A Realtime Programming Language and its Application for Measuring Processes

Presents a framework to define a semantics for a real-time object-oriented programming language and to verify programs written in the language. The semantics is defined as the collection of translation rules that map the syntactic constructions of the language into expressions in a process calculus extended with the notion of time. By using the expressive capabilities of the calculus, the semantics can appropriately capture temporal features of the language such as timeout exception and execution time, and concurrent object-oriented features such as concurrency, class, and object creation. Particularly, since it can restrict the number of concurrent activities which take place simultaneously, it allows one to analyze and predict the temporal and behavioral properties even of programs executed with a number of processors smaller than the number of active objects. Through an example, we illustrate a method of analyzing real-time programs. >

Concurrent C (ConcC) [1] is a relatively new language that extends the C programming language [2] by incorporating multitasking facilities. These facilities are mainly based on the bidirectional rendez-vous concept, and they offer flexible and efficient mechanisms for the specification of concurrency, communication and synchronization often required in real-time systems. However, as for most real-time and concurrent programming languages such as Ada [3], the description of multitasking facilities in ConcC is lacking a rigorous and formal semantical definition. Most existing introductory materials to ConcC by its authors are informally described, and cannot be easily understood. In this paper, we explain the semantics of multitasking facilities in ConcC using the Petri net model. As is well known, the Petri net model is a formal graphical model that can describe concurrent behaviours of systems in a natural and intuitive manner, and yet it is based on strong mathematical and semantical foundations. Timed, inhibitor arc and predicate Petri nets are extensions that are used to enhance the expressive power of the basic Petri net to model and explain all ConcC multitasking features.

Competing supply chain networks all around the globe are under scrutiny due to ever-growing demand for service improvement and cost reduction. A major field of action in this respect is the realization of real-time monitoring means for supply chain processes including a constant comparison of the respective progress status with the planning guidelines and the best possible management of deviations and exceptions. Control towers have been named as the future tool of supply chain monitoring for quite a while. They are defined as decision-support systems merging different data streams from various subordinate levels and displaying the consolidated information at a higher level for the purpose of monitoring and control of processes while pursuing the goal of optimal process operation. Contrary to the technological constraints of the past which prevented a continuous and fully transparent real-time monitoring of supply chain processes, innovative evolving so-called Future Internet technologies enable genuine transparency and the handling of exceptions in a timely and cost-efficient manner nowadays. With the help of such technologies, newly designed and built control towers are supposed to assist actors on the planning and execution levels of their respective supply chain networks in their decision-making in case of relevant deviations or exceptions. This again raises the market acceptance of such control towers. This paper presents a novel approach to the functional principle of Future-Internet-based control tower solutions and describes the different components therein. Especially, the incorporation of manifold information sources from the Future Internet technologies for the purpose of real-time monitoring and control of supply chain processes is highlighted in the paper.

Coral 66 was developed as a real-time programming language nearly twenty years ago. Its syntax took account of the computer architecture of the time and the compilers, which were developed over a decade ago, reflect the same standard of architecture. So it is not surprising that the portable Coral cross-compilers of today do not make use of the powerful instructions available. This paper discusses some extensions to the Coral syntax, to allow easy recognition of those constructs that can be performed efficiently by today's processors.

The design of a kernel-level thread package for dynamic, hard real-time environments is presented. A highly integrated design is used to ensure predictability. A system description language and real-time programming language are used to specify key properties of threads and thread groups. For a thread, this includes whether or not the thread spawns other threads at run-time, the type of performance guarantee the thread requires, how the thread interacts with other threads, and what processors the thread may execute on. A predictable kernel uses this information along with on-line dynamic guarantees to ensure predictable execution of threads. The first phase of the thread package has been implemented and performance measurements have indicated a 66% improvement in context switching costs.

Real-time image processing is widely used in multi-media systems, virtual reality and simulation, and remote command and control. Unfortunately, there is no standard language to support image processing in a real-time framework. Moreover, it is unwise to assume that other real-time programming languages can support the specialized needs of image processing.

Hundreds of programming languages are in use todayscripting languages for Internet commerce, user interface programming tools, spreadsheet macros, page format specification languages, and many others. Designing a programming language is a metaprogramming activity that bears certain similarities to programming in a regular language, with clarity and simplicity even more important than in ordinary programming. This comprehensive text uses a simple and concise framework to teach key ideas in programming language design and implementation. The book's unique approach is based on a family of syntactically simple pedagogical languages that allow students to explore programming language concepts systematically. It takes as its premise and starting point the idea that when language behaviors become incredibly complex, the description of the behaviors must be incredibly simple. The book presents a set of tools (a mathematical metalanguage, abstract syntax, operational and denotational semantics) and uses it to explore a comprehensive set of programming language design dimensions, including dynamic semantics (naming, state, control, data), static semantics (types, type reconstruction, polymporphism, effects), and pragmatics (compilation, garbage collection). The many examples and exercises offer students opportunities to apply the foundational ideas explained in the text. Specialized topics and code that implements many of the algorithms and compilation methods in the book can be found on the book's Web site, along with such additional material as a section on concurrency and proofs of the theorems in the text. The book is suitable as a text for an introductory graduate or advanced undergraduate programming languages course; it can also serve as a reference for researchers and practitioners.

