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PubMed1986

Developmental changes in visual and auditory contributions to speech perception.

Previous research has demonstrated that listeners make use of both auditory and visual information in bimodal speech perception. Preschool children appear to evaluate and integrate the two sources of information in the same manner as adults, but the children are less influenced by the visual source. The current experiments test a possible explanation of this difference and extend the question to younger children. It is possible that children are poorer lip-readers than adults and thus have less complete information about the visual source. Children and adults were tested with both auditory and visual sources and were also required to identify speech events on the basis of only the visual source. In addition to replicating the previous findings in the bimodal situation, the current experiments found that children are poorer lip-readers than adults. Furthermore, a positive correlation was observed between lip-reading ability and the size of the visual contribution to bimodal speech perception. A fuzzy logical model of speech perception provided a good quantitative description of the results even with the assumption that the visual information was equivalent in both the bimodal and lip-reading conditions. The results also contradict the categorical perception of speech events and any nonindependence in the evaluation of auditory and visual information in speech perception.

Adolescent↗
PubMed2006

3D computerized segmentation of lung volume with computed tomography.

Three-dimensional (3D)-based detection and diagnosis has an important role for significantly improving the detection and diagnosis of lung cancer upon computed tomography (CT). This report presents a 3D-based method for segmenting and visualizing lung volume by using CT images. An anisotropic filtering method was developed on CT slices to enhance the signal-to-noise ratio, and a wavelet transform-based interpolation method was used combined with volume rendering to construct the 3D volumetric data based on entire CT slices. Then an adaptive 3D region-growing algorithm was designed to segment lung volume, incorporated by automatic seed-locating methods through fuzzy logic algorithms and 3D morphological closing approaches. In addition, a 3D visualization tool was designed to view volumetric data, projections, or intersections of the lung volume at any view angle. This segmentation method was tested on single-detector CT images by percentage of volume overlap and percentage of volume difference. The experiment results show that the developed 3D-based segmentation method is effective and robust. This study lays the groundwork for 3D-based computerized detection and diagnosis of lung cancer with CT imaging. In addition, this approach can be integrated into a picture archiving and communication system serving as a visualization tool for radiologists' reading and interpretation.

Algorithms↗
PubMed2001

A new autotuning algorithm for PID controllers using dead-beat format.

A novel algorithm for PID controllers based on dead-beat control and fuzzy inference mechanism is presented in this paper. The proposition is an extension of the work by the authors where the PI form of the algorithm was presented. The inclusion of the derivative term makes the method suitable for application in all types of processes including the ones having high rate disturbances. The proposed algorithm seems to be a complete and generalized PID autotuner as can be seen by the simulated and experimental results. In all the cases the method shows substantial improvement over the controller tuned with Ziegler Nichol's formula and the PI controller proposed in R. Bandyopadhyay, D. Patranabis, A fuzzy logic based PI autotuner, ISA Transactions 37 (1998) 227-235.

Journal Article↗
PubMed2003

Self-tuning adaptive control for an industrial weigh belt feeder.

An industrial weigh belt feeder is used to transport solid materials into a manufacturing process at a constant feedrate. It exhibits nonlinear behavior because of motor friction, saturation, and quantization noise in the measurement sensors. To overcome the nonlinearities, a simple yet effective method of controller autotuning, an indirect self-tuning regulator, was designed and implemented for an industrial weigh belt feeder. Implementation issues are discussed and experimental results show the effectiveness of the adaptive controller for several different reference inputs. Also, the performance of the indirect self-tuning regulator is compared with that of a fuzzy logic controller for the same application.

Journal Article↗
PubMed2004

A new self-tuned PID-type fuzzy controller as a combination of two-term controllers.

The present paper is a venture into the domain of proportional-integral-derivative (PID) -type adaptive fuzzy logic controllers (FLC's) and proposes a new algorithm which is realized by a self-tuned PI-type FLC (in velocity form) in parallel with a self-tuned PD-type FLC (in position form). Each of these PI/PD controllers implements a supervisory static FLC for adaptive online modification of the output scaling factor (SF) of a static PI/PD FLC. The proposed scheme is developed with a view to having a PID-type FLC with an architecture, simple enough for practical implementation, which at the same time has substantially satisfactory performance for a wide class of processes. Simulation studies on a range of processes reveal that the proposed controller has better performance compared to many of its existing counterparts.

