The integrated academic information management system at Columbia-Presbyterian Medical Center.

Over the past seven years, Columbia-Presbyterian Medical Center has been planning and implementing an integrated academic information management system. Accomplishments to date include establishing an institutional information architecture, installing a campus-wide network of workstations, recruiting the staff needed to develop and implement the system, and developing various applications. This paper presents the rationale and steps involved in these accomplishments, as well as data on use of the system so far.     

Detecting nondeterminacy in parallel programs

Methods and tools for detecting nondeterminacy in programs for shared-memory multiprocessors are discussed. The approach described divides the debugging chore into two phases. The first phase uses tools that automatically detect nondeterminacy to debug synchronization errors, assuming it is decided at the outset to make the parallel program determinate. At the end of this phase, it is known that the program is determinate, that timing differences will not affect results, and the debugging sessions are repeatable. In the second phase, an interactive break-point debugger is used to find arithmetic and logical errors. The proposed tools fall into two groups: those that statically analyze the source program and those that analyze an execution trace of the program     

Evaluating the design of flexible manufacturing systems

Evaluating the design of flexible manufacturing systems is complex. Developing a measure of performance useful for evaluating alternate designs continues to be interesting. Here, total productivity of the system is proposed as an appropriate measure. Specification of parameters based upon strategic considerations for this measure are discussed. Finally, the usefulness of the measure is demonstrated through an example.     

PMMA tacticity and alumina powder dispersion stability

Summary Sedimentation experiments and X-ray photoelectron spectroscopy (XPS or ESCA) analyses have been used to study the effect of poly(methylmethacrylate) (PMMA) tacticity on aluminum oxide powder dispersion stability in a common solvent medium. The relative trends from sedimentation densities, and from surface analyses after solvent washing show that (PMMA) adsorption is greatest with isotactic polymer, where isotactic>atactic>syndiotactic adsorption. These results suggest that surface adsorption and hence dispersion stability can be influenced by polymer chain configuration as well as by chain conformation.     

Two-electrode DFB laser filter used as a wide tunable narrow-bandFM receiver: tuning analysis, characteristics and experimental FSK-WDMsystem

Characteristics of a two-electrode DFB laser filter are studied both theoretically and experimentally. Using a matrix analysis of spontaneous emission, a continuous tuning range of 6.7 Å is achieved by changing both net field gains of the two electrodes. A total discontinuous tuning range of over 10 nm comprising alternating mode jumps and continuous tuning range of 4 Å are measured experimentally. The laser filter presents a FWHM bandwidth of 5 GHz which depends on the optical input power. In addition, it is demonstrated that a DFB laser filter can act as a frequency discriminator/photodetector, i.e., a narrow-band FM receiver, with a uniform bandwidth of 1.5 GHz. Using the two-electrode DFB laser for both transmitter and receiver, a two-channel FSK-WDM transmission system utilizing the discontinuous tuning range is reported. The advantage of such a device is the simplicity as compared to the heterodyne technique     

The superflow state of 3He-B at a diffusive wall. Quasiclassical calculations

We report on first computations considering effects of a rough wall on the counterflow state in superfluid ³He-B for high flow velocities. Using the quasiclassical Green's-function formalism supplemented by the boundary conditions for a diffusive wall, we calculate the order-parameter field and the supercurrent near a container wall for various pressures and temperatures. One of our results is that the current density at the wall as a function of the flow has a maximum at the velocity which is about half of the pair breaking velocity.     

Municipal solid waste conversion to energy

In recent years it has been recognised by an increasing number of nations that there is considerable energy potential within MSW. As a result many countries have established R,D& D programmes to examine methods of exploiting this potential. The IEA's MSW Conversion Activity was set up in 1986 to provide an infrastructure for sharing information and co-ordinating work in this area internationally. This Activity was extended in 1989 and currently a total of 9 nations participate in it.

To cope with the wide scope of the area (encompassing both biological and thermal processing of MSW) the Activity was divided into three subgroups or Expert Working Groups (EWGs). Each of these dealt with a distinct area of expertise:

1. •Downstream effects of source separation and screening of MSW

2. •Sampling and analytical protocols

3. •Landfill gas

In addition to these groups a central secretariat based at Harwell (UK) has provided guidance, established and administered databases of contacts and produced a series of national reports.

This paper describes the achievements of the Activity and discusses work proposed for the future.     

THE OPTIMUM SPEED OF VISUAL INSPECTION USING A RANDOM SEARCH STRATEGY

Choosing a standard speed for visual inspection is difficult using standard work measurement techniques. This paper uses a different approach, taking a model of human functioning in inspection and deriving an optimum speed of working so as to balance the cost of time against the cost of errors. Random search is used as the model and both self-paced and externally-paced conditions are derived for multiple fault types. Optimization using a Golden Section search is used to provide optimum inspection speed.