of credit growth and improve bank resilience through increased capital which is expected to reduce excessive credit growth as a source of systemic risk. This causes a lack of lending to the community so that the profits obtained by the bank decrease.

The Effect of Financial Restructuring on the Overall Financial Performance of the Commercial Banks in Vietnam

  • DUONG, Tam Thanh Nguyen;PHAN, Hai Thanh;HOANG, Tien Ngoc;VO, Tien Thuy Thi
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.75-84
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    • 2020
  • The study investigates and measures the impact of financial restructuring on overall financial performance of commercial banks in Vietnam. Survey data for this research were collected from audited financial reports of 28 commercial banks in Vietnam, for the period from 2008 to 2018. In the study, we have built a model of econometric regression with the dependent variable being financial results measured through ROA and ROE. The research methods used include Pooled Ordinary Least Square Model (POLS), Fixed Effects Model (FEM), Random Effects Model (REM), and different Generalized Method of Moments (GMM). The results showed that the account payables restructuring and owners' equity restructuring are much needed. Increasing the owners' equity, decreasing the account payables would improve the overall financial performance, bad debts restructuring to decrease bad debts would also improve the financial performance as well. However, the financial restructuring in the period 2012-2015 and 2016-2018, indeed worsen the financial performance during those times. The findings of this study suggest that the evaluation of the financial performance after restructuring of commercial banks in Vietnam must be based on longer data. At the same time, it is necessary to examine differences between various banking groups to draw accurate conclusions on financial performance.

The Effect of High-Skilled Emigration, Foreign Direct Investment, and Policy on the Growth Rate of Source Countries: A Panel Analysis

  • Kim, Jisong;Lee, Nah Youn
    • East Asian Economic Review
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    • v.20 no.2
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    • pp.229-275
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    • 2016
  • We study the effect of the high-skilled emigration rate on the growth rate of the source countries. We incorporate the foreign direct investment and the policy variables into the panel model and also their interactions with the high-skilled emigration rate, as they are related to the network externality that may be created by the high-skilled emigrants working abroad. We apply the static fixed-effects model and compare it with the results obtained in the dynamic panel model with system generalized methods of moments estimators. We find the negative effect of the high-skilled emigration rate by itself and in its interaction with the foreign direct investment only in the dynamic model. However, we find positive coefficient for the interaction of the high-skilled emigration rate and the civil liberties index, which holds across the static and dynamic specifications. This implies that the effect of the high-skilled emigration rate on the growth rate of the source countries can be positive, and the extent is larger for countries with 'poor' civil liberties. The developing countries with low levels of foreign direct investment inflows and 'poor' civil liberties can best benefit from the high levels of skilled emigration outward. Through finding significant interactions with other variables, we confirm that the high-skilled emigration should be considered along with other related variables in measuring its impact on growth. The implications offer suggestions for the international trade and aid policies.

The Relationship between Corporate Social Responsibility and Corporate Financial Performance: An Empirical Study of Commercial Banks in Vietnam

  • BUI, Hang Thi Thu
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.10
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    • pp.373-383
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    • 2021
  • This article aims to examine the one-way relationship between corporate social responsibility (CSR) and the financial performance of Vietnamese commercial banks, mainly focusing on the moderating role of ownership structure. Net interest margin (NIM), return on assets (ROA), and return on equity (ROE) are selected to represent the financial performance of the bank. CSR was measured using a multi-method approach that included both quantitative and qualitative methods. Corporate Social Responsibility Expenditure (CSRE) was estimated using financial data. The Corporate Social Responsibility Disclosure (CSRD) index was created using the content analysis method. Using a sample of Vietnamese commercial banks from 2012 to 2019 to perform regressions in the dynamic panel models with the two-step system generalized method of moments (GMM) estimator, the results show a positive effect of both CSRE and CSRD on the financial performance of the bank. Empirical evidence shows that the positive relationship between CSRE and financial performance is more robust in statecontrolled banks than non-state-controlled banks. In contrast, the positive impact of CSRD on the financial performance of state-owned commercial banks is weaker than that of private banks. Finally, the paper points out the limitations and proposes future research directions.

