Anatomical Structure Sketcher for Cephalograms by Bimodal Deep Learning

The lateral cephalogram is a commonly used medium to acquire patient-specific morphology for diagnose and treatment planning in clinical dentistry. The robust anatomical structure detection and accurate annotation remain challenging considering the personal skeletal variations and image blurs caused by device-specific projection magnification, together with structure overlapping in the lateral cephalograms. We propose a novel cephalogram sketcher system, where the contour extraction of anatomical structures is formulated as a cross-modal morphology transfer from regular image patches to arbitrary curves. Specifically, the image patches of structures of interest are located by a hierarchical pictorial model. The automatic contour sketcher converts the image patch to a morphable boundary curve via a bimodal deep Boltzmann machine. The deep machine learns a joint representation of patch textures and contours, and forms a path from one modality (patches) to the other (contours). Thus, the sketcher can infer the contours by alternating Gibbs sampling along the path in a manner similar to the data completion. The proposed method is robust not only to structure detection, but also tends to produce accurate structure shapes and landmarks even in blurry X-ray images. The experiments performed on clinically captured cephalograms demonstrate the effectiveness of our method.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000346352700099&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Artificial IntelligenceCPCI-S(ISTP)

Sustainability assessment of bioenergy from a global perspective: a review

Bioenergy, as a renewable energy resource, is expected to see significant development in the future. However, a key issue that will affect this trend is sustainability of bioenergy. There have been many studies on this topic, but mainly focusing on only one- or two-dimensions of the issue, and also with much of the literature directed at studies of European regions. To help understand the wider scope of bioenergy sustainability, this paper reviews a broad range of current research on the topic, and places the literature into a multi-dimensional framework covering the economic, environmental and ecological, social, and land-related aspects of bioenergy sustainability, as well as a geographical analysis of the areas for which the studies have been carried out. The review indicates that it is hard to draw an overall conclusion on the sustainability of bioenergy because of limited studies or contradictory results in some aspects. In addition, this review shows that crop-based bioenergy and forest bioenergy are seen as the main sources of bioenergy, and that most studies discuss the final utilization of bioenergy as being for electricity generation. Finally, research directions for future study are suggested, based on the literature reviewed here

Protonic acid doping of low band-gap conjugated polyions

This paper describes the design and synthesis of a series of conjugated polyions (CPIZ-T, CPIZ-TT and CPIZ-TT-DEG) that incorporate a formal positive charge into their conjugated backbones, balanced by anionic pendant groups with increasing electron-donating ability. The energy levels and the bandgap of these conjugated polyions were determined by using optical absorption spectroscopy and cyclic voltammetry (CV) and were easily modulated by varying the electron donating group. The energies of the occupied states increase with increasing electron-donating ability, while the energies of the unoccupied states are almost unchanged due to the presence of tritylium ions in the conjugated backbone. All conjugated polyions exhibit pristine semiconducting properties in weak protonic acids, but with sufficiently strong acids, the polymers exhibit spontaneous spin unpairing and convert to a metallic state. The required strength of the acids varies with the electron-donating ability, with higher HOMO levels leading to more facile proton acid doping and higher electrical conductivities. The mechanism of protonic acid doping of conjugated polyions involves a spinless doping process (dehydration) followed by a spontaneous spin unpairing leading to the formation of polarons. While protonic acid doping occurs in polyaniline, conjugated polyions offer synthetic tunability and selective processing into insulating, semiconducting and metallic states simply by controlling acidity

TGMCF: a tree-guided multi-modality correlation filter for visual tracking.

For updating the tracking models, most existing approaches have an assumption that the target changes smoothly over time. Despite their success in some cases, these approaches struggle in dealing with occlusion, illumination changes and abrupt motion which may break the temporal smoothness assumption. To tackle this problem, in this paper we propose a tree-guided visual tracking model based on the multimodality correlation filter which could estimate the target state according to the most reliable information in previous frames. We maintain a representative target state set in a tree model over the whole tracking process. Ideally, the tree model is able to capture all the landmark states of the target, and provides a confident template for the correlation filter. Therefore, we propose an optimal updating strategy to record the most recent stable and representative states for tree updating. By utilizing stable target-states for template training, the multi-modality correlation filter is able to output a more accurate target position than the baseline and the SOTA (state-of-the-art) methods. Tested on the OTB50 (object tracking benchmark) and OTB100 dataset, the proposed TGMCF has demonstrated outstanding performance on several typical tracking difficulties and overall comparative results with the SOTA trackers are obtained on several public tracking benchmarks

EACOFT: an energy-aware correlation filter for visual tracking.

