Mobile agents for wireless computing: the convergence of wireless computational models with mobile-agent technologies

Abstract. Wireless mobile computing breaks the stationary barrier and allows users to compute and access information from anywhere and at anytime. However, this new freedom of movement does not come without new challenges. The mobile computing environment is constrained in many ways. Mobile elements are resource-poor and unreliable. Their network connectivity is often achieved through low-bandwidth wireless links. Furthermore, connectivity is frequently lost for variant periods of time. The difficulties raised by these constraints are compounded by mobility that induces variability in the availability of both communication and computational resources. These severe restrictions have a great impact on the design and structure of mobile computing applications and motivate the development of new software models. To this end, a number of extensions to the traditional distributed system architectures have been proposed [26]. These new software models, however, are static and require a priori set up and configuration. This in effect limits their potential in dynamically serving the mobile client; the client cannot access a site at which an appropriate model is not configured in advance. The contribution of this paper is twofold. First, the paper shows how an implementation of the proposed models using mobile agents eliminates this limitation and enhances the utilization of the models. Second, new frameworks for Web-based distributed access to databases are proposed and implemented

NET-CONSOLE: WEB-BASED DEVELOPMENT ENVIRONMENT FOR PARALLEL PROGRAMS

Net-Console is an integrated program development environment that can be used as a front-end for High Performance Computing (HPC) sites. It consist of an MPI-aware editor, an execution console, a debugger, monitoring tools and an account and file manager. Using Net-console the user is able to edit, execute, debug and evaluate the performance of parallel programs from anywhere in the Internet. The user interface is done through a normal Java-enabled browser. Net-console can also support processing through wireless and lightweight devices with the use of mobile agent technologies. The tools included in Net-console and their functionality, the languages used and the overall structure of the project are presented in this paper. </jats:p

M.: Tracker: A Universal Location Management System for Mobile Agents

This paper presents TRAcKER, * a distributed “location management ” middleware which has the ability to manage the location of mobile agents that travel independently the Internet in search of useful information. A major goal for this middleware is to be flexible and effective, to respond to the demands posed by the environment it aims to assist: an environment that deals with users that are accessing the Internet via static or mobile units of limited resources (e.g., palmtops, handheld devices, WAP-phones) and utilizing mobile agents that are moving “autonomously ” and asynchronously around the Internet with small, medium and in many cases high moving frequency. The mechanism we propose is modular, simple, of low overhead and able to serve all the Java based mobile agent platforms. In addition, is quite generic able to dynamically incorporate various location mechanisms. 1

A GIS-Based Assessment of Flood Hazard through Track Records over the 1886&ndash;2022 Period in Greece

This paper addresses the riverine flood events that have occurred in Greece over the last 136 years (i.e., during the 1886&ndash;2022 period), focusing, amongst others, on the case of urban floods. The flood record of various sites of the country has been collected and analyzed to determine their spatial and temporal distribution. Greece is a country where flood data and records are very scarce. Therefore, as there is not an integrated catalog of Greek floods spanning from the 19th century to recently, this is the first attempt to create an integrated catalog for Greece. The sources used include published papers, local and regional newspapers and public bodies (mainly the Ministry of Environment and Energy and the official websites of Greek municipalities). Additionally, the main factors responsible for their occurrence have been issued, regarding the country&rsquo;s climatic, geological and geomorphological setting, as well as human interventions. In addition, the atmospheric circulation driving factors of floods are assessed via an unsupervised neural network approach (i.e., Self-Organizing Maps). Based on the results of this research, an online GIS-based database has been created, depicting the areas that have been struck by riverine floods in Greece. By clicking a flood event in the online database, one can view several characteristics, depending on data availability, such as duration and height of the rainfall that caused them and number of fatalities. Long-term trends of mean and extremes seasonal precipitation also linked to the spatial distribution of floods. Our analysis shows that urban floods are a very large portion of the overall flood record, and they mainly occur in the two large urban centers, Athens and Thessaloniki, as well as near large rivers such as Pineios. Autumn months and mainly November are the periods with higher flood hazards, based on past records and cyclonic atmospheric circulation constitutes the principal driving factor. Our results indicate that a flood catalog at national level is of fundamental importance, as it can provide valuable statistical insights regarding seasonality, spatial distribution of floods, etc., while it can also be used by stakeholders and researchers for flood management and flood risk analysis and modelling

Fast microwave carbonization of aluminum-coated plastic wastes and perspectives: The examples of CDs and snack bags

Aluminum-coated plastics, such as CDs and snack bags, are widely used and consumed around the world. Since millions of CDs and trillions of snack bags end up in landfills and oceans as plastic waste every year, we suggest here an easy, fast, and cost-effective method for transforming this significant volume of garbage into added-value carbon using microwave technology. The proposed method differs from existing time- and energy-consuming pyrolytic processes employed in the traditional carbonization of this sort of waste. Conceptually, direct irradiation of the aluminum-coated plastic items in a domestic microwave oven heats up the metallic coating, thus triggering carbonization of the plastic substrate. The resulting carbon, which is characterized by means of X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) techniques, has structural similarities to carbons produced from CDs and snack bags using pyrolytic methods. In other words, the microwave technique produces similar effect, but it is faster and more energy efficient. We finally demonstrate some practical uses of the derived materials in gunpowder production, carbothermal production of metals and grey paint formulations