Towards an intelligent database system founded on the SP theory of computing and cognition

The SP theory of computing and cognition, described in previous publications, is an attractive model for intelligent databases because it provides a simple but versatile format for different kinds of knowledge, it has capabilities in artificial intelligence, it can function effectively in the face of errors in its input data, and it can function like established database models when that is required.

This paper first describes the SP theory in outline and the computer models in which it is expressed. The main sections of the paper describe, with examples from the SP62 computer model, how the SP framework can emulate other abstract models used in database applications: the relational model (including retrieval of information in the manner of query-by-example, creating a join between two or more tables, and aggregation), object-oriented models (including class-inclusion hierarchies, part-whole hierarchies and their integration, inheritance of attributes, cross-classification and multiple inheritance), and hierarchical and network models (including discrimination networks). Comparisons are made between the SP model and those other models.

The artificial intelligence capabilities of the SP model are briefly reviewed: representation and integration of diverse kinds of knowledge in one versatile format; fuzzy pattern recognition and recognition at multiple levels of abstraction; best-match and semantic forms of information retrieval; various kinds of exact reasoning and probabilistic reasoning; analysis and production of natural language; planning; problem solving; and unsupervised learning. Also considered are ways in which current prototypes may be translated into an ‘industrial strength’ working system.     

Effects of polyacrylamide‐co‐acrylic acid on cellulose production by Acetobacter xylinum

Polyacrylamide‐co‐acrylic acid (PA) added to shake flask cultures of Acetobacter xylinum at concentrations up to 3 g dm^?3 resulted in increased production of bacterial cellulose. For PA concentrations of 0–3 g dm^?3, 7‐day cellulose production rose monotonically from 2.7 ± 0.8 to 6.5 ± 0.5 g dm^?3 at a shaker speed of 175 rpm, and from 1.7 ± 0.01 to 3.7 ± 0.5 g dm^?3 at shaker speed of 375 rpm. Addition of PA also changed the morphology of the biomass from amorphous/stringy forms to spheroidal particles with diameters ≤2 mm. Similarly, bioreactor cultures grown in the absence of PA formed long fibrous masses which deposited on the internals, while those grown in the presence of 1–2 g dm^?3 PA formed small discrete particles with diameters ≤0.1 mm. Tests performed with 1 and 2 g dm^?3 PA, and stirrer speeds from 500 to 900 rpm, appeared to give the highest cellulose concentration of 5.3 ± 0.7 g dm^?3 in 64–68.5 h in the presence of 2 g dm^?3 PA at 700 rpm, although this value was statistically indistinguishable from that obtained at 1 g dm^?3 PA and 900 rpm. A qualitative model is proposed to describe the mechanisms by which PA affects biomass morphology, resulting in its advantageous formation as small, dispersed, spheroidal pellets. Quantitative analysis of the results gave inverse correlations between both the fraction of fructose carbon going to cellulose synthesis and the specific fructose consumption rate, and the maximum cellulose concentration and the fraction of fructose carbon going to by‐product formation. Since cellulose yield was almost universally improved by higher polyacrylamide concentration, it appears likely that increased viscosity reduces fructose uptake rate by limiting mass transfer. Copyright © 2003 Society of Chemical Industry     

WTFM, software for well test analysis in fractured media combining fractional flow with double porosity and leakance approaches

The identification of the hydraulic characteristics and transport properties of fractured reservoirs requires the development of specific models that account for (i) the medium heterogeneity, e.g. the presence of major conductive fractures that delimit capacitive matrix blocks, with weakly open, dead end or isolated fractures, and (ii) for the geometrical arrangement of the major conductive fractures network, which dominates the flow at the scale of the well tests.Well Tests in Fractured Media (WTFM) software takes into account these two main features by combining radial flow generalized to fractional dimension, with the theory of double-porosity, including diffusivity in the second porosity, transient inter-porosity flow and inter-porosity skin effect, and with leakance. The implementation of this nD model, with n fractional, extends usefully the domain of application of the usual 1D/2D/3D double-porosity/leakance models for a large range of connection levels of fracture networks. Although the fractures geometry and properties are not considered one by one, or by directional families, they are taken into account by averaged properties and by the impact that the whole network has on the hydrodynamic behaviour. The accuracy of the coupled transient behaviours analysis is augmented by taking into account wellbore storage and skin effects. All together, the use of these different options allows matching a wide range of pumping test curves, characteristics of distinctive behaviours, with a limited number of parameters. Distinctive well test experiments, in both sedimentary and crystalline rocks, are presented for enlightening how the pertinent use of the model options improves predictions.     

Influence of Head Geometry on Bolted Joint Behavior

Numerical models of single-fastener bolted lap joints are developed in which the effect of the head angle and height on joint elongation are studied for three fastener sizes, three panel materials, and several panel thicknesses. Baseline 100° bolt-head angle numerical models are calibrated and validated with experimental data. These baseline models are then modified to predict the load-elongation behavior of lap joints with five different head angles and four different head heights. The numerical predictions are summarized in graphical form. The results show that the fastener head height has a much greater influence on joint-slip resistance than does the angle, with the shallower heads providing the greatest resistance to joint elongation under load.     

