We report silicon (Si) nanoparticles prepared by pulsed laser ablation in constant pressure inert background gas (PLA-IBG). We demonstrate the synthesis of monodispersed, nonagglomerated Si nanocrystallites, using a novel integrated process system where a classification unit of a low-pressure-operating differential mobility analyzer (LP-DMA) was combined to the PLA-IBG unit. The LP-DMA has been designed to operate under pressures less than 5.0 Torr. We have successfully synthesized and deposited the nonagglomerated Si nanocrystallites of 3.8 nm mean diameter and 1.2 geometrical standard deviation. On the other hand, properties of indium oxide (In₂O₃) thin films prepared by pulsed laser deposition (PLD) in background gases were characterized in relation to the background gas pressures. Transparent crystalline In₂O₃ thin films could be obtained at background gas pressures above 1.0 Torr on unheated glass substrates. To develop a near-infrared-light-emitting diode with active materials of monodispersed Si nanocrystallites and with passivation layer of the In₂O₃ thin films that are highly compatible with ULSI technology. The near-infrared emission was sharp and showed a peak above the band-gap region (position: 1.17 eV, width: 0.15 eV); therefore, it presumably originates from spatial quantum confinement effects of the carriers.

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This paper presents an overview on the states of arts of laser macrofabrication in electronics industry. Various kinds of lasers and material processing technologies have been developed and applied for manufacturing electronic components and devices to meet the strong demands for high-performance, lightweight, low energy-consumption mobile digital consumer electronics, broadband optical fiber communications, etc. This paper emphasizes solid-state lasers as convenient and versatile light sources for manufacturing advanced compact components and devices with sensitive passive or active subcomponents having small feature sizes. Some of the representative material processing applications using advanced lasers for electronic components are, opaque and clear defects repairing of LCDs, trimming of chip-resistors and functional modules, laser patterning of amorphous solar-cells, forming of various micro-vias for high-density interconnection circuits, microadjustment of reed switches, and high-precision laser welding of electronic components such as optical modules, miniature relays and lithium ion batteries.

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Medical applications of laser are measurement, laser surgery, in-situ monitoring, and processing of medical devices. In this paper, author briefly reviews the trends of medical applications, describes some new applications, and then discuss about the future trends and problems of medical applications. At present, the domestic market of laser equipment for medical applications is nearly 1/10 of that for industrial applications, which has registered significant growth continuously. Laser surgery as a minimum invasive surgery under arthroscope is expected to decrease the pain of patients. Precise processing such as cutting and welding is suitable for manufacturing medical devices. Pulsed laser deposition has been successfully applied to the thin film coating. The corneal refractive surgery by ArF excimer laser has been widely accepted for its highly safe operation. Laser ablation for retinal implant in the visual prosthesis is one of the promising applications of laser ablation in medicine. New applications with femtosecond laser are expected in the near future.

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The present status of laser ablation processing applied in electric power system industries is reviewed. High average power LD-pumped Nd:YAG lasers with Q-switch have been developed and currently introduced into various applications. Optical fiber based laser beam delivery systems for Q-switched pulse laser are also being developed these years. Based on such laser and beam delivery technology, laser ablation processes are gradually introduced in maintenance of nuclear power plant, thermal power plant and electrical power distribution system. Cost effectiveness, robustness and reliability of the process is highly required for wide utilization in these fields.

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Photocatalytic titanium dioxide (TiO₂) thin films are deposited on silicon wafers by pulsed laser deposition technique. Angular distributions of droplets and growth species emitted from the target are examined. The surface roughness and the film thickness also depend on the oxygen gas pressure and laser fluence. The substrate temperature dependence of XRD data of the films is also studied. It is found that the anatase-type-crystalline TiO₂ thin films are formed at the substrate temperature of 250°C. Photocatalytic effect of the films is confirmed with methylene-blue aqueous solutions.

