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This paper reviews the features and applications of complex-valued neural networks (CVNNs). First we list the present application fields, and describe the advantages of the CVNNs in two application examples, namely, an adaptive plastic-landmine visualization system and an optical frequency-domain-multiplexed learning logic circuit. Then we briefly discuss the features of complex number itself to find that the phase rotation is the most significant concept, which is very useful in processing the information related to wave phenomena such as lightwave and electromagnetic wave. The CVNNs will also be an indispensable framework of the future microelectronic information-processing hardware where the quantum electron wave plays the principal role.

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Nonlinear electrophysiological synchronization phenomena in the brain, such as event-related (de)synchronization, long distance synchronization, and phase-reset, have received much attention in neuroscience over the last decade. These phenomena contain more electrical than physiological keywords and actually require electrical techniques to capture with electroencephalography (EEG). For instance, epoch filters, which have just recently been proposed, allow us to investigate such phenomena. Moreover, epoch filters are still developing and would hopefully generate a new paradigm in neuroscience from an electrical engineering viewpoint. Consequently, electrical engineers could be interested in EEG once again or from now on.

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Music, to many of us, is an indispensable ingredient of life for some unknown reason. Recently, it has become a quite popular research target for a number of reasons. Like language, it is learned from childhood either passively or actively. Unlike language, it cannot convey any precisely defined meaning but nevertheless can move us and make us happy. Unlike language only a small percentage of people can become truely proficient even in listening. In this survey paper, we look at how music has attracted many researchers who are endeavoring to find out how music attracts so many people from professionals to laymen.

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We have investigated an effect of immobilization of luciferase molecules at the optical fiber end on a bioluminescent reaction. The time dependence of measured count rates of emitted photons has been analyzed by fitting with numerical solution of differential equations including the effect of the product-inhibitor and the deactivation of the luciferase. Through the analysis, we have successfully extracted kinetic constants such as, reaction rate, number of active luciferase molecules, etc. Ratio of active molecules to total luciferase molecules in immobilization was one order of magnitude lower than that in solution. The reaction rate of the bioluminescent process was also different from the one of free luciferase in solution.

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Microelectrode array (MEA) has been widely used for ensemble recording. One of the advantages of MEA recording is its capability of studying correlation between network structures and the ensemble activity-patterns. Simple neuronal networks, from which activities of individual cells can be identified, are promising for this purpose. We have developed a mask-free cell-patterning method named “micropipette drawing”. In this method, a thin hydrogel layer is formed on the surface of MEA substrates, which acts as the support for growth-guidance patterns. Here in this work, we tested whether electrical signals could be detected through this gel layer. Rat cortical neurons were cultured on substrates with guiding patterns. Electrical activities could be detected after 7 days in vitro (DIV) in both patterned and normal cell cultures, though the signal to noise ratio in the normal culture was clearly higher than that in the patterned culture. Frequency analysis demonstrated that the difference of the power spectra between these cultures was particularly significant in high frequency regions. Decreases in high-frequency components were more prominent in the signals obtained from the patterned cultures. This result suggested that the hydrogel layer acted as low-pass filters probably due to its capacitive properties. The next step is to establish a method to form hydrogel layers, which maintain growth-guidance properties and have better frequency characteristics.

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We propose a highly sensitive and real-time odor biosensor by expressing ionotropic odorant receptors of insects into dissociated cultures of neurons of rats. The odorant-gated ion channel structure of insect odorant receptor is expected to allow easy functional expression into cells. The neuronal dissociated cultures of rats have two significant advantages: a long lifetime comparable to rats, i.e., a few years; and amplification ability from weak ionic currents of odorant receptors into easily detectable action potentials of neurons. In the present work, in order to show the feasibility of the proposed sensor, we attempt to express the pheromone receptors of silkmoth, Bombyx mori, into cultured neurons of rats. We demonstrate that 10% of neuronal cells transfected using Lipofectamine successfully expressed pheromone receptors, and that these cells showed significant increase of calcium signals by 50% at the presentation of pheromone.

