Feature selection in classification is a complex optimization problem that cannot be solved in polynomial time. Bi-objective feature selection, aiming to minimize both selected features and ...classification errors, is challenging due to the conflict between objectives, while one of the most effective ways to tackle this is to use multi-objective evolutionary algorithms. However, very few of these have ever reflected an evolutionary multi-tasking framework, despite the implicit parallelism offered by the population-based search characteristic. In this paper, a dynamic multi-tasking-based multi-objective evolutionary algorithm (termed DTEA) is proposed for handling bi-objective feature selection in classification, which is not only suitable for datasets with relatively lower dimensionality of features, but is also suitable for datasets with relatively higher dimensionality of features. The role and influence of multi-tasking on multi-objective evolutionary feature selection were studied, and a dynamic tasking mechanism is proposed to self-adaptively assign multiple evolutionary search tasks by intermittently analyzing the population behaviors. The efficacy of DTEA is tested on 20 classification datasets and compared with seven state-of-the-art evolutionary algorithms. A component contribution analysis was also conducted by comparing DTEA with its three variants. The empirical results show that the dynamic-tasking mechanism works efficiently and enables DTEA to outperform other algorithms on most datasets in terms of both optimization and classification.
This paper aims to promote the integration of traditional lacquerware and modern art design. AR technology is used for feature calculation of the appearance contour of traditional lacquerware. In ...this paper, the BRIEF algorithm is selected as the main algorithm for image feature calculation. The Steer BRIEF algorithm is used for key points, and the image feature points are extracted. The classical optical flow method of CMT is applied to track the appearance contour of traditional lacquerware, and the SSD and NCC are combined with filtering the measurement of tracking points. The results show that 90% of the traditional lacquerware can reflect the cultural connotation of the time, 80% of the traditional lacquerware can reflect the characteristics of the time, 80% of the traditional lacquerware has excellent craftsmanship, and the added value reflected by modern art design is much lower than that of the traditional lacquerware.
This paper presents isogeometric topology optimization (ITO) for periodic lattice materials, where non-uniform rational B-spline (NURBS) basis functions of CAD models are directly used in the finite ...element analysis to improve computational accuracy and efficiency. Two TO schemes that use asymptotic homogenization (AH) for the calculation of the mechanical properties are proposed for lattice materials with uniform and graded relative density respectively. To accelerate ITO for graded lattice materials, the mechanical properties are expressed as a function of the relative density of the unit cell, a step that avoids their iterative calculations during ITO. Three benchmark examples are presented to validate the proposed scheme with results that show tangible advantages, such as reduced computational time and faster convergence, of ITO over conventional TO.
•A multiscale isogeometric topology optimization is presented for lattice materials.•Asymptotic homogenization is coupled to topology optimization for lattice design.•The role of cell topology is demonstrated in the optimal density distribution of lattices.•Benchmark examples are presented to prove the efficiency of the proposed scheme.
A unique three-dimensional Tb-BTB framework (1) with two types of one-dimensional channels was obtained and structurally characterized, exhibiting high thermal stability. Luminescent investigations ...reveal that 1 can detect Fe3+ with relatively high sensitivity and selectivity. Importantly, 1 as the luminescent probe of Fe3+ can be simply and quickly regenerated, which represents a rare example in reported luminescent sensors of Fe3+.
The environmental pollution has become a serious issue because the pollutants can cause permanent damage to the DNA, nervous system, and circulating system, resulting in various incurable diseases, ...such as organ failure, malformation, angiocardiopathy, and cancer. The effective detection of environmental pollutants is urgently needed to keep them far away from daily life. Among the reported pollutant sensors, luminescent metal–organic frameworks (LMOFs) with tunable structures have attracted remarkable attention to detect the pollutants because of their excellent selectivity, sensitivity, and recyclability. Although lots of metal–organic framework (MOF)‐based luminescent sensors have been summarized and discussed in previous reviews, the detection of environmental pollutants, especially radioactive ions and heavy metal ions, still have not been systematically presented. Here, the sensing mechanisms and construction principles of luminescent MOFs are discussed, and the state‐of‐the‐art MOF‐based luminescent sensors of environmental pollutants, including pesticides, antibiotics, explosives, VOCs, toxic gas, toxic small molecules, radioactive ions, and heavy metal ions are highlighted. This comprehensive review may further guide the development of luminescent MOFs and promote their practical applications for sensing environmental pollutants.
