• Title/Summary/Keyword: time series regression analysis

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Supremacy of Value-Added Tax: A Perspective from South Asian Nations

  • Md Noor Uddin, MILON;Yousuf, KAMAL;Tahmina Akter, POL
    • The Journal of Asian Finance, Economics and Business
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    • v.10 no.2
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    • pp.49-60
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    • 2023
  • The study attempts to examine the relationship among revenue growth factors from different angles and provides a comprehensive overview of tax revenue collection for developing countries. The impact of income tax, customs duty, and value-added tax on the gross domestic product is examined using the ordinary least-square (OLS) multiple regression approach. To confirm the association, a multiple regression model is applied to time-series data. SPSS software, MS Excel, is used to draw the empirical results, trend analysis, and some graphical presentation to reach the study's objective. The findings show that while the value-added tax has a significant impact and the highest coefficient, regardless of country, income tax and customs duty may or may not be significant depending on the circumstances. It triggers effectual and efficacious economic growth. The paper has implications in policy-making areas where governments are seeking how to stimulate revenue growth effectively and efficiently. To promote economic growth, the tax net and tax rate on luxury goods should be increased along with human resources in the tax administration for the short term. But in the long term, decentralization & digitization of tax administration, dismantling the existing tax barriers and good governance are necessary.

A study on the Reason of China's Anti-Dumping inspection against South Korea (중국(中國)의 대한(對韓) 반(反)덤핑조사(調査) 요인(要因)에 관한 실증(實證) 연구(硏究) - 철강(鐵鋼).석유화학(石油化學).제지(製紙) 산업(産業) 중심(中心) -)

  • Sim, Yoon-Soo
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.30
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    • pp.145-174
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    • 2006
  • An anti-dumping has become the trade policy of choice for developing countries as well as advanced countries, hence it is the impending issue to the export-oriented countries including Korea. After colligating the analysis on the trade and industrial policy between Korea and China as well as the analysis on the preceding research, the main reasons of anti-dumping were selected as followings; an unemployment rate, real GDP growth rate and consumer price increase as internal factors, and trade balance, regional coefficient and trade specification index as external factors. Then, the research on how the above seven variable factors can affect the number of anti-dumping measures was accomplished. For the empirical analysis, the above information was used after reorganizing them by on the quarterly basis. Through the use of the correlation analysis, backward elimination of multiple regression analysis model and time-series analysis, it has appeared that the unemployment rate appeared to be the most important factors of anti-dumping measures in addition to the increase rate of trade balance. The variable such as the unemployment rate is uncontrollable for us, so it is appropriate to establish and operate an preemptive monitoring system based on the increasing rate of the amount of export and increasing rate of trade surplus.

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Non-stationary Rainfall Frequency Analysis Based on Residual Analysis (잔차시계열 분석을 통한 비정상성 강우빈도해석)

  • Jang, Sun-Woo;Seo, Lynn;Kim, Tae-Woong;Ahn, Jae-Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5B
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    • pp.449-457
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    • 2011
  • Recently, increasing heavy rainfalls due to climate change and/or variability result in hydro-climatic disasters being accelerated. To cope with the extreme rainfall events in the future, hydrologic frequency analysis is usually used to estimate design rainfalls in a design target year. The rainfall data series applied to the hydrologic frequency analysis is assumed to be stationary. However, recent observations indicate that the data series might not preserve the statistical properties of rainfall in the future. This study incorporated the residual analysis and the hydrologic frequency analysis to estimate design rainfalls in a design target year considering the non-stationarity of rainfall. The residual time series were generated using a linear regression line constructed from the observations. After finding the proper probability density function for the residuals, considering the increasing or decreasing trend, rainfalls quantiles were estimated corresponding to specific design return periods in a design target year. The results from applying the method to 14 gauging stations indicate that the proposed method provides appropriate design rainfalls and reduces the prediction errors compared with the conventional rainfall frequency analysis which assumes that the rainfall data are stationary.

