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著者人数: 13名, Accepted: 2016-01-12, 資料番号: SA1160158000

Over the last few decades, many experimental methods using digital image correlation (DIC) have been developed as displacement measurement techniques because DIC offers a simple, noncontact procedure for fullfield measurement. However, in addition to high spatial resolutions, it is now necessary to measure deformation at higher temporal resolution to understand in more detail the time evolution of microscale deformation, and to evaluate high-speed microscale phenomena such as crack growth. Therefore, we developed a system for measuring deformation fields at high spatial and temporal resolutions using a high-speed camera, zoom lens, DIC, and incremental evaluation method. We evaluated its accuracy, and used it to measure the deformation field around a crack tip in carbon steel. First, we performed three types of accuracy estimation for rigid displacement. Second, we applied this system to a smooth specimen of carbon steel subjected to tensile loading, and verified the measurement accuracy. Third, we applied this system to a Mode I crack in carbon steel and obtained the evolution of the strain distribution around the crack tip, where a large inhomogeneous deformation had occurred.

We present data preprocessing based on an artificial neural network to estimate the parameters of the X-ray emission spectra of a single-temperature thermal plasma. The method finds appropriate parameters close to the global optimum. The neural network is designed to learn the parameters of the thermal plasma (temperature, abundance, normalisation, and redshift) of the input spectra. After training using 9000 simulated X-ray spectra, the network has grown to predict all the unknown parameters with uncertainties of about a few percent. The performance dependence on the network structure has been studied. We applied the neural network to an actual high-resolution spectrum obtained with {\it Hitomi}. The predicted plasma parameters agreed with the known best-fit parameters of the Perseus cluster within $\lesssim10$\% uncertainties. The result shows a possibility that neural networks trained by simulated data can be useful to extract a feature built in the data, which would reduce human-intensive preprocessing costs before detailed spectral analysis, and help us make the best use of large quantities of spectral data coming in the next decades., Accepted for publication in MNRAS

The Alexander–Haasen model was originally used to model the multiplication of the mobile dislocations in crystalline silicon. Here, we extend this model for studying multiplication of basal plane dislocations (BPDs) in single-crystal sapphire. By fitting the Alexander–Haasen model to experimental data, we find that the model accurately describes the plastic deformation of sapphire caused by BPDs. The application of the Alexander–Haasen model to sapphire growth made it possible to minimize the dislocation density and residual stress in growing crystals by optimizing the furnace structure and operation conditions. We apply the Alexander–Haasen model to investigate the dynamical deformation of single-crystal sapphire during the cooling process and examine the effect of the cooling rate on the generation of BPDs and residual stress. Finally, we present the BPD distribution and discuss the main factor that influences the generation of BPDs.

Several lines of evidence strongly suggest that brain-derived neurotrophic factor (BDNF) is associated with the formation, storage and recall of memory in the hippocampus and that it is important to maintain a considerable level of hippocampal BDNF in order to keep normal functions. BDNF can be synthesized in an activity-dependent manner. In fact, kainic acid or AMPA enhances BDNF levels in hippocampal granule neurons. However, the mechanisms of BDNF production are largely unclear. Recently, we have found that riluzole, which blocks voltage-gated sodium channels and thereby reduces glutamate release, actually strengthens immunoreactivity of BDNF in hippocampal granule neurons of rats. Therefore, we examined the riluzole-activated signaling pathways for BDNF production. Riluzole increased levels of phospho-p38 mitogen-activated protein kinase (p38 MAPK), as well as BDNF levels. Inhibition of p38 MAPK by SB203580 reduced riluzole effects, while activation of p38 MAPK by anisomycin increased levels of BDNF, suggesting that p38 MAPK can mediate BDNF production. Riluzole-induced elevation of phospho-activating transcription factor-2, a transcription factor downstream of p38 MAPK, was also observed. A blocker of N-type voltage-gated calcium channels reduced the effects of riluzole on BDNF production and p38 MAPK activation. We also examined a possible involvement of the adenosine A1 receptor in BDNF production because riluzole can influence ecto-nucleotide levels. An A1 receptor agonist inhibited riluzole-induced elevation of BDNF levels, whereas an antagonist not only increased levels of BDNF and active p38 MAPK but also augmented riluzole effects. These results indicate that, in the rat hippocampus, there is an in vivo signaling pathway for BDNF synthesis mediated by p38 MAPK, and that N-type voltage-gated calcium channels and/or adenosine A1 receptors contribute to p38 MAPK activation.

