Software For Such Systems Research Articles

DESIGN AND SYNTHESIS OF TERNARY LOGIC ELEMENTS

The aim of this paper is creating some ternary elements. The threshold element of ternary logic on bipolar transistors and elements of ternary systems based on it are considered. The main disadvantages of this approach are identified. The multi-threshold element of multivalued logic and its specific four-threshold implementation are considered. The scientific nowelty is the using of a multithreshold element of multivalued logic as a basis for constructing elements of ternary systems. It is shown that the advantages of a multi-threshold element of multi-valued logic are a larger number of thresholds of input signals, a larger number of levels that it can distinguish and a larger number of output signals. The implementation of some ternary elements, such as half-adder, disjunction and strong conjunction, is given. The practical significance of obtained results is that the multithreshold element of multivalued logic allows us to use it for synthesis basic elements of ternary logic and use one approach for all of them. Additional practical advantage is that in practice it allows you to build more diverse logical and arithmetic devices with a simplified implementation. The implementation of ternary devices based on threshold logic is a way to create ternary devices that can compete with binary devices in terms of equipment, capacity, operational capabilities, and variety. This, in turn, leads to greater speed and simplification of the structure of devices, as well as increasing the speed of data processing. These advantages are significant in such areas of computer use as intelligent data processing systems, expert systems, decision theory, i.e., where data analysis is performed. Prospects for further research are to use the method of construction and synthesis of nodes of ternary computer systems, based on MTEML. Their optimization, and development of principles of mathematical modeling and software of such systems and their elements is expedient.

An end-to-end framework for safe software development

It is largely recognized that the architectures of embedded systems are becoming more and more complex both at hardware and software levels. Despite the significant advances in the development tools, developing the software of such systems while ensuring their safety is still a difficult task. In this paper, we propose an end-to-end programming framework to ease the development of safe software systems. The programming framework, supported by a proper methodology and workflow, make it possible to design safe/secure software that implements functional requirements while respecting multiple non-functional requirements and mastering architectural complexity, time-to-market and cost. The programming framework is based on five concepts: (1) model-based system engineering: MBSE, (2) design-by-contract approach, (3) formal analysis of models based on symbolic execution, (4) code generation, and (5) static and dynamic code analysis. The effectiveness of the methodology has been demonstrated through multiple use-cases. The framework is realized using CEA LIST (http://www-list.cea.fr/en/) open-source development platforms: Papyrus, Frama-C, and UNISIM-VP. These platforms are results of many research and industrial projects such as FP7-SafeAdapt11SafeAdapt project was funded by the European Commission within the 7th Framework Program under the grant number “608945”., FUI-EQUITAS22EQUITAS project was funded by Bpifrance under call FUI-AAP16 with a contract number “F1312031-Q”., FP7-STANCE33STANCE project was also funded by the European Commission under the ICT theme of the 7th Framework Program with the grant agreement number “317753”., CATRENE-OpenES44OpenES project was funded under the CATRENE Program with the agreement number “CA703–2013”., FSN-SESAM Grids55SESAM Grids is a “Programme d'Investissement d'Avenir” project funded by “FSN-Briques Génériques du Logiciel Embarqué N°3” with contract number “O14830-67155”., and H2020-VESSEDIA66VESSEDIA project is funded by the European Commission under the SEC theme of the H2020 Framework Program with the grant agreement number “731453”..

PARTICULAR CHARACTERISTICS OF TODAY’S MICROELECTRONICS AND MATTERS OF HIGHLY DEPENDABLE AND SECURE CONTROL SYSTEMS DESIGN