Seismic behavior of soft storey mid-rise steel frames with randomly distributed masonry infill

  • Quayyum, Shahriar;Alam, M. Shahria;Rteil, Ahmad
    • Steel and Composite Structures
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    • v.14 no.6
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    • pp.523-545
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    • 2013
  • In this study, the effect of presence and distribution of masonry infill walls on the mid-rise steel frame structures having soft ground storey was evaluated by implementing finite element (FE) methods. Masonry infill walls were distributed randomly in the upper storey keeping the ground storey open without any infill walls, thus generating the worst case scenario for seismic events. It was observed from the analysis that there was an increase in the seismic design forces, moments and base shear in presence of randomly distributed masonry infill walls which underlines that these design values need to be amplified when designing a mid-rise soft ground storey steel frame with randomly distributed masonry infill. In addition, it was found that the overstrength related force modification factor increased and the ductility related force modification factor decreased with the increase in the amount of masonry infilled bays and panels. These must be accounted for in the design of mid-rise steel frames. Based on the FE analysis results on two mid-rise steel frames, design equations were proposed for determining the over strength and the ductility related force modification factors. However, it was recommended that these equations to be generalized for other steel frame structure systems based on an extensive analysis.

Economic Growth, Total Factor Productivity, and Institution Quality in Low-Middle Income Countries in Asia

  • NGO, Minh Ngoc;NGUYEN, Loc Duc
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.7
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    • pp.251-260
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    • 2020
  • The purpose of this paper is to investigate the impact of total factor productivity (TFP), institutional quality, and interactive variable between them on economic growth in 13 low-middle income countries in Asia for the period 2000-2018. The paper uses the difference Generalized Method of Moments (GMM) to explore the dataset provided by the World Bank. The empirical results show that TFP and the interactive variable positively impact on the economic growth, while the institutional determinants have a negative influence. The negative effect is explained by the weak institutions in these low-middle income countries. The findings of the study suggest two points. First, the government should continue to improve TFP, which is associated with the application of technical advances, technological innovations, improvement of management methods, and skilled workers. Second, far more important, is that the authorities should pay special attention to implement institutional reform and strengthen the governance in the future. The successful experiences from Japan, Korea and Singapore will help other governments in Asian low-middle income countries to build developmental state. Probably, the developmental state actively interfere in the market to promote and realize the development goals. By doing so, these economies might overcome the so-called "middle-income trap".

Bulk-Type Cloud Microphysics Parameterization in Atmospheric Models (대기 모형에서의 벌크형 미세구름물리 모수화 방안)

  • Lim, Kyo-Sun Sunny
    • Atmosphere
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    • v.29 no.2
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    • pp.227-239
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    • 2019
  • This paper reviews various bulk-type cloud microphysics parameterizations (BCMPs). BCMP, predicting the moments of size distribution of hydrometeors, parameterizes the grid-resolved cloud and precipitation processes in atmospheric models. The generalized gamma distribution is mainly applied to represent the hydrometeors size distribution in BCMPs. BCMP can be divided in three different methods such as single-moment, double-moment, and triple-moment approaches depending on the number of prognostic variables. Single-moment approach only predicts the hydrometeors mixing ratio. Double-moment approach predicts not only the hydrometeors mixing ratio but also the hydrometeors number concentration. Triple-moment approach predicts the dispersion parameter of hydrometeors size distribution through the prognostic reflectivity, together with the number concentrations and mixing ratios of hydrometeors. Triple-moment approach is the most time expensive method because it has the most number of prognostic variables. However, this approach can allow more flexibility in representing hydrometeors size distribution relative to single-moment and double-moment approaches. At the early stage of the development of BMCPs, warm rain processes were only included. Ice-phase categories such as cloud ice, snow, graupel, and hail were included in BCMPs with prescribed properties for densities and sedimentation velocities of ice-phase hydrometeors since 1980s. Recently, to avoid fixed properties for ice-phase hydrometeors and ad-hoc category conversion, the new approach was proposed in which rimed ice and deposition ice mixing ratios are predicted with total ice number concentration and volume.