Extraterrestrial organic compounds have been considered as important sources for the origin of life on the Earth. In order to study the formation of organic compounds found in extraterrestrial bodies, simulated interstellar media were irradiated with high energy particles or photons. Particles used were protons from a van de Graaff accelerator, protons and helium ions from a cyclotron, electrons from a synchrotron, and heavy ions from “HIMAC" heavy ion accelerator. Photons used were UV light and soft X-rays from a synchrotron. Gamma-rays irradiation was performed by using a 60Co source. Amino acid precursors were formed from a mixture of carbon monoxide (or methanol), ammonia (or nitrogen) and water by high-energy particles, gamma-rays, or X-rays. If nitrogen molecule was used as N-source, amino acid precursors could be formed by high energy particles, X-rays and gamma-rays, but not by UV light. In the case that ammonia was used, amino acid precursors were detected in all the cases, but energy yields (G-values) of amino acid precursors by high energy particles were much higher than those by UV or X-ray photons. Possible formation of amino acid precursors in interstellar environments was discussed from the point of view of chemical evolution toward origins of life.
The purpose of this study is presentation of the figure information in tactile sense using the modulated vibration which is generated from the short cycle component Ts-1(40-1000Hz) and the long cycle component Tl-1(2-40Hz). In this paper, we proposed the efficient training method of the modulated vibration stimulus and examined the training and oblivion characteristics about figure discrimination. As a result, it was suggested that the training method integrated tactile stimulus and visual stimulus is efficient method, and understood that the frequency change in the long cycle component is vibration sense maintained longer than the short cycle component.
Amyotrophic Lateral Sclerosis(ALS) patients are unable to successfully communicate their desires, although their mental capacity is the same as non-affected persons. Therefore, the authors put emphasis on Event-Related Potential(ERP) which elicits the highest outcome for the target visual and hearing stimuli. P300 is one component of ERP. It is positive potential that is elicited when the subject focuses attention on stimuli that appears infrequently. In this paper, the authors focused on P200 and N200 components, in addition to P300, for their great improvement in the rate of correct judgment in the target word-specific experiment. Hence the authors propose the algorithm that specifies target words by detecting these three components. Ten healthy subjects and ALS patient underwent the experiment in which a target word out of five words, was specified by this algorithm. The rates of correct judgment in nine of ten healthy subjects were more than 90.0%. The highest rate was 99.7%. The highest rate of ALS patient was 100.0%. Through these results, the authors found the possibility that ALS patients could communicate with surrounding persons by detecting ERP(P200, N200 and P300) as their desire.
A cluster-ion irradiation system with cluster-size selection has been developed to study the effects of the cluster size for surface processes using cluster ions. A permanent magnet with a magnetic field of 1.2 T is installed for size separation of large cluster ions. Trace formations at HOPG surface by the irradiation with size-selected Ar-cluster ions under acceleration energy of 30 keV were investigated by a scanning tunneling microscopy. Generation behavior of the crater-like traces is strongly affected by the number of constituent atoms (cluster size) of the irradiating cluster ion. When the incident cluster ion is composed of 100 - 3000 atoms, crater-like traces are observed on the irradiated surfaces. In contrast, such traces are not observed at all with the irradiation of the cluster-ions composed of over 5000 atoms. Such the behavior is discussed on the basis of the kinetic energy per constituent atom of the cluster ion. To study GCIB irradiation effects against macromolecule, GCIB was irradiated on DNA molecules absorbed on graphite surface. By the GCIB irradiation, much more DNA molecules was sputtered away as compared with the monomer-ion irradiation.
In robotics applications, ultrasonic transducers are frequently used as rangefinders, thanks to their low cost and small size. The pulse compression techniques were adopted to locate multiple objects at the same time and to eliminate frequent misreadings caused by crosstalk or external ultrasound sources. However, a few problems become apparent when implementing the pulse compression techniques. First, each transducer must be equipped with a processing system for the implementation of correlation functions. This may significantly increase the complexity of the total system, cutting down one of the advantages of ultrasonic systems. Second, the majority of transducers for use in air are based on piezoelectric design, which usually used over a narrow bandwidth. Among digital correlators, significant reductions of the processing cost can be achieved with a polarity correlator. However, this polarity correlation adds quantisation noise to the signals and leads to a degradation of the output signal to noise ratio. This paper presents an analysis of the polarity correlator applying to a sonar ranging system, consisting of piezoelectric transducers and a chirp filter. A numerical evaluation of the output signal shows that the signal to noise ratio degrades only a small amount comparable with that obtained by direct digital correlators.
