Security Requirement Management for Cloud-Assisted and Internet of Things—Enabled Smart City

The world is rapidly changing with the advance of information technology. The expansion of the Internet of Things (IoT) is a huge step in the development of the smart city. The IoT consists of connected devices that transfer information. The IoT architecture permits on-demand services to a public pool of resources. Cloud computing plays a vital role in developing IoT-enabled smart applications. The integration of cloud computing enhances the offering of distributed resources in the smart city. Improper management of security requirements of cloud-assisted IoT systems can bring about risks to availability, security, performance, confidentiality, and privacy. The key reason for cloud- and IoT-enabled smart city application failure is improper security practices at the early stages of development. This article proposes a framework to collect security requirements during the initial development phase of cloud-assisted IoT-enabled smart city applications. Its three-layered architecture includes privacy preserved stakeholder analysis (PPSA), security requirement modeling and validation (SRMV), and secure cloud-assistance (SCA). A case study highlights the applicability and effectiveness of the proposed framework. A hybrid survey enables the identification and evaluation of significant challenges.     

Sizing and optimization of high throughput radio‐frequency data down link of earth observation satellites

This paper analyses the sizing of networks of radio‐frequency ground stations operating at Ka band or above for the reception of data acquired by low earth orbit observation satellites. In particular, the way to account for the use of adaptive transmission schemes, to cope with the high propagation impairments in the troposphere is detailed. A solution to size optimally the ground stations and satellite memory, relying on propagation channel simulations, is also proposed. The resulting performances are assessed in a latter stage using simulated propagation time series. Copyright © 2015 John Wiley & Sons, Ltd.     

Parameter optimisation of a greenhouse solar heating and climatisation system

A solar heating and climatisation system based on selective absorption of solar energy by a selective collector was developed at the I.A.V. (Morocco). The experimental study shows that the performance of this system depends on several parameters: the nature of the caloporter fluid, the flow of the fluid circulation, the collector's surface area and the circulation mode (opened circulation or closed circulation).The system was tested inside a greenhouse which contained a strawberry crop. A clear improvement of the performance has been achieved for an open circulation with appropriate working parameters. The experimental results showed a precocity of 13 days of the strawberry crop in comparison to a standard greenhouse.