We investigated different techniques for fitting Bézier curves to surfaces as a first step of curvilinear mesh gen- eration for high-order discretization methods. As a starting point we examined a distance-based least-squares fit- ting method. This method achieves a high accuracy, but tends to produce distorted curves where the mesh spac- ing is large compared to the radius of curvature. As remedy, we included approximations of stretch and bending energy into an incremental algorithm, resulting in an energy-minimizing fitting method. Both approaches were evaluated using two examples: an analytically defined screw surface and a surface triangulation of a rabbit aorta. The results confirm that the energy-minimizing method straightens and shortens the curves efficiently. Moreo- ver the method preserves the accuracy and convergence behavior of distance-based fitting. In accordance with previous work (see e.g.   ), our study indicates that combining stretch and bending energy yields better results than using only one of those. Additionally, we analyzed the influence of the curve fitting method on
The theoretical underpinnings of the relationship between economic growth and energy consumption with emissions have been discussed in the previous section. The relationship between economic growth and energy pollutants is termed as environmental Kuznets curve. The EKC hypothesis reveals that economic growth increases energy emissions initially. The main reason is that the principal objective of public and private sectors is to support the pace of economic growth through their contribution by creating more jobs without caring about the environmental cost. Above a certain level of per capita income, the economy starts to adopt environment-friendly technology to enhance output in the country due to the rising demand of cleaner environment as people are more conscious now about environmental quality. This implies that the relationship between economic growth and energy emissions should be inverted U-shaped termed as environmental Kuznets curve (EKC).
The above estimation results reveal noticeable differences in the dynamics of the volatility of the futures prices of the four energy commodities when the condition of the market is measured via the slope of the forward curve. The volatilities vary with shocks that differ in size and in direction. For instance, negative shocks (or bad news) tend to increase the volatility of crude oil and gasoline futures prices more than positive shocks (or good news), whereas the volatility of natural gas futures tend to increase more following a positive shock than a negative shock. The volatility of crude oil, gasoline and heating oil futures prices depend on the slope of the forward curve, whereas the volatility of natural gas futures prices is independent of market conditions. There are also differences in the degree of dependence of volatility of energy commodities on the slope of forward curve. Figure 6 presents the scatter diagram of slope of forward curve and volatility of near-month futures contract for the four commodities under investigation. The scatter plots and fitted quadratic regression lines illustrate a clear quadratic association between the two variables. However, the degree of this convexity differs among the relationships.
The quest for higher economic growth cannot be detached from the issue of energy security and environmental deterioration. On the one hand, serves as an essential input for economic activity, but on the other hand, extensive use of energy exerts greater pressure on the environment, either due to by-product pollutants or depletion of natural resources. In the context of sustainability, economic development should be achieved while making efforts to preserve the environment so that its utility for future generations is maintained. The environmental Kuznets curve (EKC) hypothesizes that instead of being harmful to the environment, economic development is favorable for improving environmental indicators that will eventually lead to a sustainable development path. The EKC hypothesis posits that the relationship between economic growth and environmental degradation follows an inverted U-shaped curve. It suggests that after exceeding a certain level of gross domestic product (GDP) per capita, the increasing trend of environmental degradation reverses so that higher GDP per capita leads to environmental recovery that reverses the environmental damage incurred at the initial stages of economic development.
Abstract — The experience curve effect has always challenged technology-related decisions. In the electricity sector, new renewable electricity generation technologies have shown a considerably high learning rate up to now, which could differentiate the profitability of energy generation technologies in the near future. The scope of this work is to investigate the effect that the Experience Curve of the renewable energy technologies may have on the orders for new electricity generation technologies and therefore, on the future electricity generation mix of Greece. The official renewable energy generation targets are considered as a constraint of the system, and the learning rates of the various technologies are included in the calculations. Three scenarios of learning rates have been applied, to examine the experience curve effect on renewable energy penetration. The national electricity generation system is modeled for long-term analysis and a linear programming method is applied, in order to come up with the optimal generating mix that minimizes electricity generation cost, while satisfying the national emissions reduction targets. In addition, two scenarios for future emission allowance prices are considered, in order to examine the effect of changes in this very volatile parameter. Furthermore, an investigation is made to identify if a point should be expected when renewable energy will be more profitable than conventional fuel electricity generation.