A field experiment on transmission of 80-Gbit/s-based wavelength division multiplexing (WDM) signals is successfully carried out. In order to keep good transmission quality, technique of an in-service dispersion monitoring and an adaptive control of the chromatic dispersion are proposed. Difference of the propagation delay between channels caused by the chromatic dispersion of the transmission line is detected using signals superimposed on the envelope of the WDM pulses. Dispersion alteration of the transmission line is estimated from the measured delay in real-time. Accuracy of the method is clarified through a transmission experiment using wound fibers in an oven changing their temperature. The field experiment on 80Gbit/s × 8WDM transmission using an OPGW with 60km × 2spans is carried out and fine BER performances are obtained in all channels. Transmission properties are found to be stable owing to the dispersion control techniques throughout the field trial.
At present the diagnosis of melanoma is mainly performed based on the experience of each doctor. They need some objective measure for diagnosis of melanoma and nevus. But there are few researches on index for the diagnosis. This study deals with features of melanoma and nevus for computer diagnosis. First, we extracted the contour of lesions by image processing. One hundred five values of features were computed based on ABCD-rule. Discriminant analysis showed the accuracy of 96.0% (Specificity of 98.3% and the Sensitivity of 90.0%). The results obviously showed the difference between melanoma and nevus.
An increase in the number of parking lots is very slow though that of cars increases much every year. Thus, efficient management of parking lots is needed. If information of vacant divisions is transmitted to cars waiting at gates of parking lots, traffic jam caused by cars searching parking divisions will be decreased. Therefore several methods for detecting parking cars have been developed. Especially, the method that detects cars hiding white lines drawn on parking lots is highly reliable. The method needs a template image for each camera. Since these images were created by human in the previous research, much cost and time was needed. In this paper, we present the method automatically generating the template images. Firstly, our method synthesizes an image of parking lots including no cars from several images. Then, the method detects white line segments from the image. The line segments are corrected in consideration of the rule that white lines on the parking lots are parallel and their length is constant. Finally, parking divisions are determined from the line segments and stored in the template image. In the experiment using the template generated by our method, accuracy of detecting cars was about 96%. The template is comparable to the manually created template in accuracy.
When we recognize target objects in the real world, we are required the deal with abstract information of target objects such as cars or persons. In pattern matching techniques, enormous quantity of data are dealt with for describing the target objects. We propose new knowledge acquisition system which can describe abstract information of the target objects. This system treats the object as the combination of common elemental objects, and obtains feature property of each object as the knowledge for the object. It can realize data compression and improvement of versatility. The performance of recognition with obtained knowledge is affected by environmental changes. Therefore, this system changes its thresholds of the sharpness according to the environmental condition.
In order to investigate the difference in cortical activations between reading letter strings in the normal direction and the reverse direction, an fMRI study was conducted. In this study, the cortical activations elicited by Japanese letter string reading and Chinese letter string reading were investigated. The subjects performed the normal direction reading task (read letter strings from left to right), and the reverse direction reading task (read letter strings from right to left). According to the experimental results, the activated brain regions during the normal and the reverse direction reading tasks were compared. It was found that visuospatial transformation was involved in the reverse direction reading task, while this function was not significant during the normal direction reading task. Furthermore, we found that there was no significant difference in cortical activation between Japanese and Chinese letter string readings.
This paper proposes a high-speed detection method of walking intruders by a rotating camera. Our detection method is composed of the next two steps. At first, it detects candidate areas including the walking intruders. Then it classifies the candidate area into two groups by pattern recognition technique: one group is the target object and another is background. We made comparison between our detection method and existing methods that are able to detect moving objects in real-time. The comparison results show that our proposed method is the best performance in response times among them. The frame rate of candidate area detection is 67.2 fps and total frame rate that includes pattern recognition is 33.9 fps for images of 360×240 pixels.
