458 research outputs found
Acoustic echo and noise canceller for personal hands-free video IP phone
This paper presents implementation and evaluation of a proposed acoustic echo and noise canceller (AENC) for videotelephony-enabled personal hands-free Internet protocol (IP) phones. This canceller has the following features: noise-robust performance, low processing delay, and low computational complexity. The AENC employs an adaptive digital filter (ADF) and noise reduction (NR) methods that can effectively eliminate undesired acoustic echo and background noise included in a microphone signal even in a noisy environment. The ADF method uses the step-size control approach according to the level of disturbance such as background noise; it can minimize the effect of disturbance in a noisy environment. The NR method estimates the noise level under an assumption that the noise amplitude spectrum is constant in a short period, which cannot be applied to the amplitude spectrum of speech. In addition, this paper presents the method for decreasing the computational complexity of the ADF process without increasing the processing delay to make the processing suitable for real-time implementation. The experimental results demonstrate that the proposed AENC suppresses echo and noise sufficiently in a noisy environment; thus, resulting in natural-sounding speech
Multimodal Compact Bilinear Pooling for Visual Question Answering and Visual Grounding
Modeling textual or visual information with vector representations trained
from large language or visual datasets has been successfully explored in recent
years. However, tasks such as visual question answering require combining these
vector representations with each other. Approaches to multimodal pooling
include element-wise product or sum, as well as concatenation of the visual and
textual representations. We hypothesize that these methods are not as
expressive as an outer product of the visual and textual vectors. As the outer
product is typically infeasible due to its high dimensionality, we instead
propose utilizing Multimodal Compact Bilinear pooling (MCB) to efficiently and
expressively combine multimodal features. We extensively evaluate MCB on the
visual question answering and grounding tasks. We consistently show the benefit
of MCB over ablations without MCB. For visual question answering, we present an
architecture which uses MCB twice, once for predicting attention over spatial
features and again to combine the attended representation with the question
representation. This model outperforms the state-of-the-art on the Visual7W
dataset and the VQA challenge.Comment: Accepted to EMNLP 201
Intra-Day Variation of Urinary Nuclear Matrix Protein 22
Nuclear Matrix Protein 22 (NMP22), a urinary tumor marker for urothelial
cancers, is directly released into the urine from the nucleus after cell death, Accordingly,
values of NMP22 do not requlre adjustment using other substances such as urinary
creatinine. On the other hand, its values might vary according to urine concentration.
This study investigated the intra-day variation in the urinary level of NMP22. NMP22
and urinary creatinine were measured in a 24-hour urine sample and 4 spot urine
samples obtained from 20 inpatients (10 with bladder cancer, and 10 with non-urothelial
cancer or benign tumors). The spot urine samples were collected at 6 a.m., 10 a.m., 2p.m.
and 9 p.m. There were no significant differences in NMP22 values between the 24-hour
and spot samples in all patients. Out of 10 bladder cancer patients, 6 had positive
24-hour samples. Among these 6 patients, only 3 had 4 positive spot samples (>12.O
U/ml): one had 3 positive samples, and 2 had one positive sample. Among the controls,
only one patient with renal cancer had a positive 24-hour sample. Only 3 controls, 2 With
prostatic cancer and one with renal cancer, had a single positive spot sample. The
highest margin between the maximum and minimum levels in the 4 spot samples was
237.8 U/ml in the bladder cancer patients and 16.6 U/ml in the controIs. When the ratios
of NMP22 and urinary creatinine values for the 24-hour to spot samples were calculated
in each patient, a significant correlation was observed between the ratios of NMP22 and
urinary creatinine (r=0.575, p<0.001). The urinary level of NMP22 shows intra-day
variation and might be affected by the extent of the concentration of urine samples. The
measurement results must be judged with this in mind, especially when judging the
results around the cut-off value
The Second Survey of the Molecular Clouds in the Large Magellanic Cloud by NANTEN. II. Star Formation
We studied star formation activities in the molecular clouds in the Large
Magellanic Cloud. We have utilized the second catalog of 272 molecular clouds
obtained by NANTEN to compare the cloud distribution with signatures of massive
star formation including stellar clusters, and optical and radio HII regions.
We find that the molecular clouds are classified into three types according to
the activities of massive star formation; Type I shows no signature of massive
star formation, Type II is associated with relatively small HII region(s) and
Type III with both HII region(s) and young stellar cluster(s). The radio
continuum sources were used to confirm that Type I GMCs do not host optically
hidden HII regions. These signatures of massive star formation show a good
spatial correlation with the molecular clouds in a sense they are located
within ~100 pc of the molecular clouds. Among possible ideas to explain the GMC
Types, we favor that the Types indicate an evolutionary sequence; i.e., the
youngest phase is Type I, followed by Type II and the last phase is Type III,
where the most active star formation takes place leading to cloud dispersal.
