Continuum of Bound States in a Non-Hermitian Model

In a Hermitian system, bound states must have quantized energies, whereas extended states can form a continuum. We demonstrate how this principle fails for non-Hermitian systems, by analyzing non-Hermitian continuous Hamiltonians with an imaginary momentum and Landau-type vector potential. The eigenstates, which we call ``continuum Landau modes'' (CLMs), have gaussian spatial envelopes and form a continuum filling the complex energy plane. We present experimentally-realizable 1D and 2D lattice models that can be used to study CLMs; the lattice eigenstates are localized and have other features that are the same as in the continuous model. One of these lattices can serve as a rainbow trap, whereby the response to an excitation is concentrated at a position proportional to the frequency. Another lattice can act a wave funnel, concentrating an input excitation onto a boundary over a wide frequency bandwidth. Unlike recent funneling schemes based on the non-Hermitian skin effect, this requires only a simple lattice design without nonreciprocal couplings

Spatial Heterogeneity of Bacteria: Evidence from Hot Composts by Culture-independent Analysis

The phylogenetic diversity of the bacteria in hot composting samples collected from three spatial locations was investigated by molecular tools in order to determine the influence of gradient effect on bacterial communities during the thermophilic phase of composting swine manure with rice straw. Total microbial DNA was extracted and bacterial near full-length 16S rRNA genes were subsequently amplified, cloned, restriction fragment length polymorphism-screened and sequenced. The superstratum sample had the highest microbial diversity among the three samples which was possibly related to the surrounding conditions of the sample resulting from the location. The results showed that the sequences related to Bacillus sp. were most common in the composts. In superstratum sample, 45 clones (33%) and 36 clones (27%) were affiliated with the Bacillus sp. and Clostridium sp., respectively; 74 clones (58%) were affiliated with the Clostridium sp. in the middle-level sample; 52 clones (40%) and 29 clones (23%) were affiliated with the Clostridium sp. and Bacillus sp. in substrate sample, respectively. It indicated that the microbial diversity and community in the samples were different for each sampling site, and different locations of the same pile often contained distinct and different microbial communities

Image reconstruction through a multimode fiber with a simple neural network architecture

Multimode fibers (MMFs) have the potential to carry complex images for endoscopy and related applications, but decoding the complex speckle patterns produced by mode-mixing and modal dispersion in MMFs is a serious challenge. Several groups have recently shown that convolutional neural networks (CNNs) can be trained to perform high-fidelity MMF image reconstruction. We find that a considerably simpler neural network architecture, the single hidden layer dense neural network, performs at least as well as previously-used CNNs in terms of image reconstruction fidelity, and is superior in terms of training time and computing resources required. The trained networks can accurately reconstruct MMF images collected over a week after the cessation of the training set, with the dense network performing as well as the CNN over the entire period.Comment: 17 pages, 10 figure

Molecular Phylogenetic Diversity and Spatial Distribution of Bacterial Communities in Cooling Stage during Swine Manure Composting

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and subsequent sub-cloning and sequencing were used in this study to analyze the molecular phylogenetic diversity and spatial distribution of bacterial communities in different spatial locations during the cooling stage of composted swine manure. Total microbial DNA was extracted, and bacterial near full-length 16S rRNA genes were subsequently amplified, cloned, RFLP-screened, and sequenced. A total of 420 positive clones were classified by RFLP and near-full-length 16S rDNA sequences. Approximately 48 operational taxonomic units (OTUs) were found among 139 positive clones from the superstratum sample; 26 among 149 were from the middle-level sample and 35 among 132 were from the substrate sample. Thermobifida fusca was common in the superstratum layer of the pile. Some Bacillus spp. were remarkable in the middle-level layer, and Clostridium sp. was dominant in the substrate layer. Among 109 OTUs, 99 displayed homology with those in the GenBank database. Ten OTUs were not closely related to any known species. The superstratum sample had the highest microbial diversity, and different and distinct bacterial communities were detected in the three different layers. This study demonstrated the spatial characteristics of the microbial community distribution in the cooling stage of swine manure compost

Comparison of percutaneous dilational tracheotomy using bronchoscope，ultrasound guidance and anatomical landmark

Objective To compare the efficacy and safety of percutaneous dilational tracheostomy（PDT）using fiberoptic bronchoscope，ultrasound guidance and anatomic landmark localization. Methods In this retrospective cohort，101 patients undergoing PDT were enrolled and divided into bronchoscope-guided group（n = 39），ultrasound-guided group（n = 27），and anatomical landmark localization group（n = 35）. Demographic data，general condition，surgical condition，postoperative complication and clinical prognosis were collected. Results No statistical significance was found in age，sex，cause of ICU stay，primary disease and preoperative coagulation status（all P > 0.05）. In the ultrasound-guided group，preoperative Sequential Organ Failure Assessment（SOFA）score was higher，the operation time was shorter and intraoperative blood loss was less compared with those in the other two groups（P < 0.05/3）. The PaCO2 in the anatomical landmark localization group was lower than that in the ultrasound-guided group（P < 0.05/3）. Conclusions Real-time ultrasound guidance during PDT can be employed to identify the anatomical structures of the neck，which can shorten the operation time，reduce intraoperative bleeding and avoid hyperventilation in patients with severe diseases. Ultrasound-guided PDT may serve as an alternative regimen for PDT using bronchoscope or anatomical landmark localization

Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study

The VESSEL12 (VESsel SEgmentation in the Lung) challenge objectively compares the performance of different algorithms to identify vessels in thoracic computed tomography (CT) scans. Vessel segmentation is fundamental in computer aided processing of data generated by 3D imaging modalities. As manual vessel segmentation is prohibitively time consuming, any real world application requires some form of automation. Several approaches exist for automated vessel segmentation, but judging their relative merits is difficult due to a lack of standardized evaluation. We present an annotated reference dataset containing 20 CT scans and propose nine categories to perform a comprehensive evaluation of vessel segmentation algorithms from both academia and industry. Twenty algorithms participated in the VESSEL12 challenge, held at International Symposium on Biomedical Imaging (ISBI) 2012. All results have been published at the VESSEL12 website http://vessel12.grand-challenge.org. The challenge remains ongoing and open to new participants. Our three contributions are: (1) an annotated reference dataset available online for evaluation of new algorithms; (2) a quantitative scoring system for objective comparison of algorithms; and (3) performance analysis of the strengths and weaknesses of the various vessel segmentation methods in the presence of various lung diseases.Rudyanto, RD.; Kerkstra, S.; Van Rikxoort, EM.; Fetita, C.; Brillet, P.; Lefevre, C.; Xue, W.... (2014). Comparing algorithms for automated vessel segmentation in computed tomography scans of the lung: the VESSEL12 study. Medical Image Analysis. 18(7):1217-1232. doi:10.1016/j.media.2014.07.003S1217123218

Analysis of the Sentiment in the Evaluation Texts of University Students by Means of the Concept of Flexible Management

With the development of information technology (IT) and the popularity of the Internet, it is easier to obtain college students’ teaching evaluation text data. However, it is still challenging to deeply understand and effectively analyze these texts. Based on the flexible management concept in universities, this study aimed to understand and analyze the teaching evaluation texts of college students more accurately, thereby improving the teaching quality. The implicit features of those texts were recognized first in this study, which aimed to supplement and improve the implicit features neglected by existing sentiment analysis methods. A sentiment analysis method based on Bidirectional Encoder Representations from Transformers (BERT) was adopted to explore the deep semantic information of texts. It was done by using deep learning technology and to improve the accuracy of sentiment analysis. This in turn provides more valuable reference information for university teaching management and further promotes the practical application of the flexible management concept in university teaching management

application of logical petri nets in web service composition

IEEE Robotics and Automaton Society; Xidian University; University of Alberta; Kagawa UniversityIn the process of Web service composition, there are several cases about working up an atomic Web service; as well as the outputs of Web service have many possibilities because of the different requirements from users. In order to address these uncertainties, Logical Petri Net(LPN) is introduced into the system of Web service composition, these problems can be well solved using the LPNs feature-passing value indeterminacy. And a model of Web service composition is proposed with the technology of ontology and Agent. Based on this model, an approach of Web service composition is presented in this paper. © 2010 IEEE

Isolation and properties of cellulose nanofibrils from coconut palm petioles by different mechanical process.

In this study, cellulose nanofibrils (CNFs) were successfully isolated from coconut palm petiole residues falling off naturally with chemical pretreatments and mechanical treatments by a grinder and a homogenizor. FTIR spectra analysis showed that most of hemicellulose and lignin were removed from the fiber after chemical pretreatments. The compositions of CNFS indicated that high purity of nanofibrils with cellulose contain more than 95% was obtained. X-ray diffractogram demonstrated that chemical pretreatments significantly increased the crystallinity of CNFs from 38.00% to 70.36%; however, 10-15 times of grinding operation followed by homogenizing treatment after the chemical pretreatments did not significantly improve the crystallinity of CNFs. On the contrary, further grinding operation could destroy crystalline regions of the cellulose. SEM image indicated that high quality of CNFs could be isolated from coconut palm petiole residues with chemical treatments in combination of 15 times of grinding followed by 10 times of homogenization and the aspect ratio of the obtained CNFs ranged from 320 to 640. The result of TGA-DTG revealed that the chemical-mechanical treatments improved thermal stability of fiber samples, and the CNFs with 15 grinding passing times had the best thermal stability. This work suggests that the CNFs can be successfully extracted from coconut palm petiole residues and it may be a potential feedstock for nanofiber reinforced composites due to its high aspect ratio and crystallinity