• 제목/요약/키워드: Time Lag Approach

검색결과 72건 처리시간 0.023초

단일 주파수 일방향 파동방정식을 이용한 중합 전 역 시간 심도 구조보정 (Prestack Reverse Time Depth Migration Using Monochromatic One-way Wave Equation)

  • 윤광진;장미경;서정희;신창수;양승진;고승원;유해수;장재경
    • 지구물리와물리탐사
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    • 제3권2호
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    • pp.70-75
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    • 2000
  • 탄성파 탐사자료의 구조보정에는 주로 Kirchhoff 및 역시간 구조보정이 이용되고 있다. 파동방정식을 이용한 역시간 구조보정에는 양방향 및 일방향 파동방정식이 이용된다. 일방향 파동방정식을 사용한 접근법은 하향 파동장 외삽연산자를 근사하게 계산하는 방식으로, 양방향 파동방정식을 이용한 방법에 비해, 계산량이 적고 작은 컴퓨터 주기억장치로 작업이 가능하다. 본 논문에서는 일방향 파동방정식을 이용하여 중합전 역시간 구조보정을 수행하였다. 주파수-공간영역에서 음원 파동장의 전파 및 관측 파동장의 역시간 전파에 단일주파수 일방향 파동방정식을 이용하였으며, 이 두 파동장의 영 지연 상호상관을 계산하여 구조보정하였다. 구조보정에는 초병렬 슈퍼검퓨터(MPP, Massively Parallel Processors) CRAYT3E가 사용되었으며, 이 작업을 통해 알고리즘이 쉽게 병렬화가 가능하여 효율적으로 구조보정에 이용될 수 있음을 확인하였다.

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Beyond Growth: Does Tourism Promote Human Development in India? Evidence from Time Series Analysis

  • SHARMA, Manu;MOHAPATRA, Geetilaxmi;GIRI, Arun Kumar
    • The Journal of Asian Finance, Economics and Business
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    • 제7권12호
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    • pp.693-702
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    • 2020
  • The present study aims to investigate the impact of tourism growth on human development in Indian economy. For this purpose, the study uses annual data from 1980 to 2018 and utilizes two proxies for tourism growth - tourism receipt and tourist arrivals - and uses human development index calculated by UNDP. The study uses control variables such as government expenditure and trade openness. The study employs auto regressive distributed lag (ARDL) approach to investigate the cointegrating relationship among the variables in the model. Further, the study also explores the causal nexus between tourism sector and human development by using the Toda-Yamamoto Granger non-causality test. The result of ARDL bounds test reveals the existence of cointegrating relationship between human development indicators, government expenditure, trade openness, and tourism sector growth. The cointegating coefficient confirms a positive and significant relationship between tourism sector growth and human development in India. The causality result suggests that economic growth and tourism have a positive impact while trade openness has a negative impact on human development in India. The major findings of this study suggest that tourism plays an important role in the socio-economic development of Indian economy in recent years and the country must develop this sector to achieve sustainable development.

Nexus between Indian Economic Growth and Financial Development: A Non-Linear ARDL Approach

  • KUMAR, Kundan;PARAMANIK, Rajendra Narayan
    • The Journal of Asian Finance, Economics and Business
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    • 제7권6호
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    • pp.109-116
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    • 2020
  • The study examines the nexus between financial development and economic growth in India during Q1: 1996 to Q3: 2018. This study employs time-series data of real GDP and ratio of broad money to GDP as a proxy for economic and financial development, respectively. The data are obtained from RBI database on the Indian economy. All variables are seasonally adjusted using X12-arima technique and expressed in natural logarithm form. Non-linear Autoregressive Distributed Lag (NARDL) bound test has been used to check for cointegrating relationship of these two variables. Empirical findings suggest that, unlike in the short run, in the long run financial development does impact economic growth positively. Further, a symmetric effect of positive and negative components of financial development is found for the Indian economy, whereas the effect of control variable like exchange rate and trade openness is in consonance with common economic intuition. Exchange rate is in consonance with intuitive economic logic that a fall in exchange rate makes exports cheaper and increases the quantity of export, which improves the balance of payment and leads to a rise in aggregate demand, hence improves economic growth. This paper contributes to the existing literature on India by breaking down financial indicator into positive and negative components to examine the finance-growth relationship.

