Identification of chemical oviposition stimulants from rice grain forSitophilus zeamais motschulsky (Coleoptera,Curculionidae)

Chemical components stimulating oviposition bySitophilus zeamais in rice grain were isolated from rice bran and were found to be a mixture of ferulates, diglycerides, and free sterols. Oviposition preference of the species can be induced by synergistic action of these compounds.     

Efficient blind dereverberation and echo cancellation based on independent component analysis for actual acoustic signals

This letter presents a new algorithm for blind dereverberation and echo cancellation based on independent component analysis (ICA) for actual acoustic signals. We focus on frequency domain ICA (FD-ICA) because its computational cost and speed of learning convergence are sufficiently reasonable for practical applications such as hands-free speech recognition. In applying conventional FD-ICA as a preprocessing of automatic speech recognition in noisy environments, one of the most critical problems is how to cope with reverberations. To extract a clean signal from the reverberant observation, we model the separation process in the short-time Fourier transform domain and apply the multiple input/output inverse-filtering theorem (MINT) to the FD-ICA separation model. A naive implementation of this method is computationally expensive, because its time complexity is the second order of reverberation time. Therefore, the main issue in dereverberation is to reduce the high computational cost of ICA. In this letter, we reduce the computational complexity to the linear order of the reverberation time by using two techniques: (1) a separation model based on the independence of delayed observed signals with MINT and (2) spatial sphering for preprocessing. Experiments show that the computational cost grows in proportion to the linear order of the reverberation time and that our method improves the word correctness of automatic speech recognition by 10 to 20 points in a RT??= 670 ms reverberant environment.     

Chemical and Chromatic Bases for Preferential Visiting By the Cabbage Butterfly, Pieris rapae, to Rape Flowers

Scent and coloration of corolla were examined as floral attributes responsible for preferential visiting by the cabbage butterfly, Pieris rapae, to rape flower, Brassica rapa. Floral volatile components that release the flower-visiting behavior of the butterfly were identified by chemical analyses, electroantennography (EAG), and two behavioral bioassays: proboscis extension reflex (PER) in response to odor and attraction to artificial flowers. GC and GC-MS analyses of the headspace volatiles from the flowers revealed the presence of six aromatic compounds, benzaldehyde, phenylacetaldehyde, benzyl alcohol, 2-phenylethanol, phenylacetonitrile, and indole in decreasing order of quantity. Of these, phenylacetaldehyde elicited the highest response in the PER assay. While benzyl alcohol, 2-phenylethanol, benzaldehyde, and phenylacetonitrile evoked moderate responses, the PER-eliciting activity of indole was very weak. In two-choice behavioral bioassays, artificial flowers scented with any one of these PER-active compounds attracted significantly more butterflies than control (unscented) flowers, whereas those treated with indole were almost inactive. The EAG activities of the six chemicals were not high and were about the same at a low dose (1 g), but phenylacetaldehyde elicited a much stronger response from both sexes at higher doses (10 and 100 g). An overall profile of EAG responses at a dose of 100 g was analogous to that of PER performance, suggesting that floral volatiles may be involved in close-range location or recognition of flowers rather than long-range attraction. By spectroscopic and UV-photographic examinations of rape flower, the central part of the corolla was found to absorb UV rays in marked contrast to the other parts, which reflected near-UV rays (_max = 350 nm). This indicates that the flower is endowed with a conspicuous nectar guide that is probably an important visual stimulus for attracting foraging adults of P. rapae. Consequently, the present findings strongly suggest that this elaborate pollination strategy of rape flower, characterized by its good combination of olfactory and visual attractiveness, accounts for preferential visiting by the cabbage butterfly to the flower.     

Studies of the pH of the membrane surface in a laboratory chlor-alkali cell

The pH on the surface of an ion-exchange membrane was measured with a microprobe in a laboratory scale chlor-alkali cell to study the leakage of OH^– through the membrane. The solution pH in the vicinity of the membrane facing the anode was found to be considerably higher than that in the bulk solution because of penetration and leakage of OH^–. The pH varied with the membrane type. This explains why the carboxylate membrane is not protonated and can be used as a separator in chlor-alkali cells.Deceased.     

Size Distribution of Gold Nanoparticles Used by Small Angle X-ray Scattering

The size distribution of gold nanoparticles was estimated based on the scattering intensity data obtained from small angle X-ray scattering (SAXS) and compared with the result of micrographs by transmission electron microscopy. The slope of the Guinier plot was used to estimate the mean size assuming a narrow particle size distribution. When the size distribution is narrow, the mean size can be easily obtained from slope of a Guinier plot of scattering data within 10% error. Additionally, assuming a lognormal size distribution, the size distribution and the mean size can be calculated using the experimental SAXS data in the fitting analysis. The histogram method, which utilizes the coefficient matrix of scattering intensity, was also applied to the estimation of the size distribution, and this method could be useful for a rough estimate of the size distribution.     