The swimbladder of fishes is readily compressed by hydrostatic pressure with depth, causing changes in buoyancy. While modern fishes can regulate buoyancy by secreting gases from the blood into the swimbladder, primitive fishes, such as sturgeons, lack this secretion mechanism and rely entirely on air gulped at the surface to inflate the swimbladder. Therefore, sturgeons may experience changes in buoyancy that will affect their behavior at different depths. To test this prediction, we attached data loggers to seven free-ranging Chinese sturgeons Acipenser sinensis in the Yangtze River, China, to monitor their depth utilization, tail-beating activity, swim speed and body inclination. Two distinct, individual-specific, behavioral patterns were observed. Four fish swam at shallow depths (7–31 m), at speeds of 0.5–0.6 m s−1, with ascending and descending movements of 1.0–2.4 m in amplitude. They beat their tails continuously, indicating that their buoyancy was close to neutral with their inflated swimbladders. In addition, their occasional visits to the surface suggest that they gulped air to inflate their swimbladders. The other three fish spent most of their time (88–94%) on the river bottom at a depth of 106–122 m with minimum activity. They occasionally swam upwards at speeds of 0.6–0.8 m s−1 with intense tailbeats before gliding back passively to the bottom, in a manner similar to fishes that lack a swimbladder. Their bladders were probably collapsed by hydrostatic pressure, resulting in negative buoyancy. We conclude that Chinese sturgeons behave according to their buoyancy, which varies with depth due to hydrostatic compression of the swimbladder.

The habitat use and migratory patterns of Osbeck’s grenadier anchovy Coilia mystus in the Yangtze estuary and the estuarine tapertail anchovy Coilia ectenes from the Yangtze estuary and Taihu Lake, China, were studied by examining the environmental signatures of strontium and calcium in their otoliths using electron probe microanalysis. The results indicated that Taihu C. ectenes utilizes only freshwater habitats, whereas the habitat use patterns of Yangtze C. ectenes and C. mystus were much more flexible, apparently varying among fresh, brackish and marine areas. The present study suggests that the spawning populations of Yangtze C. ectenes and C. mystus in the Yangtze estuary consist of individuals with different migration histories, and individuals of these two Yangtze Coilia species seem to use a variety of different habitats during the non-spawning seasons.

The influence of bending and tensile damage introduced at room temperature on the critical current at 77 K under zero magnetic field of a multifilamentary Bi2223/Ag/Ag alloy superconducting composite tape was studied. From the analysis of the tensile stress–strain curve, the residual strain and intrinsic tensile-fracture strain of Bi2223 filaments were estimated, with which the measured change of critical current with tensile strain was accounted for. A simple model, in which the damage evolution in both tensile and compressive sides was incorporated, was proposed to describe the change in critical current with bending strain. The application of the model to the experimental result indicated that the intrinsic compressive-strength of Bi2223 filaments, determining damages in the compressive side, is about five times higher than the tensile strength.

Hydrogen bond supported new iron-chloranilate assemblies, {(Hpy)[Fe(CA)2(H2O)2](H2O)}n (py = pyridine, H2CA = chloranilic acid, C6H2O4Cl2) (1), and [(phz)2[Fe(CA)2(H2O)2](H2O)2]n (phz = phenazine, ...

