10111190
MP: a protocol for efficient exchange of mathematical expressions
The Multi Protocol (MP) is designed for integrating symbolic, numeric, graphics, document processing, and other tools for scientific computation, into a single distributed problem-solving environment. MP is layered, reflecting the logically distinct aspects of tool integration. Data representation issues are addressed by specifying a set of basic data types and a mechanism for constructing non-basic types. MP passes all data in the form of annotated parse trees. The parse tree provides a simple, flexible and tool-independent way to represent and exchange data, and annotations provide a powerful and generic expressive facility for transmitting additional information. MP also provides efficient encodings for numeric data and includes different types of optimizations to reduce the cost of exchanging data. The optimizations are important when transmitting large expressions typically encountered in symbolic and numeric computation. MP is extensible. Users can define additional sets of operators and annotations as well as tailor the generic optimization mechanisms to efficiently encode their own data structures. A clear distinction between MP-defined and user-defined definitions is enforced.
5536996
DMAS: a web-based distributed mathematics assessment system (abstract only)
Assessing student performance and understanding is very important in education generally and in Mathematics education in particular. DMAS is a Web-based Distributed Mathematics Assessment system that can be of great value to teachers and students of Mathematics. Features of DMAS include: DMAD (the core Distributed Mathematics Assessment database), test authoring tool for teachers, online taking of tests, grading and results administration, comprehension diagnoses and linking to remedial materials. DMAS supports many problem types and allows mathematical formulas/expressions as well as geometry drawings/graphs to be part of questions and answers. Furthermore, DMAS supports the use of test taking as a teaching method. A teacher can monitor all students from the teacher terminal in real-time and either verbally guide the whole class on certain points or interact privately with one or more students via the Teacher-Student Interaction Mechanism (TSIM), an instant text-messaging provided by DMAS. A new Assessment Markup Language, MAML, is designed to make tests and test questions easy to share widely on the Web. Although developed as a sub-system of WME (Web-based Mathematics Education), DMAS is an independent Web system easily interfaced to any Web page through a well-defined API. The DMAS system consists of local databases at individual school websites. Teachers may publish new or improved questions to their local DMAS database to be shared with other teachers in the same school and in different schools. Teachers can use the powerful search engine (DMASEngine) to search for assessment questions. Search can be narrowed by subject, topic, grade-level, question type, keyword, and author. DMAD is designed to work as one distributed database while providing power, unity, and convenience at each participating school. The system helps create, revise, administer, and grade exams that can contain various types of questions: multiple choices, true-or-false, extended (essay) questions, short answers, two-columns matching, and fill-the-blank. Questions use a well-designed representation (encoding) allowing correct answers, rubrics, formulas, images, geometrical objects (SVG), and multimedia as well as interactive contents. DMAS system provides different views (modes): teacher and student modes. It also supports two types of testing: online and paper testing. The teacher can set Assessment test display options: display questions by a given order, by random questions none-random options, or by all questions/options are in random order. Tests taken online can be graded automatically and stored for teacher review, analysis, and printing. DMAS Assessment system has been piloted into seventh grade students at Kimpton Middle School, Stow, Ohio on 10/05/2007 for real-life testing and apparently teacher and student's feedback gave good impression and encouraging feedback about the DMAS system. However, our goal is to put DMAS system under extensive trial in schools and collecting feedback and suggestions from teachers, students, school administrators and education experts to help evolve DMAS. As more schools adopt DMAS, the distributed nature of DMAS will be demonstrated in realistic situations. Because DMAS has been designed in consultation with middle school teachers and education experts, the underline DMAS system design and framework is easy and flexible for future changes, requirements, expansions, and customizations. DMAS provides features to support real-life test giving such as loss of power to a laptop and retaking of tests.
6861036
Practical factorization of univariate polynomials over finite fields
Research presented fort to establish state-of-the-art Kent State University “ Kent, Ohio 44242-0001 here is part of an effactoring routines for polynomials. The foundation of such algorithms lies in the efficient factorization over a finite field GF(p~). The Cantor-Zassenhaus algorithm together with innovative ideas suggested by others is compared with the Berlekamp algorithm. The studies led us to design a hybrid algorithm that combine the strengths of the different approaches. The algorithms are also implemented and machine timings are obtained to measure the performance of these algorithms.