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Recently, the semiconductor substrates for integrated circuits (ICs) have been required to become as thin as 50 μm, because the many electronic devices are strongly demanded to be miniaturized and light-weighted. It is very difficult for such a thin substrate fabricated with conventional dicing techniques. Therefore, we have proposed to process them using femtosecond laser ablation, expecting advantage of efficient processing without undesirable mechanical and thermal damages such as cracking and partial melting is expected. In this work, we have investigated the influence of the laser conditions such as pulse duration and fluence on the cutting depth and diameter in order to develop a new dicing technique for very thin ICs. Within the range of pulse energy used in the present experiments, the dependence of the pulse duration did not seem to be significant. It was also found that the lower energy of the laser pulses, the smaller and the deeper, i.e., the sharper holes were formed. The typical cutting depth and diameter for 200 μJ/pulse and 5 shots were 7 μm and 40 μm, respectively. These values are very promising for the practical dicing applications.

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Tin oxide (SnO₂) thin films were deposited on silicon (100) and alumina substrates by using a pulsed laser deposition (PLD) method. X-ray diffraction pattern shows that crystallinity of the film increased with increasing oxygen gas pressure and substrate temperature. Gas sensitivity of the film for 0.31vol% H₂ gas increased with increasing oxygen gas pressure and substrate temperature. In addition, Pd doped SnO₂ thin films can be prepared using new PLD method combined with d.c. sputtering to prepare highly sensitive gas sensors.

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A new drilling technique is proposed for removing polymeric layer formed on conductive layer using IR laser light, which is not absorbed by the polymeric layer sufficiently for ablation. In this technique, a piece of polymeric film was blown off after a single shot of radiation. To apply this process to laser drilling, we have systematically measured changes in size of the resulting hole with the fluence, the irradiation area and the thickness of a polymeric layer. We also investigated the mechanism of this process by luminescence spectroscopy of the irradiated samples. We observed sharp peaks in the spectrum in the case of single laser irradiation of 8.6 J/cm² while such intense peaks could not be seen when the irradiation pulse energy decreased to 1.2 J/cm². Thus, the polymeric film was removed without violently decomposition to atomic species. Advantages of this technique are (1) the polymeric layer can be completely removed within a certain area by a single shot of laser pulse, and (2) it is possible to escape from problems such as debris, smear and delamination, which occurs when CO₂ lasers or UV laser is used.

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A carbon plasma plume was produced in a vacuum by ablating a graphite target using KrF excimer laser, Nd:YAG laser second harmonic and fundamental light. Emission spectroscopy, two-dimensional laser induced fluorescence (2D-LIF), spectral absorption and ion probe diagnostics measurements were used to measure C atoms, C⁺ ions, C₂ and C₃ molecules in the carbon plasma plume versus laser wavelength and laser fluence. The 2D-LIF images examined the temporal and spatial profiles of C₂ and C₃ near the target surface. It was found that the KrF laser of 248 nm ablated species of carbon atoms and ions with highly excited electronic states from the target, and C₂ and C₃ were also found near the target. Nd:YAG laser light of 532 nm more effectively produced C, C⁺ than the fundamental Nd:YAG laser light of 1064 nm. The carbon species produced by the Nd:YAG laser of 1064 nm were thought to result from the thermal evaporation of the target by laser heating.

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Dynamics of ablation of fused silica by multiwavelength excitation process using F₂ and KrF excimer laser has been investigated by energy analyzed mass spectrometry of ablated species. The number of generated Si⁺ ion by multiwavelength excitation process corresponds to that by single-F₂ laser ablation and to approximately 2.1 times higher than that by single-KrF excimer laser ablation. In addition, kinetic energy distribution of Si⁺ ablated by multiwavelength excitation process shows almost same as that by single-F₂ laser ablation. We regard that absorption of KrF excimer laser by excited state generated by F₂ laser (excited-state absorption: ESA) causes effective photoionization, resulting in enhancement of Si⁺ with higher kinetic energy and then in high-quality ablation.

