ACM SIGAda Ada Letters

Kerner, Judy

doi: 10.1145/181468.181469pmid: N/A

Hirasuna, Michael

doi: 10.1145/181468.181470pmid: N/A

An approach to derive an Object-Oriented Design (OOD) from a simplified Structure Analysis (SA) is presented. The approach is demonstrated with the BATCES problem statement defined by the Object Oriented Work Group (OOWG) CRA92. Unlike other methodologies, the simplified SA/OOD is targeted specifically for Ada. Assuming that Ada is self-documenting, the approach defines the diagrams and tables that complement the code, and not just repeat the information already there. As demanded by typical Ada customers, special emphasis is placed on requirements tracing.The lack of CASE tools has been the primary argument against an Ada specific methodology. Hence, the approach only uses general productivity tools that can run on today's personal computers. Such an approach is practical because the required diagrams and tables have been greatly simplified.

Carter, Jeffrey R.; Sanden, Bo I.

doi: 10.1145/181468.181471pmid: N/A

A neural network is a computer program structured as a simplified model of a brain. It contains nodes (analogous to neurons) and connections between nodes (analogous to synapses). Neural networks can solve difficult pattern-matching problems. A node sums the inputs it receives from other nodes and passes the result through a transfer function to produce its output. A modifiable weight is associated with each connection. A network is trained on a given training set of inputs. During training, the weights are successively adjusted to produce the desired output.Classical design and implementation of neural networks are based on arrays that hold the node values and connection weights. The control structure consists of nested loops through these arrays. This paper suggests instead an object-based design where the nodes are modeled as objects to be operated on. This design models the conceptual network more closely and makes the software more understandable and maintainable. A generic Ada package representing a neural network is presented in some detail.

Rybin, Sergei I.

doi: 10.1145/181468.181472pmid: N/A

An overall description of the history and current state of the Ada-situation in Russia is presented. Some key details of the situation are outlined. The Moscow State University is proposed as the base organization for international communication and cooperation with the Russian Ada community.

Moore, James W.

doi: 10.1145/181468.181473pmid: N/A

The paper begins by briefly examining the demand for reusable software components and the characteristics of the defense industry which serve to differentiate its needs from those of a broader commercial reuse industry. The approach of providing a single library for defense reuse is examined and discarded. The bulk of the paper examines how a reuse marketplace might be built upon the existence of multiple libraries. The operations of a reuse marketplace are described and possible specializations of libraries are suggested. Finally, the pioneering contributions of a few current efforts are noted.

Schilling, Jonathan L.; Nielsen, Johan Olmütz

doi: 10.1145/181468.181474pmid: N/A

Monitor tasks, also known as passive tasks, are a kind of Ada task that is subject to well-known and very powerful optimization. In most compilation systems that perform this optimization, monitor tasks are identified to the complier by the user, via an implementation-defined pragma. This paper describes an alternate approach, whereby the compiler automatically recognizes and optimizes monitor tasks, without need of a pragma, compiler option, or any other user action. The advantages and disadvantages of this approach are discussed, both in terms of the functional impact to the user and the execution-time efficiency of the optimization.

Briand, Loïc

doi: 10.1145/181468.181475pmid: N/A

The Rate Monotonic Scheduling theory is often presented as the ultimate means for improving dramatically and easily the schedulability of Ada Real-Time systems. To assess its practical impact on Real-Time systems, the behavior of a hard-deadline simulated task set is statstically analyzed in different contexts of scheduling (standard Ada FIFO scheduling or basic priority inheritance) and priority allocation (higher priority to the shorter deadline or to the shorter period).