best accuracy particularly when the results for the proposed method, Bridgeman and Bridgeman-Leory are very close. If we take the optimization method as a benchmark, it can be observed from Table 6 that best agreement is obtained for energy method and Bridgeman approach. We compared the differences of the quantities with respect to their corresponding numerical values given in the 3 rd row of Table 6. The differences are given in parenthesis in the same table. The methods can now be compared more clearly with each other. The first interesting point is that the differences(except one case for Siebel) are well below 10%. As the results indicate and as far as A and B are concerned, Siebel gives the worst results and the proposed model and Birdgeman provide the best results, although differentiation between the proposed model and Bridgeman is difficult. We think that the dominant parameters in defining the corrected stress-strain curve are A and B and fracture strain is less important. The reason is that fracture strain is obtained from the fractured specimen. When the two parts of the broken specimens are put together to measure the neck section, the two parts usually don’t match exactly and therefore, the fractured neck diameter is always accompanied by some errors. As a result, we can conclude that the performances of the proposed model and Bridgeman model are close. It is a fact that all researchers have made some simplifications in their correction models. However, we may argue that optimization aided numerical simulations provide the most accurate prediction, because it provides the best agreement with the experiment for the neck profile. Having accepted this as the benchmark for assessing the accuracy of the models, we can see that the good agreement is obtained for the energy method discussed in this work.
growth, energy consumption and foreign trade based on the environmental Kuznets curve (EKC) hypothesis for Indonesia during the period 1971 – 2007. The Auto regressive distributed lag (ARDL) methodology is used as an estimation technique. The results do not support the EKC hypothesis, which assumes an inverted U-shaped relationship between income and environmental degradation. The long-run results indicate that foreign trade is the most significant variable in explaining CO 2 emissions in Indonesia followed by Energy consumption and
The short run dynamics are reported in Table-5 and results indicate that linear and non-linear terms of real GDP per capita have positive and negative impact on energy emissions indicating the validation of environmental Kuznets curve (EKC). Energy consumption has positive and strong effect to increase energy pollutants. By consequence, if the communist regime tolerated the energy emissions in order to obtain a high output level, but with expensive costs, the actual democratic authority must stimulate energy efficiency, with a low amount of energy emissions. In this way, the Romanian actions follow the EU general energy policy.
We applied the ARDL bounds testing approach to investigate the long-run relation- ship among energy intensity, income, income squared, urbanization, industrialization, foreign aid and import in case of Ethiopia for period covering 1970–2014. The ARDL bound testing is preferred due to the fact that it is applicable irrespective of the order of integration of the series. This avoids bias due to the pretesting of the order of integration of the variables. Results in Table 1 shows that none of the variables is stationary at I (2) or beyond that order of integration for the computation of the ARDL F-statistic to be valid. In doing so, we have applied Zivot–Andrews single structural break trended and Clemente–Montane–Reyes two structural breaks unit root tests to ensure that none of the variables is integrated of order 2 or beyond. The results of both types of unit root test are reported in Table 1. Our empirical evidence reveals that all the series show unit root problem at their level but found to be integrated at I(1). This entails that the series is stationary in their first differenced form. So, it is possible for us to test the existence of a long-run relationship between energy intensity, income, income squared, urbanization, industrialization and aid in the presence of double structural break in the series over the period of 1974–2014.
