Introduction: Price fluctuation is one of the most important features of the ENERGY market that leads to price risk and economic instability. In the financial market, one of the best uses of derivative securities is in hedging. The most common way of hedging in the investment is through appropriate derivative instruments. They include options, swaps, futures and forward contracts. Even though there are many criteria used in the derivation of the optimal hedge RATIO, the minimum-variance (MV) hedge RATIO considered by Johnson (1960) has been one of the most popular choices. The basic concept of the minimum variance hedging risk lies in the combination of investments in the spot and future markets in order to reduce value fluctuations. Thus, the optimal number of futures contracts that a person must hold to hedge against the risk of price fluctuation in the underlying assets can be obtained by calculating the optimal RATIO of hedging risk. The literature shows that researchers mainly use future contracts to minimize the risk of price fluctuation in the spot market. Accordingly, in these studies, various econometric methods have been used to calculate the optimal hedging risk RATIO. Also, in order to introduce the best hedging risk model, the performances of different models have been compared. The evaluation of hedging performance is based on the percentage reduction in spot variance compared to portfolio variance. Then, the purpose of this study is to choose an optimal model with the highest degree of hedging risk for the selected commodity. Methodology: Several techniques have been proposed in the literature to estimate the hedge RATIO with index futures contracts. Many practitioners and academicians have sought to solve the problem of how to calculate the optimal hedge RATIO accurately. To achieve the goal, we compare the estimates of the hedge RATIO from the ordinary least squares methods (OLS), autoregressive model (VAR/VECM), autoregressive conditional heteroscedasticity (ARCH/ GARCH) and copula. Also, to determine the changes in the optimal hedging risk RATIO, we use the weekly time series of spot and future contract prices for crude oil and natural gas during the five-year period of 2013-2018. In the next step, the rolling window regression technique will be used to compare the performances of the studied models and select an efficient hedging risk model. The results of the weights for future by each of the four above-mentioned models will be used for hedging the spot prices of the two examined commodities. The obtained hedge RATIOs are applied on the real data in the following 20 weeks. Thus, the ability to reduce risk in every method is measured and compared during the specified period. Results and Discussion: All the models are able to offer a significate reduction in the portfolio. The conventional approach to estimating the MV hedge RATIO involves the regression of the changes in spot prices on the changes in future prices using the OLS technique. As we found, the minimum variance hedge RATIO by the OLS method was 62% for crude oil and 37% for natural gas. However, for the OLS technique to be valid and efficient, the assumptions associated with the OLS regression must be satisfied. Thus, we use an autoregressive model (VAR/VECM). The optimal hedging risk RATIO obtained from the VECM model is 98% for crude oil and 86% for natural gas. However, the OLS and VAR methods only capture the influence of two risk factors on stock returns in the mean on average but are not sufficient to capture the dependence structure in higher moments or tail dependence. The volatility clustering phenomenon and the existence of ARCH effects demonstrate that hedge funds volatility varies over time. Then, we use the conditional autoregressive model (GARCH). Furthermore, we utilize the copula method to capture the general dependence structure between the futures and spot prices. The copula method has been used for multivariate statistical modelling owing to its edibility and convenience to describe its ability to capture the nonlinear relationship of random variables. The copula approach allows us to model the marginal distributions of individual random variables and their dependence structure separately. Our finding show copula serves normally to hedge crude oil and natural gas at the rate of 98% and 93% respectively. These rates are the models for crude oil and natural gas copula at 98% and 94% respectively. In this paper, the efficiency of different models of the rolling window regression technique are compared. This section is the core of the research. The results of the effectiveness of the optimal hedging rates of the crude oil and natural gas market show that copula functions in both markets have been in better conditions than the other models. Thus, the result of the research indicates the high efficiency of the copula functions approach to calculate hedging risk rates. Conclusion: The results show that modeling the relationship between the current and future prices in the form of copula functions is more efficient.

ENERGY method of evaluation is widely employed in analyzing problems associated with sustainable agriculture. In this study, ENERGY RATIO (ER) of dryland wheat for three regions of Eghlid township was quantified. The total croppingarea of Eghlid is nearly 8282 hectares comprised of: Khosrowshirin (5000 ha), Sedeh (1682 ha) and Dezhkord (1600 ha). The corresponding values of wheat yield in these subareas are 1, 1.02 and 0.9 ton/ha, respectively. In this township, dryland cropping is performed via two methods: mechanized (using moldboard plow and then deep seed drilling) vs semi-mechanized (manual seed broadcasting, or using a "seed broadcaster and then applying the moldboard plow). In this study, the' equivalent ENERGY inputs and outputs for either one of the methods was evaluatted or then the corresponding ENERGY RATIO determined. Inputs were: fertilizer, seed, pesticide, fuel, equipment, labor, while outputs being grain yield and straw. Grain ENERGY RATIO for Khosrowshirin, Sedeh" and Dezhkord were obtained as 1.068, 1.19 and 0.91, respectively, while the corresponding values related to both grain and straw (total biological output) were 1.61, 1.80 and 1.36; respectively. Consequently, for the township, the corresponding mean values related to grain vs both grain and straw were calculated as 1.06 and 1.60, respectively. Input ENERGY of dryland wheat was found to be 12.49 GJ/ha and total output ENERGY (grain and straw) was 20.056 GJ/ha leading to the net ENERGY gain (NEG) of 7.54 GJ/ha. Mean values of fertilizer, fuel seed, equipment, pesticide, and labor were becomes evident 57.5%, 28.4%, 12.1%, 1.25%, 0.38%, and 0.02%, " respectively. It becomes evident that the input items fertilizer and fuel have dedicated to themselves the highest values of ENERGY consumption the magnitudes of which should be optimized for implementation of an efficient management. Improportionate consumption of these inputs not only increases the production costs involved but also adds to the pollution of the atmosphere, soil and water resources as well.