Novel hydrogen bond-supported intercalation compounds, {(G) m [Fe(CA) 2 (H 2 O) 2 ]} n (CA 2− =chloranilate, G=guest molecules) have been synthesized and characterized. The compound {(Hpy)[Fe(CA) 2 (H 2 O) 2 ](H 2 O)} n (py=pyridine) ( 1 ) crystallizes in the triclinic, space group P 1 (#2), with a =9.537(5), b =13.563(6), c =9.231(4) A, α =107.18(4), β =102.33(4), γ =102.12(4)°, V =1065.9(10) A 3 , and Z =2. Compound {(H 2 bipy)[Fe(CA) 2 (H 2 O) 2 ] 2 (H 2 O) 2 } n (bipy=4,4′-bipyridine) ( 2 ) crystallizes in the triclinic, space group P 1 (#2), with a =9.101(1), b =10.379(1), c =12.802(2) A, α =79.45(1), β =82.67(1), γ =66.32(1)°, V =1086.8(3) A 3 , and Z =1. The structure of 1 consists of mononuclear [Fe(CA) 2 (H 2 O) 2 ] − anions, Hpy + cations and uncoordinated water molecules. Four oxygen atoms of two CA 2− anions and two oxygen atoms from two water molecules are coordinated to the iron ion making anionic building blocks of the host layer. The compound of 2 contains the similar monomeric building blocks, H 2 bipy 2+ cations and uncoordinated water molecules. In both the compounds the coordination geometry of the building blocks are distorted octahedron, where two water molecules sit on the trans position in 1 and on the cis position in 2 . In compound 1 the [Fe(CA) 2 (H 2 O) 2 ] − anions make a two-dimensional (2-D) layer supported by hydrogen bonds. Hpy + ions are included in between the layers of 1 supported by hydrogen-bonding and electrostatic interaction with the host layers. In compound 2 the coordinated chloranilate rings of [Fe(CA) 2 (H 2 O) 2 ] − anions are stacked upon each other and make a layer with the help of hydrogen bonds. H 2 bipy 2+ cations are included in between the layers supported by hydrogen bonding, electrostatic and stacking interaction with coordinated CA 2− ions. The 57 Fe Mossbauer spectra of the compounds show that the oxidation state of iron is 3 with IS=0.41 ( 1 ) and 0.39 mm s −1 ( 2 ); QS=0.83 ( 1 ) and 1.29 mm s −1 ( 2 ) at 296 K, respectively. Compound 2 shows weak antiferromagnetic interaction over the crystal ( θ =−2.3 K).

Background: The vagus nerve is reported to play an important role in the regulation of airway responsiveness. Objective: In the present study, we investigated the role of the local vagus nerve in the changes in isometric tension of smooth muscle induced by histamine in the human airway. Methods: Eight human lung tissue specimens were obtained at thoracic surgery, and 24 bronchial smooth muscle strips were used for isometric tension recording. The changes in isometric tension were induced by histamine in the presence or absence of physostigmine (10–6 M), atropine (10–6 M), and/or tetrodotoxin (10–6 M). Results: We found that: (1) histamine induced a dose-dependent increase in the isometric tension in human bronchial smooth muscle; (2) physostigmine (10–6 M) significantly potentiated the amplitude of the histamine-induced increase in isometric tension; (3) atropine (10–6 M) significantly suppressed the histamine-induced increase in isometric tension; (4) tetrodotoxin (10–6 M), did not affect the histamine-induced increase in isometric tension of smooth muscle, and (5) in the presence of tetrodotoxin, atropine significantly suppressed the histamine-induced increase in isometric tension. Conclusion: These findings suggest that the histamine-induced increase in isometric tension is mediated partly by acetylcholine, presumably released by the direct action of histamine on the vagus efferent nerve terminals without the central reflex via vagus nerve.

The lethal effects of gallium citrate in combination with heat were studied using four cell lines, L5178Y, FM3A, P388 and HeLa. Cells were incubated with different concentrations (0.2 2 mM) of gallium citrate at 37 degrees C for 24 h and heated at a range of temperatures from 40-44 degrees C for various time periods up to 6 h in the absence of gallium citrate. Survival and cell viability were determined by clonogenic assay and the dye-exclusion test, respectively. All of the cell lines tested were insensitive to heat below 41 degrees C, but were very sensitive to heat above 43 degrees C. Gallium citrate was cytotoxic to these cell lines at different levels: P388 and HeLa were far more sensitive than L5178Y and FM3A. The killing effects of heat at 41 degrees C were greatly enhanced by gallium citrate in L5178Y and P388 cells. The Arrhenius analysis for the lethal effect of heat, determined by clonogenic assay, in L5178Y cells showed that the transition temperature was remarkably decreased for the gallium-treated cells from approximately 43 degrees C to 41 degrees C. The mechanism for this decrease in the transition temperature may be attributable to the additional effects of gallium citrate on energy metabolism. Preincubation with 0.05 mM gallium citrate at 37 degrees C for 7 days also enhanced heat sensitization at 41 degrees C in L5178Y. This preincubation condition may correspond to the condition for the continuous infusion of gallium that is clinically used for cancer treatment. In contrast, treatment with gallium did not greatly enhance the sensitivity of FM3A or HeLa cells to heat at 41 degrees C, but the effects of gallium were significant.