The number of the three types of GMCs should be proportional to the time scale
of each evolutionary stage if a steady state of massive star and cluster
formation is a good approximation. By adopting the time scale of the youngest
stellar clusters, 10 Myrs, we roughly estimate the timescales of Types I, II
and III to be 6 Myrs, 13 Myrs and 7 Myrs, respectively, corresponding to a
lifetime of 20-30 Myrs for the GMCs with a mass above the completeness limit, 5
x 10^4 Msun.Comment: accepted to the Astrophysical Journal Supplement Series. 20 figures
and 4 tables. Higher resolution color PDF is found at
http://www.a.phys.nagoya-u.ac.jp/~kawamura/research/NANTEN_LMC_2_preprint.pdf
(47 pages,32MB
Molecular Orientation in a Variable-Focus Liquid Crystal Lens Induced by Ultrasound Vibration
A method to estimate orientation direction of liquid crystal molecules three-dimensionally under ultrasound excitation was proposed and the relationship between the ultrasound vibration and the molecular orientation was discussed. Our group have reported a technique to control orientation direction of liquid crystal molecules using ultrasound vibration which could be applied to an optical variable-focus liquid crystal lens. The lens consisted of a liquid crystal layer sandwiched by two glass circular discs and a piezoelectric ring. Ultrasound vibration induces change in the refractive index of the lens, enabling the variable-focus function. The three-dimensional orientation direction of the liquid crystal molecules in the lens was predicted from the transmitted light distributions under the crossed Nicol conditions. The liquid crystal molecules were inclined from vertical alignment by the ultrasound vibration, and larger ultrasound vibration gave larger inclination of the molecules. There was a strong correlation between the distributions of ultrasound vibration and the liquid crystal molecular orientation; the molecular orientation was changed remarkably between the antinodal and nodal parts of the ultrasound flexural vibration on the glass plate and the molecules aligned towards the antinode
Photoluminescence and photoluminescence excitation spectra from AlN doped with Gd3+
The photoluminescence (PL) spectra from Al0.98Gd0.02N andAl0.87Gd0.13N consisting of Gd3+ related 3.95 eV sharp emis-sion lines and other bands, and the PL excitation (PLE) spec-tra from 3 to 7 eV have been investigated by using a highly linear polarized synchrotron radiation light source. The Gd related 3.95 eV sharp lines in the PL spectra are similar to those in other cathodoluminescence (CL) and PL research. However, the broad emission bands around 3.95 eV lineswhich are normally found in other CL works are not ob- served. Other broad emission bands are clearly observed in the energy region of 1.5 ~ 3.5 eV. PLE spectra monitored at both the 3.95 eV sharp line and the broad emission band ofAl0.98Gd0.02N clearly indicate that these emission processes are host excitations which are reflected by an AlN-like band structure and crystalline anisotropy. On the other hand, the PLE and optical reflectance spectra of Al0.87Gd0.13N reveal an unclear band structure with a long band tail in the lower en-ergy side
Bone morphogenetic protein-2 functions as a negative regulator in the differentiation of myoblasts, but not as an inducer for the formations of cartilage and bone in mouse embryonic tongue
<p>Abstract</p> <p>Background</p> <p>In vitro studies using the myogenic cell line C2C12 demonstrate that bone morphogenetic protein-2 (BMP-2) converts the developmental pathway of C2C12 from a myogenic cell lineage to an osteoblastic cell lineage. Further, in vivo studies using null mutation mice demonstrate that BMPs inhibit the specification of the developmental fate of myogenic progenitor cells. However, the roles of BMPs in the phases of differentiation and maturation in skeletal muscles have yet to be determined. The present study attempts to define the function of BMP-2 in the final stage of differentiation of mouse tongue myoblast.</p> <p>Results</p> <p>Recombinant BMP-2 inhibited the expressions of markers for the differentiation of skeletal muscle cells, such as myogenin, muscle creatine kinase (MCK), and fast myosin heavy chain (fMyHC), whereas BMP-2 siRNA stimulated such markers. Neither the recombinant BMP-2 nor BMP-2 siRNA altered the expressions of markers for the formation of cartilage and bone, such as osteocalcin, alkaline phosphatase (ALP), collagen II, and collagen X. Further, no formation of cartilage and bone was observed in the recombinant BMP-2-treated tongues based on Alizarin red and Alcian blue stainings. Neither recombinant BMP-2 nor BMP-2 siRNA affected the expression of inhibitor of DNA binding/differentiation 1 (Id1). The ratios of chondrogenic and osteogenic markers relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH, a house keeping gene) were approximately 1000-fold lower than those of myogenic markers in the cultured tongue.</p> <p>Conclusions</p> <p>BMP-2 functions as a negative regulator for the final differentiation of tongue myoblasts, but not as an inducer for the formation of cartilage and bone in cultured tongue, probably because the genes related to myogenesis are in an activation mode, while the genes related to chondrogenesis and osteogenesis are in a silencing mode.</p
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