A consistent extension of the lambda-calculus as a base for functional programming languages

Church's lambda-calculus is modified by introducing a new mechanism, the lambda-bar operator #, which neutralizes the effect of one preceding lambda binding. This operator can be used in such a way that renaming of bound variables in any reduction sequence can be avoided, with the effect that efficient interpreters with comparatively simple machine organization can be designed. It is shown that any semantic model of the pure λ-calculus also serves as a model of this modified reduction calculus, which guarantees smooth semantic theories. The Berkling Reduction Language (BRL) is a new functional programming language based upon this modification

Motivation for and concept of BolognaLife portal

The planning and implementation of study time outside the home university is currently connected with the overcoming of many hurdles. In the context of BolognaLife these shall be significantly reduced. The main goals of the Bologna reform were on the one hand the easement and enhancement of the mobility of students and lecturers and on the other hand the improvement of recognition of study achievements and final degrees. Both aspects are not implemented yet. The authors has designed a community-based web-platform for solving these problems. The paper describes motivation and concept for design and implementation of BolognaLife portal. Furthermore the challenges because of the heterogeneous national conditions in the higher education area of Europe are pointed out. The portal is a global platform for bringing universities from all over the world together to handle the challenges of Academic Globalization

An efficient parallel algorithm for the all pairs shortest path problem using processor arrays with reconfigurable bus systems

The all pairs shortest path problem is a class of the algebraic path problem. Many parallel algorithms for the solution of this problem appear in the literature. One of the efficient parallel algorithms on W-RAM model is given by Kucera [17]. Though efficient, algorithms written for the W-RAM model of parallel computation are too idealistic to be implemented on the current hardware. In this report we present an efficient parallel algorithm for the solution of this problem using a relatively new model of parallel computing, Processor Arrays with Reconfigurable Bus Systems. The parallel time complexity of this algorithm is O(log2 n) and processors complexity is n2 × n × n

A fast parallel algorithm for special linear systems of equations using processor arrays with reconfigurable bus systems

A parallel algorithm using Processor Arrays with Reconfigurable Bus Systems has been designed to solve dense Symmetric Positive Definite (SPD) systems of equations Ax = b. The key content of this report is the parallelisation of the algorithm by Delosme & Ipson [8]. In order to design a parallel algorithm for PARBS, many procedures involved in [8] are handled in a slightly different way. The parallel time and processor’s complexity of each step of the algorithm is calculated. The parallel time complexity is O(n) using 2n × 2n × 5n number of Processing Elements

A constant time parallel algorithm for the triangularization of a sparse matrix using CD-PARBS

An algorithm for the triangularization of a matrix whose graph is a directed acyclic graph, popularly known as dag, is presented. One of the algorithms for obtaining this special form has been given by Sargent and Westerberg. Their approach is practically good but sequential in nature and cannot be parallelised easily. In this work we present a parallel algorithm which is based on the observation that, if we find the transitive closure matrix of a directed acyclic graph, count the number of entries in each row, sort them in the ascending order of their values and rank them accordingly, we get a lower triangular matrix. We show that all these operations can be done using 3-d CD- PARBS(Complete Directed PARBS) in constant time. The same approach can be used for the block cases, producing the same relabelling as produced by Tarjan’s algorithm, in constant time. To the best of our knowledge, it is the first approach to solve such problems using directed PARBS

Implementation of a parallel algorithm for the symmetric positive definite systems of equations on the CRAY-T3E

A parallel algorithm for the solution of dense Symmetric Positive Definite (SPD) systems of equations Ax = b has been designed for the implementation on the CRAY T3E. One of the numerically stable methods for the solution of this system is proposed by Delosme & Ipsen [3]. In order to implement this algorithm on the CRAY T3E, we require to handle the procedures involved in a slightly different way. These implementation issues are discussed in detail. The actual timings for different communication schemes, on different sets of data values and varying number of processors have been tested and reported