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The basal ganglia (BG) have important roles in some kind of motor control and learning. Parkinson's disease is one of the motor impairment disease. Recently, to recover a motor severity in patients of Parkinsonism, the stimulus electrode is implanted to the subthalamic nucleus, which is a part of the basal ganglia, and the deep brain stimulation (DBS) is often conducted. However, the effects of the DBS on the subthalamic neurons have not been elucidated. Thus, to analyze the effects of the electrical stimulation on the subthalamic neurons, we conducted the calcium imaging at the mouse subthalamic nucleus. When the single stimulus was applied to the subthalamic nucleus, the intracellular calcium ([Ca²⁺]_i) transients were observed. In the case of application of the single electrical stimulation, the [Ca²⁺]_i arose near the stimulus position. When 100 Hz 10-100 times tetanic stimulations were applied, the responded area and the amplitudes of [Ca²⁺]_i transients were increased. The [Ca²⁺]_i transients were disappeared almost completely on the action potential blockade, but blockade of the excitatory and the inhibitory synaptic transmission had little effects on the responded area and the amplitudes of the [Ca²⁺]_i transients. These results suggested that the electrical stimulation to the subthalamic neurons led to activate the subthalamic neurons directly but not via synaptic transmissions. Thus, DBS may change the activity of the subthalamic neurons, hence, may alter the input-output relationship of the subthalamic neurons

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In this study, I aim to understand morphological changes in dopaminergic neurons of the rat midbrain during early developmental stages and their computational properties in the dendrites. To this end, firstly, I measured morphological details of dopaminergic neurons using an immunochemical double-staining technique. In the viewpoint of the Rall's equivalent-cylinder model, secondly, I tested if the data satisfied one of conditions (3/2 power law) of the Rall's model. On the basis of the experimental data, I next investigated if some branches in the individual dendrites had special selectivity in efficient passive propagation of membrane potentials between the branches of individual cells and different cells. The results show that the Rall's 3/2 power law was not satisfied in many branch points and that among branches of each dendrite, specific selectivity in efficient propagation was not found. In addition, I note an implementation method in which the finite element method is applied to one-dimensional cable model of dendrites and give some numerical examples.

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Mismatch Negativity (MMN) is an evoked potential in response to an acoustical environmental change. Hypothesizing that, for animals to survive, MMN plays important roles in sensing environmental atmosphere, we investigated MMN in the auditory cortex of anesthetized rats in response to changes of frequency and harmony of test tone pulses. We first confirmed in behavioral experiments that rats could categorize consonant and dissonant chords, and thus distinguish this kind of sound feature quality, or ‘qualia.’ In physiological experiments, a surface microelectrode array mapped auditory evoked middle-latency response (P1) and MMN. We found that MMN could be elicited from the difference of qualia between consonant and dissonant chords and that the distributions of chord-elicited MMN were different from those of tone-elicited MMN. In response to pure tones, while middle-latency response (P1) was focally evoked from primary and anterior auditory cortex (A1, AAF), MMN spread toward ventral auditory cortex (VAF) in addition to A1 and AAF. In response to chords, MMN also widely spread over the auditory cortex, yet the largest activation spot was obtained in AAF. We also found an asymmetric property of MMN: Changes from low- to high-frequency tones and from dissonant to consonant chords produced larger MMN. Taken together, MMN in the auditory cortex can be elicited by changes of distinguishable qualia in an asymmetric form, suggesting that MMN reflects a detection of change of particular environmental atmosphere of sounds, which are potentially important for a survival.

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In this study, we propose the EEG phase synchronization analysis including not only the average strength of the synchronization but also the distribution and directions under the conditions that evoked emotion by musical stimuli. The experiment is performed with the two different musical stimuli that evoke happiness or sadness for 150 seconds. It is found that the average strength of synchronization indicates no difference between the right side and the left side of the frontal lobe during the happy stimulus, the distribution and directions indicate significant differences. Therefore, proposed analysis is useful for detecting emotional condition because it provides information that cannot be obtained only by the average strength of synchronization.