Aim. Drawing the readers’ attention to the growing number of industrial disasters, associated damage, increasing human casualties and the connection of this phenomenon with computer-based automation systems. The authors produce arguments regarding the requirement for design technology with extended security features in view of the multifold growth of abnormal natural and industrial effects. The paper describes and analyzes distinctive features of control systems of critical application facilities and consequences of disregarding additional inspection of circuitry and software. Of special note is the growing risk caused by the introduction of unmanned technologies and their mass application in railway and automotive transportation. The paper examines the problems of control systems resilience to faults and external actions depending on the used components. Statistics of industrial disasters are provided, their connection with the indicators of control systems instability is examined. A special emphasis is put on the distinctive features of today’s microelectronic components and the effects of technological progress on the systems’ interference immunity and fault rate. Of note is the growing number of hazardous failures in systems based on 0.13-μm and lower microcontrollers. A significant attention is given to the research of the distinctive features of modern chips, their layout, particularly of the main element of a control system, i.e. the microcontroller and digital signal processor, the influence of the external effects on the chip. The matters related to CMOS layout in microprocessor-based units are considered, the dependance is shown between the rising noise influence and migration to new CMOS technology. Attention is drawn to the requirement to train an appropriate class of specialists able to work with such systems who have not only software engineering skills, but also profound knowledge of physics, fundamentals of control systems design and their stability. Results. A comparative evaluation of stability of 0.5 μm and 130 nm CMOS stability has been conducted. The resultant difference in threshold power of interference is over 4000 times. It is noted that most developers who design software for such systems are mislead by the non-availability of any public information on the fault rate of processing elements from the manufacturing companies. By taking the dependability figures as the main parameter they misjudge the safety integrity level, as instead of the fault rate parameters they erroneously use the microchip’s dependability figures provided by the manufacturer. Additionally, standard methods of improving the safety level used by developers (e.g. redundancy) often prove to be inefficient. Conclusions. Designing highly dependable and safe control systems must take into consideration the distinctive features of today’s computer components given the fact that new generations of modern microchips due to their fault rate characteristics are often unusable in highly dependable system design. It appears to be of relevance improving existing standards and developing new ways of increasing the stability and safety of systems. Also noted is the requirement of maintaining the level of education and awareness of a wide community of developers who work with control systems in transportation, energy, industrial automation, weapon systems, etc. as regards the importance of ensuring the required level of functional safety.

Design and Implementation of System Framework Based on Web

In the current implementation in the form of software,Web-based B/S structure has been a wide range of applications.With the gradual expansion of the scale of software for such systems need to have a good framework to support the development and maintenance processes. Quality system plays an important role in the whole system.This paper describes the design process of a good Web-based system framework from the perspective of practical application.Through practice, this framework can well support large-scale software development and maintenance process, the various types of cost savings for the enterprise.

Modeling and verifying dynamic communication structures based on graph transformations

Current and especially future software systems increasingly exhibit so-called self-* properties (e.g., self-healing or self-optimization). In essence, this means that software in such systems needs...

Reusable software components for accelerator-based clusters

Abstract The emerging accelerator-based heterogeneous clusters, comprising specialized processors such as the IBM Cell and GPUs, have exhibited excellent price to performance ratio as well as high energy-efficiency. However, developing and maintaining software for such systems is fraught with challenges, especially for modern high-performance computing (HPC) applications that can benefit the most from leveraging accelerators. If accelerator-based clusters are to deliver on their initial promise to provide a viable and cost-effective HPC solution to researchers and practitioners, one must find a software solution to lower the barrier to entry for the average user. In this paper, we investigate how a software component based approach can be used to provide a reusable and adaptable architecture for executing HPC tasks on accelerator-based clusters. In our implementation, we leverage the lessons from the software engineering research for component-based layered architectures. Our results indicate that the complexity of developing and maintaining accelerator-based cluster software can be as effectively tamed by solid software engineering approaches as that of software in more traditional domains. Specifically, we were able to reuse 83.6% of our implementation code across different architectures and resource configurations, while achieving the overall execution performance only 1.5% off that of an optimally hand-tuned, albeit non-reusable version.

Constructing a Model-Based Software Monitor for the Insulin Pump Behavior

Modern medical systems undertaking the task of surveillance of patients are safety-critical systems steered by software. Such systems will bring man's life into hazard if they fail to meet patients' requirements; so, adequate reliability of the algorithms and computations used by software of such systems is a matter of concern. The environment of a medical safety-critical system consisting of a patient has safety requirements that should be satisfied by the system. A safety requirement is the one that if it is violated, the system environment will be subject to severe risk. An effective method to verify the algorithms and computations used by software of such systems against safety requirements is to keep the software under surveillance at run-time. This paper aims to present a model-based method to construct a run-time monitor for a safety-critical medical system called Continuous Infusion Insulin Pump (CIIP).

Service-Oriented Development of Fault Tolerant Communicating Systems

Telecommunication systems must have a high degree of availability, that is, a high probability of correct and timely provision of requested services. To achieve this, correctness of software for such systems should be ensured. Application of formal methods helps increase confidence in building correct software. However, to be used in practice, formal methods should be well integrated into existing development process. In this paper, the authors propose a formal model-driven approach to development of communicating systems. The authors formalize and extend the Lyra approach—a top-down service-oriented method for development of communicating systems. Lyra is based on transformation and decomposition of models expressed in UML2. The authors formalize Lyra in the B Method by proposing a set of formal specification and refinement patterns reflecting the essential models and transformations of the Lyra phases. Moreover, this paper extends Lyra to integrate reasoning about fault tolerance in the entire development flow.

