Operational characteristics of multi-robot systems with cooperation

Cooperation among robots in multi-robot systems is called MRC (Multi-Robot Cooperation) and is defined by four cooperation modes. Measures of cooperation levels are defined. The design problem of how much cooperation to design is presented, and an analysis is described for systems with 2, 3, 4 and 5 cooperating robots. Production rate and cost effectiveness are used to compare various combinations of systems with and without cooperation. This is part of an extensive study on multi-robot systems characteristics that has been recently completed.     

Linear optimal control of national econometric models

A control optimization approach is developed in this paper for the purpose of investigating the impact of alternative development strategies on the national economy of Egypt. Basic to this approach is the formulation of an aggregate econometric model and the manipulation of its performance as a linear quadratic tracking problem. The model comprises three major sectors ; namely agriculture, industry and services. Data processing and model parameter estimation and implementation are performed for the period 1961–1976 and further projected to the period 1976–1980. In light of the assumptions made, the obtained results are interpreted and found to be satisfactory.     

SCHEDULING OF NONSERIAL LINEAR PROJECTS WITH MULTIPLE NON-OVERLAPPED LOOP STRUCTURES

Existing dynamic programming formulations are utilized for the scheduling of serial linear projects. These formulations cannot, however, be used for the scheduling of nonserial linear projects. The intent of this paper is to present a nonserial dynamic programming formulation for the scheduling of linear projects with multiple non-overlapped loop structures. The objective of the nonserial dynamic programming solution is to provide for the selection of resources, interruptions, and lags for production activities that lead to the minimum project duration. The advantages of this nonserial dynamic programming approach include its ability to handle work interruption and variable production rates. In addition, the developed system produces a graphical representation of the project schedule of minimum duration. A nonserial linear project is treated herein using the proposed method.     

Apparatus and instruments for the laboratory study of multi–anchored flexible retaining walls

Details are presented of the apparatus and instruments developed for the study of the behaviour of laboratory scale multi–anchored flexible retaining walls. The instruments enabled measurements to be made of the earth pressures on and the bending moments in very flexible walls. The shearing and thrust forces at wall base level and the individual anchor wire loads, as well as the movements of the wall and the retained sand, were also monitored throughout a simulated wall construction sequence.     

BACTERICIDAL EFFICIENCIES OF COMMERCIAL DISINFECTANTS AGAINST LISTERIA MONOCYTOGENES ON SURFACES

The efficiencies of potassium persulphate, isopropanol, hydrogen peroxide and peracetic acid, quaternary ammonium compound, hypochlorite, sodium dichloroisocyanurate, ethanol and phenol derivatives, tertiary alkylamines and dimethyl alamine betaine-based disinfectants and a hypochlorite-based disinfecting cleaning agent were evaluated against eight Listeria monocytogenes strains representing three different ribotypes. All the disinfectants were effective in a suspension test with an exposure time of 30 s at the lowest concentrations recommended by the manufacturer. The efficiencies on surfaces were reduced. However, on clean surfaces all the agents were considered effective when the exposure time was 5 min and the concentration was the average recommended by the manufacturer. Five of nine disinfectants and the disinfecting cleaning agent were considered effective in soiled conditions in the surface test. The most efficient agent was isopropanol-based and the least effective was the disinfectant containing tertiary alkylamine and dimethyl alamine betaine. Differences in bactericidal efficiencies of disinfectants against different L. monocytogenes strains on meat soiled surfaces were found.     

Textural Properties of Extruded Plant Protein Blends

Blends of corn gluten meal and soy protein concentrate in the ratio of 25:75, 50:50 and 75:25 w/w were made up. The blends at 20, 30 and 40% moisture content (db) were extruded at 145°C through 4.24, 3.0, and 2.12 mm diam dies at screw speeds of 60, 120, and 180 rpm to generate different shear environments. Multiple nonlinear regression analysis was used to develop models of bulk density, puff ratio, water-holding capacity and shear strength as a function of moisture content and shear rate. Shear rate affected the dependent variables most. Cooked and uncooked viscosity and product color were also measured. Electron micrographs confirmed some of the findings.     

Ultraviolet Radiation Affects Physical and Molecular Properties of Soy Protein Films

Films were cast from heated, alkaline aqueous solutions of soy protein (5 g/100 mL water) and glycerin (50% w/w of protein). Control and ultraviolet (UV) irradiated (13.0, 25.9,38.9, 51.8, 77.8, or 103.7 J/m²) films were evaluated for tensile strength (TS), elongation at break (E), water vapor permeability (WVP), and Hunter L, a, and b color values. TS increased (p<0.05) linearly while E decreased linearly with UV dosage. WVP was not affected (P>0.05) by UV irradiation. UV treatment intensified the yellowish coloration of films (increased +b values). SDS-PAGE patterns for UV-treated samples revealed bands of aggregates, increasing in intensity with UV dosage, which were absent in control samples. These changes suggested UV-induced cross-linking in films.     

FREEZING OF COOKED MEAT: INFLUENCE OF FREEZING RATE AND RECONSTITUTION METHOD ON QUALITY AND YIELD

The combined effects of freezing rate, frozen storage and reconstitution method on meat quality and yield were studied in multifactorial experiments using pan-fried 1.5 cm slices of longissimus muscles and deep-fat fried meat patties. On the whole, a slight improvement in sensory quality and yield was seen with increasing freezing rate, except that liquid nitrogen immersion freezing influenced flavor negatively. In contrast with earlier results of ours with raw beef, an advantage was now seen for reconstitution after previous thawing over reheating directly from the frozen state, and pan frying gave better sensory quality but lower yield than continuous microwave reheating. Tenderness of sliced, cooked beef tended to increase during frozen storage, while the opposite was earlier observed for frozen raw beef. Otherwise, a general trend was seen towards decreasing yield and sensory quality during frozen storage. A number of significant interactions between variables was obtained, suggesting that their influence on quality and yield is interrelated in a rather complex manner.