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Nowadays, medical accidents increase in Japanese patient environment. Especially, misidentification of the patients occurred in operation room of higher level hospitals. It is considered that the great deals of accidents are due to mistakes by nurse. However, the accidents are prevented by management of patients. If a suitable patient identification system is developed, the accidents are prevented. In this study, new patient identification system using battery less LF band RFID(Radio Frequency Identification) is proposed. In the method, battery less RFID tag is attached to patient. In operation room, patient is identified before operation using the proposed system. However, identification distance of RFID is small. It is important that extension of the distance. In this study, antennas of RFID tag and sensor are designed. Two types of tag are proposed. One of them is set on wristband. An antenna for the tag is designed as a circular shape with 30mm in diameter. The other one is shaped like a necklace. The antenna is also designed 220mm, 240mm and 260mm in diameter. Using necklace type new antenna, sufficient identification distance for detection of the tag in the operation room is realized. The patient identification is realized using the proposed system

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The accuracy of positioning with GPS depends on wavelength. Therefore, positioning is more precise by using the carrier whose wavelength is shorter than chip length of code. So, we propose to improve the accuracy of Inverse-GPS by applying the positioning with carrier phase to Inverse-GPS. In positioning with carrier phase, the most important problem is integer bias. By using 5 receivers or 2 frequencies, this problem can be solved. Next, we took up the multipath as an error factor of inverse-GPS. It is thought that inverse-GPS is greatly influenced by multipath compared with GPS since inverse-GPS has a transmitter and a receiver on the ground. Then, we propose using adaptive filter to remove multipath.

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A multiresolution wavelet transformation based robust watermarking method is introduced. The coefficients of watermark are embedded into those of host image at different transformation level using a secret key. Watermark is extracted using the same key and by inverse transformation at each level. Finally, the watermark is estimated by taking mean value of the obtained watermarks. The introduced method is tested on gray and color images with added Gaussian, salt and pepper, Speckle, and JPEG noises. Correlation coefficients are used to compare the embedded and extracted watermarks. Comparison result with an earlier work is presented.

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This paper proposes the viewpoint change method that uses a 3-D mouse for stereoscopic vision modeling based on the movement of objects. Our previous modeler offered only a stereoscopic perspective view. However, it was diffcult for users to precisely create and place objects with this modeler. Based on usage studies, we created an improved modeler that adds three orthographic views to the previous modeler. Examinations showed that 3-D mouse operations do not always directly correspond to cursor movements on the screen due to camera viewpoint change. We propose a new viewpoint change method that is based on the object-move method, which makes 3-D mouse movements more intuitive. We also describe tests that confirm the effectiveness of the proposed method. The results show that the proposed method is especially effective for novices.

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In the analysis-synthesis coding of speech signals, realization of the high quality in the low bit rate coding depends on the extraction of its characteristic parameters in the pre-processing. The precise extraction of the fundamental frequency, one of the parameters of the source information, guarantees the quality in the speech synthesis. But its extraction is diffcult because of the influence of the consonant, non-periodicity of vocal cords vibration, wide range of the fundamental frequency, etc..
In this paper, we will propose a new fundamental frequency extraction of the speech signals using the Wavelet transform with the criterion based on its harmonics structure.

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In this paper, we propose a novel approach to segment image using HIS color space and considering pixel block properties. HIS color space is used to express the pixel color information. Considering the hue value will be very sensitive when the saturation and intensity values are low, the color purity is used as the weight on the hue value. This method considers not only the pixel properties, such as color and position, but also the pixel block properties. An image is divided into blocks. For each block, the mean and variance values are calculated. The variance value can be seen as the pixel block property that expresses the variation of pixels in the block. Based on the block mean, the image is segmented with the region growing approach. The pixels in the small objects obtained from the image segmentation will be merged into the large object by the decision of vector distance together with the pixel position information. The experimental results confirm this approach is useful and suitable for many kinds of images.

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Three-dimensional(3D) shape representation is a powerful tool in object recognition that is an essential process in an image processing and analysis system. Skeleton is one of the most widely used representations for object recognition, nevertheless most of the skeletons obtained from conventional methods are susceptible to rotation and noise disturbances. In this paper, we present a new 3D object representation called a modified exoskeleton (mES) which preserves skeleton properties including significant characteristics about an object that are meaningful for object recognition, and is more stable and less susceptible to rotation and noise than the skeletons. Then a 3D shape recognition methodology which determines the similarity between an observed object and other known objects in a database is introduced. Through a number of experiments on 3D artificial objects and real volumetric lung tumors extracted from CT images, it can be verified that our proposed methodology based on the mES is a simple yet efficient method that is less sensitive to rotation, noise, and independent of orientation and size of the objects.