Correlation filter based trackers attribute to its calculation in the frequency domain can efficiently locate targets in a relatively fast speed. This characteristic however also limits its generalization in some specific scenarios. The reasons that they still fail to achieve superior performance to state-of-the-art (SOTA) trackers are possibly due to two main aspects. The first is that while tracking the objects whose energy is lower than the background, the tracker may occur drift or even lose the target. The second is that the biased samples may be inevitably selected for model training, which can easily lead to inaccurate tracking. To tackle these shortcomings, a novel energy-aware correlation filter (EACOFT) based tracking method is proposed, in our approach the energy between the foreground and the background is adaptively balanced, which enables the target of interest always having a higher energy than its background. The samples’ qualities are also evaluated in real time, which ensures that the samples used for template training are always helpful with tracking. In addition, we also propose an optimal bottom-up and top-down combined strategy for template training, which plays an important role in improving both the effectiveness and robustness of tracking. As a result, our approach achieves a great improvement on the basis of the baseline tracker, especially under the background clutter and fast motion challenges. Extensive experiments over multiple tracking benchmarks demonstrate the superior performance of our proposed methodology in comparison to a number of the SOTA trackers

Who buys new energy vehicles in china? Assessing social-psychological predictors of purchasing awareness, intention, and policy

This paper investigates the salience of social-psychological factors in explaining why drivers purchase (or fail to purchase) New Energy Vehicles (NEVs)—including hybrid electric vehicles, battery electric vehicles, and fuel cell electric vehicles—in China. A questionnaire measuring six dimensions (including attitudes, subjective norms, perceived behavioral control, personal norms, low-carbon awareness and policy) was distributed in Tianjin, where aggressive policy incentives for NEVs exist yet adoption rates remain low. Correlation analysis and hierarchical multiple regression analyses are applied data collected through 811 valid questionnaires. We present three main findings. First, there is an “awareness-behavior gap” whereby low-carbon awareness has a moderating effect on purchasing behavior via psychological factors. Second, subjective norms has a stronger influence on intention to purchase New Energy Vehicles than other social-psychological factors. Third, acceptability of government policies has positive significant impact on adoption of New Energy Vehicles, which can provide reference potential template for other countries whose market for New Energy Vehicles is also in an early stage

Synthesis, Optical and Electrochemical Properties of High-Quality Cross-Conjugated Aromatic Polyketones

This paper describes the synthesis and characterization of three new aromatic polyketones with repeating units based on 2,2′-(2,5-dihexyl-1,4-phenylene) dithiophene (PTK), 2,2′-(9,9-dihexyl-9H-fluorene-2,7-diyl)dithiophene (PFTK), and 4,7-bis(3-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (PBTK). These polymers were obtained with a one-pot Suzuki-Miyaura cross-coupling-promoted homopolymerization to afford high-quality, defect-free polymers. Experimental and theoretical studies were applied to investigate their optical and electrical properties. The cross-conjugated nature of aromatic polyketones imparts excellent thermal stability. Exposure to acid converts the cross-conjugation to linear-conjugation, enabling the dynamic tuning of optoelectronic properties

Controlling n-Type Molecular Doping via Regiochemistry and Polarity of Pendant Groups on Low Band Gap Donor-Acceptor Copolymers