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We propose the psychological research and physiological measurements. We used oxyHb as physiological measurements in order to evaluate the emotion of “pleasant-unpleasant”. Concretely, we evaluated the difference in the emotion of “pleasant-unpleasant” from oxyHb of the frontal lobe. The experiment showed that a relation between psychological amount and ⊿oxyHb. Based on the result, we presumed the psychological amount using the multiple regression analysis. As a result, it turned out that we can evaluate the emotion of “pleasant-unpleasant” by fNIRS.

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In this paper, we propose a CMOS image sensor device placed on the brain surface or cerebral sulcus (Fig. 1). The device has a photo detector array where a single optical detector is usually used. The proposed imaging device enables the analysis which reflects a surface blood pattern in the observed area. It is also possible to improve effective sensitivity by image processing and to simplify the measurement system by the CMOS sensor device with on-chip light source. We describe the design details and characterization of proposed device. We also demonstrate detection of hemoglobin oxygenation level with external light source, imaging capability of biological activities, and image processing for sensitivity improvement is also realized.

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In this study we performed the source reconstruction of magnetocardiographic signals generated by the human heart activity to localize the site of origin of the heart activation. The localizations were performed in a four compartment model of the human volume conductor. The analyses were conducted on normal subjects and on a subject affected by the Wolff-Parkinson-White syndrome. Different models of the source activation were used to evaluate whether a general model of the current source can be applied in the study of the cardiac inverse problem. The data analyses were repeated using normal and vector component data of the MCG. The results show that a distributed source model has the better accuracy in performing the source reconstructions, and that 3D MCG data allow finding smaller differences between the different source models.

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We make use of especially visual information though we are using a lot of information among modality in daily life. However, there is a difference between the real world and the perception of visual world. For instance, conscious perception of a briefly presented target can be reduced by a subsequent dot mask that does not touch it. However, the theory of this phenomenon, called Object Substitution Masking (OSM), is not clear. We investigated this issue by examining the effect of OSM on the N170 component of the event-related potential (ERP). As expected, subsequent dot mask significantly reduced accuracy in identifying the target. The N170 amplitude of P4 was also diminished by OSM. It was suggested that OSM is concerned in right posterior parietal cortex.

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In order to study the application of event-related potential (ERP) for performing objective evaluation of food, the ERP was measured when subjectively judging the appearance of food by three-grade scale with the opinion “like”, “favorite” and “more favorite”. Sushi and cooked rice were selected as typical foods. Five pictures of each food that the subjects liked were chosen before measurements, and then were used in opinion tests. As a result, the P300 component of the ERP was detected, and the P300 area (surrounded by ERP waveform from the latency 250 to 500ms) became larger when the subjects judged as “more favorite”, which indicates the feasibility of evaluation of food using the ERP.

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A present massage chair realizes the massage motion and force designed by a professional masseur. However, appropriate massage force to the user can not be provided by the massage chair in such a method. On the other hand, the professional masseur can realize an appropriate massage force to more than one patient, because, the masseur considers the physical condition of the patient. Our research proposed the intelligent massage system of applying masseur's procedure for the massage chair using estimated skin elasticity and DB to relate skin elasticity and massage force. However, proposed system has a problem that DB does not adjust to unknown user, because user's feeling by massage can not be estimated. Then, this paper proposed the estimation method of comfortable/uncomfortable feeling based on EEG using the neural network and k-means algorithm. The realizability of the proposed method is verified by the experimental works.

