Mario A. Bochicchio

A distributed computing approach for real-time transient stability analysis

Power system online dynamic security assessment (DSA) is a challenging computing problem. A key problem in DSA is the analysis of a large number of dynamic stability contingencies every 10-20 minutes using online data. In order to speed up the transient stability analysis, parallel processing has been applied and several results can be found in the literature. In this paper, the authors present a distributed approach for real-time transient stability analysis. Distributed computing is economically attractive providing the processing power of supercomputing at a lower cost. Several distributed software environments like the parallel virtual machine (PVM) allow an effective use of heterogeneous clusters of workstations. Both functional and domain decomposition of the transient stability problem were tested under PVM on a homogeneous cluster of eight DEC ALPHA and on an IBM SP2 machine. Functional decomposition has been obtained by the Shifted-Picard algorithm, whereas domain decomposition has been obtained concurrently running different contingencies on different nodes of the cluster, using the very dishonest Newton algorithm. In order to assess the performance of these approaches, time domain simulations, adopting detailed modeling for synchronous machines, have been carried out on a realistic-sized power network comprising 2583 buses and 511 generators.

Hands-On Remote Labs: Collaborative Web Laboratories as a Case Study for IT Engineering Classes

The development of a reusable collaborative software framework for the remote control of a large range of laboratory equipments is an interesting topic to teach information technologies in an engineering school. The design and implementation of this kind of framework, in fact, requires the ability to integrate skills about software engineering, computer networks, human-computer interaction, distributed architectures, and remote control of hardware devices (i.e., laboratory equipments). In the paper, we describe our experience in the development of a reusable framework for remote laboratories, which has been adopted as a case study in two different scenarios at our university.

JWeb: an HDM environment for fast development of web applications

JWeb is a development environment for complex WWW applications, based upon the HDM model. JWeb (entirely written in Java) consists of two different parts: the development environment and the execution environment. The development environment allows the definition of the conceptual structure of the application, the creation of a supporting DataBase and the DataBase population. The execution environment allows the running of the application, possibly after some customization operations. We envision three main ways of using JWeb: as a training tool, for students and practitioners; as a fast prototyping tool, to test different design hypothesis, and to come up with a final design; as a tool for fast development and deployment of complex, high quality, Web applications.

Extending LMS with Collaborative Remote Lab Features

In university education, classroom activities are more and more combined with on-line teaching materials, webinars, electronic forums, wikis, web calendar and so on. This “blended approach” is often based on the adoption of Learning Management Systems (LMS), which are customized in many aspects to match both the teaching style of the university and the needs of teachers and students. More recently, also laboratory experiments, that are integral parts of science and technology classes, have come online. The first generation of Remote Web Laboratories (RWL) has demonstrated the feasibility and the effectiveness of on line experiments, with two major drawbacks: the lack of integration between LMS and RWL and the lack of synchronous interaction among the participants (teacher and students) to the experiment. In this scenario, the paper discusses the principal aspects and the main results about an integration project between the Moodle LMS and the MicroNet RWL at University of Salento, in Italy.

Aligning IT Service Levels and Business Performance: A Case Study

TSF is an Italian IT service company, focused on logistics and transportation IT market segments.. It is able to support customer’s business operations through a complex IT service chain, appraised by a Service Level Management (SLM) system. Due to the long term contractual relationship (10 years) with Italian Railways, TSF developed a symbiotic relationship with its main customer, becoming co-accountable for its business performance. This aspect has highlighted the necessity of the definition of an extended SLM model able to correlate the customer business performances with the delivered ICT service levels, in the perspective of an end-to-end service delivery chain. The paper illustrates the conceptual approach and the method adopted to overcome this problem in a pilot project.

