An investigation of non-linear elastic behavior of CFRP laminates and strain measurement using Lamb waves

This paper investigates the non-linear elastic behavior of unidirectional and cross-ply CFRP laminates and proposes a new method to measure tensile strain using Lamb waves. Young’s modulus was measured as a function of strain in situ using Lamb wave velocity during a tensile test. The stiffening effect of the carbon fibers on [0]₈ specimens and the softening effect of the epoxy matrix on [90]₈ specimens were accurately evaluated. Young’s modulus of the 0° ply was obtained as a quadratic function of strain. Using the function and the rule of mixture, the dependence of Young’s modulus on strain was accurately predicted for cross-ply laminates. Based on the results, the tensile strain was quantitatively correlated with the corresponding arrival time of the Lamb waves. The strains obtained from the proposed method agreed well with those from the strain gauge. Finally, the effect of transverse cracks on the in situ Young’s modulus of the cross-ply laminate under a tensile load was investigated. This method clearly detected even a small decrease in the Young’s modulus due to the transverse cracks in stiffening cross-ply laminate.     

Incremental Focus of Attention for Robust Vision-Based Tracking

We present the Incremental Focus of Attention (IFA) architecture for robust, adaptive, real-time motion tracking. IFA systems combine several visual search and vision-based tracking algorithms into a layered hierarchy. The architecture controls the transitions between layers and executes algorithms appropriate to the visual environment at hand: When conditions are good, tracking is accurate and precise; as conditions deteriorate, more robust, yet less accurate algorithms take over; when tracking is lost altogether, layers cooperate to perform a rapid search for the target and continue tracking.Implemented IFA systems are extremely robust to most common types of temporary visual disturbances. They resist minor visual perturbances and recover quickly after full occlusions, illumination changes, major distractions, and target disappearances. Analysis of the algorithm's recovery times are supported by simulation results and experiments on real data. In particular, examples show that recovery times after lost tracking depend primarily on the number of objects visually similar to the target in the field of view.     

Molecular beam epitaxial growth of SrO and CaO with RHEED intensity oscillation

SrO and CaO, related compounds of BSCCO superconductor, are grown onto SrTiO₃(100) substrates with molecular beam epitaxy(MBE) technique. During growth, the specular spots of RHEED patterns show intensity oscillations, indicating two dimensional growth. The periods of oscillations are utilized to calculate the atom fluxes. It is shown that sublimation processes of both Sr and Ca metals in the effusion cells are stable under the growth condition of oxide films. The periods of oscillations during the SrO growth are independent of substrate temperature, confirming that Sr atoms are oxidized immediately and stay on the substrate surface without re-evaporation. These informations are practically available for precise control of the atomic layer controlled MBE of BSCCO superconductor thin films.On leave from Superconductiivity Research Laboratory, ISTEC.     