Garden flowers can be valuable to wildlife if they produce nectar, pollen and/or seeds. To provide information needed by gardeners to select wildlife-friendly plants, we investigated nectar production and insect visits to Tropaeolum majus, Consolida sp., Antirrhinum majus, Viola×wittrockiana, Tagetes patula and Alcea rosea , in each case comparing a near-original flower type with a cultivar that had spurless, doubled, peloric or enlarged flowers. All species showed high secretion rates and standing crops of nectar. In most cases the horticultural modifications affected the numbers or species composition of the assemblage of insect visitors, and they generally reduced the value of the floral reward to insects, often affecting accessibility. Effects on seed yield were not investigated directly here, but are likely to further reduce the wildlife value of modified variants.

Luminescence and decay profiles of codopant (Cr6+. V5+) and (Cr6+, Ag + ) ions in sol- gel silica glasses are investigated at temperatures between 10 and 300 K. The closed-shell electronic structures of these ions reveal luminescence and decay profiles affected sensitively by energy migration processes, surface effects and preparation methods of the nano-structured matrices.

A gas ΔE-position sensitive E counter telescope for accelerator mass spectrometry (AMS) study has been developed. The detector has been tested with both Americium α and 36Cl measurements. The total energy resolution and the position resolution are 4.5% and 2 mm, respectively. The strong background in AMS experiments can be suppressed by the combination of ΔE and position information. 36Cl can be distinguished from both 35Cl and 36S backgrounds.

The quantitative estimation of failure stress of a lithium niobate (LN) single crystal due to thermal shock was investigated. Cylindrical test specimens were used in the thermal shock tests. The thermal stress of an LN test specimen under conditions of thermal shock cracking was calculated from a computer program which takes account of the crystal anisotropy, using the surface temperature measured in the thermal shock test. Four-point bending tests were also carried out to examine the relationship between the thermal shock cracking and the failure of a small test specimen due to mechanical load. LN single crystals fractured at the cleavage planes {0 1 1 2} in the thermal shock test and the four-point bending test. Although the failure stress data obtained from both tests obey the Weibull distribution, the Weibull distribution depends not only on specimen size but also on loading type. According to the Weibull distribution of thermal shock test data, if the normal stress σn acting on the cleavage planes {0 1 1 2} is lower than 10 MPa, the probability of thermal shock cracking becomes very small — less than 2%.

During the past few years the construction of Tsukuba AMS system at the University of Tsukuba has been made. A “molecular pilot beam” method is used for AMS measurements without any modification to the existing tandem system. The efficiency and the reproducibility of 14C measurement have been improved and the results of dating of groundwater and a dating of fossil foraminifer are preliminary reported. The measurement of an absolute 36Cl35Cl ratio is tried with tri-molecular pilot beam.

The assembly technique to simply install a monitor photodiode (PD) with a LiNbO/sub 3/ (LN) Mach-Zehnder modulator in the same package is proposed. A light radiated from the Mach-Zehnder Y-branch toward the LN output facet is lead into a glass bead, which is bonded to the LN facet as a fixture of the optical fiber. The end of the glass bead is cut to have an angled face, and the radiated light is reflected normal to the LN waveguide axis and toward the PD fixed on the side of package. The curved surface of the glass bead is effective to roughly focus the light onto the PD. We demonstrate that such monitor PD outputs an intensity modulation exactly reverse to the LN output modulation with a sensitivity higher than 0.03 A/W per optical output power of LN, indicating a usability of the PD output to monitor the drift of LN modulator.

This paper proposes an open loop beamforming scheme in frequency division duplex (FDD) downlink multiuser multiple input multiple output (MIMO) transmissions. The proposed scheme estimates the downlink channel matrix by uplink direction of arrival (DOA) estimation, and generates the beamforming weight such that the effect of overlapping beams is cancelled at the respective receivers by applying the dirty paper coding principle. The simulation results show that the proposed scheme provides a gain up to 20 dB in the received signal to noise plus interference ratio (SINR) at the 50 % CDF compared to the conventional zero-forcing beamforming. In addition, it is shown that the proposed scheme has a superior performance to the limited feedback closed loop scheme.