Improved equipment for abdominal fetal electrocardiogram recording: description and clinical evaluation

Reliable computer-based equipment for transabdominal or indirect recording of fetal electrocardiogram (FECG) is described. The proposed equipment allows a real-time displaying of the signals (fetal + maternal ECG) without averaging procedures and it does not require the employment of a shielded room; moreover, it is user-friendly to medical personnel. An elementary form of semi-automatic computation of the fetal heart rate (FHR) was also implemented. The equipment simultaneously acquires three signals from seven electrodes, six placed on the maternal abdomen following the three space axes, and one placed on the left leg as a indifferent electrode. The signals are magnified and analogically filtered before undergoing digital finite impulse response (FIR) filter. Then the signals are displayed on the screen of a personal computer (PC). The PC also provides the possibility of storing the acquired signals for further analysis of elaborations. The quality of the recordings allows the analysis of both the rapid and slow electrical phenomena of the fetal heart, and it is not significantly influenced by the occurrence at the same time of uterine contractions. The performance of this method was assessed in 140 pregnant women with gestation periods of 29-42 weeks. In 131 cases (93.6%) the fetal QRS complex was detected and the FHR was obtained. A reliable evaluation of P and QRS waves and of ST interval, in spite of the interference of the maternal complexes, was possible in 102 cases (72.8%).

WARP: Web Application Rapid Prototyping

This paper describes an environment specifically tailored for the design and the rapid prototyping of Web applications. The environment, named WARP (Web Application Rapid Prototyping), offers a set of online software tools, which assist the designer and the user browsing of a Web application, in all its different aspects.The environment is based upon models and techniques already used in the hypermedia, information systems, and software engineering fields, adapted and blended in an original mix. The foundation of the proposal is the conceptual design of Web applications, starting from HDM, a notation for the specification of structure navigation, and presentation semantics.Compared to existing tools, WARP is an aid for analysis and design of Web Application because it introduces a new approach completely on-line (both the design and the execution environment). So the author can immediately formulate and evaluate requirements, specification and designs.A real-life experience of the use of the methodology and of the WARP in academic context are reported.

An HDM interpreter for on-line tutorials

The use of WWW for training purposes is rapidly growing; in a sense it could be said that training is one of the most important applications for Internet technology, in general and for WWW in particular. The overall organization of the sites, is, however, a difficult task, mostly if a standard structure must be enforced across different sets of content. In addition it is of growing interest the need for a compatibility between off-line training (e.g. CD-ROMS) and on-line training (e.g. WWW sites). A real life experience is described: a set of complex tutorials, for an industrial consortium, had to be delivered both off-line and on-line. At design time, the content was only partially known. It was important also to be able to add new material and to modify access structure, without reprogramming. The solution has been a flexible design schema (through the model HDM) and an advanced set of tools (based on Java), that allow the cost-effective development of advanced multimedia training material.

A Multi-purpose Architecture for Collaborative Web Labs

Laboratory classes are integral part of scientific education, but they are resource-intensive, imposing significant logistic constraints upon the curriculum. An option to reduce these burdens is to implement remote access laboratory classes, where students remotely interact with devices, instead of in traditional laboratory environment. This kind of remote labs are increasingly popular, but their development has been often focused on specific experiences, to address the needs of a particular lab. Moreover they are often designed for one user at a time, i.e. the user experience can not be shared with others. In the article we discuss a new Web Lab platform that can be easily adapted to a large number of different laboratory equipments and that is based on CSCL (computer-supported collaborative learning) techniques in order to share the lab experience within small groups of remote students.

The use of PVM with workstation clusters for distributed SAR data processing

The Synthetic Aperture Radar (SAR) is an active sensor widely used in remote sensing to obtain high resolution ground images from the back-scattered echo signals. When a digital processing is performed, a high computational load is involved and hw/sw solutions based on both specialized and general pupose machines can be exploited to speedup the image focusing algorithm. A more economical solution based on cluster of workstations is presented. The performance results of the version 1.0 of our distributed SAR processor achieved on a homogeneous cluster of IBM RISC System 6000/360 under PVM are reported.