Journal Article↗
PubMed2004

Comparison of two approaches to automated PI controller tuning for an industrial weigh belt feeder.

In this paper, two advanced PI controller tuning methods, unfalsified control and fuzzy control, are applied to an industrial weigh belt feeder that has significant nonlinearities. Both methods do not require an explicit plant model. The advantage of the unfalsified PI control design method is that it is able to directly incorporate multiple performance criteria, while the advantage of fuzzy logic is that it is able to directly incorporate human reasoning in the design process. Experimental results exhibit the effectiveness of both control methods. A detailed comparison of the two approaches is given in the areas of allowed design specifications, process knowledge requirements, computational requirements, controller development effort, transient performance, and the ability to handle motor saturation.

Journal Article↗
PubMedDate not supplied

Models to predict the intensity of Plasmodium falciparum transmission: applications to the burden of disease in Kenya.

There is an increasing need to provide spatial distribution maps of the clinical burden of Plasmodium falciparum malaria in Africa. Recent evidence suggests that risk groups and the clinical spectrum of severe malaria are related to the intensity of P. falciparum transmission. Climate operates to affect the vectorial capacity of P. falciparum transmission and this is particularly important in the Horn of Africa and parts of East Africa. We have used a fuzzy logic climate suitability model to define areas of Kenya unsuitable for stable transmission. Kenya's unstable transmission areas can be divided into areas where transmission potential is limited by low rainfall or low temperature and, combined, encompass over 8 million people. Among areas of stable transmission we have used empirical data on P. falciparum infection rates among 124 childhood populations in Kenya to develop a climate-based statistical model of transmission intensity. This model correctly identified 75% (95% confidence interval CI 70-85) of 3 endemicity classes (low, < 20%; high, > or = 70%; and intermediate parasite prevalences). The model was applied to meteorological and remote sensed data using a geographical information system to provide estimates of endemicity for all of the 1080 populated fourth level administrative regions in Kenya. National census data for 1989 on the childhood populations within each administrative region were projected to provide 1997 estimates. Endemicity-specific estimates of morbidity and mortality were derived from published and unpublished sources and applied to their corresponding exposed-to-risk childhood populations. This combined transmission, population and disease-risk model suggested that every day in Kenya approximately 72 and 400 children below the age of 5 years either die or develop clinical malaria warranting in-patient care, respectively. Despite several limitations, such an approach goes beyond 'best guesses' to provide informed estimates of the geographical burden of malaria and its fatal consequences in Kenya.

Child, Preschool↗
PubMed2006

Tumor markers in detection of lung cancer.

The expression of biomarkers by lung cancers is useful in the diagnosis and clinical management of patients with lung cancer. Biomarkers provide insight into histogenesis, interrelationships, and biological behavior of lung tumors. This chapter presents data on lung cancer detection, involving some of the most studied and interesting lung cancer biomarkers to date-CYFRA 21-1, NSE, ProGRP, SCC, CEA, Tumor M2-PK, as well as markers in clinical application such as CRP, LDH, tumor-suppressor genes and oncogenes, CA125, CgA, NCAM, and TPA. Biomarker profiles in combination with fuzzy logic techniques have also been addressed. Serum markers used alone or in combination with other indices might play an important role in monitoring response to therapy in early detection of tumor reactivation in new treatment strategies as well as in secondary prevention.

Biomarkers, Tumor↗
PubMed2000

Biomass Production System (BPS) plant growth unit.

The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses its own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive.

Air Conditioning↗
PubMed2000

A fuzzy-neural system for identification of species-specific alarm calls of Gunnison's prairie dogs.