Luminescent MOFs have attracted remarkable attention to detect environmental pollutants because of their excellent selectivity, sensitivity, and recyclability. In this review, the sensing mechanisms and construction principles of luminescent MOFs are discussed, and the state‐of‐the‐art luminescent MOF‐based sensors of environmental pollutants, including pesticides, antibiotics, explosives, VOCs, toxic gas, toxic small molecules, radioactive ions, and heavy metal ions are highlighted.
A novel 3D Eu-BTB framework () containing three types of 1D channels was synthesized and structurally characterized. Compound exhibits high thermostability and water stability with the pH range from ...2 to 12. Additionally, the luminescence explorations revealed that can sensitively and selectively detect pollutant PO4(3-) among various colourless anions. More importantly, represents the first example of regenerable MOF-based luminescent probes for detecting PO4(3-).
In recent ten years, 3D printing technology has been developed rapidly. As an advanced technology, 3D printing has been used to fabricate complex and high-precision objects in many fields. 3D ...printing has several technologies. Among these technologies, photo-curing 3D printing was the earliest and most mature technology. In 1988, the first 3D printing machine which was based on photo-curing and called Stereo lithography Appearance (SLA) technology was produced by 3D system Corp. After 30 years of development, many new technologies based on photocuring mechanism emerged. Based on the different principle of pattern formation and character of printing technology, numerous photocuring 3D printing techniques, such as SLA, DLP, LCD, CLIP, MJP, two-photon 3D printing, holographic 3D printing and so on, have been developed. Photo-curing 3D printing has many advantages, such as high precision, smooth surface of printing objects, rapid printing speed and so on. Here, we would introduce five industrial photocuring 3D printing technologies, which are SLA, DLP, LCD, CLIP and MJP. The characters of the materials and the progress of the application of the technique in the biomedical field is also overviewed. At last, the difficulties and challenges of photo-curing 3D printing are also discussed.
•Different techniques of photocuring 3D printing were overviewed.•The advantage, disadvantage and application of the different techniques of photocuring 3D printing were discussed.•The progress of photocuring 3D printing technique in biomedical application is commented.•The existing problems and challenges of photocuring 3D printing were presented.
The growing prevalence of metabolic syndrome (MetS) in the U.S. and even worldwide is becoming a serious health problem and economic burden. MetS has become a crucial risk factor for the development ...of type 2 diabetes mellitus (T2D) and cardiovascular diseases (CVD). The rising rates of CVD and diabetes, which are the two leading causes of death, simultaneously exist. To prevent the progression of MetS to diabetes and CVD, we have to understand how MetS occurs and how it progresses. Too many causative factors interact with each other, making the investigation and treatment of metabolic syndrome a very complex issue. Recently, a number of studies were conducted to investigate mechanisms and interventions of MetS, from different aspects. In this review, the proposed and demonstrated mechanisms of MetS pathogenesis are discussed and summarized. More importantly, different interventions are discussed, so that health practitioners can have a better understanding of the most recent research progress and have available references for their daily practice.
The isolation between antenna elements is a key metric in some promising fifth generation technologies such as beamforming and in-band full-duplex. However, the multimode decoupling technology ...remains a great challenge, especially for mobile terminals. One difficulty in achieving multidecoupling modes is that the operating modes of closely packed decoupling elements have very strong mutual effect, which makes the tuning complicated and even unfeasible. Thus, in physical principle, a novel idea of achieving the stability of the boundary conditions of decoupling elements is proposed to solve the mutual effect problem; in physical structure, a metal boundary is adopted to realize the stability. One distinguished feature of the proposed technique is that the independent tuning characteristic can be maintained even if the number of decoupling elements increases. Therefore, wideband/multiband high isolation can be achieved by using multidecoupling elements. To validate the concept, two case studies are given. In a quad-mode decoupling design, the isolation is enhanced from 12.7 to >21 dB within 22% bandwidth by using a 0.295λ 0 × 0.059λ 0 × 0.007λ 0 decoupling structure. The mechanism of the decoupling technique and the mutual effect between decoupling elements are investigated.
The mixed convection flow of a hybrid nanofluid in an inclined channel with top wall-slip due to wall stripe and constant heat flux conditions is studied. Explicit analytical solutions are given to ...the flow velocity, temperature, as well as the pressure in non-dimensional forms. The flow regime domain, the velocity and temperature distributions, and the dependence of various physical parameters such as the hybrid nanoparticle volume fractions, the wall-slip, the Grashof number, the Reynolds number, and the inclined angle are analyzed and discussed. It is found that the hybrid nanofluid delays the appearance of flow reversal on both walls and the wall-slip postpones the flow reversal on the top wall.
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