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71.
The recent introduction of wind power futures written on the German wind power production index has brought with it new interesting challenges in terms of modelling and pricing. Some particularities of this product are the strong seasonal component embedded in the underlying, the fact that the wind index is bounded from both above and below and also that the futures are settled against a synthetically generated spot index. Here, we consider the non-Gaussian Ornstein–Uhlenbeck type processes proposed by Barndorff-Nielsen and Shephard in the context of modelling the wind power production index. We discuss the properties of the model and estimation of the model parameters. Further, the model allows for an analytical formula for pricing wind power futures. We provide an empirical study, where the model is calibrated to 37 years of German wind power production index that is synthetically generated assuming a constant level of installed capacity. Also, based on 1 year of observed prices for wind power futures with different delivery periods, we study the market price of risk. Generally, we find a negative risk premium whose magnitude decreases as the length of the delivery period increases. To further demonstrate the benefits of our proposed model, we address the pricing of European options written on wind power futures, which can be achieved through Fourier techniques.  相似文献   
72.

The effects of flooring materials on the combustion behavior of thermoplastics is investigated. Based on the ISO 9705 fire test setup, an experimental rig was designed. Full‐scale experiments of PP combustion were carried out using five flooring boards, namely gypsum, steel, wood, ceramic tile and PVC. The experimental results indicate that the flooring boards play an important role in the heat release rates of typical thermoplastics combustion. Specifically, the time for the sharp increase of heat release rate is generally later for the flooring boards with larger thermal conductivity, except for the case of PVC. Preliminary analyses suggest that the reason for the exception of PVC is the expansion and carbonization of PVC at high temperature. In addition, experimental results also show that the corresponding peak heat release rate of thermoplastics combustion would be generally smaller for the flooring board with a larger thermal mass, except for the case of gypsum. The primary cause for the exception of gypsum may be the heat absorption by the crystal water released from the gypsum during the burning of hot pool oil.  相似文献   
73.
In this work, a corrosion prediction mathematical model for risk assessment in oil and gas production and transportation facilities has been created. This work focuses on partial pressure of carbon (iv) oxide, CO2 and the operating temperature in process equipment and transportation facility pipes as a function of corrosion rate. The model equation formulated was based on the principle of multiple linear regressions of data. The final model representing the corrosion rate of crude oil equipment was obtained CR = b o + b 1 T + b 2 P (CO 2). The model was simulated using polymath software. The correlation between the experimental and simulated resulted obtained using root mean square deviation (coefficient of determination) was 99.74% which is high, suggesting that the relationship between the predictor and response variables is linear. The variation in the model equation is 0.0066374. This low value of the variance shows that the model is accurate.  相似文献   
74.
Abstract

Total Diet Studies on pesticide residues in foods carried out in Italy in the last two decades are briefly summarized and data are discussed. Health risk assessment is expressed by the ratio total intake/ADI (%ADI ingested) for each compound and by the sum of the percentages of ADI for each compound within the same class of pesticides.

The total dietary intake of chlorinated pesticides, that was almost 100% of ADI in the years 1970-74, decreased down to 10% in the period 1978-84. This trend was confirmed for DDT in recent years, while data on Lindane and Heptachlor seem to be constant.

As regards the organophosphorus pesticides the sum of the percentages of ADI ingested for each compound, extrapolated from recent data (1990-1991) is about 20% and can be regarded as reasonably acceptable because the study included practically all the mainly used compounds.

Only few data are available for some pesticides like dithiocarbamates, especially EBDCs and their derivatives (e.g. ETU), other carbamates (e.g. aldicarb), paraquat etc. Moreover, analytical methods for these compounds should be improved.