Analysis of PD-generated SF/sub 6/ decomposition gases adsorbed on carbon nanotubes

Chemical byproducts analysis has been recognized as a powerful diagnosis method for SF₆ gas-insulated switchgear (GIS). The authors have previously demonstrated that a carbon nanotube (CNT) gas sensor could detect partial discharge (PD) generated in SF₆ gas. However, PD-generated decomposition gas species, which were responsible for the CNT gas sensor response, have not been identified yet. In this paper, two kinds of experiments were conducted in order to identify the responsible decomposition gas species. At first, the decomposition gas molecules adsorbed on CNTs were analyzed by Fourier transformation infrared (FTIR) spectroscopy. FTIR absorbance was observed around 735 cm^-1 after CNTs were exposed to PD generated in SF₆. In the second experiment, the CNT gas sensor responses to typical SF₆ decomposition products (HF and SF₄) were examined. The CNT gas sensor responded to these gases in the same way as to PD generated in SF₆. SF₄ response was larger than HF response. Based on these results, SF ₄ and SOF₂ emerged as candidates for the responsible decomposition gases. Electrochemical interactions between adsorbed gas molecules and CNT were discussed based on theoretical predictions of molecular orbital calculations. The calculation results suggested that both of SOF₂ and SF₄ could increase the CNT gas sensor conductance     

Impurity effect on Kramer-Pesch core shrinkage ins-wave vortex and chiralp-wave vortex

The low-temperature shrinking of the vortex core (Kramer-Pesch effect) is studied for an isolated single vortex for chiral p-wave and s-wave superconducting phases. The effect of nonmagnetic impurities on the vortex core radius is numerically investigated in the Born limit by means of a quasiclassical approach. It is shown that in the chiral p-wave phase the Kramer-Pesch effect displays a certain robustness against impurities owing to a specific quantum effect, while the s-wave phase reacts more sensitively to impurity scattering. This suggests chiral p-wave superconductors as promising candidates for the experimental observation of the Kramer-Pesch effect.     

Multi-modal Information Integration for Interactive Multi-agent Systems

This paper proposes a multi-agent system that carries out cooperative work. To achieve this, we use Fuzzy Associative Memory Organizing Unit Systems (FAMOUS) and Conceptual Fuzzy Sets (CFS). By using these proposed methods, each agent robot can decide its own behaviour to suit the situation in its environment. We apply this system to an Intelligent Transportation System (ITS) and do simulations.     

Work-time optimal k-merge algorithms on the PRAM

For 2⩽k⩽n, the k-merge problem is to merge a collection of ksorted sequences of total length n into a new sorted sequence. The k-merge problem is fundamental as it provides a common generalization of both merging and sorting. The main contribution of this work is to give simple and intuitive work-time optimal algorithms for the k-merge problem on three PRAM models, thus settling the status of the k-merge problem. We first prove that Ω(n log k) work is required to solve the k-merge problem on the PRAM models. We then show that the EREW-PRAM and both the CREW-PRAM and the CRCW require Ω(log n) time and Ω(log log n+log k) time, respectively, provided that the amount of work is bounded by O(n log k). Our first k-merge algorithm runs in Θ(log n) time and performs Θ(n log k) work on the EREW-PRAM. Finally, we design a work-time optimal CREW-PRAM k-merge algorithm that runs in Θ(log log n+log k) time and performs Θ(n log k) work. This latter algorithm is also work-time optimal on the CREW-PRAM model. Our algorithms completely settle the status of the k-merge problem on the three main PRAM models     

Effect of O2 on NO removal by ammonia radical injection using one-cycle sinusoidal power source

NO reduction experiment was performed by injecting ammonia radicals, which were externally generated by flowing the NH₃ gas diluted with Ar gas through a dielectric barrier discharge with a one-cycle sinusoidal-wave power source. The discharge was intermittently formed between coaxial cylindrical electrodes with a space of 1.5 mm at an applied peak-to-peak voltage of 3-25 kV. The generated radicals were injected into simulation gas (NO/O₂/N₂). The simulation gas contained 0-5.6% O₂, and the effect of O₂ on NO_x removal was discussed. The minimum reaction temperature for NO reduction was low when simulation gas contained O₂. High O₂ concentration (O₂=5.6%) in simulation gas, high repetition rate to NH₃, and high applied power to NH₃ decreased NO removal efficiency.