Large-Scale Network Topological Optimization

A cost-effective structure for a large network is a multilevel hierarchy consisting of a backbone network and a family of local access networks. The backbone network is generally a distributed network, while the local access networks are typically centralized systems. In special cases, the network may consist primarily of either centralized or distributed portions. This paper discusses topological design problems for such systems, including the concentrator location problem, the terminal assignment problem, the terminal layout problem (the constrained minimum spanning tree problem), the distributed network topological layout problem, and the backbone node location problem. Recent algorithm research, including exact and heuristic problem solutions, are described and computational experience is given. Finally, open problems in large-scale topological design are reported.     

Light Scattering by Commercial Sugar Solutions

Using a direct measure of scattered light, it was found that commercial sugar solutions scatter light predominantly in a forward direction. The scattering at angles less than 30° was as much as one hundred times that at right angles to the incident beam.It was found that the light scattering by commercial sugar solutions is inversely dependent on wavelength to a power of between 2 and 3, and that severe multiple scattering occurs when the turbidity of the solution is larger than 2×10⁻¹cm⁻¹ at 436 mµ. The scattering of commercial sugar solutions is compared with that of highly purified sucrose.A method is discussed that will enable a good approximation of the turbidity of commercial sugar solutions to be made from a single forward scattering measurement at an angle of about 20° with respect to the incident light beam. A correction for scattered light in transmission measurements of these solutions is also introduced.     

LOCA hydroloads calculations with multidimensional nonlinear fluid-structure interaction

A methodology for realistically analyzing three-dimensional fluid-structure interaction effects and the resulting hydrodynamic loads during the subcooled portion of a hypothetical loss of coolant accident (LOCA) in a pressurized water reactor (PWR) is discussed. The methodology uses a hydrodynamic computer program, STEALTH 3D, coupled with a structural response program, WHAMSE 3D, to calculate the dynamic interaction of fluid and structure during a reactor vessel blowdown. This coupled program is user oriented and highly versatile in modeling the various components in complex reactor systems. Assessment of the methodology is provided by STEALTH/WHAMSE 3D calculations of blowdown tests in the German Battelle-Frankfurt RS-16B facility (Test DWR5) and the HDR facility (Test V31.1). The calculations are described and the results compared with experimental data. Agreement between the calculational results and experimental data is extremely good.     

Freezing point behavior of the ternary reciprocal salt pair system involving the morpholine and 2,2′-dipyridylamine salts of stearic and palmitic acids

Binary and quasi-binary freezing point data have been obtained to establish the freezing point diagram for the ternary reciprocal salt pair system, involving the morpholine and 2,2′-dipyridylamine salts of stearic and palmitic acids. The diagram shows that there are six crystallization surfaces representing equilibrium with crystals of MS, MP, DS, DP, DS·DP, and MS·DP. The compositions and primary freezing points of the six peritectic and five eutectic mixtures have been determined. From the diagram it is possible to predict for any molten mixture of these four salts under equilibrium conditions the temperature at which crystals of each component will appear on cooling, the yields of these crystals and the composition of the liquid phase at various temperatures, and the temperature at which maximum yields of crystals of the specific salts can be obtained. Presented at AOCS meeting in New Orleans, La., May 7–9. 1962. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S.D.A.     

Chlorophenols from wood preservatives in broiler house litter

A survey of fresh shavings from 32 commercial broiler houses for 2,3,4,6-tetra-and pentachlorophenols has shown levels of 4 to 307 parts/million (mean 53) and 1 to 83 parts/million (mean 12), respectively. Most of this was lost during the period of growth of the chickens, residual levels of 0 to 5.6 parts/million (mean 0.7) and 0 to 4.1 parts/million (mean 0.3), respectively, being present in the spent litter. Only traces of the corresponding anisoles were found in a few samples. Observations on the source of these chlorophenols, their implications in relation to musty taint in chickens and the route by which they are lost from the litter are discussed.     

Team productivity and contradiction of management policy commitments.

What is the relationship between management consistency of policy and team productivity? "A simulated small industrial plant was the setting for an experiment in which a team of Ss worked together on a manufacturing problem. Their assigned task was to produce different kinds of toys at a profit… . Twenty four-man teams were divided into ten consecutive team pairs, each member of a pair being subjected either to (a) a condition under which the team's expectations of management were contradicted by subsequent events or (b) a condition under which the team's expectations were confirmed. The hypothesis that team productivity would be greater under the confirmation condition was supported by the data. Some theoretical implications of the experiment were suggested." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantifying the effects of psychological interventions on employee job performance and work-force productivity.

Quantifying the economic impact of psychological programs in organizations requires determination of (a) the size and variability of the resulting increase in job performance and (b) the economic value of the increase in job performance. New methods of meta-analysis allow attainment of the 1st of these; and in relation to the 2nd, utility analysis methods provide the ability to translate job performance increases into estimates of the economic value of the program. In the area of personnel selection, many meta-analytic studies have resulted in precise and generalizable estimates of the validity of cognitive ability tests and other selection procedures. Utility analyses show that the job performance increases resulting from use of valid selection methods have substantial economic value. Valid selection produces major increases in work-force productivity. It is concluded that the combined effects of selection and nonselection interventions can be expected to produce substantial increases in workforce productivity. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determining Component Reliability and Redundancy for Optimum System Reliability

The usual constrained reliability optimization problem is extended to include determining the optimal level of component reliability and the number of redundancies in each stage. With cost, weight, and volume constraints, the problem is one in which the component reliability is a variable, and the optimal trade-off between adding components and improving individual component reliability is determined. This is a mixed integer nonlinear programming problem in which the system reliability is to be maximized as a function of component reliability level and the number of components used at each stage. The model is illustrated with three general non linear constraints imposed on the system. The Hooke and Jeeves pattern search technique in combination with the heuristic approach by Aggarwal et al, is used to solve the problem. The Hooke and Jeeves pattern search technique is a sequential search routine for maximizing the system reliability, RS (R, X). The argument in the Hooke and Jeeves pattern search is the component reliability, R, which is varied according to exploratory moves and pattern moves until the maximum of RS (R, X) is obtained. The heuristic approach is applied to each value of the component reliability, R, to obtain the optimal number of redundancies, X, which maximizes RS (R, X) for the stated R.