The problems of fuzzy and qualitative modeling and prediction of dynamic (chaotic) biologic processes are discussed and contrasted. The use of fuzzy logic systems as nonlinear models and predictors is addressed. Sugeno-type fuzzy systems are focussed. The models are based on single-input, single-output fuzzy systems with linear feedback loops. Such systems were previously proved to have a chaotic behavior under certain conditions. Prediction is applied to the logistic growth process. The training of the fuzzy system loop is performed by genetic algorithms. Issues related to the coplexity of the predictors and of the generated time series are also discussed.

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The problems of teaching fuzzy and qualitative theory and methods, in relation to the interest of students in bio-medical engineering, is explored, based on the personal experience.

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Strongly nonlinear multi-variate functions, for example the artificial neural network models, hardly have insights into the local relationships between inputs and outputs. This paper proposes a weakly nonlinear version of Fuzzy c-Regression Models by Hathaway and Bezdek. Min-imization of Lagrangian function yields simultaneous estimates for the parameters of projection pursuit regression models, together with a fuzzy partitioning of mixed data. The data in each fuzzy cluster is projected in a single dimensional space and a latent weakly nonlinear (increasing, decreasing or unimodal) relationship between each independent observation and its corresponding dependent observation can be found. The proposed method is applied to an analysis of psychological feelings for T-shirt patterns.

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A new model of actin myosin system named Stochastic Inclined Rods Model (SIRM), whose energy of motion is supplied from random noise (or thermal noise) and always moves to one direction, has been proposed. SIRM has a simple structure, which is composed of an inclined spring, a myosin head, and bundle of rods. In an open system, the myosin head works as a resonator of random noise, which accepts the energy through a resonance. It is shown that the inclined rod and a spherical shape of G-actin are very important elements for a purpose of breaking symmetric vibration of stochastic resonance (SR) and of generating the one directional motion. When the myosin head interacts with the sphericl potential of G-actin, the trigonometric wave of stochastic resonance is distorted by the collision between the head and G-actin, and after all it obliquely kicks the actin fiber by using the spring. It is thus shown that the inclined rod and the shape of G-actin makes SIRM move to one direction, even if the potentials between the myosin head and G-actin is perfectly symmetric.

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In order to elucidate relation of five enzymes and the susceptibility of stomach cancer and cigarette-smoking, epidemiological studies is performed. We have accumulated the blood sample of the stomach cancer patients and healthy people and analyzed the gene identification by PCR method. There data are analyzed by several statistical methods, i.e., odds ratio calculations, chi-square calculation and logistic regression. From the analysis, we have confirmed a strong correlation of the gene GSTM1 with the stomach cancer. Both calculations of odds ratio and chi-square indicate that the gene is considered with over 95% reliability as an important gene for the stomach cancer. As for the effect of the other genes, the order ot the correlation is obtained as GSTM1 > GSTT1 > NAT1 > GSTP1 > NAT2 from both the odds ratio analysis an chi-square analysis. The analysis of the effect of cigarette smoking as an environmental factor gives a quite interesting result. The logistic regression analysis shows that the people who does not have the gene is easy to raise the susceptibility a little smoking. On the other hand, the susceptibility of the people who has the gene goes down by a little smoking.

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The authors have developed a computer-assisted system for ultrasonography using fuzzy reasoning. The system was constructed to differentiate a metastatic lymph node from an inflammatory one. To construct the system, we set up three fuzzy production rules according to the diagonostic criteria. Futhermore, in order to simulate the experienced clinician's consideration, we referred to the method of analytic hierarchy process (AHP). Consequently, the diagonostic accuracy was improved and the usefulness of the AHP was suggested.

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With regard to the better display of visual stimuli, one of the key parameters to match with human short-term memory is the presentation time of the information. The optimum apportionment of the presentation time of eight randomly-selected Roman alphabet letters sequentially presented through a visual display is determined for four young models by means of our time-continuous model of short-term memory. These apportionments are thought to allow for the easiest retention by short-term memory. The average optimum apportionment, as an average of individual scores of the optimum-apportionment, was also obtained. This apportionment has shown the same tendency as that in the case of eight randomly-selected Roman sounds. That is, the presentation time of the alphabet letters present in the first part is long and presentation time of the alphabet letters presented in the letter part is short. Individual differences in the optimum apportionment appear in the middle part, from the third to seventh alphabet letters, where the presentation time of one or two alphabet letters is longer than that of the previous alphabet letter and the following alphabet letter.

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Contrast enhanced computed tomogram (CT) images of thyroid tumors were analyzed to determine if the heterogeneity could be quantified by a fractal dimension. MATERIALS AND METHODS: Contrast enhanced CT images were obtained after the injection of iodipamide ethyl ester, a vascular marker, into the patient. Nine CT images of the thyroid tumors taken between 1994 and 1995 were used to trace the enhanced inner patterns of the tumors with a pencil allowing calculation of the fractal dimension using the box counting method and the straight line fit method. RESURT. All traced inner figures of the tumors met the requirements for a fractal analysis because all patterns showed self-similarities. The mean fractal dimensions were significantly different between benign and malignant thyoid tumors. CONCLUSIONS. Fractal dimension measurement provides a new means to examine the enhanced inner images of thyoid tumors using the box counting method in contrast enhanced computed tomograms. This may prove useful in understanding and quantifying the pathophysiologic changes in thyoid tumors.

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This paper describes about image retrieval system which can treat each user's subjective interpretation. ART MUSEUM is our prototype system for advanced image database. It allows users to retrieve images from a database of impressionist paintings by using adjective words. The system learns the correlation between the feature of sample paintings and user's descriptions, and provides interactive and progressive learning mechanisms. We show the interesting experimental results on ART MUSEUM system.

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