In this paper, we use the cross-layer connectivity of residual networks in deep learning to convert convolutional and fully connected layers into sparse connections and cluster sparse matrices into ...relatively dense subspaces. Extracted features are used to perform target class prediction and regression of target coordinates using a target detection algorithm to meet the demand for real-time target detection. The model's use resulted in a head-up rate of 83.57% in the classroom, with the least serious students at 0.8 and above. Deep learning technology can enhance students' learning experience in English classrooms by providing personalized learning and a deep learning environment.
Prefabricated construction has attracted worldwide concern because of its significant role in the creation of sustainable urbanization. In Mainland China, the practice of applying prefabrication ...technology in the construction industry still lags behind. In fact, the economic benefit is a key concern of various stakeholders involved in the construction process and is expected to influence the delivery of prefabricated buildings significantly. Therefore, this study established a cost–benefit analysis framework to explore the basic cost composition of prefabrication and examined the effect of adopting prefabrication on the total cost of real building projects. Results show that the concrete and steel used in the typical prefabricated components were responsible for 26% to 60% of the total cost, followed by labor cost (17%–30%) and transportation (10%). The average incremental cost is highly linearly correlated with the prefabrication rate, which ranged from 237 yuan/m2 to 437 yuan/m2, in eight building projects. To fully gain the economic benefits from the precast construction, the future focus should lie in providing financial support for promoting the development of prefabrication technology, optimizing the structure integrity of prefabricated buildings, and improving the maturity of the precast market.
•We developed a cost–benefit analysis framework to explore cost composition.•We examined the effect of adopting prefabrication on the total cost of buildings.•We explored the relationship between prefabrication rate and incremental cost.•We identified the cost difference between precast and conventional construction.•We explored the driving factors causing the cost increment in prefabrication domain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Summarize the four fundamental issues in BUS image segmentation.•Study the basic ideas, theories, pros and cons of BUS image segmentation approaches, group them into categories, and extensively ...review each category in depth by discussing the principles, application issues, and advantages/disadvantages.•Discuss the four major directions of BUS image segmentation.
Breast cancer is one of the leading causes of cancer death among women worldwide. In clinical routine, automatic breast ultrasound (BUS) image segmentation is very challenging and essential for cancer diagnosis and treatment planning. Many BUS segmentation approaches have been studied in the last two decades, and have been proved to be effective on private datasets. Currently, the advancement of BUS image segmentation seems to meet its bottleneck. The improvement of the performance is increasingly challenging, and only few new approaches were published in the last several years. It is the time to look at the field by reviewing previous approaches comprehensively and to investigate the future directions. In this paper, we study the basic ideas, theories, pros and cons of the approaches, group them into categories, and extensively review each category in depth by discussing the principles, application issues, and advantages/disadvantages.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
If a bulk material can withstand a high load without any irreversible damage (such as plastic deformation), it is usually brittle and can fail catastrophically1,2. This trade-off between strength and ...fracture toughness also extends into two-dimensional materials space3-5. For example, graphene has ultrahigh intrinsic strength (about 130 gigapascals) and elastic modulus (approximately 1.0 terapascal) but is brittle, with low fracture toughness (about 4 megapascals per square-root metre)3,6. Hexagonal boron nitride (h-BN) is a dielectric two-dimensional material7 with high strength (about 100 gigapascals) and elastic modulus (approximately 0.8 terapascals), which are similar to those ofgraphene8. Its fracture behaviour has long been assumed to be similarly brittle, subject to Griffith's law9-14. Contrary to expectation, here we report high fracture toughness of single-crystal monolayer h-BN, with an effective energy release rate up to one order of magnitude higher than both its Griffith energy release rate and that reported for graphene. We observe stable crack propagation in monolayer h-BN, and obtain the corresponding crack resistance curve. Crack deflection and branching occur repeatedly owing to asymmetric edge elastic properties at the crack tip and edge swapping during crack propagation, which intrinsically toughens the material and enables stable crack propagation. Our in situ experimental observations, supported by theoretical analysis, suggest added practical benefits and potential new technological opportunities for monolayer h-BN, such as adding mechanical protection to two-dimensional devices.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Orofacial clefts are the most common congenital malformation, but the global burden and trends of orofacial clefts have not been comprehensively analysed. The aim of this study was to assess the ...global incidence, deaths and disability-adjusted life years (DALYs) of orofacial clefts by countries, regions, sex and sociodemographic index (SDI) from 1990 to 2019.
The data on orofacial clefts were obtained from the Global Burden of Disease Study 2019. The incidence, deaths and DALYs were analysed by countries, regions, sex and SDI. Age-standardized rates and estimated annual percentage change (EAPC) were calculated to evaluate the burden and temporal trend of orofacial clefts. The association between EAPC and the human development index was assessed.
Globally, the incidence, deaths and DALYs of orofacial clefts decreased from 1990 to 2019. The high SDI region showed the biggest downward trend in incidence rate from 1990 to 2019, along with the lowest age-standardized death rate and DALY rate. Some countries, such as Suriname and Zimbabwe, experienced increased death rate and DALY rate over time. The age-standardized death rate and DALY rate were negatively associated with the level of socioeconomic development.
Global achievement is evident in the control of the burden of orofacial clefts. The future focus of prevention should be on low-income countries, such as South Asia and Africa, by increasing healthcare resources and improving quality.
KEY MESSAGES
This is the most recent estimate of the global epidemiology of orofacial clefts, with some countries not previously assessed.
The global burden of orofacial clefts showed downward trends from 1990 to 2019; however, some low-income countries are still suffering from increasing burdens.