The need for a considerable improvement in the number and organization of monitoring structures, in the use of standardized analytical procedures, in good laboratory practice standards and in the realibility of “monitoring protocols” and their homogeneity is evidenced.  相似文献   
75.
Different from the short‐term risk measure for traditional financial assets (stocks, bonds, etc.), the key to illiquid inventory portfolio traded in the over‐the‐counter markets is to estimate the long‐term extreme price risk with time varying volatility. In this article, a new long‐term extreme price risk (value at risk and conditional value at risk) measure method for inventory portfolio and an application to dynamic impawn rate interval are proposed. To realize this, we first establish AutoRegressive Moving Average‐Exponential Generalized Autoregressive Conditional Heteroskedasticity‐Extreme Value Theory model and multivariatet‐Copula to depict the autocorrelation, fat tails, and volatility clustering of returns of inventories and the nonlinear dependence structure of inventories. Furthermore, we obtain the long‐term extreme price risk with time varying volatility via Monte Carlo simulation instead of square‐root‐of time rule. The results show that, first, benefits from risk diversification is significant; second, long‐term extreme price risk measure of inventory portfolio via Monte Carlo method outperforms the square‐root‐of time rule; the last is that the dynamic rate interval based on the long‐term price risk is superior to the crude rules of thumb in terms of reducing efficiency loss and improving risk coverage. In summary, this article provides a new quantitative framework for managing the risk of portfolio in inventory financing practice for banks constrained by risk limitation. © 2014 Wiley Periodicals, Inc. Complexity 20: 17–34, 2015  相似文献   
76.
The present study aimed to develop n-propyl gallate (PG)-encapsulated liposomes through a novel direct pouring method using the quality-by-design (QbD) approach. A further aim was to coat liposomes with hyaluronic acid (HA) to improve the stability of the formulation in nasal mucosa. The QbD method was used for the determination of critical quality attributes in the formulation of PG-loaded liposomes coated with HA. The optimized formulation was determined by applying the Box–Behnken design to investigate the effect of composition and process variables on particle size, polydispersity index (PDI), and zeta potential. Physiochemical characterization, in vitro release, and permeability tests, as well as accelerated stability studies, were performed with the optimized liposomal formulation. The optimized formulation resulted in 90 ± 3.6% encapsulation efficiency, 167.9 ± 3.5 nm average hydrodynamic diameter, 0.129 ± 0.002 PDI, and −33.9 ± 4.5 zeta potential. Coated liposomes showed significantly improved properties in 24 h in an in vitro release test (>60%), in vitro permeability measurement (420 μg/cm2) within 60 min, and also in accelerated stability studies compared to uncoated liposomes. A hydrogen-peroxide-scavenging assay showed improved stability of PG-containing liposomes. It can be concluded that the optimization of PG-encapsulated liposomes coated with HA has great potential for targeting several brain diseases.  相似文献   
77.
Nowadays, the purpose of human genomics is widely emerging in health-related problems and also to achieve time and cost-efficient healthcare. Due to advancement in genomics and its research, development in privacy concerns is needed regarding querying, accessing and, storage and computation of the genomic data. While the genomic data is widely accessible, the privacy issues may emerge due to the untrusted third party (adversaries/researchers), they may reveal the information or strategy plans regarding the genome data of an individual when it is requested for research purposes. To mitigate this problem many privacy-preserving techniques are used along with cryptographic methods are briefly discussed. Furthermore, efficiency and accuracy in a secure and private genomic data computation are needed to be researched in future.  相似文献   
78.
A spectrum sharing system with primary and secondary nodes, each equipped with an arbitrary number of antennas, is investigated. Particularly, the outage performance of an underlay cognitive system is analytically studied, in the case when the end-to-end (e2e) communication is established via an intermediate relay node. To better enhance the e2e communication, successive interference cancellation (SIC) is adopted, which compensates for both the transmission power constraint and the presence of interference from primary nodes. Both the relay and secondary receiver perform unordered SIC to successively decode the multiple streams, whereas the decode-and-forward relaying protocol is used for the e2e communication. New closed-form expressions for the e2e outage performance of each transmitted stream are derived in terms of finite sum series of the Tricomi confluent hypergeometric function. In addition, simplified yet tight approximations for the asymptotic outage performance are obtained. Useful engineering insights are manifested, such as the diversity order of the considered system and the impact of interference from the primary nodes in conjunction with the constrained transmission power of the secondary nodes.  相似文献   
79.
The role of decision support systems in mitigating operational risks in firms is well established. However, there is a lack of investment in decision support systems in emerging markets, even though inadequate operational risk management is a key cause of discouraging external investment. This has also been exacerbated by insufficient understanding of operational risk in emerging markets, which can be attributed to past operational risk measurement techniques, limited studies on emerging markets and inadequate data.  相似文献   
80.
We investigate the existence of affine realizations for Lévy driven interest rate term structure models under the real-world probability measure, which so far has only been studied under an assumed risk-neutral probability measure. For models driven by Wiener processes, all results obtained under the risk-neutral approach concerning the existence of affine realizations are transferred to the general case. A similar result holds true for models driven by compound Poisson processes with finite jump size distributions. However, in the presence of jumps with infinite activity we obtain severe restrictions on the structure of the market price of risk; typically, it must even be constant.  相似文献   
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