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A robust matching scheme for computing optical flow within a sequence of grayscale images is proposed. The technique employs the gradient information in textured images for extracting features in the form of orientation codes, which are then used for matching. The proposed method has been found to be robust in cases of matching under different ill-conditionings especially illumination variations. We utilize its robustness to compute optical flow in cases where illumination fluctuation is a problem and matching pixel brightness can introduce errors. Results of computation of optical flow field on real world scenes in the cases of translation, rotation and zooming have been presented and compared with other region matching techniques.

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Recently, various medias (film, TV, computer, and so on) are changing from analog to digital, and capturing human motion in computer graphics has attracted public attention. Therefore, we suggest a new human model for computer graphics. We use a muscle-based model “action unit”, and produce a software package. Present system can produce movements and compositions of the lower part of the body.
We suggest a new composition method using muscles of human body movement, and suggest a new storage method of movement information for the field of human body animation of VRML. Furthermore, we confirmed effectiveness of present method by experiments on the basis of usability engineering.

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In this paper, we propose an approximate design method for feedforward element of discrete-time 2DOF controller parameterized by stable rational function. The proposed method is based on the approximate matching of the response sequence in time domain. The relation of the parameter of feedforward element and output sequence is expressed in the form of simple linear equation, through which we can design low order feedforward element. The proposed method also has a feature that the iterative controller parameter tuning algorithm can be derived by applying the iterative solution commonly utilized in numerical calculation. The results of the numerical simulation show the effectiveness of the proposed method.

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In this study, we present a numerical model of the time dependence of blood glucose value after ingesting a meal. Two numerical models are proposed in this paper to explain a digestion mechanism and an adjustment mechanism of blood glucose in the body, respectively. It is considered that models are exhibited by using simple equations with a transfer function and a block diagram. Additionally, the time dependence of blood glucose was measured, when subjects ingested a sucrose or a starch. As a result, it is clear that the calculated result of models using a computer can be fitted very well to the measured result of the time dependence of blood glucose. Therefore, it is considered that the digestion model and the adjustment model are useful models in order to estimate a blood glucose value after ingesting meals.

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PID control schemes have been widely used for various process control systems. However, most processes are represented by multivariable systems with ambiguous time-delays. Therefore, it is necessary to consider how to choose a suitable set of PID parameters for such systems. In this paper, a design scheme of multiloop robust PID control systems is proposed for multivariable systems. The PID parameters are calculated based on the relationship between the PID control and the generalized predictive control laws. The effectiveness of the newly proposed scheme is numerically evaluated on a simulation example.

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In this paper, a new approach is proposed to determine the structure of radial basis function (RBF) networks. This approach starts with an enough number of hidden nodes and reduces the number of nodes in the course of learning. The algorithm can be employed in the problems where only the performance index of the network output is given, as well as in the supervised training problems where the desired output values are available. Also, it is applicable to either of classification problems and function approximation problems.

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When people carry out collaborative works, conceptual difference due to different backgrounds and knowledge can hinder their communication and deteriorate collaboration. We have been carrying out research on detecting conceptual difference by focusing on the situation in which different symbols are used to denote the same meaning and the same symbols are used to denote different meaning. In our approach each user’s knowledge is represented as a decision tree respectively and difference in concept is detected as difference in the structure of decision trees. This paper points out some problems in constructing a unique decision tree based on a single information criterion. Based on the idea of diverse structure, this paper proposes a new method for increasing the performance of detection by constructing multiple decision trees with diverse structure. Genetic algorithm is utilized to realize the idea of diverse structure and experiments with motor diagnosis cases on the implemented system confirmed the improvement on the performance of detection.

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In this paper, we propose a saturation computation method of neural networks for efficiently solving combinatorial optimization problems. In this computation method, once the neuron is in excitatory state, then its input potential is considered to be in positive saturation where the input potential can only be reduced but cannot be increased, and once the neuron is in inhibitory state, then its input potential is considered to be in negative saturation where the input potential can only be increased but cannot be reduced. The proposed method is applied to N-Queens problem. The performance is evaluated through simulations where the results show that the saturation method improves the searching capability of neural networks and shortens the computation time. Particularly, the simulation results show that the performance of the proposed method surpasses the exiting methods for N-queens problem in synchronous parallel model.