We demonstrate the impact of the type and position of pendant groups on the n-doping of low-band gap donor-acceptor (D-A) copolymers. Polar glycol ether groups simultaneously increase the electron affinities of D-A copolymers and improve the host/dopant miscibility compared to nonpolar alkyl groups, improving the doping efficiency by a factor of over 40. The bulk mobility of the doped films increases with the fraction of polar groups, leading to a best conductivity of 0.08 S cm(-1) and power factor (PF) of 0.24 mu W m(-1) K-2 in the doped copolymer with the polar pendant groups on both the D and A moieties. We used spatially resolved absorption spectroscopy to relate commensurate morphological changes to the dispersion of dopants and to the relative local doping efficiency, demonstrating a direct relationship between the morphology of the polymer phase, the solvation of the molecular dopant, and the electrical properties of doped films. Our work offers fundamental new insights into the influence of the physical properties of pendant chains on the molecular doping process, which should be generalizable to any molecularly doped polymer films

Efficient Selective Sorting of Semiconducting Carbon Nanotubes Using Ultra-Narrow-Band-Gap Polymers

[Image: see text] Conjugated polymers with narrow band gaps are particularly useful for sorting and discriminating semiconducting single-walled carbon nanotubes (s-SWCNT) due to the low charge carrier injection barrier for transport. In this paper, we report two newly synthesized narrow-band-gap conjugated polymers (PNDITEG-TVT and PNDIC8TEG-TVT) based on naphthalene diimide (NDI) and thienylennevinylene (TVT) building blocks, decorated with different polar side chains that can be used for dispersing and discriminating s-SWCNT. Compared with the mid-band-gap conjugated polymer PNDITEG-AH, which is composed of naphthalene diimide (NDI) and head-to-head bithiophene building blocks, the addition of a vinylene linker eliminates the steric congestion present in head-to-head bithiophene, which promotes backbone planarity, extending the π-conjugation length and narrowing the band gap. Cyclic voltammetry (CV) and density functional theory (DFT) calculations suggest that inserting a vinylene group in a head-to-head bithiophene efficiently lifts the highest occupied molecular orbital (HOMO) level (−5.60 eV for PNDITEG-AH, −5.02 eV for PNDITEG-TVT, and −5.09 eV for PNDIC8TEG-TVT). All three polymers are able to select for s-SWCNT, as evidenced by the sharp transitions in the absorption spectra. Field-effect transistors (FETs) fabricated with the polymer:SWCNT inks display p-dominant properties, with higher hole mobilities when using the NDI-TVT polymers as compared with PNDITEG-AH (0.6 cm(2) V(–1) s(–1) for HiPCO:PNDITEG-AH, 1.5 cm(2) V(–1) s(–1) for HiPCO:PNDITEG-TVT, and 2.3 cm(2) V(–1) s(–1) for HiPCO:PNDIC8TEG-TVT). This improvement is due to the better alignment of the HOMO level of PNDITEG-TVT and PNDIC8TEG-TVT with that of the dominant SWCNT specie

Polar Side Chains Enhance Selection of Semiconducting Single-Walled Carbon Nanotubes by Polymer Wrapping

This paper describes the effectiveness of donor-acceptor (D-A) conjugated polymers to disperse and select for semiconducting single-walled carbon nanotubes (s-SWCNTs) when enhanced by the inclusion of polar oligoethylene glycol-based side chains, without altering the D-A backbone. We designed and synthesized two sets of naphthalenediimide(NDI)-alt-bithiophene(T2)-based conjugated polymers with one of two alkyl side chains (decyl and dodecyl chains) of different lengths and with or without polar triethylene glycol side chains. The resulting low-band-gap copolymers all effectively disperse and select for s-SWCNT, but the inclusion of polar side chains enhances the interactions between the polymer backbone and the walls of the s-SWCNTs relative to the polymers with only alkyl side chains. As a result, the wrapping and selection efficiency of the polymer-SWCNT systems with polar side chains are both significantly enhanced. We further optimized the binding energy and surface coverage by combining glycol ether and dodecyl side chains to maximize wrapping efficiency, leading to a field-effect mobility of 2.82 cm2 V-1 s-1 and on/off current ratios of ∼2 × 107 in polymer-wrapped SWCNTs. Our results provide insight into the role of the side-chain interactions in the polymer wrapping and dispersion technique, and, because we focus on manipulating side chains, they can be generalized for other conjugated polymer backbones