Conditional composition

Generalizing the notion of function composition, we introduce the concept ofconditional function composition and present a theory of such compositions. We use the theory to describe the semantics of a programming language with exceptions, and to relate exceptions to theIF statement.Supported in part by Air Force Office of Scientific Research grant number 91-0070. Now at DEC Systems Research Center, Palo Alto, CA.     

Behaviour of shear connectors under dynamic loads

The details of an experimental investigation of the fatigue strength of stud type shear connectors are described. A new type of test set-up called ‘New Standard Test Method’ has been employed to assess the fatigue strength of an individual shear connector. The results of the fatigue tests are discussed and a simple relationship between the stress range and the number of cycles has been obtained. This relationship is compared to the one obtained by Slutter on the basis of his experiments.     

Geometric abstractions to support disassembly analysis

Determining whether an assembly can be constructed from its components at the design stage potentially reduces downstream assembly problems. This determination can be accomplished by performing a disassembly analysis of the assembly's geometric model. This paper presents two abstractions derived from the assembly's geometric model that can determine the validity of the assembly: (1) the Assembly Topology Graph (ATG); and (2) the set of boundary components. The first abstraction, the ATG, in a graph whose nodes represent the components in the assembly and whose edges represent a non-null interjection of the convex hulls of component pairs. The second abstraction, the set of boundary components, represents components that intersect the boundary (or convex hull) of the assembly. These boundary components are typically the ones most accessible with respect to disassembly. This paper also discusses an algorithm, which utilizes the ATG to determine pair-wise interlocking components. If such component pairs are absent, then the disassembly sequence for the removal of components in the assembly is determined by analyzing the set of boundary components for disassembly. This procedure is repeated until all the components in the assembly are disassembled (for a valid assembly).     

Wireless Industrial Monitoring and Control Using a Smart Sensor Platform

A wireless smart sensor platform (based on patent pending technologies, Ramamurthy ) targeted for instrumentation and predictive maintenance systems is presented. The generic smart sensor platform with "plug-and-play" capability supports hardware interface, payload and communications needs of multiple inertial and position sensors, and actuators, using a RF link (Wi-Fi, Bluetooth, or RFID) for communications, in a point-to-point topology. The design also provides means to update operating and monitoring parameters as well as sensor/RF link specific firmware modules "over-the-air." Sample implementations for industrial applications and system performance are discussed     

State-of-the-art virtual reality hardware for computer-aided design

Virtual reality is an exciting new field, which may offer significant improvements in the efficiency of human-computer interface for a wide variety of computer applications. This paper serves to identify technology developments in virtual reality hardware devices that may allow for development of a more efficient user interface for computer-aided design packages for mechanical design functions. Presented is a survey of the current state of the art in the rapidly changing field of virtual reality hardware devices. The devices are broken down into classes that are related to user interface features that may improve the efficiency of computer-aided design functions. Classes of virtual reality hardware devices are identified needing future research and development to implement the most effective virtual reality computer-aided design interface.     

Performance and portability of an air quality model

We present a portable, parallel implementation of an urban air quality model. The parallel model runs on the Intel Delta, Intel Paragon, IBM SP2, and Cray T3D, using a variety of standard communication libraries. We analyze the performance of the air quality model on these platforms based on a model derived from the parallel communication behavior and sequential execution time of the air quality model. We predict the performance of the next generation air quality models based on this analysis.     

A non-interfering selective disassembly sequence for components with geometric constraints

This paper analyzes the problem of global disassembly of a selected component from a geometrically constrained assembly. The geometric constraints are: (i) spatial constraints due to the three-dimensional geometric interactions between the components in an assembly; and (ii) user-defined constraints, such as grouping of components as subassemblies and directional constraints on component geometry. A new algorithm has been proposed to determine a non-interfering disassembly sequence for a selected component, minimizing the number of simultaneous component removals. The algorithm analyzes both the spatial constraints of the assembly geometry and the user-defined constraints in evaluating the accessibility of components, which is followed by determining the topological disassembly ordering of the components to evaluate an optimal sequence. Preliminary implementation results of the algorithm for a geometrically constrained assembly are presented.     

Aqueous-phase biofunctionalized NH2-MIL-53(Al) MOF for biosensing applications

Journal of Porous Materials - Here, we synthesize an amino-based metal–organic framework (MOF) encompassing NH2-MIL-53(Al) in water using chemical stirring at room temperature. The pendent...     

On the Identification Device Management and Data Capture via WinRFID1 Edge-Server

In this paper, we present a layered architecture and approach for creating a high performance edge server called reader coordinator (RC) for managing variety of automatic identification hardware such as radio frequency identification (RFID) reader, RFID printer, sensor, barcode scanner, or a controllable device (e.g., programmable logic controller). A unique hardware abstraction approach is used to provide device extensibility and manageability. Rule-based device configuration and control which allows the real-time changing of system behavior is presented. Various data encoding schemes used to accommodate data captured by a device and used as the input of rule based data filtration and aggregation are discussed. We discuss a mechanism of building self-governed automation processing in the data capture process. Performance is measured by using virtual reader that generates high volume of data at high speed. The measurement shows the RC is capable of handling such data.     

Selective disassembly for virtual prototyping as applied to de-manufacturing

Selective disassembly involves separating a selected set of components from an assembly. Applications for selective disassembly include de-manufacturing (maintenance and recycling), and assembling. This paper presents a new methodology for performing design for selective disassembly analysis on the CAD model of an assembly. The methodology involves the following three steps: (i) identifying the components to be selectively disassembled for de-manufacturing by a software program or designer, (ii) determining an optimal (e.g. minimal cost) disassembly sequence for the selected components that involves a computationally efficient two-level reduction procedure: (a) the determination of a set of sequences with an objective of minimal component removals via a wave propagation approach that topologically order components in an assembly for selective disassembly, and (b) the evaluation of resulting sequences based on an objective function (e.g. minimal cost) to identify an optimal sequence, and (iii) Performing disassembly design decisions based on the evaluated optimal sequence. Preliminary implementation results of the selective disassembly methodology in sequencing and disassembly cost evaluation, and application of the selective disassembly technique for de-manufacturing assessment are presented.