In this study we describe the design and application of an automated classification system that utilizes artificial intelligence to corroborate the finding that Gunnison's prairie dogs have different alarm calls for different species of predators. This corroboration is strong because it utilizes an entirely different analysis technique than that used in the original research by Slobodchikoff et al. [Slobodchikoff, C.N., Fischer, C., Shapiro, J., 1986. Predator-specific alarm calls of prairie dogs. Am. Zool. 26, 557] or in subsequent study done by Slobodchikoff et al. [Slobodchikoff, C.N., Kiriazis, J., Fischer, C., Creef, E., 1991. Semantic information distinguishing individual predators in the alarm calls of Gunnison's prairie dogs. Anim. Behav. 42, 713-719]. The study described here also is more completely automated than earlier study in this area. This automation allowed a large volume of field data to be processed where all measurements of relevant parameters were performed through software control. Previous study processed a smaller data set and utilized manual measurement techniques. The new classification system, which combines fuzzy logic and an artificial neural network, classified alarm calls correctly according to the eliciting predator species, achieving accuracy levels ranging from 78.6 to 96.3% on raw field data digitized with low quality audio equipment.

Journal Article↗
PubMed2001

Process control and scale-up of pharmaceutical wet granulation processes: a review.

In this paper the techniques for process control and scale-up of pharmaceutical wet granulation processes are reviewed. For wet granulation in high-shear mixers, specific methods based on the liquid saturation and the consistency of the wet mass are described. Both parameters can be used to quantify the deformability of the wet granules, and relate well with the particle size of the end granules. In practice, the power consumption of the high-shear mixer is used for the monitoring of the wet granulation process, whilst for scale-up, it is helpful to use the underlying relationship between power consumption and saturation level or wet mass consistency. In fluid bed granulation the granulation process is different and the moisture content in the bed is the key parameter to control. This can be monitored directly by near infrared probes or indirectly with temperature probes. As a large number of inter-related variables can be adjusted to modify the process, computerized techniques have become popular for fluid-bed process control--fuzzy logic, neural networks, and models based on experimental design techniques are several examples. In addition, engineering techniques based on particle size population balance modelling are under development for both fluid bed and high-shear granulation.

Particle Size↗
PubMed1997

[Signal processing in electromyography: a review].

Automatic analysis of electromyography (EMG), signals, first operated in 1950 with analogic machines, steeply expanded from 1980 when fast computers and worthwhile programs became available. On-line measurement of response area and latency, averaging of low amplitude waves, fast sorting of motor unit potential shape parameters, computation of the "jitter" between two muscle fibers, turns/amplitude and spectral analysis of interferential pattern records, are some examples of programs currently offered in modern EMG machines. Other techniques are still reserved for research purposes: scanning EMG, decomposition of nerve and muscle compound potentials, measurement of the threshold and firing rate of motor units, trace analysis using tracking models. Finally, the credit for artificial intelligence systems (knowledge based systems, fuzzy logic, neuronal networks) is still not clearly stated.

Artifacts↗
PubMed1999

Computer evaluation of left ventricular wall motion by means of shape-based tracking and symbolic description.

Relevant cardiac pathologies manifest themselves as abnormal movements of left ventricular (LV) myocardial wall. An objective quantification is usually accomplished by computer analysis of temporal sequences of LV contours, as obtained by angiography or echography. However the choice of the reference system for measuring motion is still open to discussion. Simple geometric models cannot deal with the non-uniform myocardial fibre structure, which gives rise to non-rigid movements, asynchronous even in normal subjects. Therefore, a new method, Curvature-Motion (CM), was developed for improving motion assessment. Since LV contour shape and position change smoothly throughout the cardiac cycle, the points of curvature extremes are tracked frame-to-frame and selected by exploiting physiologically-based assumptions; then, the points lying among these landmarks are mapped onto sequential contours, according to local displacements and curvature changes. In this way point-trajectories are allowed to be curvilinear and different in systole and diastole. CM gave no significant differences in estimating the known motion of computer-generated contours (R=0.88), unlike other methods commonly adopted (R<0.80). Moreover, for the evaluation of regional wall motion of a preclassified set of angiographic contours, CM showed a greater specificity (88%) and accuracy (90%) with respect to the centre-line method (respectively 83% and 87%). Finally, a fuzzy logic inference system is proposed for translating significant motion patterns from the quantitative form, as provided by the analysis method, into the linguistic terms used by cardiologists in their clinical examinations. This makes the interpretation of quantitative analysis easier and allows medical users to interact with the system for searching particular properties in a single clinical report as well as in a large database.

Algorithms↗
PubMed1999

Speechreading: illusion or window into pattern recognition.