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Hopfield Associative Memory (HAM) is a typical model of associative memories. Complex-valued Associative Memory is a complex-valued version of HAM. They store not only learning patterns but other undesired patterns, which are called spurious states. The reversed patterns in HAM and the rotated patterns in CAM are typical spurious states. We propose to reduce spurious states by using Rotor Associative Memory (RAM). The RAM does not store the rotated patterns except the reversed patterns. So the RAM removes most of spurious states from the CAM. By adding a dummy state, the RAM also can remove them from the HAM. To find spurious states, we construct a searching system similar to the chaotic CAM. By using the searching system, we investigate whether the RAM can reduce the number of spurious states.

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Complex-valued Associative Memory (CAM) is an extended model of Hopfield Associative Memory (HAM). The fundamental elements, such as input-output signals and connection weights of the CAM are extended to complex numbers. The CAM can deal with multi-states information. Rotor Associative Memory (RAM) is an extended model of the CAM. Rotor neurons are essentially equivalent to complex-valued neurons. Connection weights of the RAM are expressed by two by two matrices. Only hebb rule has been proposed for the learning of the RAM. Its storage capacity is small, so advanced learning methods are necessary. In this paper, we propose gradient descent learning rule for the RAM (GDR RAM). It is based on that for the CAM (GDR CAM) proposed by Lee. We solved the learning rule and performed computer simulations to compare the GDR CAM and the GDR RAM. At last, it turned out that the storage capacity of the GDR RAM is approximately twice as much as that of the GDR CAM and the noise robustness of the GDR RAM is much better than that of the GDR CAM.

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The purpose of this study is to investigate the effect of magnetic stimulation for muscle fatigue. The six healthy subjects participated in the experiment with the repetition grasp using a hand dynamometer. The measurement of EMG (electromyography) and MMG (mechanomyography) is performed on the left forearm. All subjects performed MVC (maximum voluntary contraction), and repeated exercise in 80%MVC after the MVC measurement. The repetition task was entered when display muscular strength deteriorated. We used an EMG and MMG for the measurement of the muscle fatigue. Provided EMG and MMG waves were calculated integral calculus value (iEMG, and iMMG). The result of iEMG and iMMG were divided by muscular strength, because we calculate integral calculus value per the unit display muscular strength. The result of our study, we found recovery effect by the magnetic stimulation in voluntarily muscular strength and iEMG. However, we can not found in a figure of iMMG.

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In this research, we examined a tactile sense for sensory substitution in people who have lost a certain sense. We considered use of apparent movement to communicate something via a tactile sense. It is necessary to measure a tactile apparent movement objectively and quantitatively because of an apparent movement is normally a subjective sense. This paper proposes the technique which measure the body sway accompanied by the recognition of a tactile apparent movement more securely. We examined the sway of body part by using EMGs around a shoulder, 3 axes acceleration data of the forearm, tracking data based on CCD camera of the upper part, and center of gravity sways of a person's body. By assuming a causal relationship between the sway of body part and EMGs, as an input and an output of the information channel, the transition probabilities and the averaged mutual information were obtained for 4 normal subjects. Moreover, relationship between a tactile apparent movement and tactile stimuli was investigated by the multiple comparison test. As a result, relevance with the body sway accompanied by the recognition of a tactile apparent movement and EMGs was evaluated quantitatively.

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When the kinesthesia and the touch act at the same time, such perception is called haptic perception. This sense has the key role in motor information on the force and position control. The haptic perception is important in the field where the evaluation of the motor control is needed. The purpose of this paper is to evaluate the motor control, perception of heaviness and distance in normal and fatigue conditions using psychophysical experiment. We used a haptic device in order to generate precise force and distance, but the precedent of the evaluation system with the haptic device has been few. Therefore, it is another purpose to examine whether the haptic device is useful as evaluation system for the motor control. The psychophysical quantity of force and distance was measured by two kinds of experiments. Eight healthy subjects participated in this study. The stimulation was presented by haptic device [PHANTOM Omni: SensAble Company]. The subjects compared between standard and test stimulation, and answered it had felt which stimulation was strong. In the result of the psychophysical quantity of force, just noticeable difference (JND) had a significant difference, and point of subjective equality (PSE) was not different between normal and muscle fatigue. On the other hand, in the result of the psychophysical quantity of distance, JND and PSE were not difference between normal and muscle fatigue. These results show that control of force was influenced, but control of distance was not influenced in muscle fatigue. Moreover, these results suggested that the haptic device is useful as the evaluation system for the motor control.