An object-oriented approach to software development in C for small embedded systems

This paper is concerned with the development of software for embedded systems which will typically be implemented using a small microcontroller (8051, PIC, HC08 or similar device). It is argued that C remains the most appropriate means of developing software for such systems, and guidelines are presented that allow the use of key object-oriented development techniques with this language. Two additional design techniques are also discussed: these are referred to as Project Header and Port Header. An example is used to illustrate the techniques described in the paper.

Evolution designing of energy accounting intelligent systems

The paper is concerned with evolution design concept of energy accounting intelligent systems. The concept is formulated for creating automated systems for monitoring and accounting of energy resources, as well as hardware and software of such systems. The example of application of evolution designing methodology to designing of energy accounting systems data server is described in this paper.

Compiling java for low-end embedded systems

The production of embedded systems is continuously increasing, but developing reusable software for such systems is notoriously difficult, in particular in the case of low-end embedded systems based on 16-bit or 8-bit processors. We have developed a compilation system for executing Java byte code on low-end embedded systems, and we demonstrate how this system permits object-oriented programming techniques to be used on devices with only a few hundred bytes of RAM and a few kilobytes of ROM.We analyze the execution overheads of using object-orien\-ted programming on low-end embedded systems. Based on the conclusion that memory consumption is the major obstacle, we show how the configuration features and optimizations integrated into our compiler can be used to significantly reduce memory requirements. In particular, we use a novel approach based on Java interfaces to control integration of Java programs with the hardware, and demonstrate how aggressive whole-program optimization can significantly reduce the size of the compiled program.

OBJ-NET: An Object Oriented System Design Tool

Computer-based Systems are used in a wide range of complex systems like automobile assembly lines, power plants, etc. These systems consist of heterogeneous subsystems having a multitude of interactions with other subsystems and environments. Designing software for such systems is a difficult task due to the inherent complexity both at conceptual and implementation levels. When developing a large system, the constituent subsystems may be developed separately. Those subsystems may work well on their own, but may fail to work together with other subsystems and fail to respond to interfacing events. This paper presents OBJ-NET, an object oriented system design tool, which provides a suitable framework for the specification and simulation of complex dynamic systems. The theoretical basis of OBJ-NET is from Category Theory and Petri Nets. OBJ-NET helps users to integrate complex systems by modeling a system as a hierarchy of components. It accepts the flow of control from one set of objects to another and simulates the flow of control among the various components of the system. This will allow a user to validate the correctedness of design and interactively change the design to refine the working of the system. This paper describes the various components of OBJ-NET in detail and illustrates the application of OBJ-NET using, as a working example, the specification and simulation of an Automotive Dashboard System.

Position Kinematics of a Three-Limbed Mixed Mechanism

Although robotics has traditionally focused on the serial chain structures typical of industrial robots, fully parallel structures such as the Stewart Platform have also found considerable industrial use. Actively coordinated mechanisms which have combinations of serial and parallel characteristics have been practically employed, and can be expected to become more important in the future. There has been very little study of the kinematic and static characteristics of these mechanisms which have combinations of the characteristics of fully serial and fully parallel structures. This work addresses the direct and inverse position kinematics of such a hybrid mechanism with combination of serial and parallel structure which has multiple, actively controlled actuators. While not the most general possible configuration, this particular case does include many important features of the general mechanism, and the solution obtained gives useful insight for developing a general theory of forward and inverse kinematics which will be equally applicable to serial, parallel and combination structures. Such a theory is necessary for rational design of hardware and software for such systems.

Safety-critical systems, formal methods and standards

Standards concerned with the development of safety-critical systems, and the software in such systems in particular, abound today as the software crisis increasingly affects the world of embedded computer-based systems. The use of formal methods is often advocated as a way of increasing confidence in such systems. This paper examines the industrial use of these techniques, the recommendations concerning formal methods in a number of current and draft standards, and comments on the applicability and problems of using formal methods for the development of safety-critical systems on an industrial scale. Some possible future directions are suggested.

