346 research outputs found
Ambient Sound Helps: Audiovisual Crowd Counting in Extreme Conditions
Visual crowd counting has been recently studied as a way to enable people
counting in crowd scenes from images. Albeit successful, vision-based crowd
counting approaches could fail to capture informative features in extreme
conditions, e.g., imaging at night and occlusion. In this work, we introduce a
novel task of audiovisual crowd counting, in which visual and auditory
information are integrated for counting purposes. We collect a large-scale
benchmark, named auDiovISual Crowd cOunting (DISCO) dataset, consisting of
1,935 images and the corresponding audio clips, and 170,270 annotated
instances. In order to fuse the two modalities, we make use of a linear
feature-wise fusion module that carries out an affine transformation on visual
and auditory features. Finally, we conduct extensive experiments using the
proposed dataset and approach. Experimental results show that introducing
auditory information can benefit crowd counting under different illumination,
noise, and occlusion conditions. The dataset and code will be released. Code
and data have been made availabl
Deep Koopman Learning of Nonlinear Time-Varying Systems
A data-driven method is developed to approximate an nonlinear time-varying
system (NTVS) by a linear time-varying system (LTVS), based on Koopman Operator
and deep neural networks. Analysis on the approximation error in system states
of the proposed method is investigated. It is further shown by simulation on a
simple NTVS that the resulted LTVS approximate the NTVS very well with small
approximation errors in states. Furthermore, simulations on a cartpole further
show that optimal controller developed based on the achieved LTVS works very
well to control the original NTVS
An Event-Based Synchronization Framework for Controller Hardware-in-the-loop Simulation of Electric Railway Power Electronics Systems
The Controller Hardware_in_the_loop (CHIL) simulation is gaining popularity
as a cost_effective, efficient, and reliable tool in the design and development
process of fast_growing electrified transportation power converters. However,
it is challenging to implement the conventional CHIL simulations on the railway
power converters with complex topologies and high switching frequencies due to
strict real_time constraints. Therefore, this paper proposes an event-based
synchronization CHIL (ES_CHIL) framework for high_fidelity simulation of these
electrified railway power converters. Different from conventional CHIL
simulations synchronized through the time axis, the ES_CHIL framework is
synchronized through the event axis. Therefore, it can ease the real_time
constraint and broaden the upper bound on the system size and switching
frequency. Besides, models and algorithms with higher accuracy, such as the
diode model with natural commutation processes, can be used in the ES-CHIL
framework. The proposed framework is validated for a 350 kW wireless power
transformer system containing 24 fully controlled devices and 36 diodes by
comparing it with Simulink and physical experiments. This research improves the
fidelity and application range of the power converters CHIL simulation. Thus,
it helps to accelerate the prototype design and performance evaluation process
for electrified railways and other applications with such complex converters
Performance Evaluation of a THz Pulsed Imaging System: Point Spread Function, Broadband THz Beam Visualization and Image Reconstruction
Terahertz (THz) technology is a promising research field for various applications in basic science and technology. In particular, THz imaging is a new field in imaging science, where theories, mathematical models and techniques for describing and assessing THz images have not completely matured yet. In this work, we investigate the performances of a broadband pulsed THz imaging system (0.2–2.5 THz). We characterize our broadband THz beam, emitted from a photoconductive antenna (PCA), and estimate its point spread function (PSF) and the corresponding spatial resolution. We provide the first, to our knowledge, 3D beam profile of THz radiation emitted from a PCA, along its propagation axis, without the using of THz cameras or profilers, showing the beam spatial intensity distribution. Finally, we evaluate the THz image formation on a test-sample composed by a regular linen natural pattern
Identification and interaction analysis of key genes and microRNAs in hepatocellular carcinoma by bioinformatics analysis
Complete list of differentially expressed genes (DEGs) in GSE22058. (DOCX 183Ă‚Â kb
Simplified amino acid alphabets based on deviation of conditional probability from random background
The primitive data for deducing the Miyazawa-Jernigan contact energy or
BLOSUM score matrix consists of pair frequency counts. Each amino acid
corresponds to a conditional probability distribution. Based on the deviation
of such conditional probability from random background, a scheme for reduction
of amino acid alphabet is proposed. It is observed that evident discrepancy
exists between reduced alphabets obtained from raw data of the
Miyazawa-Jernigan's and BLOSUM's residue pair counts. Taking homologous
sequence database SCOP40 as a test set, we detect homology with the obtained
coarse-grained substitution matrices. It is verified that the reduced alphabets
obtained well preserve information contained in the original 20-letter
alphabet.Comment: 9 pages,3figure
Short-term surgical and long-term survival outcomes after laparoscopic distal gastrectomy with D2 lymphadenectomy for gastric cancer
BACKGROUND: Laparoscopic distal gastrectomy (LDG) for gastric cancer has gradually gained popularity. However, the long-term oncological outcomes of LDG have rarely been reported. This study aimed to investigate the survival outcomes of LDG, and evaluate the early surgical outcomes of laparoscopy-assisted distal gastrectomy (LADG) and totally laparoscopic distal gastrectomy (TLDG). METHODS: Clinical outcomes of 240 consecutive patients with gastric cancer who underwent LDG at our institution between October 2004 and April 2013 were analyzed. Early surgical outcomes of LADG and TLDG were compared and operative experiences were evaluated. RESULTS: Of the 240 patients, 93 underwent LADG and 147 underwent TLDG. There were 109 T1, 36 T2, 31 T3, and 64 T4a lesions. The median follow-up period was 31.5 months (range: 4–106 months). Tumor recurrence was observed in 40 patients and peritoneal recurrence was observed most commonly. The 5-year disease-free survival (DFS) and overall survival (OS) rates according to tumor stage were 90.3% and 93.1% in stage I, 72.7% and 67.6% in stage II, and 34.8% and 41.5% in stage III, respectively. No significant differences in early surgical outcomes were noted such as operation time, blood loss and postoperative recovery between LADG and TLDG (P >0.05). CONCLUSIONS: LDG for gastric cancer had acceptable long-term oncologic outcomes. The early surgical outcomes of the two commonly used LDG methods were similar
Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction
Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15\u201320 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801\u20133). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E \u3b3 \u2009\u2009>\u2009\u2009200\u2009keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7\u201319.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc
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