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Autonomic nervous system is important in maintaining homeostasis by the opposing effects of sympathetic and parasympathetic nervous activity on organs. However, it is known that they are at times simultaneously increased or decreased in cases of strong fear or depression. Therefore, it is required to evaluate sympathetic and parasympathetic nervous activity independently. In this paper, we propose a method to evaluate sympathetic nervous activity by analyzing the decreases in blood pressure by utilizing the Windkessel model. Experiments are performed in sitting and standing positions for 380 s, respectively. First, we evaluate the effects of length for analysis on the Windkessel time constant. We shorten the length for analysis by multiplying constant coefficients (1.0, 0.9, and 0.8) to the length of blood pressure decrease and then cut-out the waveform for analysis. Then it is found that the Windkessel time constant is decreased as the length for analysis is shortened. This indicates that the length for analysis should be matched when the different experiments are compared. Second, we compare the Windkessel time constant of sitting to that of standing by matching their length for analysis. With statistically significant difference (P<0.05) the results indicate that the Windkessel time constant is larger in the sitting position. Through our observations this difference in the Windkessel time constant is caused by sympathetic nervous activity on vascular smooth muscle.

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In this study, a novel approach towards the evaluation of students in e-learning sessions is regarded; the physiological responses of the students who were engaged in e-learning materials were investigated. Among a full battery of physiological signals, we focused on human hemodynamic activity, which is represented by the blood pressure. The past hemodynamic studies on mental stress showed that the difference in subject's stress coping style, i.e., active and passive coping, induced different hemodynamic responses. Such a variety of stress coping styles is also anticipated to be prevailing in attendees of e-learning course. In the experiment, the hemodynamic responses of the students who were engaged in the e-learning session were investigated with two considerably contrasting e-learning materials, one is characterized by an interactive material and the other is by non-interactive material. As a developing result, a particular hemodynamic pattern, which is involved in the subject's active coping, was observed in the interactive condition, and that of passive coping was observed in the non-interactive condition, whereas there was no significant difference in the score of questionnaire on the materials. These results thus led to an idea of the objective evaluation of the attendees of e-learning courses.

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We proposed a calculation method of the ventilation threshold using the non-contact respiration measurement with dot-matrix pattern light projection under pedaling exercise. The validity and effectiveness of our proposed method is examined by simultaneous measurement with the expiration gas analyzer. The experimental result showed that the correlation existed between the quasi ventilation thresholds calculated by our proposed method and the ventilation thresholds calculated by the expiration gas analyzer. This result indicates the possibility of the non-contact measurement of the ventilation threshold by the proposed method.

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Vascular access for hemodialysis is a lifeline for over 280,000 chronic renal failure patients in Japan. Early detection of stenosis may facilitate long-term use of hemodialysis shunts. Stethoscope auscultation of vascular murmurs has some utility in the assessment of access patency; however, the sensitivity of this diagnostic approach is skill dependent. This study proposes a novel diagnosis support system to detect stenosis by using vascular murmurs. The system is based on a self-organizing map (SOM) and short-time maximum entropy method (STMEM) for data analysis. SOM is an artificial neural network, which is trained using unsupervised learning to produce a feature map that is useful for visualizing the analogous relationship between input data. The author recorded vascular murmurs before and after percutaneous transluminal angioplasty (PTA). The SOM-based classification was consistent with to the classification based on MEM spectral and spectrogram characteristics. The ratio of pre-PTA murmurs in the stenosis category was much higher than the post-PTA murmurs. The results suggest that the proposed method may be an effective tool in the determination of shunt stenosis.