Synergistic Effect of Slightly Acidic Electrolyzed Water and Ultrasound at Mild Heat Temperature in Microbial Reduction and Shelf-Life Extension of Fresh-Cut Bell Pepper

  • Luo, Ke;Oh, Deog-Hwan
    • Journal of Microbiology and Biotechnology
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    • 제25권9호
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    • pp.1502-1509
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    • 2015
  • The objectives of this study were to evaluate the effect of combined treatments (slightly acidic electrolyzed water (SAEW), ultrasound (US), or mild heat (60℃)) on the growth of Listeria monocytogenes and Salmonella enterica serovar Typhimurium in fresh-cut bell pepper, and the shelf-life and sensory quality (color and texture) were followed during storage at 4℃ and 25℃. An additional 0.65, 1.72, and 2.70 log CFU/g reduction was achieved by heat treatments at 60℃ for 1 min for DW, SAEW, and SAEW+US, respectively. Regardless of the type of pathogen, the combined treatment (SAEW+US+60℃) achieved a significantly (p < 0.05) longer lag time in all treatment groups. This combined treatment also prolonged the shelf-life of bell pepper up to 8 days and 30 h for the storage at 4℃ and 25℃, respectively. There was also no significant difference in the color and hardness of treated (SAEW+US+60℃) bell pepper from that of control during the storage. This new hurdle approach is thus expected to improve the microbial safety of bell peppers during storage and distribution.

Treatment of cutting-oily wastewater by electrocoagulation-flotation (ECF) process: Modeling approach

  • Chawaloesphosiya, Nattawin;Mongkolnauwarat, Jittrapa;Prommajun, Chayanin;Wongwailikhit, Kritchart;Painmanakul, Pisut
    • Environmental Engineering Research
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    • 제20권4호
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    • pp.392-396
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    • 2015
  • This work aims to investigate the oily wastewater treatment by the electrocoagulation-flotation (ECF) and propose a mathematical model for the efficiency prediction. Cutting oil was used to prepare the synthetic oily wastewater with submicron droplet sizes. The chemical coagulation by aluminium sulfate was firstly tested following by the electrocoagulation-flotation with aluminium electrodes. Both processes gave the effective treatment performance with the efficiencies higher than 90%. However, the ECF consumed less aluminium dosage as well as produced less sludge, which were its advantage on the chemical coagulation. The performance of the ECF was found to be affected by the current density, oil concentration, and reaction time according to the analysis by the design of experiment (DOE). Finally, the prediction model was proposed by two approaches, including linear and logarithm function. The latter model gave more accuracy prediction results in terms of treatment efficiency and duration in the lag and stable stages.

The Determinants of Foreign Exchange Reserves: Evidence from Indonesia

  • ANDRIYANI, Kurnia;MARWA, Taufiq;ADNAN, Nazeli;MUIZZUDDIN, Muizzuddin
    • The Journal of Asian Finance, Economics and Business
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    • 제7권11호
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    • pp.629-636
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    • 2020
  • This study aims to identify and analyze the factors that affect foreign exchange reserves in Indonesia. We consider the variables of external debt, exchange rate, inflation, and exports as explanatory factors referring to previous studies. We apply the Autoregressive Distributed Lag approach to time-series data retrieved from the Central Bank of Indonesia (BI), the Central Bureau of Statistics (BPS), and International Monetary Funds (IMF) from January 2016 to December 2018. Our results show that foreign debt, exchange rates, inflation, and exports significantly affect the simultaneous fluctuation of foreign exchange reserves in Indonesia. Partially, foreign debt has a significant and positive effect on foreign exchange reserves. The exchange rate has a significant and negative effect on foreign exchange reserves in Indonesia. However, our findings explain that inflation does not significantly affect foreign exchange reserves in Indonesia, and exports have a significant and positive effect on foreign exchange reserves. This study is expected to be useful to policymakers in managing foreign exchange reserves, so the economy of Indonesia can grow sustainably. One of the exciting things in this study lies in the model that uses the Autoregressive Distributed Log, which can explain long-term relationships through adjusted coefficient and cointegration tests.

The Relationship between Exchange Rate and Trade Balance: Empirical Evidence from Sri Lanka

  • FATHIMA THAHARA, Aboobucker;FATHIMA RINOSHA, Kalideen;FATHIMA SHIFANIYA, Abdul Jawahir
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.37-41
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    • 2021
  • This study aims to investigate the relationship between the exchange rate and Trade Balance. Trade Balance is used as the dependent variable, and the independent variables are Exchange Rate, Gross Domestic Product, and Inflation. Augmented Dickey-Fuller unit root test was adopted to test the stationary property of time series data, Auto Regressive Distributed Lag model was employed to find the long run and short-run relationship and long-run adjustment, Bound test approach, the unrestricted Error Correction Model and Granger Causality Test are used to analyze the data from 1977 to 2019. The research findings suggest that inflation has a positive impact on the trade balance in the short run. The exchange rate and the Gross Domestic Product have adverse effects on Trade balance in the long run. The coefficient of ER in the previous year is negative, and the coefficient of TB in the previous year is positive and significant. This is consistent with the J-Curve phenomenon, which states that devaluation may not improve trade balance in the immediate period, but will significantly impact the trade balance improvement in subsequent periods. Hence Marshall Lerner Condition exists in Sri Lanka.