Improved quantitation of minimal residual disease in multiple myeloma using real-time polymerase chain reaction and plasmid-DNA complementarity determining region III standards

The complementarity determining region III of the rearranged immunoglobulin heavy chain gene has been the target for tumor-specific PCR assays for the detection and follow-up of B-cell malignancies. Previously, these assays have relied on gel-based end point data collection methods (i.e., band densitometry) and, thus, have provided at best a semiquantitative assessment of tumor levels. We show the development of a novel, real-time TaqMan PCR assay to quantitate residual multiple myeloma cells in clinical samples after high-dose chemotherapy and autologous stem cell transplantation. We provide evidence that real-time PCR is reproducible, sensitive, and quantitative. In a 40-replicate PCR experiment targeting the beta-actin gene, the coefficient of variation for threshold cycle data was 1.6%, whereas it increased to 13.6% and 31%, respectively, for end point fluorescence and gel densitometry. Moreover, in an experiment directly comparing standard curves obtained from band densitometry and threshold cycle data, the standard curve constructed from threshold cycle data had a multiple R2 value of 1.00 and demonstrated a dynamic range >4 logs, compared with the 2-log linear range of gel densitometry. Finally, we show that when a complementarity determining region III-specific PCR primer is used in conjunction with a consensus primer for the immunoglobulin heavy chain joining gene, plasmid DNA can be used as a readily available and effective substitute for clonal plasma-cell genomic DNA when preparing standards. By applying real-time PCR to the analysis of clinical samples, we are able to quantitate levels of tumor involvement with unparalleled reproducibility and statistical confidence. Real-time PCR technology may well provide the accuracy and reliability necessary for minimal residual disease detection to have real prognostic significance.     

State-space caching revisited

State-space caching is a verification technique for finite-state concurrent systems. It performs an exhaustive exploration of the state space of the system being checked while storing only all states of just one execution sequence plus as many other previously visited states as available memory allows. So far, this technique has been of little practical significance: it allows one to reduce memory usage by only twoo to three times, before an unacceptable blow-up of the run-time overhead sets in. The explosion of the run-time requirements is due to redundant multiple explorations of unstored parts of the state space. Indeed, almost all states in the state space of concurrent systems are typically reached several times during the search.In this paper, we present a method to tackle the main cause of this prohibitive state matching: the exploration of all possible interleavings of concurrent executions of the system which all lead to the same state. Then, we show that, in many cases, with this method, most reachable states are visited only once during state-space exploration. This enables one not to store most of the states that have already been visited without incurring too much redundant explorations of parts of the state space, and makes therefore state-space caching a much more attractive verification method. As an example, we were able to competely explore a state space of 250,000 states while storing simultaneously no more than 500 states and with only a three-fold increas of the run-time requirements.     

The impact of September 11 on psychologists.

A variety of recent research studies have investigated the psychological impact on victims of the devastating events of September 11, 2001. The present study adopted a different approach, instead focusing on the experience of caregivers through a brief survey of state psychological association members. Overall, practitioners described modest but significant changes in both their professional work and their personal lives. Not surprisingly, those respondents working closest to Ground Zero reported the greatest changes. The sample also reported more positive than negative feelings regarding their work in the post-9/11 environment. Although the survey return rate was only 15%, the findings shed light on several important professional issues related to disaster relief, including service utilization, preparedness, and vicarious traumatization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tolerant low-loss three-lens coupling system for 1.48-μmunstable-cavity lasers

A 1.48-μm unstable-cavity laser is coupled into single-mode fiber using three microlenses. Reproducible coupling of very high power is demonstrated with different types of lenses (plano-convex or biconvex, with different apertures). Over 550 mW in single-mode fiber (SMF) were reproducibly reached; to our knowledge, it is the highest power coupled into an SMF from a single semiconductor laser at this wavelength. Tolerance measurements on all of the coupling elements of a three-lens system are reported for the first time; an unexpected very large tolerance an the axial displacement of the second lens was measured. Results and interpretation with the aid of Gaussian and aberration simulations are also presented     

A Markov model of solar energy space and hot water heating systems

This paper presents a Markov model approach to the generalized solar energy space heating performance analysis problem. Specifically, Markov chain models are developed to represent ambient temperature, insolation, hot water load and system performance. From the Markov transition probability matrices for these variables, long-term expected performance is calculated. The theoretical development is implemented in FORTRAN IV on a Control Data 6400 Computer System. Computational experience gained, using STOLAR 3.1 (STOchastic soLAR energy systems model), indicates the stochastic approach requires approximately five per cent of the time necessary for standard dynamic simulation approaches with comparable performance results. The method also compared favorably with FCHART, a simplified design procedure.     

L-dopa repairs deficits in locomotor and investigatory exploration produced by denervation of catecholamine terminal fields in the forebrain of rats.

In a previous study by the authors (see record 1980-27512-001), rats were shown to have decreased locomotor and investigatory exploration after bilateral microinjections of 6-hydroxydopamine (6-OHDA) into the anterolateral hypothalamus. Theses deficits correlated with the loss of catecholamine (CA) terminals in neocortical, limbic, and anteromedioventral striatal brain sites. To test whether this correlation was causal, central CAs were increased in 2 experiments with male Sprague-Dawley rats by the ip injection of levodopa (10–40 mg/kg) after inhibition of extracerebral levo-amino-acid decarboxylase. Such treatment repaired the deficits in locomotor exploration and investigation in 6-OHDA Ss. Pretreatment with the CA antagonist chlorpromazine (1–2 mg/kg) blocked the increase in locomotor exploration and investigation produced by levodopa in 6-OHDA Ss. Results suggest, but do not prove, that levodopa produced these behavioral effects by increasing central CAs at the denervated CA receptor sites in the forebrain. Data are complementary evidence for the hypothesis that forebrain CA synaptic action is necessary for normal exploratory behavior. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)