Early generic concepts in programming languages were mixed-type arithmetic (e.g., “+” used with any combination of fixed-and floating-point numbers) and “print” functions which could be applied to any of a language's objects. Generic concepts reduce the number of terms which must be remembered and permit considerable condensation of language design. Three different paths in the development of generic-concept languages have been followed by APL, Algol 68, and object-oriented languages such as SIMULA 67 and Smalltalk. APL was the earliest and one of the most interesting applications of generic-concept methods, but now makes the weakest use of these ideas. My talk will use slides and movies to show how the message-object programming system Smalltalk makes use of generic concepts embedded in class descriptions to give rise to a wide variety of simply programmed dynamic simulations including graphic animation, music synthesis, document layout and retrieval, and APL-like calculation features. Many of these systems have been brought to life by child and adult novice programmers. A short list of references is given for those wishing more introductory information about Smalltalk.

Batch-to-batch reproducibility of animal cell cultures can significantly be enhanced using process control procedures. Most informative signals for advanced process control can be derived from the volume fractions of oxygen and carbon dioxide in the vent line of the reactors. Here we employed simple low-cost sensors, previously not considered for off-gas analysis at a laboratory-scale cell cultures, and compared them with a simultaneously used quadrupole mass spectrometer, i.e., the standard equipment. A decisive advantage is that the sensors did not need any calibration and are easy to use. We show that monitoring and advanced control of cell cultures can significantly be simplified using the devices tested here and that the same batch-to-batch reproducibility can be obtained with much less effort than before.

Christopher Strachey’s paper on Fundamental Concepts in Programming Languages is being published here for the first time. Written in the autumn of 1967, it is based on the lectures given by Strachey at an International School in Computer Programming, held in Copenhagen in August 1967. Strachey intended the paper to be published in the proceedings of the School—but the proceedings never materialized, and Strachey’s paper has remained an unpublished preprint for more than three decades. It is, however, one of Strachey’s most significant and lengthy papers; widely circulated in the original typescript version, it has also been highly influential. Strachey’s paper starts with some philosophical remarks about the need to focus on semantic issues in the design of programming languages, and to “recognise and isolate the central concepts—things analogous to the concepts of continuity and convergence in analysis”. Strachey then proceeds to give a clear and incisive exposition of many of his insights into programming language design and formal semantics, covering the following main topics: r assignment commands, Land R-values; r expression evaluation and environments; r commands and sequencing; r modes of parameter-passing and variable binding; r functions and routines as data items; r types and (parametric) polymorphism; and r compound data structures and pointers.

article Free Access Share on Values and objects in programming languages Author: B. J. MacLennan Naval Postgraduate School, Monterey, CA Naval Postgraduate School, Monterey, CAView Profile Authors Info & Claims ACM SIGPLAN NoticesVolume 17Issue 12December 1982 pp 70–79https://doi.org/10.1145/988164.988172Online:01 December 1982Publication History 43citation121DownloadsMetricsTotal Citations43Total Downloads121Last 12 Months27Last 6 weeks14 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Abstract. This paper presents a completeness result, with respect to a possible world semantics, for a combination of a first-order temporal logic and neighbourhood logic. This logic was considered by Qiu and Zhou (1998, Proceedings of the PROCOMET ‘98 , pp 444–461) to define semantics of a real-time OCCAM-like programming language.

Part 1 Computers in control systems: historical development digital computer interfacing structure of a digital control loop interface units data representation and aliasing. Part 2 The z-transformation: definition of the z-transform z-transform properties inverse z-transform pulse of z-transfer functions of systems discrete approximations numerical integration pole-zero mapping modified z-transform multi-rate sampling systems analysis of multi-rate systems fast-slow multi-rate systems closed-loop multi-rate systems. Part 3 Analysis of sampled-data control systems z-transformation of systems stability in discrete systems time domain analysis root locus analysis frequency domain analysis. Part 4 Digital compensator design: continuous domain design digital design digital root locas design state feedback design digital PID control disign deadbeat response design optimal control design controller design in the presence of noise. Part 5 Real-time computer control systems: hardware requirements the digital computer and peripheral equipment the real-time clock interface units software aspects controller implementation programming languages system design co-ordination sampling rate selection and quantization errors computer/device communications interrupt handling multi-tasking and background/foreground. Part 6 Advances in computer control: artificial intelligence expert systems examples of expert systems knowledge based systems in control engineering conventional controller design methods manual control methods fuzzy sets and rule-based control basic fuzzy operations fuzzy relations fuzzy control algorithms parallel processing techniques parallel computers algorithms for parallel (MIMD) computers programming parallel computers performance of parallel computers parallel processing in control engineering matrix algebra numerical integration fault tolerance. Appendices: Table of laplace and z-transforms continuous second-order systems response specifications frequency response characteristics the transputer and occam occam overview transputer systems and occam configuration vibration control of a flexible cantilever system simulation modelling and state estimation controller design user interface solutions.

The total functional real-time data-flow programming language Sig features a core layer with elegant denotational semantics, in terms of Mealy stream transducers and coiterative causal stream functions, that is convenient for domain experts in the primary application domains, such as scientific modeling and digital music and event arts. The core suffices for the implementation of many basic signal processing components. For the expression of more sophisticated computations, a second layer of Sig provides additional features, namely higher-order functional programming and multi-rate synchronicity, reducible by transformational semantics to the core layer. Here we describe the design of the upper layer of Sig and demonstrate its usage with the Shepard Tone, a well-known sound synthesis problem and model of psycho-acoustically paradoxical perception of relative musical pitch.

This paper presents an overview of the design of a real-time programming language whose purpose is to permit an inexperienced programmer to quickly and efficiently implement control of multiple, parallel industrial processes. The programming language is compiled on one microprocessor-based system and then executed on another. The language divides the program logic into two types: (1) combinational logic which requires both fast and frequent execution, and (2) sequential logic which is more powerful but proceeds more slowly. A discussion of the language design, development, syntax, and semantics is presented.