Effective measures should be taken to reduce the burden of orofacial clefts in the uncontrolled regions.
In the ultimatum game, two players divide a sum of money. The proposer suggests how to split and the responder can accept or reject. If the suggestion is rejected, both players get nothing. The ...rational solution is that the responder accepts even the smallest offer but humans prefer fair share. In this paper, we study the ultimatum game by a learning-mutation process based on quantal response equilibrium, where players are assumed boundedly rational and make mistakes when estimating the payoffs of strategies. Social learning is never stabilized at the fair outcome or the rational outcome, but leads to oscillations from offering 40 percent to 50 percent. To be precise, there is a clear tendency to increase the mean offer if it is lower than 40 percent, but will decrease when it reaches the fair offer. If mutations occur rarely, fair behavior is favored in the limit of local mutation. If mutation rate is sufficiently high, fairness can evolve for both local mutation and global mutation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fabricating inorganic materials with designed three-dimensional nanostructures is an exciting yet challenging area of research and industrial application. Here, we develop an approach to 3D print ...high-quality nanostructures of silica with sub-200 nm resolution and with the flexible capability of rare-earth element doping. The printed SiO
can be either amorphous glass or polycrystalline cristobalite controlled by the sintering process. The 3D-printed nanostructures demonstrate attractive optical properties. For instance, the fabricated micro-toroid optical resonators can reach quality factors (Q) of over 10
. Moreover, and importantly for optical applications, doping and codoping of rare-earth salts such as Er
, Tm
, Yb
, Eu
and Nd
can be directly implemented in the printed SiO
structures, showing strong photoluminescence at the desired wavelengths. This technique shows the potential for building integrated microphotonics with silica via 3D printing.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
•Elucidation of mechanisms describing the complexation of amylose and linoleic acid.•Amylose acquires a V-type helical conformation in the presence of linoleic acid.•4C1 is the predominant chair ...conformation of the glucose ring when complexing with a fatty acid such as linoleic acid.
Amylose is a linear polymer formed by α-1,4 linkages and one of the major components of starch. It is often used to encapsulate hydrophobic molecules of health benefit, such as fatty acids (FA), flavonoids or polyphenols. Amylose and linoleic acid form a complex when the amylose molecule is folded in a V-type conformation. However, it is still not clear how amylose and linoleic acid interact with each other and what is the conformation of the complex adopts under different conditions. Molecular dynamics (MD) simulation is a useful tool used to describe the structure of molecules and complex systems. In this work, MD simulations were used to illustrate conformational changes of the amylose-FA complex and the single amylose molecule, which was used as a reference, in water. During simulations, the conformation of the complex remained stable and the linoleic acid and the amylose molecules formed a helical structure. Furthermore, fatty acid molecules were located in cavity of the amylose helix with the hydrophobic tail inside it. Results also showed that 4C1 was the predominant ring conformation of glucose unit in amylose during interaction with fatty acids. Once the fatty acid was able to form the complex with amylose, the inter turn hydrogen bonds between O6 and neighboring O2/O3 groups were preferentially retained and allowed the complex to keep its helix conformation. Our analysis also shows that the amylose-linoleic acid complex is slightly less stable than the one formed between stearic acid and amylose.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The emergence of cesium lead iodide (CsPbI3) perovskite solar cells (PSCs) has generated enormous interest in the photovoltaic research community. However, in general they exhibit low power ...conversion efficiencies (PCEs) because of the existence of defects. A new all‐inorganic perovskite material, CsPbI3:Br:InI3, is prepared by defect engineering of CsPbI3. This new perovskite retains the same bandgap as CsPbI3, while the intrinsic defect concentration is largely suppressed. Moreover, it can be prepared in an extremely high humidity atmosphere and thus a glovebox is not required. By completely eliminating the labile and expensive components in traditional PSCs, the all‐inorganic PSCs based on CsPbI3:Br:InI3 and carbon electrode exhibit PCE and open‐circuit voltage as high as 12.04% and 1.20 V, respectively. More importantly, they demonstrate excellent stability in air for more than two months, while those based on CsPbI3 can survive only a few days in air. The progress reported represents a major leap for all‐inorganic PSCs and paves the way for their further exploration in order to achieve higher performance.
A new all‐inorganic perovskite material, CsPbI3:Br:InI3, is prepared through defect engineering of CsPbI3. This new perovskite retains the same bandgap as CsPbI3, but with intrinsic defect concentration largely suppressed. Moreover, it can be prepared in an extremely high humidity atmosphere. By completely eliminating the labile and expensive components in traditional perovskite solar cells (PSCs), these all‐inorganic PSCs exhibit high photovoltaic performances.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Suppose
Σ
is a compact oriented surface (possibly with boundary) that has genus zero, and
L
is a link in the interior of
(
-
1
,
1
)
×
Σ
. We prove that the Asaeda–Przytycki–Sikora (APS) homology of
...L
has rank 2 if and only if
L
is isotopic to an embedded knot in
{
0
}
×
Σ
. As a consequence, the APS homology detects the unknot in
(
-
1
,
1
)
×
Σ
. This is the first detection result for generalized Khovanov homology that is valid on an infinite family of manifolds, and it partially solves a conjecture in Xie and Zhang (Instantons and Khovanov skein homology on
I
×
T
2
, 2020.
arXiv:2005.12863
). Our proof is different from the previous detection results obtained by instanton homology because in this case, the second page of Kronheimer–Mrowka’s spectral sequence is not isomorphic to the APS homology. We also characterize all links in product manifolds that have minimal sutured instanton homology, which may be of independent interest.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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