Dynamic Link Library Research Articles

Using ASCII text files in post-fix notation (reverse Polish) to define mathematical models and systems of differential equations for simulation and non-linear regression

We discuss current methods for supplying equations in ASCII text form to executables for simulation or fitting, then we define a technique using stack notation that has many advantages over traditional approaches to this problem. Simulations are described to compare the cpu time consumed for function evaluation when the models are supplied as object code in dynamic-link libraries, and when they are supplied as ASCII text files in post-fix notation, otherwise known as last-in-first-out or reverse Polish. It is concluded that this new method is extremely convenient; it can be easily extended to include loops for numerical integration, special function evaluation or root finding; it can be optimized by the user for execution speed; and the cpu overhead when the models are involved in regression are minimal.

Object-oriented developmental environment for image-analysis applications: implementation for 2D gel electrophoretogram analysis

The principal motivation was to design an environment for the development of image-analysis applications which would allow the integration of independent modules into one frame and make available tools for their build-up, running, management and mutual communication. The system was designed as modular, consisting of the core and work modules. The system core focuses on overall management and provides a library of classes for build-up of the work modules, their user interface and data communication. The work modules carry practical implementation of algorithms and data structures for the solution of a particular problem, and were implemented as dynamic-link libraries. They are mutually independent and run as individual threads, communicating with each other via a unified mechanism. The environment was designed to simplify the development and testing of new algorithms or applications. An example of implementation for the particular problem of the analysis of two-dimensional (2D) gel electrophoretograms is presented. The environment was designed for the Windows NT operating system with the use of Microsoft Foundation Class Library employing the possibilities of C++ programming language. Available on request from the authors.

Windows Remote Control for the Philips CM Microscope

New software has been developed to make it possible to control the CM microscope under Windows. The software structure is such that all programs communicate through a dynamic link library CMREMOTE.DLL and communication program SECS2.EXE with the microscope (Fig. 1). Due to this structure, the amount of memory required is minimised since functional duplication is avoided, and the remote control handling is simplified because the user programs do not need to handle the complicated communication protocol but instead use simple functions such as Get Alignment and CompuStage Goto Position. Several sets of programs are finished, with further additions planned to replace currently available software running under MS-DOS.Available at the moment is the Windows CM Remote Control package which contains the Windows CM Monitor, a program to read alignments, stigmator settings and mode settings from microscope and store them in a file on the PC. With the file are stored an operator name and comments to allow identification who stored the data and for what reason.

Dynamic link libraries II. Development

We have discussed the advantages to be gained from the use of dynamic link libraries (DLLs) for the development of knowledge based systems for the Microsoft Windows operating system. The implementation aspects are now described, and we provide general directions, background information and a number of fragments of useful code for DLL development. As an illustration, a DLL for classical statistical distributions is developed by writing a set of interface functions for an available C library.

Dynamic link libraries I. Introduction

Many tools for developing knowledge-based systems or for fast prototyping lack the ability to perform complex numerical computations. This disadvantage can be removed if one extends these tools, when running under Microsoft Windows, with dynamic link libraries (DLLs). This paper explains the main advantages and disadvantages of DLLs. The implementation aspects are given in Part II.

Two-dimensional polygon modeling using Windows graphical interface

A practical, user-friendly interface for use in two-dimensional polygon modeling is presented in this paper. The interface is written for the Microsoft Windows environment and modeling is achieved by the interactive creation and manipulation of polygonal bodies on the screen using a mouse. The program makes use of the dynamic link library (DLL) principle to decouple the interface from its response calculation routine. Examples of the interface applied to two-dimensional gravity and magnetic models are given.

Intelligent manufacturing systems (Smart Mechatronics & CIM) at Louisiana State University

The Smart Mechatronics/Intelligent Manufacturing Research initiative at Louisiana State University has designed and implemented an object control model for a simple manufacturing cell. Using object oriented programming and design has allowed the internal program structure (virtual cell space) to closely match the physical cell construction (physical cell space). This paper discusses the second phase of the cell implementation in which the existing C++ objects were implemented as autonomous units under operating system control. The operating system used is Microsoft R Windows™ and Windows for Workgroups™ 3.1. Since each object is autonomous, they can assume the properties of self-monitoring agents in the system rather than simple request servers under the sole control of the calling object. Communication between objects is facilitated by the operating system using dynamic data exchange (DDE) calls or by compiling the module into dynamic link library (DLL) modules. This arrangement of system control architecture increases system autonomy, concurrence, and ease of use for a relatively small overhead penalty.

Virus protection using dynamic linking

Dynamic linking is a concept provided by manmy new operating systems. Besides advantages over conventional linking it provides very interesting techniques for the system programmer, too. After general discussion about dynamic linking this paper demonstrates how dynamic link libraries can be useful for virus protection. A technique for redirecting dynamic link library calls in OS/2 is worked out which is used to implementa virus protection dynamic link library.

Developing an expert system for diagnosis of problem gas chromatographic data

An expert system with a user-friendly interface has been developed to aid in the diagnosis of faulty analysis by gas chromatography as a first step towards totally automated analysis. The system advises users on the identity of faulty components and the possibility of improper operation based on the appearance of the chromatograms that result from the experiment. The knowledge used in this expert system has been assembled into a knowledge domain matrix and was coded using case histories. One case serves as an example: “A leaking syringe will result in loss of signal intensity and the appearance of false peaks due to contamination”, is coded to give two entries in the knowledge domain matrix the cause “leaking syringe” is “True” for both “sensitivity loss” and “syringe related peaks”. The knowledge base can be readily expanded through use of Table Edit and Rule Edit (programs developed in our laboratory). The inference engine (EAengine) can apply forward, backward or mixed chaining strategies to obtain a cause for the symptoms that are observed. The system is written in Microsoft Visual BASIC 2.0 within Window 3.x, calling the inference engine as a dynamic link library (DLL). The user can enter observations easily using a powerful new graphical-based interface. Gas chromatograph operation and control systems that use Windows 3.1 may be in progress at the same time. The diagnostic program may be suspended while a more urgent task is run. Communication between a Varian Star Workstation and this system was realized through the dynamic data exchange (DDE) facilities of the Windows 3.1 shell.

Binding fortran layered earth modeling routines with windows graphical user interface

The paper presents a straightforward approach to using existing FORTRAN code within the Microsoft Windows environment. The approach requires little or no understanding of the internal complexities of the Windows operating system and of the C or C++ languages usually used to write Windows applications. The method makes use of the dynamic link library (DLL) principle introduced in Microsoft Windows. A simple demonstration in resistivity modeling showing the application of the DLL approach also is given.

A universal data acquisition program for use with anesthetic monitors and Windows 3.0

A method is described whereby a single program can acquire data from any patient monitor which has a data output facility. No changes are necessary to the program for different monitors. It provides a method of standardizing data transfer between computers and monitors. The program runs in the Microsoft Windows 3.0 operating system. It utilizes Dynamic Link Libraries (DLL) which enable the operating system to communcate with monitors. Each kind of monitor will use a unique DLL in order to provide a standard interface to the Windows 3.0 operating system.