A ROUGH SET/FUZZY LOGIC BASED DECISION MAKING SYSTEM FOR MEDICAL APPLICATIONS

Abstract

A method of performing prognostic modeling of disease states is proposed. The technique uses rough sets to extract rules from a database. The data is then reformatted into a fuzzy logic template, and a learning algorithm is used to adjust the fuzzy set membership functions. The method is applied to the POSCH problem, which looks at risk factors associated with the progression of coronary artery disease. The POSCH data has several shortcomings, including a limited number of cases, correlated inputs, as well as noise on both the inputs and outcome. The problem was to predict progression of atherosclerosis in the LAD three years after baseline based on physiologic data available at baseline. The proposed rough/fuzzy set method correctly predicted progression of atherosclerotic disease in 69% of the patients, which is statistically better than neural network, rough set and logistic models performed.     

An assessment of a FMICW ground-wave radar system for ocean wave studies

In February 1982 the first successful trial of a frequency modulated, interrupted, continuous wave (FMICW), monostatic ground-wave radar for sea backscatter studies was carried out. Since then data have been collected in a number of different meteorological conditions over a range of HF frequencies. The data are presented and compared with simulated Doppler spectra obtained by evaluating the integral equation, which relates the sea backscatter spectrum to the ocean wave directional spectrum (Barrick 1972). The dynamic range performance of the system is as good as or better than has been achieved by pulse radars currently in operation. Good agreement with the theoretical formulation is demonstrated     

An agile manufacturing workcell design

This paper introduces a design for agile manufacturing worked Is intended for light mechanical assembly of products made from similar components (i.e., parts families). We define agile manufacturing as the ability to accomplish rapid changeover from the assembly of one product to the assembly of a different product. Rapid hardware changeover is made possible through the use of robots, flexible part feeders, modular grippers, and modular assembly hardware. The division of assembly, feeding, and unloading tasks between multiple robots is examined with prioritization based upon assembly time. Rapid software changeover will be facilitated by the use of a real-time, object-oriented software environment utilizing graphical simulations for off-line software development. An innovative dual VMEbus controller architecture permits an open software environment while accommodating the closed nature of most commercial robot controllers. These agile features permit new products to be introduced with minimal downtime and system reconfiguration.     

IMPROVED ESTIMATIONS OF TOTAL AND PSYCHROTROPHIC MICROFLORA IN RAW MILK USING REFLECTANCE COLORIMETRY AT 32°C1

A reflectance colorimeter with 32°C incubation/detection temperature successfully quantitated total and psychrotrophic microflora in raw milk. Correlations between reflectance colorimetry and the Standard Plate Count improved with preliminary incubation time: .50 (no preliminary incubation), .74 (24 h at 7°C), to .84 (48 h at 7°C). Correlations between reflectance colorimetry and the Psychrotrophic Bacterial Count were better than those achieved with the Standard Plate Count and improved: .53 (no preliminary incubation). 80 (24 h at 7°C), to .91 (48 h at 7°C). The 48 h preliminary incubation method would cost less and data would be available in 48 to 72 h compared to the 98 to 240 h for psychrotrophic plating methods. A second sample set (no preliminary incubation) could be analyzed to identify high-count samples in less than 24 h. Color detection times following sample refrigeration for 24 h at 0, 4. and 7°C were significantly different from samples tested before refrigeration. Identical sample time/temperature storage conditions are suggested     

Quantification of the 3D microstructure of SC surfaces

This study presents the development of an ImageJ plugin for surface characterization. Based on gradient analysis, parameters, such as the gradient magnitude, orientation, mean resultant vector and surface area are derived. A comparative study of supercalendered (SC) papers was performed to verify the surface representations yielded by a laser profilometer. The surface representations of samples covered with carbon and gold were compared to untreated samples. The results confirm the suitability of gold coating for reducing the artefacts encountered on laser profilometry surface representations of paper. In addition, a complete scanning electron microscopy analysis is performed on the assessed samples to quantify the surface fraction covered by mineral fillers and to reveal the true 3D microstructure of SC surfaces. The influence of filler coverage and filler type on the gloss level of commercial SC papers is evaluated. The relationship between the surface topography, gloss and PPS roughness for a series of commercial SC papers is established.     

Electrical Resistance of Liquid Sulfur to 420°C and of Liquid Selenium to 700°C

The electrical resistance of liquid sulfur was measured from just below the polymerization temperature to the vaporization point. Turning points in the resistance vs temperature curve, resulting presumably from polymerization and depolymerization, and a sharp decrease in resistance at 212°C agree well with previous results. Between ∼230° and 420°C, the resistance decreased without discontinuity. The resistance of selenium increased sharply by 3 orders of magnitude on melting and then decreased steadily by 5 orders of magnitude until the experiment was ended at 700°C. In both liquids, the electrical resistance as a function of temperature decreased more rapidly than that of an ideal intrinsic semiconductor whose molecular structure is stable over the temperature interval investigated. This rapid decrease is believed to result from chain dissociation and ring scission.     

Reaction of Sodium with Ionic Conductors Containing P-O Bonds at Elevated Temperatures

Sodium phosphate and a series of compounds containing Na, Zr, Si, P, and O were found to react with sodium at 380°C. The reaction products formed phosphine on hydrolysis. On the basis of these reactions and some thermodynamic calculations, it is not likely that any materials containing P-O bonds will be stable to sodium at the temperatures required for the Na-S battery or Na heat engine operation.     

Precipitation in LiF-MgF2 Solid Solutions

Precipitation was studied for LiF single crystals containing up to 4 wt% MgF₂. Replica electron microscopy observations, combined with hardness and lattice parameter measurements, showed that, irrespective of the level of MgF₂, precipitation consistently occurs during quenching. Rapidly cooled crystals with lower MgF₂ concentrations (<1 wt%) develop large cruciform particles of a metastable phase with approximate composition MgF₂-6LiF. Lower cooling rates or higher MgF₂ contents caused transformation of these metastable particles to rod-shaped stable MgF₂ phase. This occurs via nucleation on the metastable crosses. The large misfit between the LiF matrix and the MgF₂ phase causes development of an incoherent interface and an associated disturbance of a propagating crack was observed near each MgF₂ particle.