Search results for "symbolic"

xloops - Automated Feynman diagram calculation

1998

The program package xloops, a general, model independent tool for the calculation of high energy processes up to the two-loop level, is introduced. xloops calculates massive one- and two-loop Feynman diagrams in the standard model and related theories both analytically and numerically. A user-friendly Xwindows frontend is part of the package. xloops relies on the application of parallel space techniques. The treatment of tensor structure and the separation of divergences in analytic expressions is described in this scheme. All analytic calculations are performed with Maple. We describe the mathematical methods and computer algebra techniques xloops uses and give a brief introduction how to …

Computer-aided synthesis of complex pump and valve operations

1988

Abstract Process plant operators often have to synthesize sequences of valve and pump operations. On large plants there may be so many possible pipe routes and vessels that it is not practical to provide a priori computer support for every possible operation. The paper describes a program that could form the basis of an operator aid to synthesize appropriate operations from a knowledge of the plant layout and existing pumping operations. The paper concentrates on finding paths through the pipework and on generating a sequence of operations that establishes the path whilst simultaneously satisfying other safety and operating constraints. The paper includes two example problems which were use…

Risks of Concurrent Execution in E-Commerce Processes

2021

The development of ICT facilitates replacing the traditional buying and selling processes with e-commerce solutions. If several customers are served concurrently, e.g. at the same time, the processes can interference each other causing risks for both the buyer and the seller. The paper offers a method to identify purchase/sale risks in simultaneous multi-customer service processes. First, an exact model of buying-selling processes is created and the conditions for the correct process execution are formulated. Then an analysis of all the possible scenarios, including the concurrently executed buying-selling scenarios, is performed using a symbolic execution of process descriptions. The obtai…

The set of conjugacy class sizes of a finite group does not determine its solvability

2014

Abstract We find a pair of groups, one solvable and the other non-solvable, with the same set of conjugacy class sizes.

An Ambient Intelligence Architecture for Extracting Knowledge from Distributed Sensors

2009

Precisely monitoring the environmental conditions is an essential requirement for AmI projects, but the wealth of data generated by the sensing equipment may easily overwhelm the modules devoted to higher-level reasoning, clogging them with irrelevant details. The present work proposes a new approach to knowledge extraction from raw data that addresses this issue at different levels of abstraction. Wireless sensor networks are used as the pervasive sensory tool, and their computational capabilities are exploited to remotely perform preliminary data processing. A central intelligent unit subsequently extracts higher-level concepts represented in a geometrical space and carries on symbolic re…

A New Embedded Coprocessor for Clifford Algebra based Software Intensive Systems

2011

Computer graphics applications require efficient tools to model geometric objects and their transformations. Clifford algebra (also known as geometric algebra) is receiving a growing attention in many research fields, such as computer graphics, machine vision and robotics, as a new, interesting computational paradigm that offers a natural and intuitive way to perform geometric calculations. At the same time, compute-intensive graphics algorithms require the execution of million Clifford operations. Clifford algebra based software intensive systems need therefore the support of specialized hardware architectures capable of accelerating Clifford operations execution. In this paper the archite…

Symbolic Programming of Distributed Cyber-Physical Systems

Cyber-Physical Systems (CPSs) tightly integrate physical world phenomena and cyber aspects of computational units. The composition of physical, computational and communication systems demands different levels and types of abstraction as well as novel programming methodologies allowing for homogeneous programming, knowledge representation and exchange on heterogeneous devices. Current modeling approaches, frameworks and architectures result fairly inadequate to the task, especially when resource-constrained devices are involved. This work proposes symbolic computation as an effective solution to program resource constrained CPS devices with code maintaining strict ties to high-level specific…

DC4CD

2017

In this article, we present Distributed Computing for Constrained Devices (DC4CD), a novel software architecture that supports symbolic distributed computing on wireless sensor networks. DC4CD integrates the functionalities of a high-level symbolic interpreter, a compiler, and an operating system, and includes networking abstractions to exchange high-level symbolic code among peer devices. Contrarily to other architectures proposed in the literature, DC4CD allows for changes at runtime, even on deployed nodes of both application and system code. Experimental results show that DC4CD is more efficient in terms of memory usage than existing architectures, with which it also compares well in te…

Programming distributed applications with symbolic reasoning on WSNs

2015

Programming Wireless Sensor Networks (WSNs) is a complex task for which existing approaches adopt rigid architectures that are only suitable for specific application fields. In previous papers we introduced a programming methodology and a lightweight middleware based on high-level programming and executable code exchange for distributed processing on WSNs. In this paper, we show how high-level programming can be effectively used on WSNs to implement symbolic reasoning. In order to prove the feasibility of our approach, we present a Fuzzy Logic system where the value updates and the rule evaluations are performed in a distributed way. Through the proposed methodology, we discuss the developm…

A Middleware to Develop and Test Vehicular Sensor Network Applications

2019

The Smart city ecosystem is composed of several networked devices that provide services to citizens and improve their quality of life. Basic services, which must be exposed by the underlying software infrastructure, require efficient networking and communication protocols to coordinate and manage all the system components. In particular, Vehicular Sensor Networks (VSNs) are envisioned as key components of smart cities. Verification is crucial in such a highly dynamic scenario to ensure operation correctness and to reduce the development cost of smart applications. However, the rigidity of existing middlewares makes development, reconfiguration, and testing rather difficult. In this work, we…