5,784 research outputs found
An Improved Lagrangian Relaxation Method for VLSI Combinational Circuit Optimization
Gate sizing and threshold voltage (Vt) assignment are very popular and useful techniques in current very large scale integration (VLSI) design flow for timing and power optimization. Lagrangian relaxation (LR) is a common method for handling multi-objectives and proven to reach optimal solution under continuous solution space. However, it is more complex to use Lagrangian relaxation under discrete solution space. The Lagrangian dual problem is non-convex and previously a sub-gradient method was used to solve it. The sub-gradient method is a greedy approach for substituting gradient method in the deepest descent method, and has room for further improvement. In addition, Lagrangian sub-problem cannot be solved directly by mathematical approaches under discrete solution space. Here we propose a new Lagrangian relaxation-based method for simultaneous gate sizing and Vt assignment under discrete solution space. In this work, some new approaches are provided to solve the Lagrangian dual problem considering not only slack but also the relationship between Lagrangian multipliers and circuit timing. We want to solve the Lagrangian dual problem more precisely than did previous methods, such as the sub-gradient method. In addition, a table-lookup method is provided to replace mathematical approaches for solving the Lagrangian sub-problem under discrete size and Vt options. The experimental results show that our method can lead to about 50 percent and 58 percent power reduction subject to the same timing constraints compared with a Lagrangian relaxation method using sub-gradient method and a state-of-the-art previous work. These two methods are implemented by us for comparison. Our method also results in better circuit timing subject to tight timing constraints
Diethyl 2,5-diphenylfuran-3,4-dicarboxylate
In the title compound, C22H20O5, the substituted benzene rings are twisted away from the furan ring, making dihedral angles of 54.91 (14) and 20.96 (15)° with the furan ring. The dihedral angle between the two benzene rings is 46.89 (13)°. One ethyl group of one ethoxycarbonyl unit is disordered over two sets of sites with occupancies of 0.56 (12) and 0.44 (12). In the crystal, weak intramolecular C—H⋯O hydrogen bonds link the molecules into chains along the c axis
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Dual-band filtering power divider with capacitor-loaded centrally coupled-line resonators
In this paper, a dual-band filtering power divider (DB-FPD) with capacitor-loaded centrally coupled-line resonators (CLCCLRs) is presented. The proposed design utilizes four CLCCLRs, two resistors and one inductor to achieve the dual functions of dual-band filtering and power division. By altering the values of the capacitors loaded at the ends of the coupled-lines, the center frequencies of the two passbands can be adjusted independently. It is noted that changing one passband will not affect the other. For demonstration, a microstrip filtering power divider is designed, fabricated and measured. Under different values of the loaded capacitors, experimental results show that the lower band center frequency varies from 0.7 GHz to 1.0 GHz with the upper band fixed at 1.75 GHz, whereas the upper band center frequency varies from 1.65 GHz to 1.95 GHz when the lower band is fixed at 1.0 GHz. The measured results show good agreement with the simulations
AcrFinder: genome mining anti-CRISPR operons in prokaryotes and their viruses
Anti-CRISPR (Acr) proteins encoded by (pro)phages/(pro)viruses have a great potential to enable a more controllable genome editing. However, genome mining new Acr proteins is challenging due to the lack of a conserved functional domain and the low sequence similarity among experimentally char- acterized Acr proteins. We introduce here AcrFinder, a web server (http://bcb.unl.edu/AcrFinder) that combines three well-accepted ideas used by pre- vious experimental studies to pre-screen genomic data for Acr candidates. These ideas include ho- mology search, guilt-by-association (GBA), and CRISPR-Cas self-targeting spacers. Compared to existing bioinformatics tools, AcrFinder has the following unique functions: (i) it is the first online server specifically mining genomes for Acr-Aca operons; (ii) it provides a most comprehensive Acr and Aca (Acr-associated regulator) database (populated by GBA-based Acr and Aca datasets); (iii) it combines homology-based, GBA-based, and self-targeting approaches in one software package; and (iv) it provides a user-friendly web interface to take both nucleotide and protein sequence files as inputs, and output a result page with graphic representation of the genomic contexts of Acr-Aca operons. The leave-one-out cross-validation on ex- perimentally characterized Acr-Aca operons showed that AcrFinder had a 100% recall. AcrFinder will be a valuable web resource to help experimental microbiologists discover new Anti-CRISPRs
2-{[3-Methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl]methylsulfanyl}-1H-benzimidazole monohydrate