The study of using Electromagnetic Acoustic Transducer (EMAT) to generate and detect the low frequency Lamb wave A0 mode in the thin steel plate is described. On the base of analysis of dispersion curves, a Lorentz force type EMAT is designed to generate and detect the single Lamb wave A0 mode in the low frequency range of 0∼300kHz in 1∼2mm thin steel plate. The preliminary experiments are presented on the generation of the low frequency A0 mode, and the detection measurement using the low frequency A0 mode in the steel plate with a defect.
In thermal processes, thermal distribution on the conduction surface is observed in both steady state and transient state. Uniform temperature control is required in many industrial application fields for quality improvement. For thermal plant with strong interference, decoupling controller using black-box model based on input-output relations has been applied. In this paper, a novel cell model with feedback structure which describes the thermal interaction explicitly is derived, and its application to a new decoupling control is proposed. First, uniform cell model is considered based on physical energy, and is applied to experimental plant. The thermal distribution is simulated by the FEM method. Secondly, design of decoupling controller using the proposed cell model is shown, and the effectiveness is evaluated.
This paper proposes a practicable navigation method for multiple mobile robots in a realistic environment. In the past, many navigation methods have been developed, however, they were often limited to a single robot and sometimes assumed robots with special mobility such as holonomic ones. From the viewpoint of practical applications it is indispensable that the number of robots is arbitrary and general shape and mobility of them is allowed. In this study a deadlock-free navigation for non-holonomic mobile robots in a practical environment is given. In the proposed scheme, states of the environment and robots are fed-back in real-time and global path planning is cyclically executed. It enables an adaptation to a changing environment and a reliable deadlock-free navigation of multiple robots. The real-time online path planning is performed by an efficient A* search in Configuration Spaces representing the robots and environment. The proposed method is tested by several simulations which represent typical complicated navigation situations. As a result, the effectiveness of the methods is verifyied.
This paper introduces a new artificial immune system (AIS) model to pattern recognition. Inspired by natural immune system, we propose the AIS model, by considering not only the B cells' T-cell-dependent and T-cell-independent antigen recognition, but also the different affinities among Th cells and antigens, and apply the model to pattern recognition. We present noisy binary patterns to test its recognition performance. Simulation results indicate that the proposed AIS model has more stable memory capabilities and stronger noise tolerance ability.
We have developed a paraconsistent annotated logic program called Extended Vector Annotated Logic Program with Strong Negation (abbr. EVALPSN), which can deal with defeasible deontic reasoning and contradiction, and we have already applied it to safety verification and control such as railway interlocking safety verification and traffic signal control. In this paper, we introduce process safety verification as an application of EVALPSN with a small example for brewery pipeline valve control. The safety verification control is based on EVALPSN defeasible deontic reasoning to avoid unexpected mix of different sorts of liquid in pipeline networks.
We have investigated ways to reduce congestion in a theme park with multi-agents. We constructed a theme park model called Digital Park 1.0 with twenty-three attractions similar in form to Tokyo Disney Sea. We consider not only congestion information (number of vistors standing in line at each attraction) but also the advantage of a priority boarding pass, like Fast Pass which is used at Tokyo Disney Sea. The congestion-information-usage ratio, which reflects the ratio of visitors who behave according to congestion information, was changed from 0% to 100% in both models, with and without priority boarding pass. The “mean stay time of visitors" is a measure of satisfaction. The smaller mean stay time, the larger degree of satisfaction. Here, a short stay time means a short wait time. The resluts of each simulation are averaged over ten trials. The main results are as follows. (1) When congestion-information-usage ratio increased, the mean stay time decreases. When 20% of visitors behaved according to congestion information, the mean stay time was reduced by 30%. (2) A priority boarding pass reduced congestion, and mean stay time was reduced by 15%. (3) When visitors used congestion information and apriority boarding pass, mean stay time was further reduced. When the congestion-information-usage ratio was 20%, mean stay time was reduced by 35%. (4) When congestion-information-usage ratio was over 50%, the congestion reduction effects reached saturation.