Although the importance of the vagal nerve in the pathogenesis of bronchial asthma has been reported, its precise contribution is still not fully understood. To shed more light on this area, we evaluated the possible contribution of vagal reflex in histamine-induced bronchoconstriction (HIB), and decided the site of action of histamine on the vagal nerve. For this purpose, we studied the effects of the bilateral cervical vagotomy, hexamethonium (2 mg.kg-1) or tetrodotoxin (0.5 mg.kg-1) on HIB (8 micrograms.kg-1, iv) in anaesthetized and mechanically-ventilated guinea-pigs. We also studied whether or not atropine (1 mg.kg-1) decreases HIB after vagotomy, including either the treatment of hexamethonium or tetrodotoxin. Airway responses were assessed by measurement of pulmonary resistance. The following results were obtained; 1) the response to histamine was significantly enhanced by the vagotomy, hexamethonium or tetrodotoxin; 2) propranolol increased HIB, and HIB was further enhanced by the vagotomy in the animals treated with propranolol; 3) atropine significantly suppressed HIB after the vagotomy, hexamethonium or tetrodotoxin. These results suggest that the postganglionic vagal nerve plays an excitatory role in HIB through the release of acetylcholine from the nerve terminals. It is also suggested that the vagal reflex mainly exhibits an inhibitory role in the HIB of guinea-pigs, presumably by the action of the nonadrenergic inhibitory nervous system.

A new type of magnetic linear actuator based on a friction drive is presented, It consists of a magnet mover with inclined legs and a solenoid coil wound around a pipe. rein alternating magnetic field produced by the coil causes the magnet to vibrate angularly due to magnetic torque and then the vibration is converted to a linear movement through a friction between the legs and the stator wan. The prototype exhibited the maximum velocity of 33 cm/s and the maximum thrust of approximately ly 0.05 N around the mechanical resonant frequency.

This paper presents an experimental evaluation of open-loop precoding MIMO (multiple input multiple output) using a testbed targeted at IMT-Advanced systems. Open-loop MIMO is realized by applying rotational OFDM (R-OFDM), that is previously proposed by authors, to MIMO transmission. MIMO R-OFDM is more robust with respect to correlated channels than conventional open-loop MIMO-OFDM, because it optimizes the distances between the constellation points using simple phase rotation. The angle of phase rotation depends on the modulation orders and coding rate, hence the receiver does not need to feed the CSI (channel state information) back to the transmitter. In this paper, MIMO R-OFDM is implemented in a testbed targeted at IMT-Advanced systems, it is then evaluated experimentally and by computer simulations. The results of the evaluation reveal that MIMO R-OFDM is effective in correlated channels, and the gain in terms of the CIR (carrier to interference ratio) with respect to conventional MIMO OFDM to achieve PER (packet error rate) = 0.01 is about 1.5 dB when MIMO R-OFDM is used in correlated channels.

This paper presents the experimental results of rotational orthogonal frequency division multiplexing (R-OFDM) performance with a turbo decoder implemented in an IMT-Advanced testbed. Taking into account recent advances in research and development toward realization of the IMT-Advanced system era, the authors are developing the testbed. The R-OFDM is multi-carrier transmission scheme and previously proposed by the authors. Its feature is to use rotational code division multiplexing that enables OFDM to obtain suitable frequency diversity gain. However, the previous work is only predicated on computer simulation. In this paper, the R-OFDM is implemented on the testbed and experimentally evaluated by distorting the R-OFDM signal on radio wave with a fading simulator. When packet error rate is measured, it is verified that measurement results are in good agreement with simulation results. The measured deterioration of required carrier-to-interference power ratio (CIR) is suppressed by about 0.5 dB compared with the simulation. The experimental results also demonstrate that the R-OFDM can reduce the required CIR of OFDM even without T2 decoder by about 1.1 dB.

Aims To compare enhanced pathology with serial sectioning and the transcription–reverse transcription concerted reaction (TRC) for detecting sentinel node (SN) metastasis in breast cancer cases. Methods In total, 115 SN samples from 32 breast cancer cases were investigated by pathological examination with 2.0-mm serial sectioning and by quantitative analysis of carcinoembryonic antigen messenger RNA with the TRC. Results The results were concordant in 98.3% of these cases. Two histologically metastatic nodes tested negative by TRC, whereas none tested positive by TRC alone. Conclusion Pathological examination with 2-mm sectioning showed superior performance to TRC under the study conditions.

