---

One of the key concepts in risk managing of financial portfolios is the probability based risk measurement method known as value at risk. During recent years, various methods have been introduced by researchers to compute this criterion. Because of their dissimilar assumptions and procedures, making the use of each of which creates different results. Therefore, this paper uses two main methods in order to measure the value at risk of foreign exchange portfolio. They comprise generalized autoregressive conditional heteroskedasticity model and Monte Carlo Simulation. Using failure rate back testing, the results of these methods are compared. The results of the evaluation demonstrate that the mentioned methods have different performances.

---

The aim of this study is to explore the feasibility of setting up a Commodities Futures Market in Iran. Specifications for the margin requirements, daily price movement limits, the length of expiration intervals, tick sizes and contract size of various potential future contracts are hereby examined. Saffron, pistachio and rice emerge as the three suitable Iranian agricultural commodities. A new computational method of Value at Risk (VaR) optimization model, using a nonparametric sampling approach, is employed to determine the daily margin requirements and daily price fluctuation limits. Expiration intervals are determined by the simulated daily future price with a minimum of volatility. The daily risk free interest rate and the minimum daily average trading value of a participant in the Tehran Stock Exchange (TSE) are used as benchmarks to determine the minimum tick size and contract size for each commodity. These contract specifications are the initially suggested quantities for setting up an agricultural futures market in Iran.

---

This study computes the value at risk (VAR) of metal ores and pharmaceutical industries in Tehran Stock Exchange by using parametric approach (GARCH Models) and semi-parametric approach (the combination of Wavelet Analysis and GARCH). The results and evaluation of two approaches confirms the hypothesis indicating better and more efficient performance of Semi-parametric approach compared with that of parametric methods. In fact, in high confidence levels, the semi-parametric approach proposed has lower MSE and failure rates compared to parametric approach. On the other hand, investing in pharmaceutical industry due to the increasing health needs, increase in life expectancy and its effect on public health is less-risky than that of metal ores industry.

---

The types and varieties of peppers grown in Mediterranean areas are a response to the demand of European markets, although in each Autonomous Community local varieties are grown to satisfy the national demand. Nowadays, the range of shapes, colours, tastes and uses is wider than ever as a result of greenhouse cultivation, national and international tendencies and increased demand. In Murcia, the growing cycle runs from December to July or August, depending on the market and the growth of the crop. Sweet pepper is normally grown in greenhouses, using a variety of technologies: from simple shaded greenhouses, to the most-advanced multitunnels (large, in the form of a round arch or Gothic arch and with sophisticated ventilation). Due to the high cost of fuel, it is impossible to use heating during winter after transplanting, so alternative techniques are used to raise the temperature a few degrees and improve crop production. The aim of this work was to increase the precocity and productivity of sweet pepper grown in greenhouses. The effect of a Polypropylene Spunbonded Nonwoven Microtunnel (PSNM) was studied. The results show that, although the increase in production was not great (lower than 5% in both years of the study), precocity increased by 16% in both years. Since the increased cost of using this technology is not excessive, crop profitability increases if precocity is taken into account, as all our indicators show. The study suggests that the use of a PSNM raises the marketable production and brings forward the first harvests.