Over the past few years, much experience has been gained in semi-automatic protocol implementation using an existing Estelle-C compiler developed at the University of British Columbia. However, with the continual evolution of the Estelle language, that compiler is now obsolete. The present study found substantial syntactic and semantic differences between the Estelle language as implemented by the existing compiler and that specified in the latest ISO document to warrant the construction of a new Estelle-C compiler. The result is a new compiler which translates Estelle as defined in the second version of the ISO Draft Proposal 9074 into the programming language C. The new Estelle-C compiler addresses issues such as dynamic reconfiguration of modules and maintenance of priority relationships among nested modules. A run-time environment capable of supporting the new Estelle features is also presented. The implementation strategy used in the new Estelle-C compiler is illustrated by using the alternating bit protocol found in the ISO Draft Proposal 9074 document. / Science, Faculty of / Computer Science, Department of / Graduate

One of the basic requirements of communication protocols in a heterogeneous computer network is a standard external data-transfer representation. Abstract Syntax Notation One (ASN.1) has been widely used in international standard specifications. Its transfer-syntax of Basic Encoding Rules (BER) is applied as the standard external data representation. This thesis presents an efficient BER implementation, called the ED library. The ED library includes a number of encoding and decoding routines that may be used as primitive functions to compose encoders and decoders for arbitrarily complicated ASN.1 data-types. The Performance of the ED library is measured and discussed. Based on the ED library, an ASN.1-C compiler, called CASN1, is designed and implemented to release communication software programmers from the arduous work of translating protocol-defined data-types and constructing their encoders and decoders. Given an ASN.1 protocol specification, CASN1 automatically translates the input ASN.1 modules into C and generates the BER encoders and decoders for the protocol denned data-types. This thesis discusses the design principles, user interface, internal structures, and the implementation and of CASN1. Example applications are given. Both the ED library and CASN1 are implemented in C on UNIX 4.2 BSD using the YACC and LEX tools. / Science, Faculty of / Computer Science, Department of / Graduate

The dissertation presents the computational technique Particle-In-Cell, or PIC for short, and its applications in studying the magnetospheres of neutron stars, modeled as conducting rotators with strong magnetic fields. Pigeon, an open-source PIC simulator written by the author in modern C++, is anatomically examined as an instrument to illustrate the principles, algorithms and engineering difficulties of the PIC technique. Two types of rotators are studied using Pigeon. The monopolar rotator, which has an exact solution in the force free limit, serves as a tester for the code, as well as an example of the PIC's capability. The main application of Pigeon is on the ab initio simulation of an (axisymmetric) dipolar rotator with self-consistent gamma ray photon emission and pair creation, the study of which could reveal valuable information of the mechanism of the pulsars. Thanks to the performance boost brought by Pigeon's dynamic load balancing functionality, we are able to perform the simulation with a 4096x4096 high resolution grid. The high resolution is critical in obtaining a Lorentz factor of 10000 of the polar cap potential drop, which in turn enables good separations of energy levels and hence makes the simulation closer to representing the real-life pulsars. With the high resolution, we are also able to study the Y point more closely, where we find that the angular momentum conservation dictates the process of magnetic flux surface crossing that is responsible for the release of electromagnetic energies into the plasma.

The WWW (World Wide Web) is a great place to share information - information can be shared across the entire world. By studying the characteristics of the WWW, we can make this information easier to find and access. Information on the web is accessed by use of web crawlers, like the search engine Google. A user types in what he/she is searching for and search results are displayed, where the user can click on a result and be taken to the corresponding website. In order for the search engine to come up with these results, algorithms must be created to search through the web and find websites relevant to the user's query. These algorithms must be quick, since web users often want information right away. They also must be accurate; A user does not want to have to weed through search results for what he/she wants; the user may get frustrated or lose interest. To create algorithms that are quick and that display accurate results, certain characteristics of the WWW must be discovered and considered. The web must be searched and the pages and hyperlinks must be stored to perform these algorithms and to discover these characteristics. The intention of this thesis is to present a library of functions in C++ for building and manipulating large graphs. These functions can be used to discover properties of graphs like degree distribution and diameter, which can be useful when studying graphs and subgraphs of the WWW.

In this research, a C-Based Simulation Toolkit (CBST) was developed. It supports discrete, continuous, and combined simulation. CBST is a group of simulation support functions written in the language C. CBST functions are used within a specific framework similar to that of GASP IV. It employs the event scheduling world view for next event selection. The Runge-Kutta-Fehlberg integration method is used to update state variables. The simulation framework of CBST, descriptions of CBST functions, and details of program construction using CBST are described. Four models are developed using CBST and the results are analyzed. CBST is compared to similar software packages, namely GASP IV, DISC, and CSIM. CBST has more flexibility than GASP IV because it is C-based and because it offers resource management functions. CBST supports continuous and combined simulation, whereas DISC and CSIM do not. / Master of Science

Due to the significant limitations of static analysis and the dynamic nature of pointers in weakly typed programming languages like C and C++, the points-to sets obtained at compile time are quite conservative. Most static pointer analysis methods trade the precision for the analysis speed. The methods that perform the analysis in a reasonable amount of time are often context and/or flow insensitive. Other methods that are context, flow, and field sensitive have to perform the whole program inter-procedural analysis, and do not scale with respect to the program size. A large class of problems involving optimizations such as instruction prefetching, control and data speculation, redundant load/store instructions removal, instruction scheduling, and memory disambiguation suffer due to the imprecise and conservative points-to sets computed statically. One could possibly live without optimizations, but in domains involving memory security and safety, lack of the precise points-to sets can jeopardize the security and safety. In particular, the lack of dynamic points-to sets drastically reduce the ability to reason about a program's memory access behavior, and thus illegal memory accesses can go unchecked leading to bugs as well as security holes. On the other hand, the points-to sets can be very useful for other domains such as the heap shape analysis and garbage collection. The knowledge of precise points-to sets is therefore becoming very important, but has received little attention so far beyond a few studies, which have shown that the pointers exhibit very interesting behaviors during execution. How to track such behaviors dynamically and benefit from them is the topic covered by this research. In this work, we propose a technique to compute the precise points-to sets through dynamic pointer tracking. First, the compiler performs the pointer analysis to obtain the static points-to sets. Then, the compiler analyzes the program, and inserts the necessary instructions to refine the points-to sets. At runtime, the inserted instructions automatically update the points-to sets. Dynamic pointer tracking in software can be expensive and can be a barrier to the practicality of such methods. Several optimizations including removal of redundant update, post-loop update, special pattern driven update removal, pointer initialization update removal, update propagation, invariant removal, and on demand update optimization are proposed. Our experimental results demonstrate that our mechanism is able to compute the points-to sets dynamically with tolerable overheads. Finally, the memory protection and garbage collection work are presented as the consumers of dynamic pointer tracking to illustrate its importance. In particular, it is shown how different memory properties can be easily tracked using the dynamic points-to sets opening newer possibilities.

Thesis (M.Sc. (Computer Science)) - Rhodes University, 2008.

In this project,European Call and Put options,and also American Call and Put options have been priced by some finite difference methods using the C++ programming language.The report describes the following:The theory behind the pricing of options,some pricing methods,and how some finite difference pricing methods have been implemented in C++.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries / Department: Electrical and Computer Engineering.