Large-scale circulation departures related to wet episodes in northeast Brazil

Large scale circulation features are presented as related to wet spells over northeast Brazil (Nordeste) during the rainy season (March and April) of 1979. The rainy season season is devided into dry and wet periods, the FGGE and geostationary satellite data was averaged and mean and departure fields of basic variables and cloudiness were studied. Analysis of seasonal mean circulation features show: lowest sea level easterlies beneath upper level westerlies; weak meridional winds; high relative humidity over the Amazon basin and relatively dry conditions over the South Atlantic Ocean. A fluctuation was found in the large scale circulation features on time scales of a few weeks or so over Nordeste and the South Atlantic sector. Even the subtropical High SLP's have large departures during wet episodes, implying a short period oscillation in the Southern Hemisphere Hadley circulation

System dynamics-based modelling and analysis of greening the construction industry supply chain

Increasing concern on global warming and corporate social responsibility have made environmental issues an area of importance to address for governments and businesses across the world. Among the Middle East countries, the United Arab Emirates (UAE) tops the list in terms of per capita energy spending and per capita carbon footprints. The construction industry is the major contributor to environmental pollution due to its size and nature of activity. The rapid growth of construction sector has a significant environmental impact with increase in carbon footprints. This paper analyses the environmental implications of the rapidly growing construction industry in UAE using system dynamics approach. Quantitative modelling of the construction industry supply chain helps to measure the dynamic interaction between its various factors under multiple realistic scenarios. The potential carbon savings and the impact of each factor are calculated using scenario development analysis. The paper has addressed in detail the various drivers and inhibitors of carbon emission in the construction industry supply chain and ways to evaluate the carbon savings. The paper provides an analytical decision framework to assess emissions of all stages applicable to the construction industry supply chain

Lightweight and privacy-preserving two-factor authentication scheme for IoT devices

Device authentication is an essential security feature for Internet of Things (IoT). Many IoT devices are deployed in the open and public places, which makes them vulnerable to physical and cloning attacks. Therefore, any authentication protocol designed for IoT devices should be robust even in cases when an IoT device is captured by an adversary. Moreover, many of the IoT devices have limited storage and computational capabilities. Hence, it is desirable that the security solutions for IoT devices should be computationally efficient. To address all these requirements, in this paper, we present a lightweight and privacy-preserving two-factor authentication scheme for IoT devices, where physically uncloneable functions have been considered as one of the authentication factors. Security and performance analysis show that our proposed scheme is not only robust against several attacks, but also very efficient in terms of computational efficiently

An efficient privacy-preserving authentication scheme for energy internet-based vehicle-to-grid communication

The energy Internet (EI) represents a new electric grid infrastructure that uses computing and communication to transform legacy power grids into systems that support open innovation. EI provides bidirectional communication for analysis and improvement of energy usage between service providers and customers. To ensure a secure, reliable, and efficient operation, the EI should be protected from cyber attacks. Thus, secure and efficient key establishment is an important issue for this Internet-based smart grid environment. In this paper, we propose an efficient privacy-preserving authentication scheme for EI-based vehicle-to-grid communication using lightweight cryptographic primitives such as one-way non-collision hash functions. In our proposed scheme, a customer can securely access services provided by the service provider using a symmetric key established between them. Detailed security and performance analysis of our proposed scheme are presented to show that it is resilient against many security attacks, cost effective in computation and communication, and provides an efficient solution for the EI

Modeling of Congestion: A Tool for Urban Traffic Management in Developing Countries

In order to formulate rational traffic management measures for urban roads, it is essential to understand the effect of different types of vehicle on congestion. The effect of different types of vehicle on congestion has been captured on the basis of marginal congestion. Using congestion models, the marginal congestions have been estimated for different road widths, traffic compositions and on-street parking levels. The peak hour vehicular composition and volume level vary for different roads in an urban area. Therefore, for assessing the operating conditions for different roads based on a comparable quantitative measure, the marginal congestion caused per Passenger Car Unit (PCU) of mixed traffic stream has been estimated and denominated ‘Marginal Congestion Index (MCI)’. The use of MCI for prioritization of management actions for different urban roads is discussed. It is shown that a congestion model explicitly accounts for the effects of traffic composition and volume level. Therefore, the effect of different types of vehicles on congestion at all traffic volumes could be estimated using congestion models. Altogether, modeling of congestion is established as a tool for formulating rational traffic management measures for urban roads in developing countries

An efficient privacy-preserving authenticated key agreement scheme for edge-assisted internet of drones

There has been a a significant increase in the popularity of using Unmanned Aerial Vehicles (UAVs), popularly known as drones, in several applications. In many application scenarios, UAVs are deployed in missions where sensitive data is collected, such as monitoring critical infrastructure, industrial facilities, crops, and public safety. Due to the sensitive and/or safety critical nature of the data collected in these applications, it is imperative to consider the security and privacy aspects of the UAVs used in these scenarios. In this article, we propose an efficient privacy aware authentication scheme for edge-assisted UAVs (Internet of Drones). Unlike the existing security solutions for UAV, our proposed scheme does not require to store any secret key in the devices but still can ensure the desired security level. To the best of our knowledge, this is the first article, where physical security of the UAV has taken into account. The proposed system allows third-party communication and mobile edge computing service provides to authenticate the UAVs without any loss of provacy and outperforms existing methods in terms of computational complexity

A Congestion Controlled Logical Topology for Multihop Optical Networks

This paper considers the problem of designing the logical topology for any wavelength routed optical network, given the traffic matrix. An heuristic algorithm is proposed here for designing topologies based on the De-Bruijn graph and we compare our results with those obtained through the deterministic approach. The De-Bruijn graph is selected in this context as the logical topology due to some of its characteristic features like simple routing scheme, low diameter and small degree

COMPARISON OF THE EFFECTS OF GROWTH REGULATORS ON IN VITRO REGENERATION OF RIDGE GOURD AND SPONGE GOURD THROUGH SHOOT

Abstract Context: Luffa cylindrica and Luffa acutangula are highly cross pollinated crops and propagated mainly by seeds. Genetic stability cannot be maintained easily by seed propagation. It can be maintain by developing special vegetative technique through tissue culture. Objectives: To compare the effects of growth regulators between two species of Luffa using shoot tips for develop the rapid, simple and efficient in vitro regeneration protocol. Materials and Methods: Shoot tips used were collected from in vivo grown plants. They were excised from plants and surface sterilized by HgCl2 treatment. The isolated tips were cultured on semisolid MS medium supplemented with different concentrations and combinations of different growth regulators. Results: The highest result of direct shoot multiplication of ridge gourd was observed using 2 mg/l BAP + 0.2 mg/l GA and in case of sponge gourd it was 1.5 mg/l BAP. For callus induction significant result was found using 4 mg/l BAP + 0.2 mg/l NAA in ridge gourd and 3 mg/l BAP + 0.2 mg/l NAA in sponge gourd. Indirect regeneration was performed by subculturing organogenic callus of sponge gourd on MS with 1.5 mg/l BAP + 0.2 mg/l GA3 and the callus of ridged gourd on MS + 1.5 mg/l BAP + 0.2 mg/l NAA + 0.2 mg/l nicotinic acid. Regenerated shoots of both species were rooted well on MS containing NAA at low concentration. Conclusion: Hormonal differences and simple rapid in vitro regeneration protocol of L. cylindrica and L. acutangula have been established