Reduction Efficiency Analysis of Furrow Vegetation and PAM (Polyacrylamide) Mulching for Non-Point Source Pollution Load from Sloped Upland During Farming Season (경사밭 고랑 식생 및 PAM (Polyacrylamide) 멀칭에 따른 영농기 비점오염 저감효과 분석)

  • Yeob, So-Jin;Kim, Min-Kyeong;An, Nan-Hee;Choi, Soon-Kun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.4
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    • pp.1-10
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    • 2023
  • As a result of climate change, non-point source pollution (NPS) from farmland with the steep slope during the rainy season is expected to have a significant impact on the water system. This study aimed to evaluate the effect of furrow mulching using alfalfa and PAM (Polyacrylamide) materials for each rainfall event, while considering the load characteristics of NPS. The study was conducted in Wanju-gun, Jeollabuk-do, in 2022, with a testbed that had a slope of 13%, sandy loam soil, and maize crops. The testbed was composed of four plots: bare soil (Bare), No mulching (Cont.), Vegetation mulching (VM), and PAM mulching (PM). Runoff was collected from each rainfall event using a 1/40 sampler and the NPS load was calculated by measuring the concentrations of SS, T-N, T-P, and TOC. During farming season, the reduction efficiency of NPS load was 37.1~59.5% for VM and 38.2~75.7% for PM. The analysis found that VM had a linear regression correlation (R2=0.28~0.86, P-value=0.01~0.1) with elapsed time of application, while PM had a quadratic regression correlation (R2=0.35~0.80, P-value=0.1). These results suggest that the selection of furrow mulch materials and the appropriate application method play a crucial role in reducing non-point pollution in farmland. Therefore, further studies on the time-series reduction effect based on the application method are recommended to develop more effective preemptive reduction technologies.

Dynamics in Election News Making: An Exploratory Study (선거보도의 역동성에 대한 탐색적 연구)

  • Lee, Han Soo
    • Korean Journal of Legislative Studies
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    • v.27 no.3
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    • pp.155-188
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    • 2021
  • This study examines dynamics in election news making. It is important to understand when and how news media produce election news in order to grasp news making and voting behavior. The news media sometimes make election news by focusing on issues and policies. Often they frame elections as a game and focus on election strategies while covering elections. This article argues that as time goes by during the election period, the number of policy news tends to decrease while the frequency of strategic news is likely to increase. Also, TV's and newspapers show distinctive patterns of election news making. In order to examine the arguments, this study categorizes election news stories into policy and strategic news stories produced during the 2020 Korean congressional elections and constructs daily time-series data of them. The results of structural break and regression analyses partially support the arguments.

Characteristic Analysis of the Changes of Landscape Architecture Construction Costs in Time-series - Focused on the Cases of Works of Public Institution's at Capital Area - (아파트단지 조경 공사비의 공종별 경년변화 특성 분석 - 공공기관 시행의 수도권 아파트단지를 중심으로 -)

  • Park, Sang-Jin;Cho, Se-Hwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.6
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    • pp.150-159
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    • 2015
  • This study was conducted for the purpose of presenting basic data for calculating a more reasonable landscaping project cost in the future through the construction cost calculation ratio of scenic planting and facilities and their time series trend analysis targeting 'J' corporation, a representative Korean public institution that creates apartment complexes. This study targeted scenic planting and the facility construction costs of 37 apartment complexes in the capital area from 2004 to 2012, using statistical analysis methods such as technical analysis, correlation analysis, and regression analysis to analyze the characteristics of the time series change. The conclusion was drawn as follows. First, breaking down the cost of overall landscaping projects to scenic planting and facility construction, the ratio of the average cost of scenic planting to that of facility construction showed 56.1% to 43.9% from 2004 to 2012. Second, the costs of planting construction and facility construction both showed a fluctuation range of about ${\pm}3%$, implying relatively steady costs considering the inflation rate. Third, the landscape construction cost for each type of construction resulted in a fluctuation range from minimum ${\pm}3%$(exercise facility) to maximum ${\pm}5%$(packing facility), reflecting that among the landscaping projects, the facility construction costs tended to show relatively large fluctuations in accordance with the change of time series. Fourth, the comprehensive indication of the ratio of landscaping project costs by time series and landscaping construction type implies that the regional characteristics and positional condition of the apartment complexes were not reflected sufficiently. Fifth, the high level of correlation of landscaping construction types and landscaping construction elements imply that the entire construction costs were controlled through partial adjustment of cost components within the overall frame of construction cost. These results reveal the problems of standardized landscaping cost irrespective of user satisfaction or environmental traits such as the conditions of the apartment complexes.

