Nicola Zingirian

Image processing on high-performance RISC systems

The recent progress of RISC technology has led to the feeling that a significant percentage of image processing applications, which in the past required the use of special purpose computer architectures or of ad hoc hardware, can now be implemented in software on low cost general purpose platforms. We decided to undertake the study described in this paper to understand the extent to which this feeling corresponds to reality. We selected a set of reference RISC-based systems to represent RISC technology, and identified a set of basic image processing tasks to represent the image processing domain. We measured the performance and studied the behavior of the reference systems in the execution of the basic image processing tasks by running a number of experiments based on different program organizations. The results of these experiments are summarized in a table, which can be used by image processing application designers to evaluate whether RISC-based platforms are able to deliver the computing power required for a specific application.

Sensor clouds for Intelligent Truck Monitoring

The paper presents a new service paradigm for Vehicle Communication Platforms (VCPs), based on the Sensor Cloud concept. According to this paradigm, VCPs make available their components, including vehicle sensor and devices, to third-party vehicle monitoring applications, as virtual resources. We prototyped a Sensor Cloud service on the Click & Find™ VCP, currently supporting real-time Intelligent Truck Monitoring (ITM) services on about one thousand tank trucks for fuel distribution in Europe. The paper presents the Sensor Cloud service architecture and implementation, discussing the main benefits delivered to the ITM domain.

Internet protocol support for telephony

In this paper, we consider the evolution of telephone networks from time-division multiplexing circuit switching to packet switching and, in particular, to packet switching-based on Internet Protocol (IP-supported telephony). We analyze IP-supported telephony design solutions by proposing a layered reference model in which each layer is associated to a subset of the functions that support telephony. We use the reference model to establish a terminology and a framework for the comparison of the design solutions. We group the design solutions in scenarios and compare them in terms of the reference model proposed. We then focus on IP telephony, in which IP is used in telephone company networks, and on Internet telephony, in which the Internet is used to support telephony. We show that they both can be seen as implementations of the same architecture, which consists of a set of components, associated to functions, and of the interactions among these components. We then consider the issue of voice-data integration and analyze the variety of design solutions that can be adopted to integrate voice and data.

VISIONS: A Service Oriented Architecture for Remote Vehicle Inspection

This paper presents a system for remote vehicle inspection developed within the VISIONS (vehicular system interface for open network service) research project funded by the European Commission. The system architecture allows digital service exchange between vehicles and road infrastructures (e.g., road, tunnel, terminal containers) and makes available a large set of significant vehicle data (e.g., engine status, tire pressure, cargo documents) directly to the infrastructure information system applications. The VISIONS system, based on the service oriented architecture, includes appropriate extensions to such an architecture to meet domain-specific requirements such as highly dynamic event handling and short service persistence in the network. The paper describes the architecture, the system prototype and the experimental results obtained in a pilot system located in the Mont Blanc Tunnel

Extensive GPRS Latency Characterization in Uplink Packet Transmission from Moving Vehicles

The GPRS (general packet radio service) broad availability is driving a widespread development of mobile telemetry systems for fleet management, supply chain management and dangerous goods monitoring applications. In this paper we present the results of extensive measurements of the GPRS network-layer uplink latency performed over a four-month period from about fifty road trucks using telemetry service, providing an uplink latency characterization in a moving vehicle environment. The results show the relationship between vehicle speed and latency. Furthermore, the performances of the stop-and-wait in a moving vehicle environment are evaluated in order to design a variant of such a protocol based on a vehicle speed-aware retransmission timeout.

Finding the Optimal Unroll-and-Jam

Reducing the traffic between CPU and main memory is one of the main issues in the optimization of programs for load/store architectures. It is the register allocation module of optimizing compliers that keeps this traffic low by cleverly associating the program variables to the CPU registers. Since register allocation takes place during code generation and works on the intermediate code produced by the compiler front-end, the structure of such a code, which closely depends on the structure of the source code, heavily affects the effectiveness of register allocation. Proper techniques can be used to restructure the source programs in such a way to produce intermediate code able to take advantage of advanced register allocation schemes.

Development of a service-oriented architecture for the dynamic integration of mobile remote software components

The paper presents the work in progress of a project funded by the European Commissions aimed at enabling the integration between software components running on onboard truck terminals and ground based information systems to increase safety, efficiency and quality of road infrastructures. Despite the fact that the system originates in a automotive context, the architecture can be used for a wide range of control applications characterized by mobile software components. The system architecture goals are to collect vehicle data and make such data accessible from external information system through open application interfaces over standard wireless network technology

On the efficiency of image and video processing programs on instruction level parallel processors

While in the last decade image and video processing (IVP) have gradually moved from special purpose computer architectures based on massive parallelism (MP) to general purpose computer architectures based on instruction-level parallelism (ILP), a new challenge is now to be faced by the IVP community, namely the application of IVP also in small-size embedded systems (e.g., video players, smart cameras, digital diaries, etc.) based on ILP processors. Because of the requirements of low size, weight, and power consumption, these embedded systems do not take advantage of processors that feature advanced dynamic code optimization mechanisms such as those based on instruction reordering and register renaming. On the other hand, the compile time techniques of present generation compilers do not appear to be aggressive enough to exploit the massive parallelism of IVP tasks in ILP architectures, thus leading to inefficient programs. This paper analyzes the efficiency of IVP programs on ILP CPUs. In particular it presents: (1) a reference model for the efficient design and implementation of highly parallel programs, such as the ones of the IVP domain; (2) an analysis of the inefficiencies of IVP programs implemented on ILP processors; and (3) a set of techniques, deriving from the reference model, that overcome these inefficiencies. These techniques are based on a novel computing paradigm called bucket processing.

Scheduling Image Processing Program Activities on Instruction Level Parallel RISC Through Program Transformations

The success of image processing (IP) applications implemented on Instruction Level Parallel (ILP) RISC systems relies on the efficient utilization of the CPU resources. While in general it is the compiler that organizes the machine code in such a way to maximize the hardware resource utilization it was recently shown that in the case of IP programs compilers do not actually produce efficient machine code. Therefore special coding schemes (based for example on loop unrolling) must be adopted to help compilers to produce efficient code. This paper investigates some of these special coding schemes. More specifically it describes the effects of different loop unrolling schemes and introduces a new source program transformation based on the dynamic scheduling of the program iterations which, under some hypotheses, is shown to be more efficient than unrolling. A case study on the implementation of the Hough Transform is presented to validate the results of this paper.

Customizing MPEG Video Compression Algorithms to Specific Application Domains: The Case of Highway Monitoring

This paper describes the design of a MPEG coding algorithm targeted to compress video sequences generated by highway surveillance cameras. The physical constraints of vehicles as well as the geometry of the highway environment projected into the camera determine a relevant base of a-priori knowledge, which allows obtaining considerable processing speed up as well as higher compression ratio. This paper models the highway environment in terms of rules and shows how a a customized MPEG coding algorithm can take advantage of such rules to improve processing speed and compression ratio.