Logical sensor systems

Journal ArticleMulti-sensor systems require a coherent and efficient treatment of the information provided by the various sensors. We propose a framework the Logical Sensor Specification System, in which the sensors can be abstractly defined in terms of computational processes operating on the output from other sensors. Various properties of such an organization are investigated, and a particular implementation is described

Sensitivity of the Physical Database Design to Changes in Underlying Factors

Several articles have reported on the optimization of the complete physical database design or significant parts of it. However, few results are available on the sensitivity of the physical database design to change in underlying factors that influence the design decisions. Such tenths would be of significant practical value in both the design of the initial physical database and its subsequent restructuring. This paper considers underlying factors related to logical data structure, queries, computer system and physical implementation. An experimental design based on these factors is developed and experiments are conducted to determine the sensitivity effects, and these are reported and discussed

Description of the control system design for the SSF PMAD DC testbed

The Power Management and Distribution (PMAD) DC Testbed Control System for Space Station Freedom was developed using a top down approach based on classical control system and conventional terrestrial power utilities design techniques. The design methodology includes the development of a testbed operating concept. This operating concept describes the operation of the testbed under all possible scenarios. A unique set of operating states was identified and a description of each state, along with state transitions, was generated. Each state is represented by a unique set of attributes and constraints, and its description reflects the degree of system security within which the power system is operating. Using the testbed operating states description, a functional design for the control system was developed. This functional design consists of a functional outline, a text description, and a logical flowchart for all the major control system functions. Described here are the control system design techniques, various control system functions, and the status of the design and implementation

Aircraft systems architecting: a functional-logical domain perspective

Presented is a novel framework for early systems architecture design. The framework defines data structures and algorithms that enable the systems architect to operate interactively and simultaneously in both the functional and logical domains. A prototype software tool, called AirCADia Architect, was implemented, which allowed the framework to be evaluated by practicing aircraft systems architects. The evaluation confirmed that, on the whole, the approach enables the architects to effectively express their creative ideas when synthesizing new architectures while still retaining control over the process

COSO Internal control - integrated framework: Guidance on monitoring internal control systems, Volume III: Examples

https://egrove.olemiss.edu/aicpa_assoc/1462/thumbnail.jp

The Design and Implementation of the RPC Device Drivers

The RPC project group is investigating high performance communication network interface structures which are compatible with existing operating systems, in this instance SunOS 4.1 Unix. The use of parallel processing in the marshalling and unmarshalling of RPC arguments together with direct I/O to and from the user's data area and early scheduling of user processes, are expected to give a higher throughput than more traditional implementations. The network front end comprises PC based TRAM's. The Unix machine is a Sun SPARC1+ running SunOS 4.1.3. The interconnection between the two systems is by the SCSI bus. To implement this structure requires a kernel device driver to act as a bridge between the Unix environment on the SPARC station and the TRAM's in the PC. This report describes the structure and implementation of this device driver, showing the design adopted to provide multiple rpc interfaces over a single SCSI bus

Formal verification and co-simulation in the design of a synchronous motor control algorithm

Mechatronic systems are a class of cyber-physical systems, whose increasing complexity makes their validation and verification more and more difficult, while their requirements become more challenging. This paper introduces a development method based on model-based design, co-simulation and formal verification. The objective of this paper is to show the applicability of the method in an industrial setting. An application case study comes from the field of precision servo-motors, where formal verification has been used to find acceptable intervals of values for design parameters of the motor controller, which have been further explored using co-simulation to find optimal values. The reported results show that the method has been applied successfully to the case study, augmenting the current model-driven development processes by formal verification of stability, formal identification of acceptable parameter ranges, and automatic design-space exploration

Accessing files in an Internet: The Jade file system

Jade is a new distribution file system that provides a uniform way to name and access files in an internet environment. It makes two important contributions. First, Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Jade is designed under the restriction that the underlying file system may not be modified. Second, rather than providing a global name space, Jade permits each user to define a private name space. These private name spaces support two novel features: they allow multiple file systems to be mounted under one directory, and they allow one logical name space to mount other logical name spaces. A prototype of the Jade File System was implemented on Sun Workstations running Unix. It consists of interfaces to the Unix file system, the Sun Network File System, the Andrew File System, and FTP. This paper motivates Jade's design, highlights several aspects of its implementation, and illustrates applications that can take advantage of its features