Formal Methods and Software Safety

The safety of software is becoming increasingly important as computers pervade control systems on which human life depends. Whilst hardware has become significantly more reliable over the years, the same cannot be said of software. This has become more complex and methods to ensure its correctness have been slow in development. One approach is to mathematically verify software in such systems. This paper investigates the industrial use of these techniques, their advantages and disadvantages, and the introduction of standards and their recommendations concerning formal methods in this area. The cost of safety is also considered.

Dynamic adaptation of real-time software

In large, dynamic, real-time computer systems, it is frequently most cost effective to employ different software performance and reliability techniques at different levels of granularity, at different times, or within different subsystems. These techniques may include regulation of redundancy and resource allocation, multiversion and multipath execution, adjustments of program attributes such as time-out periods and others. The management of software in such systems is a difficult task. Software that may be adapted to meet varying performance and reliability requirements offers a solution. A REal-time Software Adaptation System (RESAS) includes a uniform model of adaptable software and provides the tool necessary for programmers to implement algorithms that choose and enact adaptations in real time. RESAS has been implemented on a testbed consisting of a multiprocessor and an attached workstation, and adaptation algorithms have been developed that address the problem of adapting software to achieve two goals: software execution within specified time constraints and software resiliency with respect to computer hardware failures.

New developments in medical microbiology: computer-assisted diagnosis and automated instruments.

Time and accuracy required for diagnosis are two of the most important factors in medical microbiology. Computer-assisted diagnosis is one tool to overcome these problems. The software of such systems, much more than the hardware, is of utmost importance and both have to fulfill several items. 1) High flexibility and integration within the already existing working schemes of the laboratory. 2) Terminals in every laboratory. 3) High speed of calculation. 4) Online data transfer from automated instruments. 5) External terminals on intensive care units. 6) Epidemiological and etiopathological investigations have to be possible at any time. In the laboratory the burden of simple, repeating tasks is diminished, inquiries can be made in a minute and precise information about the epidemiological situation can be gained within a few hours. Thus, calculated antimicrobial therapy depending on the incidence of certain pathogens in given specimens in different departments is possible. In the case of fast-growing bacteria, preliminary reports, including susceptibility testing available within the first 24 h, are possible and will be of great help to the clinician in monitoring the calculated antimicrobial regimen. External terminals will allow continuous flow of data from the laboratory to wards and vice versa.

End-Effector Guidance of Robot Arms

This paper deals with a robotic system in which the end-point is directly controlled. It consists of a remote guidance subsystem and a manipulator with an end-of-arm sensor subsystem. The guidance subsystem transmits and manipulates a laser beam in space, and the sensor detects the beam, sends the information to the robot controller, which, in turn, instructs the manipulator to follow the beam. The possible modifications in the manipulator structure, electronic hardware, and controller software of such systems are discussed. An experimental system consists of a SCARA-type flexible arm was constructed, and the results of the experiments are reported in the paper.

Security in the Nebula computer architecture

The problem of security in multi-function computer systems arises because the software in such systems is too complex to be proven to be correct. Multilevel secure operating systems attempt to deal with this problem by dividing the applications software into separate "tasks" and controlling the ways in which these tasks interact. While the internal behavior of each task still cannot be guaranteed, the security of the system as a whole can be demonstrated, provided the restrictions on task interaction can be enforced.To control the interaction of tasks, it must be possible to isolate each task from undesired examination or interference by other tasks. This isolation is usually accomplished by providing each untrusted task with its own "virtual" environment. The trusted system software and the hardware are responsible for making sure that an untrusted program cannot operate outside its own environment and that the physical resources allocated to establish the virtual environment do not violate the isolation requirements. Communication between these virtual environments is then controlled by the trusted system software.Ultimately, the realization of such an operating system structure produces a quantity of "trusted system software" that still must be verified to insure the security of the system. To practically realize such a system, careful design of the software and hardware is required to minimize the amount of verified code and isolate it from corruption by the unverified system software.The Nebula computer architecture includes a set of mechanisms that are designed to provide the isolation necessary to establish a secure system. Of more practical importance is the fact that these mechanisms will allow valid operations to be identified with minimal overhead and to proceed with minimal interference. These mechanisms are described below under the general headings of virtual addressing, protection states, secure user I/0 and task execution control.

Mini-notes

The appearance of microprocessor based computing systems has put the cost of hardware virtually within the reach of everybody. Software for such systems, however, hasn't even come near matching the ever expanding selection of gear. To help solve the software generation problem, many language processors have been developed. Since the products involved tend to have such restricted environments, these processors are usually run on machines that are much larger than the target processing system. It is quite common to have these processors available on the local time sharing network.