10974617
PRELUDE: A System for Portable Parallel Software
Abstract : In this paper we describe PRELUDE, a programming language and accompanying system support for writing portable MIMD parallel programs. PRELUDE supports methodology for designing and organizing parallel programs that makes them easier to tune for particular architectures and to port to new architectures. It builds on earlier work on Emerald, Amber, and various Fortran extensions to allow the programmer to divide programs into architecture-dependent and architecture-independent parts, and then to change the architecture-dependent parts to port the program to a new machine or to tune its performance on a single machine. The architecture-dependent parts of a program are specified by annotations that describe the mapping of a program onto a machine. PRELUDE provides a variety of mapping mechanisms similar to those in other systems, including remote procedure call, object migration, and data replication and partitioning. In addition, PRELUDE includes novel migration mechanisms for computations based on a form of continuation passing. The implementation of object migration in PRELUDE uses a novel approach based on fixup blocks that is more efficient than previous approaches, and amortizes the cost of each migration so that the cost per migration drops as the frequency of migrations increases.
22564863
The TMS390C602A floating-point coprocessor for Sparc systems
A recent Sparc (scalable processor architecture) processor consists of a two-chip configuration, containing the TMS390C601 integer unit (IU) and the TMS390C602A floating-point unit (FPU). The second device, an innovative coprocessor that lets the processor execute single- or double-precision floating-point instructions concurrently with IU operations is described. Dedicated floating-point hardware in the FPU increases the performance of the system. Running at clock periods as small as 20 ns, the chip should deliver 5.5 million double-precision floating-point operations per second under the Linpack benchmark (50-MHz clock rate). The FPU provides single- and double-precision arithmetic functions: addition, subtraction, multiplication, division, square root, compare, and convert. To minimize its math unit's latency, the FPU uses a highly parallel architecture requiring separate math units to optimize additions and multiplications. Traps stop the execution of a program to jump to software routine for handling data-dependent errors or to execute instructions not implemented in the hardware. Benchmark results are presented.<<ETX>>
42642346
Multi-version memory: software cache management for concurrent B-trees
The authors describe a new concurrent B-tree algorithm. The algorithm is designed to work well in large-scale parallel or distributed systems in which the number of processors sharing the tree is large or the communication delay between processors (or between processors and the global memory for a shared-memory system) is large relative to the speed of local computation. The basis of the algorithm is an abstraction that is similar to coherent shared memory, but provides a weaker semantics; this abstraction is called multiversion memory. Multi-version memory uses caches but weakens the semantics of ordinary shared memory by allowing process reading data to be given an old version of the data. This semantics is adequate for the non-leaf nodes in the B-tree algorithms presented.<<ETX>>
3478780
Time-domain simulation of uniform and nonuniform multiconductor lossy lines by the method of characteristics
A numerical technique to compute the time-domain response of multiconductor lossy uniform and nonuniform lines terminated in general nonlinear elements is presented. The technique is based on the method of characteristics and is used to study the propagation characteristics of multiple coupled uniform and nonuniform transmission line structures terminated in linear and nonlinear elements. This includes signal delay, distortion and crosstalk in interconnections in high-frequency analog and digital integrated circuits and chip modules. >
5084706
Pipes: linguistic support for ordered asynchronous invocations
We describe pipes, a new linguistic mechanism for sequences of ordered asynchronous procedure calls in multiprocessor systems. Pipes allow a sequence of remote invocations to be performed in order, but asynchronously with respect to the calling thread. Using pipes results in programs that are easier to understand and debug than those with explicit synchronization between asynchronous invocations. The semantics of pipes make no assumptions about the underlying architecture, which enhances code portability. However, the implementation of pipes by the language compiler can be optimized so as to take advantage of any underlying message ordering a particular architecture may provide. Pipes also provide application-transparent flow control for asynchronous invocations and are able to throttle invocations from multiple calling threads. We present four implementations of pipes and show that the performance and space overheads associated with pipes are low.