This paper discusses the relationship between two optimization methods in deductive databases: the distribution of selections and the magic sets method. The former is a direct generalization of pushing selections in relational databases, and the latter realizes a more general view of selection propagation. The characteristics of the generalized form of the distribution of selections are discussed and compared to other methods. It is shown that the distribution of selections corresponds to one of the least effective variations of the magic sets method. It is also shown that both methods have essentially the same power for non-recursive queries. Hence, the magic sets method can be regarded as a natural generalization of pushing selections in relational databases.

This paper presents a method for estimating an object's two-dimensional (2D) position and orientation based on topological information collected using infrared tags without any special location sensors or direction sensors. Estimating a user's and articles' location, irrespective of circumstances, is an important issue for context-aware systems. Users are present in a location with some purpose or intention. Therefore, a user's position and orientation clearly reflect their context. Especially, orientation information can reflect a more detailed context than that obtained merely according to location: people standing face- to-face or back-to-back would have vastly different contexts. The analyses explained in this paper particularly examine an object's orientation and describe a new method for estimating an object's position and orientation in an indoor, real-world environment. Using a simulation and an implemented prototype system, the experimental results demonstrate the feasibility of our topological estimation method.

Aiming at high spectrum efficiency, this paper proposes the twin turbo decoder. The received symbol carried by multi-level modulation or MIMO (multi-input multi-output) transmission consists of two or more bits, and these bits share mutual information. However, the conventional likelihood estimation neglects this mutual information and deteriorates the estimation accuracy. This paper presents an alternative estimation method taking into account the above mutual information and applies our proposal to an iterative MAP (maximum a posteriori probability) decoder in order to improve its error correction capability. Computer simulations verify that the proposed scheme improves the PER (packet error rate) performance with the conventional method, and the required E SN0 obtaining a PER of 1 % is improved by about 1.0 dB at maximum. Note that our proposed method is called the twin iterative decoder (twin turbo decoder) because it has double feedback loops

This paper proposes rotational orthogonal frequency division multiplexing (R-OFDM) transmission with multi-dimensional demodulator (MDD) and twin turbo decoder (T2D). R-OFDM uses rotational multi-carrier modulation (R-MCM), which provides suitable frequency diversity gain in any coding rates although coded OFDM cannot obtain it in high coding rates. In addition, by applying MDD to its receiver, R-OFDM does not cause inter symbol interference degrading multi-carrier code division multiplexing (MC-CDM) with Walsh code multiplexing (WCM). Then, aiming at high spectrum efficiency, T2D is also proposed. T2D is based on a turbo decoder and has the proposed likelihood estimation taking into account the mutual information between multiplexed bits in the identical received symbol. Computer simulations verify that the proposed scheme improves the packet error rate (PER) performance of not only MC-CDM with WCM, but also OFDM, and the required Es/N0 of the OFDM obtaining a PER of 1% is improved by about 1.5 dB at the maximum.

This paper proposes a symbol mapping scheme on sub-carriers in use of MC-CDMA (multi carrier-code division multiple access) and LDPC (low-density parity-check) codes. Aiming at high spectrum efficiency, 16QAM modulation and LDPC codes with the PICW (progressively increased column-weight) are used here. The PICW-LDPC code is proposed in our previous studies and is proved to have better decoding performance as rate-compatible LDPC codes. By adopting the proposed symbol mapping method, the FER (frame error rate) performance of the PICW-LDPC code is improved, the required Es/N0 is reduced by 0.12 dB in an AWGN channel. In order to improve FER performance in the multi-path channel, the proposed sub-carrier mapping is further applied, and the required Es/N0 can also be reduced by 2.32 dB

We have developed an AMS 41Ca measurement technique using a 7Li37Cl molecular pilot beam with which the terminal voltage can be stabilized precisely. 41CaH3− ions have been produced from mixtures of CaF2 and TiH2. 40Ca and 42Ca ions produce a strong background. 41Ca is clearly identified from these background ions by using a newly developed gas ΔE-position sensitive E counter telescope.

This paper proposes a feature extraction method that represents both the periodicity and aperiodicity of speech for robust speech recognition. The development of this feature extraction method was motivated by findings in speech perception research. With this method, the speech sound is filtered by Gammatone filter banks, and then the output of each filter is comb filtered. Individual comb filters designed for each output signal of the Gammatone filter are used to divide the output of each filter into its periodic and aperiodic features in the sub band. The power suppressed by comb filtering is considered to be a periodic feature, whereas the power of the residue after comb filtering is considered to be an aperiodic feature. This method uses both features as the feature parameters for automatic speech recognition. A preliminary experiment using a five vowel recognition task designed to compare the proposed approach with the conventional MFCC-based feature extraction method shows that the proposed method improves vowel recognition rates by as much as 14.7 % in the presence of pink noise or a harmonic complex tone interferer. An evaluation experiment undertaken using the Aurora-2J database (Japanese noisy digit recognition database) to compare the proposed approach with the MFCC-based conventional (baseline) feature extraction method shows that the proposed method reduces the word error rate by as much as 59.62 %, with an average value of 18.21 %.

