Qusay H. Mahmoud

Cyber physical systems security

Cyber Physical Systems (CPS) are networked systems of cyber (computation and communication) and physical (sensors and actuators) components that interact in a feedback loop with the possible help of human intervention, interaction and utilization. These systems will empower our critical infrastructure and have the potential to significantly impact our daily lives as they form the basis for emerging and future smart services. On the other hand, the increased use of CPS brings more threats that could have major consequences for users. Security problems in this area have become a global issue, thus, designing robust, secure and efficient CPS is an active area of research. Security issues are not new, but advances in technology make it necessary to develop new approaches to protect data against undesired consequences. New threats will continue to be exploited and cyber-attacks will continue to emerge, hence the need for new methods to protect CPS. This paper presents an analysis of the security issues at the various layers of CPS architecture, risk assessment and techniques for securing CPS. Finally, challenges, areas for future research and possible solutions are presented and discussed.

Localization in terrestrial and underwater sensor-based m2m communication networks: architecture,classification and challenges

Summary Localizing machine-type communication (MTC) devices or sensors is becoming important because of the increasing popularity of machine-to-machine (M2M) communication networks for location-based applications. These include such as health monitoring, rescue operations, vehicle tracking, and wildfire monitoring. Moreover, efficient localization approaches for sensor-based MTC devices reduce the localization error and energy consumption of MTC devices. Because sensors are used as an integral part of M2M communication networks and have achieved popularity in underwater applications, research is being conducted on sensor localization in both underwater and terrestrial M2M networks. Major challenges in designing underwater localization techniques are the lack of good radio signal propagation in underwater, sensor mobility management, and ensuring network coverage in 3D underwater M2M networks. Similarly, predicting the mobility pattern of MTC devices, trading-off energy consumption and location accuracy pose great design challenges for terrestrial localization techniques. This article presents a comprehensive survey on the current state-of-the-art research on both terrestrial and underwater localization approaches for sensor-based MTC devices. It also classifies localization approaches based on several factors, identifies their limitations with potential solutions, and compares them. Copyright

An evaluation framework for cross-platform mobile application development tools

The mobile application market is becoming increasingly fragmented with the availability of multiple mobile platforms that differ in development procedures. Developers are forced to choose to support only some platforms and specific devices because of limited development resources. To address these challenges, numerous tools have been created to aid developers in building cross‐platform applications; however, there is no metric to evaluate the quality of these tools or the applications produced by them. This paper introduces a framework for evaluating the features, performance, and development experience of existing and future cross‐platform development tools. The framework is implemented by benchmarking several tools, and the results identify a disparity in the features and performance of applications built using different development tools. Copyright

Range-free localization approach for M2M communication system using mobile anchor nodes

Most existing range-free localization approaches use static anchor nodes. These approaches cannot be used for large scale Machine to Machine (M2M) communication networks since a fixed number of static anchor nodes cannot localize Machine Type Communication (MTC) devices such as sensors whenever more MTC devices are deployed in the network. Thus, this article introduces a Range-free, Energy efficient, Localization technique that uses Mobile Anchor (RELMA) nodes. This approach is scalable since the anchor nodes can move close to the newly deployed MTC devices in the network to localize them. The un-localized MTC devices receive beacon messages with the location information of mobile anchors whenever the anchors are within the sensing range of un-localized devices. Thus, RELMA is energy efficient and accurate because (i) the sensing range is much shorter than the communication range that other approaches use, and (ii) the intersected region of three sensing circles, where the un-localized device resides in, is very small. Simulation results show that RELMA outperforms existing Neighbor information Based Localization Scheme (NBLS) and Sink at the Origin Localization (SOL) approaches in terms of localization error and network energy consumption.

Application and network performance of Amazon elastic compute cloud instances

The computing and networking infrastructure in public clouds is shared between multiple users and can create abnormal variations in the performance of applications running in cloud. In this paper we compare the performance of compute-intensive applications on CPUs and GPUs offered by Amazons cloud and show that not all applications exhibit speedups when executed on the GPU. Even for applications that exhibit speedup on the GPU, the overall application performance may be bottlenecked by network delay. For such cases, the high cost of GPU instances is inefficient since it does not improve application performance. We also show that the network performance of different instances can vary significantly overtime and public clouds may throttle network bandwidth for applications that generate significant network traffic.