Dual-Mode Space-Temporal Simultaneous Processing Equalizer

A tapped delayed line adaptive array antenna (TDL-AAA) and a space-temporal simultaneous processing equalizer (ST-SPE) are proposed as simple space-temporal equalizers based on minimum mean square error (MMSE) criterion. The ST-SPE has a compact hardware with a small number of taps compared to that of the TDL-AAA. The ST-SPE can reduce the computational complexity of the space-temporal joint equalization and it works effectively under the minimum phase condition such as appeared at line-of-sight (LOS) propagation environments at a high antenna height base station. However the ST-SPE cannot work under a non-minimum phase condition caused under N-LOS (non-line-of-sight). On the other hand, the TDL-AAA whose reference signal is synchronized at the center tap (TDL-AAA_C) can work even in the non-minimum phase condition. In this paper, we propose a dual-mode space-temporal simultaneous processing equalizer (Dual-mode ST-SPE) which has a simple configuration and also works in non-minimum phase condition. The Dual-mode ST-SPE can reduce the computational complexity compared to the TDL-AAA_C. Yoshihiro Ichikawa received the B.E. degree in department of communication engineering, in National Defense Academy in 1995, and M.E. and D.E. degree from Ibaraki University in 2001 and 2004, respectively. He joined the Japan Air Self Defense Force in 1995. His research interests are an adaptive algorithm, an antenna design, and an adaptive array antenna. Shigeki Obote received his B.E., M.E. and D.E. degrees in electrical and electronic engineering from Tottori University, Tottori, Japan, in 1996, 1998 and 2000, respectively. Since 2000, he has been with department of media and telecommunications engineering, faculty of engineering, Ibaraki University, Ibaraki, Japan, where he is currently a associate professor. His research interests are in adaptive array antenna and wireless communications systems. Kenichi Kagoshima received the B.E., M.E. and D.E. degrees in electronics engineering from the Tokyo Institute of Technology, Tokyo, Japan, in 1969, 1971, and 1974, respectively. He joined the Nippon Telegraph and Telephone Corporation (NTT) Laboratory in 1974 and researched and developed many kinds of radio communication antennas. Since 1997, he has been a professor at Ibaraki University, Ibaraki, Japan. Dr. Kagoshima was a Secretary and Treasure, Vice Chairman, and Chairman of the IEEE AP-S Tokyo Chapter in 1992, 1993, and 1994, respectively. He was a chair of antennas and propagation professional group of IEICE in 1999 and 2000. In 1973, he received the Yonezawa Prize for Young Engineers and 1998, best paper award from IEICE, respectively.     

Quantum search with certainty based on modified Grover algorithms: optimum choice of parameters

In the original Grover algorithm, an exact or almost exact search such that the success probability is unity or infinitesimally close to unity is possible only for certain values of the fraction λ =  M/N where M is the number of marked items that are stored in an unsorted database of N items. There are various modified algorithms with an adjustable phase or phases such that an exact search can be done for any value of λ by means of a finite number of Grover-type operations. Among them, the algorithm proposed by Long is the simplest in the sense that it has only one adjustable phase and that the phase can be obtained in a closed form. We show that other more general algorithms with additional phases are not more efficient than Long’s version with a single phase.     

Temporal segmentation and assignment of successive actions in a long-term video

Temporal segmentation of successive actions in a long-term video sequence has been a long-standing problem in computer vision. In this paper, we exploit a novel learning-based framework. Given a video sequence, only a few characteristic frames are selected by the proposed selection algorithm, and then the likelihood to trained models is calculated in a pair-wise way, and finally segmentation is obtained as the optimal model sequence to realize the maximum likelihood. The average accuracy on IXMAS dataset reached to 80.5% at frame level, using only 16.5% of all frames in computation time of 1.57 s per video which has 1160 frames on the average.     

Synthesis of the Bi-2222 Compounds of Bi–Sr–Ln(Zr)–Cu–O (Ln = Sm,Eu, Gd,and Dy)

Bi-based superconducting compounds with the 2222 structure has been already synthesized in the Bi₂Sr₂- (Ln_1−x Ce _x )₂Cu₂O_10+y (Ln = Sm, Eu, and Gd) systems. One of the characteristics of these compounds is the existence of the fluorite-like (Ln_1−x Ce _x )₂O₂ block between two CuO₅ pyramids in the crystal structure. The tetravalent ions of Ce⁴⁺ are reported to be necessary to stabilize the 2222 structure. Recently, we have discovered that the Bi-2222 phase could be composed in the Bi₂Sr₂(Ln_2−x Zr _x )Cu₂O _z (Ln = Sm, Eu, Gd, and Dy) systems, where Zr⁴⁺ is used as a new tetravalent ion stabilizing the 2222 structure in stead of Ce⁴⁺. In the new system, nearly single 2222 phase samples have been obtained at the nominal composition of x=0.5 (Ln = Sm, Eu, and Gd) and in the range of 0.1≤x≤0.3 (Ln = Dy). Among them, the sample with Ln = Gd has the smallest resistivity at 273 K. But it is a semiconductor, and the conduction process at low temperatures is assumed to be followed by a two-dimensional VRH. The experimental results for the Gd samples with a partial substitution of Pb for Bi in the Bi₂Sr₂(Gd_2−x Zr _x )Cu₂O _z system are also reported.     