There are many kinds of delay in real-world production systems caused by many reasons including unexpected accidents. A delay of order may inflict great damages for not only itself but also the other affected orders. To prevent these types of loss from frequent delay, DBR (Drum-Buffer-Rope) scheduling method of TOC (Theory of Constraints) manages production schedule observing the state of time buffers. The current buffer size setting method for DBR scheduling is very simple and depends on user's experience. Although it makes possible to keep the due time for production orders, it leads to the redundant production lead time and stock. For DBR scheduling, it is not clear how the buffer size should be set. Therefore, this paper proposes a buffer size setting method for DBR scheduling providing a numerical model for the buffer size. In addition, a simulation gives the result of comparison between the current method and the proposed method, and the effect of the proposed method is shown.
A business risk management method has been developed for a supply-chain without a storage function under demand uncertainty. Power supply players in the deregulated power market face the need to develop the best policies for power supply from self-production and reserved purchases to balance demand, which is predictable with error. The proposed method maximizes profit from the operation of the supply-chain under probabilistic demand uncertainty on the basis of a probabilistic programming approach. Piece-wise linear functions are employed to formulate the impact of under-booked or over-booked purchases on the supply cost, and constraints on over-demand probability are introduced to limit over-demand frequency on the basis of the demand probability distribution. The developed method has been experimentally applied to the supply policy of a power-supply-chain, the operation of which is based on a 3-stage pricing purchase contract and on 28 time zones. The characteristics of the obtained optimal supply policy are successfully captured in the numerical results, which suggest the applicability of the proposed method.
Emotion is one of the most essential and basic attributes of human intelligence. Current AI (Artificial Intelligence) research is concentrating on physical components of emotion, rarely is it carried out from the view of psychology directly(1). Study on the model of artificial psychology is the first step in the development of human-computer interaction. As affective computing remains unpredictable, creating a reasonable mental model becomes the primary task for building a hybrid system. A pragmatic mental model is also the fundament of some key topics such as recognition and synthesis of emotions. In this paper a Mental State Transition Network Model(2) is proposed to detect human emotions. By a series of psychological experiments, we present a new way to predict coming human's emotions depending on the various current emotional states under various stimuli. Besides, people in different genders and characters are taken into consideration in our investigation. According to the psychological experiments data derived from 200 questionnaires, a Mental State Transition Network Model for describing the transitions in distribution among the emotions and relationships between internal mental situations and external are concluded. Further more the coefficients of the mental transition network model were achieved. Comparing seven relative evaluating experiments, an average precision rate of 0.843 is achieved using a set of samples for the proposed model.
This paper aims at evaluating the performance of mobile agent in obtaining data in servers by introducing a factor “lifetime". Lifetime is the time from a mobile agent's creation to dispatch. After clarifying correlations of factors which have been introduced for mobile agent performance, we discuss about the meaning to introduce the lifetime for more efficient information retrieval by mobile agents. Then, with focucing on the lifetime and the number of mobile agents, we formalize the problem about an efficient mobile agent information retrieval, and show that this problem is NP complete. With computer simulations, we examine the effect of lifetime on mobile agent performance in terms of traffic rates. In low traffic rate, the lifetime needs to be determined with taking target existing rates of servers into consideration. On the other hand, in high traffic rate, despite the increase of the number of mobile agents, the use of short lifetime can increase the efficiency in obtaining targets not depending on target existing rates at servers.
A bone-conductive microphone which transforms bone-transmitted speech sounds through skull into electronic signals has two advantages. One is to operate in hands free mode, and another is to be anti-noise. Therefore, it is expected to match the man-machine interface for wearable computers. Here, we examined and analyzed the possibility of a speaker identification system with the MFCC of air and bone-transmitted speech sounds to 5 Japanese vowels. This paper shows that the system using spectral ratio between air-transmitted speech sounds and bone-transmitted speech sounds gives better performance than the system using air-transmitted speech sounds.