NASA Model Deviation Correction for Accuracy Improvement of Land Surface Temperature Extraction in Broad Region (NASA 모델의 편차보정에 의한 광역지역의 지표온도산출 정확도 향상)

  • Um Dae-Yong;Park Joon-Kyu;Kim Min-Kyu;Kang Joon-Mook
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.281-286
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    • 2006
  • In this study, acquired time series Landsat TM/ETM+ image to extract land surface temperature for wide-area region and executed geometric correction and radiometric correction. And extracted land surface temperature using NASA Model, and I achieved the first correction by perform land coverage category for study region and applies characteristic emission rate. Land surface temperature that acquire by the first correction analyzed correlation with Meteorological Administration's temperature data by regression analysis, and established correction formula. And I wished to improve accuracy of land surface temperature extraction using satellite image by second correcting deviations between two datas using establishing correction formula. As a result, land surface temperature that acquire by 1,2th correction could correct in mean deviation of about ${\pm}3.0^{\circ}C$ with Meteorological Administration data. Also, could acquire land surface temperature about study region by relative high accuracy by applying to other Landsat image for re-verification of study result.

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Trend Analysis of Rainfall Data Using Stochastic Time Series Models (추계학적 모의발생기법을 이용한 강우자료의 경향성 분석)

  • Seo, Lynn;Kim, Tae-Woong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1282-1286
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    • 2009
  • 최근에 빈번하게 발생하는 집중호우로는 강우자료의 경향성에 영향을 주고 있다. 하지만, 우리나라의 강우관측기록이 충분하지 못하여 통계학적 경향성 분석은 유의한 결과를 보여주고 있지 않아, 확률강우량 산정시 강우자료가 정상성을 지니고 있다고 가정하여 빈도분석을 실시하고 있다. 본 연구에서는 경향성이 나타나지 않는 강우관측소 49개지점중 4개의 지점을 선정하여 향후 경향성 여부를 분석하였다. 이들 관측자료가 가지는 경향성을 유지하면서 추계학적 시계열 모의발생기법을 이용하여 강우자료를 발생시킨 후 경향성 검정을 실시하였다. 이를 위하여 Regression model, ARMA model을 이용하여 강우자료를 발생시켰으며, 발생된 강우자료는 Mann-Kendall test, Hotelling-Pabst test, Wald-Wolfowitz test를 사용하였다. 그 결과 거의 모든 지점에서 가까운 미래에 경향성을 갖게 될 것임을 알 수 있었다.

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A Statistical Analysis for El Nino Phenomenon (엘니뇨현상에 대한 통계적분석)

  • 김해경
    • 한국해양학회지
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    • v.27 no.1
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    • pp.35-45
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    • 1992
  • This paper is concerned with the development and application of a stochastic model for predicting E1 nino phenomenon. For this, first a general criterion for determining E1 nino phenomenon, including period and strength, which is based on partial sum of monthly sea surface temperatures (SST) anomalies, is proposed, Secondly, the annual fluctuations, periodicity and dependence of monthly mean of equatorial Pacific SST during the period 1951-1990 are analyzed. Based on these, time series nonlinear regression model for the prediction of SST have been derived. A statistical procedure for using the model to predict the SST have been derived. A statistical procedure for using the model to predict the SST level is also proposed.

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Model- Data Based Small Area Estimation

  • Shin, Key-Il;Lee, Sang Eun
    • Communications for Statistical Applications and Methods
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    • v.10 no.3
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    • pp.637-645
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    • 2003
  • Small area estimation had been studied using data-based methods such as Direct, Indirect, Synthetic methods. However recently, model-based such as based on regression or time series estimation methods are applied to the study. In this paper we investigate a model-data based small area estimation which takes into account the spatial relation among the areas. The Economic Active Population Survey in 2001 are used for analysis and the results from the model based and model-data based estimation are compared with using MSE(Mean squared error), MAE(Mean absolute error) and MB(Mean bias).