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The expertise and experience are required for an examiner to diagnose using echocardiogram. To evaluate the malfunction of motion in the heart, many research of image processing method have developed but they were useful only for expert examiners. To bring benefit of portability in echography to wider medical staff, we have developed software to recognize the synchronous motion of heart by calculating intersection points between the instantaneous velocities of ventricular wall flow from successive echocardiograms. In addition, we defined intersection index to evaluate synchronous motion of heart by dividing echogram into small regions to calculate distribution of intersection points. Finally we introduced gravity point of the distribution and calculated its trajectory through a heartbeat. As the result, fluctuation of the gravity point in heart disease patients was strongly observed where the trajectory of the gravity point was stable in normal subjects.

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It is important to relate the physiological characteristics of the subject to the physical parameters of the image being viewed. In this study, we employed image analysis to extract the spatial frequency characteristics associated with fixation information; this information provides the visual physiological responses of the subjects viewing stationary images. The fast Fourier transform (FFT) technique was applied to a circular-shaped area of each of the images and the slope of the regression curve fitted to the power spectral density was determined as β value. The centers of the selected circular areas of each image were set as fixation points with respect to a viewer. We observed a significant difference in the β values in the vicinity of the two fixation points corresponding to long and short fixation durations. The results suggest that the physiological responses constituting fixation information can extract the physical properties of an image.

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Recently, it often said that it is one of the means that the observational learning promotes the acquisition of sports and athletic skills. We think that the inexperienced person can efficiently acquire athletic skills by using the observational method of the expert as an index of the observational method in the observational learning. Then, in the present study, the expert and inexperienced person's glance characteristic were compared, and it was examined whether the observational method of the expert was able to be used as an index of the observational method of the inexperienced person. The glance characteristics are a glance transition, glance total moved distance, the gazing duration, moreover glance moved distance and radial velocity between each gaze points. Additionally, we investigated whether there was a change in physical performance before and after the observational learning, and two different observational learning groups (the expert's observational method group, the free observation group). In result, it was clarified that the expert concentrated, observed a constant part of the movement, and the inexperienced person was observing the entire movement. Moreover, the result that glance total moved distance was shorter than the inexperienced person, and expert's gazing duration was longer than the inexperienced person. It was clarified that the expert was efficiently emphatically observing the point of the movement from these results. In addition, the inexperienced persons have advanced physical performance through the observational learning. Then the expert's observational method group advanced physical performance better than the free observation group. Therefore we suggested that the observational method of the expert be able to be used as an index of the method of observing the inexperienced person.

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In previous study, we recorded electroencephalogram (EEG) of patients with dementia and healthy subjects during Sternberg task. But, only one presentation method of Sternberg task was considered in previous study. Therefore, we examined whether the EEG was different in two different presentation methods wrote letters horizontally and wrote letters vertically in this study. We recorded EEG of six healthy subjects during Sternberg task using two different presentation methods. The result was not different in EEG topography of all subjects. In all subjects, correct rate increased in case of vertically arranged letters.

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Recently, the stiff shoulder accompanying the muscle fatigue becomes an issue of public concern. Therefore, we paid attention to the effect of the thermal and magnetic stimulation for the muscle fatigue.
The maximum voluntary contraction has recovered significantly, and also peripheral blood flow has increased by stimulation. In order to evaluate if the thermal and magnetic stimulation has any effects, three parameters was measured, which are the maximum voluntary contraction, peripheral blood flow and skin temperature. The skin temperature, however, did not changed significantly.

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Recently, three-phase complex filters attract attention because the number of required elements of the three-phase complex filter is lower than that of the four-phase (balanced) complex filter. In this paper, three-phase complex filters based on a leapfrog configuration are realized. The method for removing the inverter is proposed. The resulting circuit can be realized by using 3n operational amplifiers for n-th order complex filter. It is shown that the sensitivity of the proposed circuit is lower than that of the conventional one. The deviation of the passband response from the ideal one is due to the finite gain bandwidth of operational amplifiers. By taking the finite gain bandwidth of operational amplifiers into account, it is shown that the passband response of the proposed circuit is improved. The validity of the proposed method is confirmed through both of computer simulation and experiment. The experimental circuit exhibits complex bandpass characteristics (18-22kHz) and an image rejection ratio of 60.91dB.