This paper presents an analysis of technical efficiency and technology gap RATIO (TGR) in greenhouse cucumber in Fars Province, Iran. Cucumber production was chosen for this study for the reason that greenhouse productions in this province mainly have focused on this product. The data used in this study was obtained from a random sample of 127 greenhouse s in Fars Province for 2010 to 2011. Metafrontier production function model for firms was used within the parametric framework of stochastic frontier analysis (SFA). The frontier models are applied in the analysis of cross-sectional data by assuming a translog functional form. Results indicate that eliminating ENERGY input subsidies has led to significant decrease in greenhouse cucumber production efficiency so that the mean technical efficiency declined from 98% to 67 % during 2010-2011. Furthermore, subsidies elimination has also led to decrease of the mean technology gap RATIO in greenhouses from 0.92 to 0.87, in other words, it has caused more distance from efficient production frontier.

The aim of this study was to investigate of ENERGY technology gap RATIO of main crops in Sari city in 2016. The ENERGY technical efficiency and ENERGY technology gap RATIO indices were computed using three approaches; group frontier stochastic production function, pooled frontier stochastic production function and the metafrontier function. Data were collected from Agriculture Jihad Organization of Mazandaran. The results showed that in case of filling the gap between other units and units of efficient products, whit no change in technologies the average amount of ENERGY production for soybeans, canola, alfalfa, barley, wheat and rice could be 19, 23, 35, 33, 39 and 28 percent increase. The results also showed that highest ENERGY technology gaps RATIO for the products studied was related to soybean (0.81) and canola (0.67). Thus it is suggested that researchers and policymakers should be more attention about environmental goals, especially ETGR to sustainable use of ENERGY consumption to at least one of the goals in optimization of cropping pattern.

With respect to expansion and development of high rise buildings in Iran and their high ENERGY consumption, it is vital to apply certain solutions in order to reduce the ENERGY consumption. Shells and its components are the most essentials factors which impact in ENERGY consumption. Regarding the importance of present research, the relation of openings and ENERGY consumption in high rise building and Tehran’s climatic conditions is discussed. In this research, the basic model of research in regard to annual ENERGY consumption has been stimulated by eQuest. In this process, the opening RATIO in basic model is considered 10% and then other tests with 80%, 60%, 40%, 20% as a whole and direction to direction have been carried out. The result displays that the opening RATIO and annual ENERGY consumption of research model have a direct relationship in such a way that the reduction of opening RATIOn up to 20% can almost reduce the annual ENERGY consumption to 17%. Also, the effectiveness of opening RATIOn differs in different buildings directions. The priority is given to south, east, west and north.

This research focuses on the effect of passive methods in the field of ENERGY storage, produce ENERGY by using renewable energies, and also to achieve the construction patterns of residential buildings in the climate conditions of Shiraz, with the aim reducing ENERGY consumption. Statistics show that in Iran, fuel consumption in residential and commercial buildings with an average annual growth of 7. It is about 2.37% of the country's total fuel consumption. One way to minimize ENERGY consumption in this sector is to increase the role of zero-ENERGY buildings. Zero-ENERGY buildings provide technical ways to consume less ENERGY in buildings. These buildings are designed and built so that all or a large part of these provide the ENERGY they need through the combination of ENERGY saving and the use of renewable ENERGY technology. In this research, after studying the climate condition of the city of Shiraz, a building in the ENERGY Plus software, the simulation and climatic data of the Shiraz station was introduced to the software. To achieve the most optimal conditions of ENERGY consumption in the climatic conditions of Shiraz, each of the building elements Residential was optimized. The simulation shows that it is possible to reduce the ENERGY consumption of the building by using passive building materials and designs, including double-glazed glass, Wall insulation, etc. On the other hand, by using solar ENERGY, using pvsyst software, you can supply the ENERGY needed by the building.

Introduction: Clinical use of the late responses during routine neurophysiological examination has significantly increased the diagnostic yield of the neurophysiological evaluation. The H max to M max RATIO (H/M RATIO) is considered a suitable index for illustrating the level of reflex excitability of the motor pool.Methods: In this study posterior tibial nerve H/M RATIO changes in cerebrovascular accidents (CVA) evaluated. This investigation was carried out in 22 normal subjects aged 40-65 years with mean 52 years, and in 40 patients with CVA aged 42-63 years with mean 57 years.Results: In normal subjects no significant differences were found between the mean values observed between right and left sides. In patients significant increased H/M RATIOs in both sides with more in non-plegic leg (P<0.01) were found. The facilitation of Babinsky sign in patients is significantly associated with low H/M RATIOs (P=0.003). The H/M RATIO changes were not significantly associated with severity of hemiplegia (P=0.3 for lower extremities, P=0.9 for upper extremities). The H/M RATIO was increased in ischemic lesions (P<0.01), but in intracerebral hemorrhages the soleus H/M RATIO increases in non-plegic side the same as the plegic side.Conclusion: The posterior tibial nerve H/M RATIOs are increased in CVA bilaterally due to decreased presynaptic inhibition Ia terminals, thus amplitude of H reflexes increased without increased amplitude of M response.

The method of selection of the study design decides the type of analysis 10 be used. Case-Control studies assess the causes of a particular outcome, comparing a group of individuals who have experienced the outcome under study with a group who have net.Results appear as a two by two table. As these two groups are sampled separately, the rate of the disease in the exposed or unexposed groups can not be calculated. However, the Odds RATIO can be obtained. The Odds RATIO is sometimes referred to as the cross product RATIO.                        Cases                            Controls Exposed            a                                  b Unexposed         c                                  d Odds RATIO (a/b)I (c/d) = ad/bc