Integrating scheduling and control functions in computer integrated manufacturing using artificial intelligence

Proper integration of scheduling and control in Flexible Manufacturing Systems will make available the required level of decision-making capacity to provide a flexibly-automated, efficient, and quality manufacturing process. To achieve this level of integration, the developments in computer technology and sophisticated techniques of artificial intelligence (AI) should be applied to such FMS functions as scheduling. In this paper, we present an Intelligent Scheduling System for FMS under development that makes use of the integration of two AI technologies. These two AI technologies — Neural Networks and Expert Systems — provide the intelligence that the scheduling function requires in order to generate goodschedules within the restrictions imposed by real-time problems. Because the system has the ability to plan ahead and learn, it has a higher probability of success than conventional approaches. The adaptive behavior that will be achieved contribute to the integration of scheduling and control in FMS.     

Yeast exo-β-glucanases can be used as efficient and readily detectable reporter genes in Saccharomyces cerevisiae

Yeast exo-1,3-β-glucanases are secretable proteins whose function is basically trophic and may also be involved in cell wall glucan hydrolytic processes. Since fluorescein di(β-D -glucopyranoside) is a fluorogenic substrate detectable and quantifiable by flow cytometry, it was used for testing the ability of the EXG1 gene product of Saccharomyces cerevisiae and its homologous gene in Candida albicans to function as reporter genes. These open reading frames were coupled to different promoters in multicopy plasmids, and exoglucanase activity quantified at flow cytometry. Exoglucanases were found to be useful tools for the study of promoter regions in S. cerevisiae. This technique has the advantage over other reporter gene systems—such as β-galactosidase fusions—that it does not require permeabilization of yeast cells and therefore it allows the recovery of viable cells—by sorting—after flow cytometry analysis.     

The Los Alamos beacon receiver array

Describes radio receivers that monitor transmissions from beacons on geosynchronous satellites. The receivers can detect ionospheric perturbations of a 300-3000 s period in the electron density integrated from beacon to receiver, for amplitudes as low as (1-2)×10¹³ m^-2. Data are used in studies of atmospheric acoustic and acoustic-gravity waves     

Longitudinal investigation of the abstinence violation effect in binge eaters.

This study, guided in part by G. A. Marlatt and J. R. Gordon's (1985) abstinence violation effect (AVE) model, examined whether variability in cognitive and emotional reactions to binges accounts for recurrence of binge eating. Attributional, cognitive, and affective reactions to 2 successive binges, as well as the latencies between each binge and a subsequent binge, were evaluated through a series of structured phone interviews with 50 nonpurging normal-weight female bingers. Reported mood after binging was unrelated to binge latency. However, when Ss made more intense internal, global, and uncontrollable causal attributions for a binge, a subsequent binge followed significantly sooner. Within-subject variations in AVEs across binges prospectively predicted within-subject variations in the speed with which another binge followed. Analyses suggested that cognitive states (e.g., AVE and guilt) evoked by particular events were better predictors of how quickly binging repeats than were stable differences in attributional style. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 2.2 W, 80 MHz superscalar RISC microprocessor

A 28 mW/MHz at 80 MHz structured-custom RISC microprocessor design is described. This 32-b implementation of the PowerPC architecture is fabricated in a 3.3 V, 0.5 μm, 4-level metal CMOS technology, resulting in 1.6 million transistors in a 7.4 mm by 11.5 mm chip size. Dual 8-kilobyte instruction and data caches coupled to a high performance 32/64-b system bus and separate execution units (float, integer, loadstore, and system units) result in peak instruction rates of three instructions per clock cycle. Low-power design techniques are used throughout the entire design, including dynamically powered down execution units. Typical power dissipation is kept under 2.2 W at 80 MHz. Three distinct levels of software-programmable, static, low-power operation-for system power management are offered, resulting in standby power dissipation from 2 mW to 350 mW. CPU to bus clock ratios of 1×, 2×, 3×, and 4× are implemented to allow control of system power while maintaining processor performance. As a result, workstation level performance is packed into a low-power, low-cost design ideal for notebooks and desktop computers     

Electrochemical study of 7α,12,20-O-trimethyl-conacytone in acetonitrile

An electrochemical study of the electroreduction in anhydrous acetonitrile of 7α,12,20-O-trimethyl-conacytone, an abietane quinoid diterpene derivative from the natural product 7α-O-methyl-conacytone, showed two reduction signals. At the first reduction step, fast chemical reactions involving the loss of the methoxyl group located at C-7 with simultaneous regeneration of the quinoid moiety were observed. This electrogenerated quinone is reduced again, at the same potential used with the former quinone, resulting in a two-electron peak. These results were obtained by cyclic voltammetry and double-step chronoamperometry experiments. The electrolysis under methylating conditions of 7α-O-methyl-conacytone, at potential values of the second electron transfer, generates as major products, methoxy-hydroquinone, where the methoxy group at C-7 is lost, which is in agreement with the proposed mechanism. Therefore, the second reduction signal was attributed to the reduction of semiquinone intermediates by a mechanism not elucidated.     

Process heat integration of a heavy crude hydrotreatment plant

The present paper focuses on the study of process alternatives for heat integration of a heavy crude oil hydrotreatment plant. Experimental information obtained from a pilot scale, kinetics and reactor modeling tools, and a commercial process simulator were employed to develop mass and energy balances. Four study cases, which employ a combination of quenching and heat exchangers, were identified and evaluated. The results indicated that the case with two quenches with hydrogen and three heat exchangers is the best process heat integration (PHI) option from an energetic point of view.     

A Study of Ozone Generation by Negative Corona Discharge Through Different Plasma Chemistry Models

The Steady radial distribution of chemical species in a wire‐to‐cylinder ozone generator filled with pure oxygen has been computed by applying four different plasma chemistry models of increasing complexity. The most complete model considers ten species (e, O₂ ⁺, O₂ ^?, O₃ ^?, O^?, O₂, O₂(¹Δ_g), O₂(¹∑_g ⁺), O and O₃) and 79 reactions, including ionization by electron impact, electron attachment and detachment, electron-ion recombination, charge transfer, etc. The chemical model is coupled with the electrical model through Poisson's equation. The spatially averaged ozone density has been computed as a function of the current intensity and compared with the experimental values obtained by UV spectroscopy.     

Rheology of concentrated solutions of hyperbranched polyesters

The solution rheology of different generations of hyperbranched polyesters in N‐methyl‐2‐pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amidoamine) (PAMAM) dendrimers in ethylenediamine were compared with those of the hyperbranched polyesters in NMP. Both types of dendritic polymers have relative viscosities that are exponential functions of their molar fraction in solution. The slopes of these relative viscosity curves show a linear relationship with respect to the generation number. PAMAM dendrimers have the greater slopes for each generation, reflecting their relatively larger intrinsic viscosity values.