5,318 research outputs found
4-Chloro-N-methylÂbenzamide
There are two molÂecules in the asymmetric unit of the title compound, C8H8ClNO, which are linked in the crystal structure via N—H⋯O hydrogen bonds into chains along the b axis. C—H⋯O contacts also occur. The benzene ring makes dihedral angles of 5.9 (1) and 16.7 (1)°with the attached amide group in the two independent molecules
Molecular Logic Computation with Debugging Method
Seesaw gate concept, which is based on a reversible DNA strand branch process, has been found to have the potential to be used in the construction of various computing devices. In this study, we consider constructing full adder and serial binary adder, using the new concept of seesaw gate. Our simulation of the full adder preformed properly as designed; however unexpected exception is noted in the simulation of the serial binary adder. To identify and address the exception, we propose a new method for debugging the molecular circuit. The main idea for this method is to add fan-outs to monitor the circuit in a reverse stepwise manner. These fan-outs are fluorescent signals that can obtain the real-time concentration of the target molecule. By analyzing the monitoring result, the exception can be identified and located. In this paper, examples of XOR and serial binary adder circuits are described to prove the practicability and validity of the molecular circuit debugging method
The localization of single pulse in VLBI observation
In our previous work, we propose a cross spectrum based method to extract
single pulse signals from RFI contaminated data, which is originated from
geodetic VLBI postprocessing. This method fully utilizes fringe phase
information of the cross spectrum and hence maximizes signal power, however the
localization was not discussed in that work yet. As the continuation of that
work, in this paper, we further study how to localize single pulses using
astrometric solving method. Assuming that the burst is a point source, we
derive the burst position by solving a set of linear equations given the
relation between residual delay and offset to a priori position. We find that
the single pulse localization results given by both astrometric solving and
radio imaging are consistent within 3 sigma level. Therefore we claim that it
is possible to derive the position of a single pulse with reasonable precision
based on only 3 or even 2 baselines with 4 milliseconds integration. The
combination of cross spectrum based detection and the localization proposed in
this work then provide a thorough solution for searching single pulse in VLBI
observation. According to our calculation, our pipeline gives comparable
accuracy as radio imaging pipeline. Moreover, the computational cost of our
pipeline is much smaller, which makes it more practical for FRB search in
regular VLBI observation. The pipeline is now publicly available and we name it
as "VOLKS", which is the acronym of "VLBI Observation for frb Localization Keen
Searcher".Comment: 11 pages, 4 figures, 3 tables, accepted for publication in A
TetraÂkis(1-allyl-1H-imidazole-κN 3)bisÂ(thioÂcyanato-κN)manganese(II)
The structure of the title compound, [Mn(NCS)2(C6H8N2)4], consists of isolated molÂecules of [Mn(NCS)2(Aim)4] (Aim = 1-allylÂimidazole), which contain a compressed octaÂhedral MnN6 chromophore (site symmetry ). The NCS− anions are trans and four N atoms from the Aim ligands define the equatorial plane. The mean Mn—N(Aim) and Mn—N(NCS) distances are 2.270 and 2.229 Å, respectively. Weak C—H⋯N interÂactions contribute to the crystal packing stability
Clinical observation of macular grid photocoagulation before cataract surgery for diabetes patients with diffuse macular edema
AIM: To explore the effects and reliability of macular grid photocoagulation before cataract surgery for diabetes patients with diffuse macular edema.<p>METHODS: A total of 30 patients(40 eyes)were enrolled in the study. All the patients were randomly divided into two groups: group A: 20 eyes were treated with macular grid photocoagulation before cataract surgery; group B: 20 eyes were treated with cataract surgery only. <p>RESULTS: The patients treated with macular grid photocoagulation before cataract surgery. Postoperative visual acuity was improved, the edema of macular decreased. The patients treated with cataract surgery only, visual acuity showed no evident change and macular edema remained stable or creased. <p>CONCLUSION: Macular grid photocoagulation before cataract surgery for diabetes patients can improve the outcome and vision of the patients
Meta-Reinforcement Learning for Timely and Energy-efficient Data Collection in Solar-powered UAV-assisted IoT Networks
Unmanned aerial vehicles (UAVs) have the potential to greatly aid Internet of
Things (IoT) networks in mission-critical data collection, thanks to their
flexibility and cost-effectiveness. However, challenges arise due to the UAV's
limited onboard energy and the unpredictable status updates from sensor nodes
(SNs), which impact the freshness of collected data. In this paper, we
investigate the energy-efficient and timely data collection in IoT networks
through the use of a solar-powered UAV. Each SN generates status updates at
stochastic intervals, while the UAV collects and subsequently transmits these
status updates to a central data center. Furthermore, the UAV harnesses solar
energy from the environment to maintain its energy level above a predetermined
threshold. To minimize both the average age of information (AoI) for SNs and
the energy consumption of the UAV, we jointly optimize the UAV trajectory, SN
scheduling, and offloading strategy. Then, we formulate this problem as a
Markov decision process (MDP) and propose a meta-reinforcement learning
algorithm to enhance the generalization capability. Specifically, the
compound-action deep reinforcement learning (CADRL) algorithm is proposed to
handle the discrete decisions related to SN scheduling and the UAV's offloading
policy, as well as the continuous control of UAV flight. Moreover, we
incorporate meta-learning into CADRL to improve the adaptability of the learned
policy to new tasks. To validate the effectiveness of our proposed algorithms,
we conduct extensive simulations and demonstrate their superiority over other
baseline algorithms
Biased compensation recursive least squares-based threshold algorithm for time-delay rational models via redundant rule
© 2017, Springer Science+Business Media B.V., part of Springer Nature. This paper develops a biased compensation recursive least squares-based threshold algorithm for a time-delay rational model. The time-delay rational model is transformed into an augmented model by using the redundant rule, and then, a recursive least squares algorithm is proposed to estimate the parameters of the augmented model. Since the output of the augmented model is correlated with the noise, a biased compensation method is derived to eliminate the bias of the parameter estimates. Furthermore, based on the structures of the augmented model parameter vector and the rational model parameter vector, the unknown time delay can be computed by using a threshold given in prior. A simulated example is used to illustrate the efficiency of the proposed algorithm
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