Neural Computing and Applications - Cryptography often involves substituting (and converting) the secret information into dummy data so that it could reach the desired destination without leakage.... 相似文献
In this investigation, a comparative study for a NOX storage catalytic system was performed focusing on the parameters that affect the reduction by using different reductants (H2, CO, C3H6 and C3H8) and different temperatures (350, 250 and 150 °C), for a Pt/BaO/Al2O3 catalyst. Transient experiments show that H2 and CO are highly efficient reductants compared to C3H6 which is somewhat less efficient. H2 shows a significant reduction effect at relatively low temperature (150 °C) but with a low storage capacity. We find that C3H8 does not show any NOX reduction ability for NOX stored in Pt/BaO/Al2O3 at any of the temperatures. The formation of ammonia and nitrous oxide is also discussed.
Internet Protocol version 6 (IPv6) is the latest version of IP that goal to host 3.4 × 1038 unique IP addresses of devices in the network. IPv6 has introduced new features like Neighbour Discovery Protocol (NDP) and Address Auto-configuration Scheme. IPv6 needed several protocols like the Address Auto-configuration Scheme and Internet Control Message Protocol (ICMPv6). IPv6 is vulnerable to numerous attacks like Denial of Service (DoS) and Distributed Denial of Service (DDoS) which is one of the most dangerous attacks executed through ICMPv6 messages that impose security and financial implications. Therefore, an Intrusion Detection System (IDS) is a monitoring system of the security of a network that detects suspicious activities and deals with a massive amount of data comprised of repetitive and inappropriate features which affect the detection rate. A feature selection (FS) technique helps to reduce the computation time and complexity by selecting the optimum subset of features. This paper proposes a method for detecting DDoS flooding attacks (FA) based on ICMPv6 messages using a Binary Flower Pollination Algorithm (BFPA-FA). The proposed method (BFPA-FA) employs FS technology with a support vector machine (SVM) to identify the most relevant, influential features. Moreover, The ICMPv6-DDoS dataset was used to demonstrate the effectiveness of the proposed method through different attack scenarios. The results show that the proposed method BFPA-FA achieved the best accuracy rate (97.96%) for the ICMPv6 DDoS detection with a reduced number of features (9) to half the total (19) features. The proven proposed method BFPA-FA is effective in the ICMPv6 DDoS attacks via IDS. 相似文献
ABSTRACT Despite nearly a century of water regulation projects on the Nile Basin, today Egypt faces a genuine crisis with respect to water supply. The crisis has been brought on by a combination of drought and greatly increased usage by all riparian nations along the Nile. It is highly probable that Egypt will need to search for new sources of water, reallocate existing water supply and reduce demand simultaneously in order to stave off major water shortfalls. It is unlikely that these measures can be accomplished without both internal and external conflict. This paper describes the current state of water supply and usage in Egypt. Further we examine potential sources of conflict over water allocation decisions. Finally, the paper presents a method for evaluating alternative strategies that could be implemented by Egypt to avoid future conflict. 相似文献
Abstract In 1981, a mathematical simulation model for Lake Nasser (SMLN) was developed to test different hydrologic conditions and operation policies of the Aswan High Dam (AHD). At that time, AHD had been operating for around 12 years. Over the thirty years of the dam operation, the Egyptian water resources managers experienced cycles of floods and droughts. Also, data and information about the hydrologic parameters of the lake as well as the dam performance were accumulated. This by itself constitutes a good reason for re-calibrating of the SMLN. The 1998–1999 flood, which manifested the need to reconsider the dominant operation policy, also called for the adjustment and re-calibration of the SMLN or at least to retest its accuracy. This paper describes the effort carried out to recalibrate this model using few parameters and adjust its original mathematical formulation. Elements of the mass balance equation of the lake, which are uncertain and at the same time seem to have significant impact, have been used in the modification and re-calibration. The presented results show, in many cases, an improvement in the model performance and accuracy when compared with the original version calibrated in 1981. Nevertheless, these results should not be considered a final step in improving the model performance. Actual measurements of evaporation rates and piezometric heads of the groundwater around the lake may be used to formulate new and better loss equations 相似文献
Water problems are omnipresent and are already becoming a limiting factor in the development of many countries. Currently the balance between the available and required water in Egypt is fragile. Any movement away from the balancing point means either less ambitious economic development or depletion of the resources and degradation of the environment. The continuing revolution in computer hardware and software is expected to provide more insight into the water problems and to alleviate some of the future water crises. In this paper we have investigated potential benefits which can be accrued from the application of object-oriented modeling in water resources. 相似文献
Several techniques can be used to improve surface properties of metals. These can involve changes on the surface chemical composition such as alloying or on the surface microstructure, such as hardening. In the present work, melting of the surface by a 9 kW CO2 CW laser of wavelength 10.6 μm was used to alter surface features of D2 tool steel. Carbon powder and nitrogen gas were used as sources of alloying elements during laser processing. The effect of various laser parameters (power and speed) on the microstructure and hardness of D2 tool steel was investigated. Laser powers from 1 to 8 kW and laser speeds from 5 to 15 mm/s were employed. It was found that as the laser power increases, the hardness of the melted zone decreases while that of the heat-affected zone increases. On the other hand, the depth of both of melted and heat-affected zones increases with power. 相似文献
This work aims to evaluate the influence of olive pomace drying (a solid by-product of the olive oil industry) on both antioxidant potential and drying kinetics. The two main fractions of olive pomace (pits, PI and pulps + peels, P + P) were characterized by image analysis and density measurement. The drying process was analyzed in experiments carried out at different temperatures (from 50 to 150 °C) and mathematically described from the diffusion and Weibull models. The antioxidant potential of the extracts (ethanol–water 80:20 v/v, 22 ± 1 °C, 170 rpm for 24 h) obtained from the dry product was analyzed by measuring the total phenolic content and antioxidant capacity and the main polyphenols were quantified by HPLC–DAD/MS–MS. 相似文献