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The maximum clique problem is a classic graph optimization problem that is NP-hard even to approximate. For this and related reasons, it is a problem of considerable interest in theoretical computer science. The maximum clique also has several real-world applications. In this paper, an efficient algorithm for the maximum clique problem using improved Hopfield neural network is presented. In this algorithm, the internal dynamics of the Hopfield neural network is modified to efficiently increase exchange of information between neurons and permit temporary increases in the energy function in order to avoid local minima. The proposed algorithm is tested on two types of random graphs and DIMACS benchmark graphs. The simulation results show that the proposed algorithm is better than previous works for solving the maximum clique problem in terms of the computation time and the solution quality.

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Recently, high speed processing computers are inevitably required for many kinds of scientific and engineering applications, for example, graphics and simulations. The solution ways for this demand are, for example, cooperative controlled multi-nodes system and centrally controlled multi-nodes system.
In this paper, we propose an idea to diffuse these two systems into one system to make much more effective and speedy system. In this system, even if the communication speed between each node is relatively slow, the total processing speed is rather higher compared with two systems. The dominance is certified using simulation results. And we consider of emergency halt to realize robustness.

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We evaluated the functions and the performance of a highly reliable system which is the tightly-coupled duplex system made up of two microprocessors, the GMICRO/100 and the G100FTS (GMICRO/100 for Fault-Tolerant System) which is a fault tolerant microprocessor.
During normal operation mode, normal processing of data transfer and further more, processing for recovery from a transient fault and a permanent fault as well as maintenance of processing continuity have been confirmed.It has been demonstrated that this system enables us to obtain high reliability. On the other hand, it was revealed that the average performance of numerical calculation and data transfer of this system was 69 to 75 % that of a simplex system. From this result, it was found that when the duplex system is to be applied to an application system that requires real time operations, it is necessary to recognize in advance the relationship between the tolerable maximum response time and the feasible fault-tolerant function of the application system.

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In this letter, the surface-index change and diffusion coefficient of the Ag-ion in the diffused waveguides made by diluted AgNO₃ melts in the BK7-glass substrate are determined from the measured effective indices. Based on the determined parameter values, the index profiles are calculated in the planar diffused-waveguides, and also two-dimensional index-profiles in the channel-type diffused waveguides are calculated.

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Optical forces exerted on a microsphere by the laser beam from an optical fiber inserted at an angle were theoretically analyzed. From these results, we verified that the laser beam emitted at an angle from an optical fiber could obtain a two-dimensional optical trapping of a microsphere on the surface of a sample cell.

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Optical trapping and manipulation of a microsphere were experimentally demonstrated using a YAG laser emerging from an optical fiber end. Optically trapped microsphere was freely transferred synchronized to the optical fiber without physical contact. Furthermore, the green light emission from an optically trapped polystyrene particle could be observed through a microscope.

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Optical fiber trapping method was experimentally investigated by measuring the reflected beam from an optically trapped microsphere. From these results, we verified that our proposed fiber optic trapping system captured a microsphere by a mechanism different from traditional trapping systems using a high-numerical-aperture objective.

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The influence of N₂ gas pressure on a Nitrogen ion beam etching of a polymethylmethacrylate(PMMA) was investigated in detail in order to discuss the dry etching mechanism of polymer. From these experimental results, it was found that N₂ gas pressure was a critical parameter for polymer dry etching.

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We have already proposed a new automatic logic circuit design method using genetic algorithm based on the coexistence of heterogeneous populations. In this letter, we apply the proposed method to the design of the artificial ant control circuit, and clarify that the proposed method is effective also to the design of the logic circuit of which the I/O specification is not given beforehand.

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This letter proposes a new tabu search heuristic to select the optimal traffic route. The traffic network is completely assumed to be covered by a mesh structure. The objective is to minimize total necessary time to the goals of all cars. In the other words, it can be resolved into the minimization of total stoppage time. Each car has been assigned some routes in advance, and then all routes are numbered. Tabu search gives the best route-numbers to all the cars so as to avoid congestion. The method makes use of not only usual tabu lists but also a move frequency-based memory and a residence measure memory.

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