The relationship of energy consumption and economic growth has been investigated extensively as well. For example, Kraft and Kraft  for USA, Masih and Masih  for Taiwan and Korea, Aqeel and Butt  for Pakistan, Wolde-Rufael  for African, Narayan and Singh  for Fiji, Reynolds and Kolodzieji  for Soviet Union, Chandran et al.  for Malaysia, Narayan and Smyth  for Middle Eastern and Yoo and Kwak  for South American concluded that energy consumption causes economic growth. Opposite causality is also found running from economic growth to energy consumption by Altinay and Karagol  and Halicioglu  for Turkey, Squalli  for OPEC, Yuan et al.  for China and Odhiambo  for Tanzania. Bivariate causality between energy consumption and economic growth is also documented by Asafu-Adjaye  for Thailand and Philippines.
Fig. 7 presents the functions (2), (3), (4), (5), which describe the measured values of the impact energy. For these functions the same values of the upper (H) and lower (L) limits were entered in the same way as for the model program. At the arcustangent function (3) the same parameters were looked for as at the function (2). But the arcustangent function demands to look not only for the inﬂexion point and the transi- tion range width, but in addition to look for the limits H and L. The signum function has the same curve as the hyperbolic tangent function and is unambiguous for the description. The exponential function (5) is of the deﬁcient curvature in the curve bendings.
The experimental device set is shown in the Figure 1. The ND: YAG laser made by BigSky Company is plas- ma excitation source, the output wavelength is 1064 nm, the maximum output energy is 200 mJ. The pulse laser produced plasma at the sample surface through a 75 mm focal lens. Detection device is composed of 4 piece of Ocean Optics company HR2000+ spectrometer, the opt- ical resolution of 0.1 nm (FWHM), the integration time is 1ms, the measurement wavelength range is 199 - 631 nm. The timing controller is made by us to control Q delay of laser device and delay between spectrometer and laser device, the Q delay range is 120 μs - 220 μs, adjustable step is 5 μs, spectral acquisition delay range is 0 μs - 10 μs, adjustable step is 0.1 μs. The analyzed lead brass sam- ple is spectral purity Chinese standard sample; the GB number is GSB 04-2416-2008. The Composition is shown on the “Ref. (Reference) line” in Table 1.
In this paper an analysis is made on light energy consumption with respect to weather condition. The purpose of this analysis is to understand the relationships between light energy consumption with outside temperature, and humidity. Section 2 shows the related work of the research, followed by section 3 describes the house description and experimental setup, and the section 4 shows analysis for season-wise and ends with Section 5 shows results and conclusion.
driven nonlinear oscillator have been investigated by means of analog experiments and numerical simulations in the non-adiabatic limit for a wide range of oscillator param- eters. It is shown that, for over-damped motion, the eld-induced corrections to the activation energy can be described quantitatively in terms of the logarithmic suscepti- bility (LS) and that the measured frequency dispersion of the corresponding corrections for a weakly damped nonlinear oscillator is in qualitative agreement with the theoreti- cal prediction. Resonantly directed diusion is observed in numerical simulations of a weakly damped oscillator. The possibility of extending the LS approach to encompass escape from the basin of attraction of a quasi-attractor is discussed.
A method has been developed for fitting of a mathematical curve to numerical data based on the application of the least squares principle separately for each of the parameters associated to the curve. The method has been termed as step-wise least squares method. In this paper, the method has been presented in the case of fitting of a polynomial curve to observed data.
One of the key persons on the road to unification of the diverse views and manifestations of energy is un- doubtedly Michael Faraday (1791-1867), who from an apprentice bookbinder, went on to become an extremely important figure in XIXth century physics. Coming from the poorest social classes of English society, he managed to get a job as an apprentice bookbinder which had a singular advantage, “There were many books there”, as he revealed to a friend years later. Sometimes he spent the night alone reading by candlelight those books which most interested him. When he was twenty years old, a visitor to the workshop offered him a ticket for a series of con- ferences at the Royal Institution. The conferences were on electricity and the occult energies which must exist in nature. These not only awoke Faraday’s interest but also pointed the way to a better life. But how was he to enter