In the Fuzzy Logical Model of Perception (FLMP) perceivers are conceptualized as forming perceptual judgments by evaluating and integrating multiple ambiguous sources of information, in an optimal manner based on relative goodness of match. This model has been tested favorably against a variety of competing theories and models. Recent extensions of the FLMP are described in this article along with empirical applications and verification, and progress in the study of speech perception by ear and eye is reviewed within this general theoretical framework. The model illuminates the differences that are observed across different languages in terms of information as opposed to information-processing. Pattern recognition of bimodal speech is representative of pattern recognition in a variety of other domains, such as emotion perception, and there are several domain-dependent reasons why multimodal presentation of audible and visible speech is particularly conducive to accurate pattern recognition. We believe that the positive outcome of this research provides a framework for the development of computer-animated agents, which can serve as language tutors and as conversational characters in other domains, easing the interaction of humans and machines.

Journal Article↗
PubMed1999

Knowledge-based design and operation of bioprocess systems.

Almost twenty years have passed since the first applications of the knowledge-based approach to bioprocess operations were reported. During this period, approaches such as fuzzy logic, artificial neural network modeling, expert systems and genetic algorithms have been extensively studied and successfully used in the design and control of various bioprocesses. The recent development of these approaches in the design and operation of biological processes is summarized and reviewed, especially focusing on the studies reported in biochemical engineering journals.

Journal Article↗
PubMedDate not supplied

Clavulanic acid degradation in Streptomyces clavuligerus fed-batch cultivations.

Clavulanic acid (CA) is an important antibiotic that is produced by Streptomyces clavuligerus. CA is unstable and product degradation has turned out to have a major impact on product titers in fed-batch cultivations. Three different types of experiments have been used to elucidate CA degradation under fed-batch cultivation conditions. First, the influence of individual medium compounds was examined. Second, degradation was monitored during the exponential growth phase in batch cultivations. Third, CA degradation was studied in the supernatant of samples taken during a fed-batch. In addition, data from six fed-batch cultivations were studied to derive information about CA degradation during the production phase. These cultivations were based on a mineral medium, containing glycerol, glutamate, ammonium, and phosphate as the main nutrients. The ammonium concentration had a large influence on the degradation rate constant. In addition, either changes in the substrate availability or high concentrations of ammonium or glycerol cause a major increase in the degradation rate constant. Finally, a linear and a fuzzy logic model were made to predict CA degradation rates in these fed-batches.

Biodegradation, Environmental↗
PubMed2000

Structural analysis of transition metal beta-X substituent interactions. Toward the use of soft computing methods for catalyst modeling

Fuzzy logic and neural network techniques are used to classify intramolecular interactions between transition metals (M) and beta-X substituents in the following structural motif (LnMC(alpha)(A1)(A2)-C(beta)(B1)(B2)X). These interactions are relevant to the direct polymerization of functionalized olefins by Ziegler-Natta (ZN) catalysis. The efficiency and effectiveness of different soft computing techniques are compared. These methods give not only encouraging results with respect to general data mining issues but also insight into the factors that effect interactions between transition metals and beta-X substituents.

Journal Article↗
PubMed1991

Audiovisual investigation of the loudness-effort effect for speech and nonspeech events.

There is some evidence that loudness judgments of speech are more closely related to the degree of vocal effort induced in speech production than to the speech signal's surface-acoustic properties such as intensity. Other researchers have claimed that speech loudness can be rationalized simply by considering the acoustic complexity of the signal. Because vocal effort can be specified optically as well as acoustically, a study to test the effort-loudness hypothesis was conducted that used conflicting audiovisual presentations of a speaker that produced consonant-vowel syllables with different efforts. It was predicted that if loudness judgments are constrained by effort perception rather than by simple acoustic parameters, then judgments ought to be affected by visual as well as auditory information. It is shown that loudness judgments are affected significantly by visual information even when subjects are instructed to base their judgments only on what they hear. A similar (though less pronounced) patterning of results is shown for a nonspeech "clapping" event, which attests to the generality of the loudness-effort effect previously thought to be special to speech. Results are discussed in terms of auditory, fuzzy logical, motor, and ecological theories of speech perception.

Adult↗