The asymmetric unit of the title compound, C16H14F3N3OS·H2O, contains two independent molecules (A and B) and two water molecules, one of which is disordered over two positions in a 0.790 (8):0.210 (8) ratio. The molecular conformations are close, the benzimidazole mean plane and pyridine ring forming dihedral angles of 1.8 (3) and 0.1 (2)° in molecules A and B, respectively. The water molecules are involved in formation of two independent hydrogen-bonded chains via N—H⋯O and O—H⋯N hydrogen bonds. Chains propagating along the a axis are formed by molecule A and one independent water molecule, while chains propagating along the b axis are formed by molecule B and the other independent water molecule. The crystal packing exhibits π–π interactions, as indicated by short distances of 3.607 (3) and 3.701 (3) Å between the centroids of the imidazole and pyridine rings of neighbouring molecules
Enhanced surface acceleration of fast electrons by using sub-wavelength grating targets
Surface acceleration of fast electrons in intense laser-plasma interaction is
improved by using sub-wavelength grating targets. The fast electron beam
emitted along the target surface was enhanced by more than three times relative
to that by using planar target. The total number of the fast electrons ejected
from the front side of target was also increased by about one time. The method
to enhance the surface acceleration of fast electron is effective for various
targets with sub-wavelength structured surface, and can be applied widely in
the cone-guided fast ignition, energetic ion acceleration, plasma device, and
other high energy density physics experiments.Comment: 14 pages, 4figure
Molluscicidal efficacies of different formulations of niclosamide: result of meta-analysis of Chinese literature
The control efforts on Oncomelania hupensis, the intermediate snail host of Schistosoma japonicum, cannot be easily excluded from the integrated approach of schistosomiasis control in China. Application of chemical compounds, molluscicides, in snail habitats is a common method for snail control in addition to environmental modification. We conducted a systematic review and meta-analysis to assess the molluscicidal effects of the currently recommended 50% niclosamide ethanolamine salt wettable powder and a new 4% niclosamide ethanolamine salt powder developed by Chinese researchers. Literature was searched from three Chinese databases, i.e. Chinese Biomedical Database, VIP Database and Wanfang Database, on field mollusciciding trials of niclosamide in China (from January 1, 1990 to April 1, 2010). Molluscicidal effects on reduction of snail population of the 50% or 4% niclosamide formulations in field trial were evaluated 3 days, 7 days or 15 days post-application. Out of 90 publications, 20 papers were eventually selected for analysis. Publication bias and heterogeneity tests indicated that no publication bias existed but heterogeneity between studies was present. Meta-analysis in a random effect model showed that the snail mortality of 3, 7 and 15 days after spraying the 50% niclosamide ethanolamine salt wettable powder were 77% [95%CI: 0.68-0.86], 83% [95%CI: 0.77-0.89], and 88% [95%CI: 0.82-0.92], respectively. For the 4% niclosamide ethanolamine salt powder, the snail mortality after 3, 7 and 15 days were 81% [95%CI: 0.65-0.93], 90% [95%CI: 0.83-0.95] and 94% [95%CI: 0.91-0.97], respectively. Both are good enough to be used as molluscicides integrated with a schistosomiasis control programme. The 4% niclosamide ethanolamine salt powder can be applied in the field without water supply as the surrogate of the current widely used 50% niclosamide ethanolamine salt wettable powder. However, to consolidate the schistosomiasis control achievement gained, it is necessary to continuously perform mollusciciding more than twice annually in the field
Label-free timing analysis of modularized nuclear detectors with physics-constrained deep learning
Pulse timing is an important topic in nuclear instrumentation, with
far-reaching applications from high energy physics to radiation imaging. While
high-speed analog-to-digital converters become more and more developed and
accessible, their potential uses and merits in nuclear detector signal
processing are still uncertain, partially due to associated timing algorithms
which are not fully understood and utilized. In this paper, we propose a novel
method based on deep learning for timing analysis of modularized nuclear
detectors without explicit needs of labelling event data. By taking advantage
of the inner time correlation of individual detectors, a label-free loss
function with a specially designed regularizer is formed to supervise the
training of neural networks towards a meaningful and accurate mapping function.
We mathematically demonstrate the existence of the optimal function desired by
the method, and give a systematic algorithm for training and calibration of the
model. The proposed method is validated on two experimental datasets. In the
toy experiment, the neural network model achieves the single-channel time
resolution of 8.8 ps and exhibits robustness against concept drift in the
dataset. In the electromagnetic calorimeter experiment, several neural network
models (FC, CNN and LSTM) are tested to show their conformance to the
underlying physical constraint and to judge their performance against
traditional methods. In total, the proposed method works well in either ideal
or noisy experimental condition and recovers the time information from waveform
samples successfully and precisely.Comment: 25 pages, 10 figure
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