Causal Links among Stock Market Development Determinants: Evidence from Jordan

  • MUGABLEH, Mohamed Ibrahim
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.543-549
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    • 2021
  • The stock market plays a crucial role in the growth of industry and trade, which eventually affects the economy. This paper studies the determinants of stock market development in Jordan using yearly time-series data (1978-2019). The autoregressive distributed lag approach is applied to examine co-integration, while the vector error correction model is employed to estimate (long-run and short-run) causal relationships. The results show that macroeconomic determinants such as gross domestic product, gross domestic savings, investment rate, credit to the private sector, broadest money supply, stock market liquidity, and inflation rate are important determinants of stock market development. These findings provide vital implications for policymakers in developed and emerging stock markets. First, economic development plays an imperative role in stock market development. Second, developing the banking sector is mandatory because it can significantly promote stock market development. Third, domestic investment is a significant determinant of stock market development, especially in emerging countries. However, it is vital to launch policies that lead to encourage investment and promote stock market development, and this could be done through (1) encouraging competition, (2) improving the institutional framework, and (3) removing trade blocks by establishing a mutual connection between foreign private investment entities and government authorities.

Revolution of nuclear energy efficiency, economic complexity, air transportation and industrial improvement on environmental footprint cost: A novel dynamic simulation approach

  • Ali, Shahid;Jiang, Junfeng;Hassan, Syed Tauseef;Shah, Ashfaq Ahmad
    • Nuclear Engineering and Technology
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    • 제54권10호
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    • pp.3682-3694
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    • 2022
  • The expansion of a country's ecological footprint generates resources for economic development. China's import bill and carbon footprint can be reduced by investing in green transportation and energy technologies. A sustainable environment depends on the cessation of climate change; the current study investigates nuclear energy efficiency, economic complexity, air transportation, and industrial improvement for reducing environmental footprint. Using data spanning the years 1983-2016, the dynamic autoregressive distributed lag simulation method has demonstrated the short- and long-term variability in the impact of regressors on the ecological footprint. The study findings revealed that economic complexity in China had been found to have a statistically significant impact on the country's ecological footprint. Moreover, the industrial improvement process is helpful for the ecological footprint in China. In the short term, air travel has a negative impact on the ecological footprint, but this effect diminishes over time. Additionally, energy innovation is negative and substantial both in the short and long run, thus demonstrating its positive role in reducing the ecological footprint. Policy implications can be extracted from a wide range of issues, including economic complexity, industrial improvement, air transportation, energy innovation, and ecological impact to achieve sustainable goals.

Nuclear energy consumption and CO2 emissions in India: Evidence from Fourier ARDL bounds test approach

  • Ozgur, Onder;Yilanci, Veli;Kongkuah, Maxwell
    • Nuclear Engineering and Technology
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    • 제54권5호
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    • pp.1657-1663
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    • 2022
  • This study uses data from 1970 to 2016 to analyze the effect of nuclear energy use on CO2 emissions and attempts to validate the EKC hypothesis using the Fourier Autoregressive Distributive Lag model in India for the first time. Because of India's rapidly rising population, the environment is being severely strained. However, with 22 operational nuclear reactors, India boasts tremendous nuclear energy potential to cut down on CO2 emissions. The EKC is validated in India as the significant coefficients of GDP and GDP.2 The short-run estimates also suggest that most environmental externalities are corrected within a year. Given the findings, some policy recommendations abound. The negative statistically significant coefficient of nuclear energy consumption is an indication that nuclear power expansion is essential to achieving clean and sustainable growth as a policy goal. Also, policymakers should enact new environmental laws that support the expansion and responsible use of nuclear energy as it is cleaner than fossil fuels and reduces the cost and over-dependence on oil, which ultimately leads to higher economic growth in the long run. Future research should consider studying the nonlinearities in the nuclear energy-CO2 emissions nexus as the current study is examined in the linear sense.