Relative permeability measurements for two phase flow in unconsolidated sands

This paper presents the results of laboratory measurements of relative permeability for two phase flow in partially saturated samples of unconsolidated sands. Relative permeabilities for tap water and air, de-aired water and nitrogen were measured using a steady—state technique. Three different sand samples (fine sand, heterogeneous sand and coarse sand) were tested.     

Designing the world we live in

Engineering designers, who decide the physical shape and technical features of the built world, tend to forget that their predecessors have been making design decisions for hundreds of years. This paper gives several historical examples of design experience which can supply useful insights today, because the essential nature of engineering has not changed.Adapted from: Eugene S. Ferguson,Engineering and the Mind's Eye. Cambridge, Massachusetts: MIT Press, 1992     

A general identification technique for nonlinear differential equations of motion

This paper develops and demonstrates by computer simulations new nonlinear system stochastic techniques to determine the amplitude-domain and frequency-domain properties of nonlinear systems as described in nonlinear differential equations of motion. From measurements of input excitation data and output response data, this new method, based upon multiple-input/single-output (MI/SO) linear analysis of reverse dynamic systems, allows for the efficient identification of different nonlinear systems. Nonlinear systems simulated here include Duffing, Van der Pol, Mathieu, and Dead-Band systems. Features of this new method are: (1) it can be implemented using established MI/SO linear procedures and computer programs; (2) it determines nonlinear system amplitude properties separate from nonlinear system frequency properties; (3) it quantifies relative contributions from different nonlinear terms by using appropriate coherence functions; (4) it gives results that are independent of the input or output probability distributions, spectral properties, and input excitation levels.     

Recursive optimal pruning with applications to tree structuredvector quantizers

A pruning algorithm of P.A. Chou et al. (1989) for designing optimal tree structures identifies only those codebooks which lie on the convex hull of the original codebook's operational distortion rate function. The authors introduce a modified version of the original algorithm, which identifies a large number of codebooks having minimum average distortion, under the constraint that, in each step, only modes having no descendents are removed from the tree. All codebooks generated by the original algorithm are also generated by this algorithm. The new algorithm generates a much larger number of codebooks in the middle- and low-rate regions. The additional codebooks permit operation near the codebook's operational distortion rate function without time sharing by choosing from the increased number of available bit rates. Despite the statistical mismatch which occurs when coding data outside the training sequence, these pruned codebooks retain their performance advantage over full search vector quantizers (VQs) for a large range of rates.     

Film-Flow Mechanism of Flaw Development in Penetrant-Dye Tests

A new mechanism of aw development has been discovered and experimentally tested. The mechanism is based on the film ow of the penetrant inside the aw channel.     

School psychologists' acceptability of behavioral and traditional assessment procedures for externalizing problem behaviors.

A national survey of school psychologists' acceptability of psychological assessment techniques in the area of externalizing problem behaviors was examined. School psychologists' ratings of 2 procedures, Behavioral Assessment (BA) and Traditional Assessment (TA), were compared using an analog case study methodology. Using a random sample of 500 National Association of School Psychologists members from the 1991–1992 membership directory, 339 Ss completed the Assessment Rating Profile after reading a hypothetical case summary describing a student with suspected externalizing problem behaviors. Results indicated statistically significant differences between assessment methods and ratings of acceptability. BA procedures were found to be more acceptable than TA procedures. Implications related to the acceptability of psychological assessment techniques, as well as implications for school psychology practitioners are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A system for recognizing a large class of engineering drawings

We present a system for recognizing a large class of engineering drawings characterized by alternating instances of symbols and connection lines. The class includes domains such as flowcharts, logic and electrical circuits, and chemical plant diagrams. The output of the system, a netlist identifying the symbol types and interconnections, may be used for design simulation or as a compact portable representation of the drawing. The automatic recognition task is divided into two stages: 1) domain-independent rules are used to segment symbols from connection lines in the drawing image that has been thinned, vectorized, and preprocessed in routine ways; 2) a drawing understanding subsystem works in concert with a set of domain-specific matchers to classify symbols and correct errors automatically. A graphical user interface is provided to correct residual errors interactively and to log data for reporting errors objectively. The system has been tested on a database of 64 printed images drawn from text books and handbooks in different domains and scanned at 150 and 300 dpi resolution