584 research outputs found
Robust estimation of directions-of-arrival in diffuse noise based on matrix-space sparsity
We consider the estimation of the Directions-Of-Arrival (DOA) of target signals in diffuse noise. The state-of-the-art MUltiple SIgnal Classification (MUSIC) algorithm necessitates accurate identification of the signal subspace. In diffuse noise, however, it is difficult to identify it directly from the observed spatial covariance matrix. In our approach, we estimate the target spatial covariance matrix, so that we can identify the orthogonal complement of the signal subspace as its null space. We present a unified framework for modeling noise covariance in a matrix space, which generalizes four state-of-the-art diffuse noise models. We propose two alternative algorithms for estimating the target spatial covariance matrix, namely Low-rank Matrix Completion (LMC) and Trace Norm Minimization (TNM). These rely on denoising of the observed spatial covariance matrix via orthogonal projection onto the orthogonal complement of the noise matrix subspace. The missing component lying in the noise matrix subspace is then completed by exploiting the low-rankness of the target spatial covariance matrix. Large-scale experiments with real-world noise show that TNM with a certain noise model outperforms conventional MUSIC based on Generalized EigenValue Decomposition (GEVD) by 5% in terms of the precision averaged over the dataset
Arsenic Contamination of Groundwater at the Middle Basin of Ganges in India
This paper shows the situation and mechanism of arsenic contamination of groundwater at the worst contaminated areas in UP (Uttar Pradesh) state, India, which is obtained from the integrated arsenic mitigation project by University of Miyazaki under the Japan International Cooperation Agency (JICA) Partnership Program (JPP). The project has been executed from 2008 until now. The integrated mitigation, such as the raising awareness of villager, installing of alternative water supply units and healthcare of arsenocosis patients, have been executed at the 2 villages. The symptom of the arsenocosis patients was not so severe, which will be, therefore, improved by drinking arsenic-safe water supplied through arsenic removal units, installed by this project. We have obtained following results for the situation and mechanism of arsenic contamination of groundwater, objected in connection with the installation of arsenic removal units:(1) Groundwater is almost contaminated with arsenic in deep tubewell (depth: about 30m), but scarcely in shallow tubewell (depth: about 10m). (2) Arsenic contaminated groundwater is under the reduced condition with the oxidized condition for no-arsenic contaminated groundwater. (3) Arsenic concentration shows almost linear correlation with concentrations of Fe2+ and NH4+-N. (4) Ground is composed of sand with high arsenic content at around 25m depth. (5) Arsenic exists mainly in the phase of reducible fraction or weak acid soluble fraction but no oxidizable fraction in the ground
Discovery and Disposal of an "Educational Problem" and Develoment of a Movement. : A Case Study of School Refusal
When an educational phenomenon becomes a social problem, we should not only be skeptical of such a definition but also analyze it in its own right. In modern Japan, educational problems are discovered one after another. However, they are only \u27disposed\u27 by means of medical treatment or moral condemnation, and the phenomena themselves never vanish. We then refer to a case of contemporary School Refusal Problem. Professionals such as psychiatrists attempt to define it as sick and to deal with it exclusively. But on the other, some people actively claim that it is a sign of illness of school, education, or society and that it affects sensitive children. Children who refuse to attend school are potential threats to compulsory educaton system. So it is possible that this problem develops into dispute about maintenance and change of the most fundamental assumption of educational system
Synthesis of Novel Phosphorus-Substituted Stable Isoindoles by a Three-Component Coupling Reaction of ortho-Phthalaldehyde, 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-Oxide, and Primary Amines
A three-component coupling reaction of ortho-phthalaldehyde, 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide, and various primary amines readily afforded novel phosphorus-substituted stable isoindoles in good to excellent yields. The importance of the reversible ring-opening of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide by methanolysis in the three-component coupling reaction became apparent
Predictors of cognitive function in patients with hypothalamic hamartoma following stereotactic radiofrequency thermocoagulation surgery
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138275/1/epi13838.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138275/2/epi13838_am.pd
Realtime Motion Generation with Active Perception Using Attention Mechanism for Cooking Robot
To support humans in their daily lives, robots are required to autonomously
learn, adapt to objects and environments, and perform the appropriate actions.
We tackled on the task of cooking scrambled eggs using real ingredients, in
which the robot needs to perceive the states of the egg and adjust stirring
movement in real time, while the egg is heated and the state changes
continuously. In previous works, handling changing objects was found to be
challenging because sensory information includes dynamical, both important or
noisy information, and the modality which should be focused on changes every
time, making it difficult to realize both perception and motion generation in
real time. We propose a predictive recurrent neural network with an attention
mechanism that can weigh the sensor input, distinguishing how important and
reliable each modality is, that realize quick and efficient perception and
motion generation. The model is trained with learning from the demonstration,
and allows the robot to acquire human-like skills. We validated the proposed
technique using the robot, Dry-AIREC, and with our learning model, it could
perform cooking eggs with unknown ingredients. The robot could change the
method of stirring and direction depending on the status of the egg, as in the
beginning it stirs in the whole pot, then subsequently, after the egg started
being heated, it starts flipping and splitting motion targeting specific areas,
although we did not explicitly indicate them
S-Wave Site Amplification Factors from Observed Ground Motions in Japan: Validation of Delineated Velocity Structures and Proposal for Empirical Correction
We first derived site amplification factors (SAFs) from the observed strong motions by the Japanese nationwide networks, namely, K-NET and KiK-net of National Institute of Earthquake Research and Disaster Resilience and Shindokei (Instrumental Seismic Intensity) Network of Japan Meteorological Agency by using the so-called generalized spectral inversion technique. We can use these SAFs for strong motion prediction at these observation sites, however, we need at least observed weak motion or microtremor data to quantify SAF at an arbitrary site. So we tested the capability of the current velocity models in Japan whether they can reproduce or not the observed SAFs at the nearest grid of every 250Â m as the one-dimensional theoretical transfer functions (TTF). We found that at about one-half of the sites the calculated 1D TTFs show more or less acceptable fit to the observed SAFs, however, the TTFs tend to underestimate the observed SAFs in general. Therefore, we propose a simple, empirical method to fill the gap between the observed SAFs and the calculated TTFs. Validation examples show that our proposed method effectively predict better SAFs than the direct substitute of TTFs at sites without observed data
Effective Synthesis of Poly(2,6-Dimethyl-1,4-Phenylene Oxide) Derivatives by Oxidative Coupling Copolymerization of Alkoxyphenols with Copper(II) Catalyst
The oxidative coupling copolymerization between 2,6-dimethylphenol (DMP) and phenols having various alkoxy groups, such as methyoxy (MOP), ethoxy, benzyloxy, butoxy, and 2-hydroxyethoxy groups, was carried out using a copper(II) catalyst under an O2 atmosphere. The copolymerizations with alkoxyphenols effectively proceeded, and the unit ratios of the obtained copolymers were in good agreement with those in the feed. The coupling regioselectivity, such as oxyphenylene (CO) and phenylene (CC), of the alkoxyphenol unit constructed during the copolymerization was also estimated by the 1H NMR analysis of the acetylated polymer. As an example, the copolymer with the unit ratios of DMP:p-MOP = 50:50 and CO:CC = 67:33, was obtained in 71% yield during the copolymerization with p-MOP (feed ratio, 50:50) in a mixed solvent of CH2Cl2 and methanol (7/1 (v/v)) for 24 h. The solubility and thermal property of the obtained copolymers were significantly affected by the structure of alkoxyphenol unit
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