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Lip motion features such as lip width and lip length provide important information to identify individuals or commands. The interface using lip motion features is practical because operation is possible without touching devices. However, changes regarding sentiments using lip motion features have never been detected yet. Therefore, we reduce the influence of the unevenness in the lip motion features and then detect the sentiments changes. The proposed method has four steps. First, we extracted the lip motion features on the basis of both positions and shapes of lip in each frame of facial images. Second, features were created from the lip length of six utterances, which were made on the basis of these features' relative values obtained from the primary and object frame. Third, we select the data with little unevenness out of six utterances. Finally, the days when sentiments changes occurred were detected by fuzzy c-means. Our experimental results for three persons suggest that the proposed method is able to detect sentiments changes at about 73 percent.

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We have proposed a self-position estimation method for an autonomous mobile robot with variable processing time. In this method, the processing time for self-position estimation can be varied by changing the image size, and image templates are generated with Genetic Algorithm in order to realize efficient and stable self-position estimation for the size change. However, it takes enormous time to generate image templates even if the number of the image templates is very small. Considering the application of the proposed method to more practical problems for self-position estimation, it is necessary to generate image templates in shorter time. In order to overcome this problem, we apply Genetic Algorithm with a fitness inference system for template generation instead of SGA(Simple Genetic Algorithm) in this paper. Some simulation results show that the time for image template generation is reduced drastically with the proposed method.

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Anti-lock brake system and brake-by-wire are proposed in the vehicle control using a brake, and the braking power is expected to be improved more than ever. The researches such as an application to the ABS of Siliding mode control which considered a actuator dynamics and a hybrid control of the brake using model reference adaptive control are done so far. However, in the former case, speed following that becomes a target exists physically impossible situation by saturation of tire frictional force because only speed following is done. In the latter, the model error is caused because the simulation model and the controller design model are different. Therefore, there is a problem that an accurate follow cannot be done. In this paper, the braking control is performed using the sliding mode control which has high robustness for disturbance that fulfils matching conditions. In so doing, it aims at the achievement of optimal braking control to switch wheel speed following to slip ratio following.

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In the field of the ubiquitous computing, positioning systems which can provide users' location information have paid attention as an important technical element which can be applied to various services, for example, indoor navigation services, evacuation services, market research services, guidance services, and so on. A lot of researchers have proposed various outdoor and indoor positioning systems. In this paper, we deal with indoor positioning systems. Many conventional indoor positioning systems use expensive infrastructures, because the propagated times of radio waves are used to measure users' positions with high accuracy. In this paper, we propose an indoor autonomous positioning system using radio signal strengths (RSSs) based on ISM band communications. In order to estimate users' positions, the proposed system utilizes a particle filter that is one of the Monte Carlo methods. Because the RSS information is used in the proposed system, the equipments configuring the system are not expensive compared with the conventional indoor positioning systems and it can be installed easily. Moreover, because the particle filter is used to estimate user's position, even if the RSS fluctuates due to, for example, multi-paths, the system can carry out position estimation robustly. We install the proposed system in one floor of a building and carry out some experiments in order to verify the validity of the proposed system. As a result, we confirmed that the average of the estimation errors of the proposed system was about 1.8 m, where the result is enough accuracy for achieving the services mentioned above.

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This paper proposes a new method to detect the displacement and the rotational angle to match between the input and the template image. The proposed method calculates the correlation by matching the images given by eigen decomposition of the template image to the input image instead of matching the template image to the input image directly. The proposed method can detect the displacement and rotational angle more accurately than the previous method with the same calculation cost as the previous method.

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