Macrocytic anemia with anisocytosis due to alcohol abuse and vitamin B6 deficiency

The effect of the choice of maternal age-specific prevalence curve on the model predicted Down syndrome detection rate was examined. All 19 published regression curves from 11 birth prevalence series in four meta-analyses were included. The detection rate for a five per cent false-positive rate was estimated for three combinations of markers. For free beta human chorionic gonadotropin and alpha-fetoprotein the lowest predicted detection rate was 62.3 per cent and the highest 64.1 per cent, a range of 1.8 per cent. When unconjugated oestriol was added as a third marker it was 65.6-67.3 per cent, a 1.7 per cent range, and when inhibin A was the fourth marker the detection rate was 72.0-73.4 per cent, a 1.4 per cent range. The number of series included in the regression had the biggest effect: when the authors had used a subset thought to have the highest ascertainment the predicted detection rate generally increased. The type of regression equation used and restrictions on the age range over which the regression was performed were less important factors. The effect of the choice of curve on the predicted increase in detection achieved by incorporating additional markers was relatively small: 3.1-3.3 per cent for unconjugated oestriol and a further 6.1-6.5 per cent for inhibin A. This analysis shows that the model inaccuracy caused by the maternal age curve is not small but is unlikely to be large enough to influence Down syndrome screening policy decisions.     

Synergetic improvement strategy on thermoelectric performance of CuAlO2 compacts

We fabricated Sr and Ca-doped CuAlO₂ compacts from the mixed powder of CuO, Cu₂O, Al₂O₃, and SrO or CaO by multi-pass hot pressing followed by spark plasma sintering (SPS). The XRD results showed the reaction of CuO, Cu₂O and Al₂O₃ was rather complete and only CuAlO₂ single phase was formed when the additive amount of SrO or CaO was appropriate. Multi-pass hot pressing increased the relative density and the usage of plate-like Al₂O₃ as reaction raw material enhanced the orientation degree. In spite of performance improvement conflicts through elemental doping, density increase and orientation improvement, the measurement on the thermoelectric performance indicated that the electrical resistivity, Seebeck coefficient, power factor, dimensionless figure of merit (ZT) were improved to varying degrees through the synergetic action of elemental doping, density increase, and orientation control. The highest power factor and ZT of the Ca-doped CuAlO₂ compacts reached 1.54?×?10^?4 W?m^?1 K^?2 and 0.015 at 973?K, respectively. The thermoelectric performance was higher than those of CuAlO₂ at the same temperature in published work before.     

Effect of surface roughness and surface modification of indium tin oxide electrode on its potential response to tryptophan

The effect of surface modification of indium tin oxide (ITO) electrode on its potential response to tryptophan was investigated for ITO substrates with different surface roughness. It was found that a small difference in surface roughness, between ∼1 and ∼2 nm of R_a evaluated by atomic force microscopy, affects the rest potential of ITO electrode in the electrolyte. A slight difference in In:Sn ratio at the near surface of the ITO substrates, measured by angle-resolved X-ray photoelectron spectrometry and Auger electron spectroscopy is remarkable, and considered to relate with surface roughness. Interestingly, successive modification of the ITO surface with aminopropylsilane and disuccinimidyl suberate, of which essentiality to the potential response to indole compounds we previously reported, improved the stability of the rest potential and enabled the electrodes to respond to tryptophan in case of specimens with R_a values ranging between ∼2 and ∼3 nm but not for those with R_a of ∼1 nm. It was suggested that there are optimum values of effective work function of ITO for specific potential response to tryptophan, which can be obtained by the successive modification of ITO surface.