Schoolteachers are still confused with ICT education in Japan. Teachers who have already practiced ICT education and have practical know-how should be delivered to assist ordinary teachers. We developed and distributed the useful materials for practice of Japanese ICT education through the website "FATHeRS". We had run it as a pavilion in Japanese Internet Fair 2001. Consequently, the website obtained a lot of accesses of about 9,000 page views per a day. The mainly used contents were "Everyday Digital Camera Map" and "ICT quiz" for students. In the materials for teachers, "the Collection of Practical Illustrations," "One Point Advice" and "Let's Try ICT Education" were often accessed. "FATHeRS" is the only website distributes such materials systematically for schools in Japan. So, "FATHeRS" was thought advisable and won many prizes in ICT education area.

A chip level redundant self-checking fail-safe microprocessor has been developed using a 0.35 /spl mu/m CMOS embedded gate array. The microprocessor integrates two synthesizable processor cores and a self-checking comparator in a single chip. A full-custom processor core was transformed into each of the synthesizable cores for this purpose. Design methodologies suitable for reusing synthesizable processor cores has also been developed. Developed synthesizable processor cores and design methodologies reduce the cost of process migration of the chip. Migrating to the newer process improves the performance of the developed microprocessor with low development cost.

Parameters of a weaving trajectory consisting of amplitudes and phases are learned so that an evaluating function of error which is computed from accelerometer data is minimized. Two methods of learning are applied to robot manipulators: a basic method with high stability and a high speed algorithm using a model. Experimental results showed that learning methods can successfully improve weaving trajectories. The second method considerably improved the learning efficiency to only less than 30 times of repetitions of the learning process at most. A good weaving motion along welding lines was realized without any sensor feedback by interpolating the learned parameter values. >

The muscles of mastication and their related skull characters in the Caspian seal (Phoca caspica) were anatomically examined and compared with those of the Baikal (Phoca sibirica) and ringed (Phoca hispida) seals. A well-developed masseter muscle was observed in the Caspian seal, whereas the temporal muscle consisted of thin bundles. The skull of the Caspian seal possessed the same thin frontal bone and the dorso-ventrally developed zygomatic arch found in the Baikal seal that are required to install the enlarged eyeball into the orbit. The temporal bone was not robust, and the digastric muscle was well-developed in the ventral space of the auditory bulla. The present results suggest that the skull form of the Caspian seal has changed morphologically from its ringed seal-like ancestors, and suggest that the evolutionary strategy of the muscles of mastication in the Caspian seal is principally consistent with that of the Baikal seal.

PHI is an experimental distributed deductive database system. It is implemented on personal sequential inference machines (PSIs). A deductive database consists of intensional and extensional databases. PHI is composed of two layers which handle intensional and extensional databases, respectively. The query language of PHI is Datalog and its query processing is performed in a bottom-up manner. Query optimization of PHI is the combination of query transformation and techniques developed for relational databases. A discussion is presented of the design, implementation, and evaluation of the deductive database part of PHI. >

Fast fault detection and recovery are indispensable to improve the availability of fail-safe and fault-tolerant systems. Fast fault detection and recovery can be realized by clock-synchronized duplicated systems with optimal time diversity, which have fast fault detection and recovery features. The experiments presented in this paper compare fault detection coverage and retry recovery coverage of a clock-synchronized system without optimal time diversity, a clock-synchronized system with optimal time diversity, and an I/O synchronized system. The experimental results show that clock-synchronized systems with optimal time diversity realize the highest fault detection and recovery coverage.

This paper discusses global query processing of databases scattered in large networks. These databases may be independently designed even if they store related information. Ordinal multidatabase approach may not be effective in open environment because user may want to get information from many sites whose database schemas are not known. We propose an approach based on an incomplete database concept in order to retrieve necessary information by simultaneously querying various databases without knowing the exact schema of each database. The proposed approach can be implemented using existing database management systems.