The Sensorian IoT platform

The Sensorian platform is an add-on sensor shield that transforms the Raspberry Pi into an IoT platform. It is compatible with all of the existing models of the Raspberry Pi (A/B, B+, version 1 and 2), and the firmware has been tested with the Raspbian operating system, and a custom image is available for download from [1]. A Kickstarter campaign has been successfully completed and 400 shields have been shipped. The Sensorian IoT platform can be used for tinkering and for teaching, learning and research.

QoS traffic mapping for a multi-participant session in unified communications networks

Unified communications (UC) offers users an uninterrupted communication service regardless of the device which the user is using, the heterogeneous networks to which he might be connected, the physical and logical context in which he exists and the diversity of QoS requirements by different session participants and services. Providing and maintaining an acceptable level of QoS, as perceived by all session participants, is a major issue in UC as well as in next generation networks (NGN) at large. QoS provisioning in such networks is a multi stage problem that starts from receiving the traffic, classifying it, mapping it to the appropriate UC class and finally queuing and scheduling it for delivery. In this paper, we introduce a novel mapping technique that accepts traffic belonging to a diverse set of applications coming from different networks and then maps it to one of eight UC classes based on the QoS requirements of each of the sessions participants. The proposed mapping algorithm performs this by calculating an agreed upon set of QoS performance metrics and then map this set to the closest UC class. Evaluation results demonstrate the efficiency of the proposed mapping technique.

Middleware for writing distributed applications on physical computing devices

A computer program, at its most basic level is a series of low level processor instructions which are executed sequentially. These instructions take time to execute, thus longer programs have longer execution times. One way to decrease the execution time for a program is to decrease the required time for each instruction. This is called frequency scaling. The disadvantage of frequency scaling is that running a processor at higher speeds causes it to generate more heat and consume more power. The physical properties of transistors also impose limits on how fast a microprocessor can be built. The solution to the problem of frequency scaling is to, instead of decreasing the time to execute an instruction, increase the number of instructions that can be run in a given amount of time, by running these instructions in parallel. This is known as parallel computing, and in this paper we present a solution for using many off-the-shelf computers to build a computing cluster which will accelerate computing performance by running tasks in parallel. To this end, we introduce a middleware for writing distributed applications on physical computing devices, such as the Raspberry Pi computer.

Storming the cloud: A look at denial of service in the Google App Engine

The past several years have seen many new services spread across the Internet. One of the biggest trends has been social media services such as Facebook and Twitter. Although social media is the major trend, it is not the only one. Cloud computing has made a large impact on the computing industry in recent years. Whether being utilized to provide highly scalable robust environments for applications or just being used as a marketing ploy, one thing is certain: cloud computing has the potential to yet again change the way we interact with computer systems. There is just one major factor separating cloud computing from becoming widely accepted both personally and commercially and that is security. As cloud systems re-innovate ways of request distribution and load balancing, it is important to test these systems against attacks such as the denial of service attack. There is a strong emphasis on researching these attacks since cloud computing is re-inventing the payment systems in which consumers utilize resources. This paper examines the Google App Engine and its resilience to denial of service attacks. Further the paper demonstrates the strain such an attack has on the servers that facilitate the services and finally discuss the preventative measures set in place by Google and how they are only temporary solutions.

A framework for the service provisioning of community-contributed web APIs

With the increased adoption of cloud computing in recent years due to its projected benefits as a computing-as-a-utility paradigm, the industry has consequently seen a rise in software-as-a-service via Web services. Serving as a safe and valuable interface between the providers data and outsider parties who have a potential use for the data, services allow developers to enhance the value of their applications by integrating with them. Initially, standardization and research efforts were geared largely towards enterprise use-cases of Web services. This resulted in the global Web service vision becoming largely privatized. But in recent years, the number and diversity of Web APIs have increased tremendously and developers have additionally become more open and decentralized. This poses the interesting problem of aggregating the vast number of distributed codebases and exposing them as consumable services for the benefit of all. The existing enterprise-oriented standards are unable to cater to such a scenario. We respond to this by presenting an alternative to the status quo of service registries. We specifically argue for the feasibility of a RESTful framework for the design and implementation of an open service registry that serves a community of Web services that can be contributed to or consumed by any developer on the Web.