The Internet of Things (IoT) shall be able to incorporate transparently and seamlessly a large number of different and heterogeneous end systems, while providing open access to selected subsets of data for the development of a plethora of digital services. Building a general architecture for the IoT is hence a very complex task, mainly because of the extremely large variety of devices, link layer technologies, and services that may be involved in such a system. In this paper, we focus specifically to an urban IoT system that, while still being quite a broad category, are characterized by their specific application domain. Urban IoTs, in fact, are designed to support the Smart City vision, which aims at exploiting the most advanced communication technologies to support added-value services for the administration of the city and for the citizens. This paper hence provides a comprehensive survey of the enabling technologies, protocols, and architecture for an urban IoT. Furthermore, the paper will present and discuss the technical solutions and best-practice guidelines adopted in the Padova Smart City project, a proof-of-concept deployment of an IoT island in the city of Padova, Italy, performed in collaboration with the city municipality.

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Internet of Things for Smart Cities

Efficient application scheduling is critical for achieving high performance in heterogeneous computing environments. The application scheduling problem has been shown to be NP-complete in general cases as well as in several restricted cases. Because of its key importance, this problem has been extensively studied and various algorithms have been proposed in the literature which are mainly for systems with homogeneous processors. Although there are a few algorithms in the literature for heterogeneous processors, they usually require significantly high scheduling costs and they may not deliver good quality schedules with lower costs. In this paper, we present two novel scheduling algorithms for a bounded number of heterogeneous processors with an objective to simultaneously meet high performance and fast scheduling time, which are called the Heterogeneous Earliest-Finish-Time (HEFT) algorithm and the Critical-Path-on-a-Processor (CPOP) algorithm. The HEFT algorithm selects the task with the highest upward rank value at each step and assigns the selected task to the processor, which minimizes its earliest finish time with an insertion-based approach. On the other hand, the CPOP algorithm uses the summation of upward and downward rank values for prioritizing tasks. Another difference is in the processor selection phase, which schedules the critical tasks onto the processor that minimizes the total execution time of the critical tasks. In order to provide a robust and unbiased comparison with the related work, a parametric graph generator was designed to generate weighted directed acyclic graphs with various characteristics. The comparison study, based on both randomly generated graphs and the graphs of some real applications, shows that our scheduling algorithms significantly surpass previous approaches in terms of both quality and cost of schedules, which are mainly presented with schedule length ratio, speedup, frequency of best results, and average scheduling time metrics.

/pdf/performance-effective-and-low-complexity-task-scheduling-for-51tejcgo0m.pdf

Performance-effective and low-complexity task scheduling for heterogeneous computing

In the Hamadryas baboon, males are substantially larger than females. A troop of baboons is subdivided into a number of ‘one-male groups’, consisting of one adult male and one or more females with their young. The male prevents any of ‘his’ females from moving too far from him. Kummer (1971) performed the following experiment. Two males, A and B, previously unknown to each other, were placed in a large enclosure. Male A was free to move about the enclosure, but male B was shut in a small cage, from which he could observe A but not interfere. A female, unknown to both males, was then placed in the enclosure. Within 20 minutes male A had persuaded the female to accept his ownership. Male B was then released into the open enclosure. Instead of challenging male A , B avoided any contact, accepting A’s ownership.

Evolution and the Theory of Games

https://www.engr.colostate.edu/~hj/journals/71.pdf

A Comparison of Eleven Static Heuristics for Mapping a Class of Independent Tasks onto Heterogeneous Distributed Computing Systems

Multiple applications request data from multiple storage units over a computer network. The data is divided into segments and each segment is distributed randomly on one of several storage units, independent of the storage units on which other segments of the media data are stored. At least one additional copy of each segment also is distributed randomly over the storage units, such that each segment is stored on at least two storage units. This random distribution of multiple copies of segments of data improves both scalability and reliability. When an application requests a selected segment of data, the request is processed by the storage unit with the shortest queue of requests. Random fluctuations in the load applied by multiple applications on multiple storage units are balanced nearly equally over all of the storage units. This combination of techniques results in a system which can transfer multiple, independent high-bandwidth streams of data in a scalable manner in both directions between multiple applications and multiple storage units.

Computer system and process for transferring multiple high bandwidth streams of data between multiple storage units and multiple applications in a scalable and reliable manner

On the capacity of multi-packet reception enabled multi-channel multi-interface wireless networks

Face detection system for SVGA source with hecto-scale frame rate on FPGA board

Sensor networks generate a large amount of data during monitoring process. These data must be sparingly exacted to conserve energy. There are two methods to obtain data: “push” and “pull”. When the sensory data satisfied a preset condition, they are “push”ed towards the base station. The “pull” method is to actively query the sensor networks for any interesting sensory data. The problem is how to plan the query and save the energy. When a query has been executed, there are some hints that can be kept to optimize the subsequent query processing. Energy consumption can be reduced by not contacting nodes whose values either can be predicted or are unlikely to be used. In this paper, we propose a history-sensitive based method to optimize top-k query processing in sensor networks. The top-k query looks for and utilizes the historical data in each sensor node. Subsequent top-k queries are guided by these historical data, therefore, to improve the entire query process. Simulation results show that the number of query hops can be reduced and the delays in response are improved.

History-sensitive based approach to optimizing top-k queries in sensor networks

Global parallel scheduling is a new approach for runtime load balancing. In parallel scheduling, all processors cooperate together to schedule work. Parallel scheduling accurately balances the load by using global load information. As an alternative strategy to the commonly used dynamic scheduling, it provides a high-quality, low-overhead load balancing. This paper presents a parallel scheduling algorithm for interconnection networks of the tree topology. This algorithm minimizes communications and maximize locality.

A parallel scheduling algorithm for tree structured interconnection networks

A robust solution for context-aware multimedia delivery in the pervasive computing environment remains a challenging problem. Its heterogeneous and dynamic nature demands a more flexible and intelligent framework than Internet does. We propose an adaptive middleware solution to address this issue. The system responds to the condition of the network to offer extensibility and efficiency. Furthermore, we propose an active controlling scheme, in which the multimedia delivery is able to adapt to the environment variation in a timely fashion. In addition, we describe an application scenario of our framework, which opens out a wide prospect.

Min-You Wu

Papers

On the capacity of multi-packet reception enabled multi-channel multi-interface wireless networks

Face detection system for SVGA source with hecto-scale frame rate on FPGA board

History-sensitive based approach to optimizing top-k queries in sensor networks

A parallel scheduling algorithm for tree structured interconnection networks

Context-Aware adaptation for media delivery in pervasive computing environment