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As a chemotherapeutic drug, cyclophosphamide (CP) has a negative impact on male fertility due to its reproductive toxicity. Melatonin (Mel) promotes the male reproductive system and increases testosterone synthesis. This study is aimed at exploring the molecular mechanism of Mel as a protector of male fertility against CP-induced cytotoxicity. A CP toxicity model was established in adult ICR male mice by intraperitoneal injection of 100 mg/kg CP every other day for a week. Protective effects of Mel on the testis from CP-induced damage were evaluated using four groups of ICR male mice that received intraperitoneal injections of normal saline, 100 mg/kg CP, 10 mg/kg Mel, or the same dosage of CP and Mel, respectively. Testis morphology was observed by hematoxylin and eosin (HE) staining. Sperm quality parameters were evaluated, and sperm function was studied by in vitro fertilization (IVF). Proliferation, meiosis, and pyroptosis markers were examined by western blot. Results showed that CP treatment induced testis toxicity in a time-dependent manner with the most severe damage to the testis at two weeks post CP treatment. CP-treated mice showed reduced testicular weight and impaired spermatogenesis by downregulating PCNA and SYCP3, reduced serum testosterone levels, decreased sperm counts and motility, increased seminiferous tubule vacuolization, and oxidative damage to spermatogenic cells. All these effects, apart from testicular weight, could be ameliorated by Mel administration. The IVF experiment revealed that CP treatment reduced the rates of sperm fertilization and blastocyst development, which were also enhanced by Mel. Mel-treated mice also showed increased expression of proliferation-associated protein PCNA and meiosis-associated proteins REC8, STRA8, and SYCP3, which were all reduced by CP. Furthermore, Mel inhibited the pyroptosis of spermatogenic cells by reducing GSDMD and IL18 expression. In conclusion, this study indicated that Mel might protect the testis from CP-induced DNA damage to germ cells through the alleviation of pyroptosis. [ABSTRACT FROM AUTHOR]

In this article, we consider an extended dual risk model under a mixed dividend strategy, which is a combination of ratcheting dividend strategy and periodic dividend strategy. The expected present value of dividends paid up to ruin is studied by using Lévy fluctuation theory, and its accurate expression is given in terms of scale functions. Numerical analysis under three different gain distributions is given for characterizing the impact of parameters on the expected present value of dividends paid up to ruin. [ABSTRACT FROM AUTHOR]

The acquisition of 3D facial models is crucial in the gaming and film industries. In this study, we developed a facial acquisition system based on infrared structured light sensors to obtain facial-expression models with high fidelity and accuracy. First, we employed time-multiplexing structured light to obtain an accurate and dense point cloud. The template model was then warped to the captured facial expression. A model-tracking method based on optical flow was applied to track the registered 3D model displacement. Finally, the live 3D mesh was textured using high-resolution images captured by three color cameras. Experiments were conducted on human faces to demonstrate the performance of the proposed system and methods. [Display omitted] • A high-fidelity realtime facial animation pipeline based on an infrared structured light imaging system is built. • The facial 3D imaging system enables the game and film makers to capture dense and accurate facial models. • A nonrigid registration running on GPU is proposed to fast blend the target model according to captured models. • Varies experimental results have been presented to verify our system's efficiency and accuracy. [ABSTRACT FROM AUTHOR]

• Accuracy of existing DOE-based 3D sensors is usually below mm-level (like the well-known Intel Realsense sensor etc.), and thus not suitable for high precision 3D sensing applications. • A binary encoded structured light pattern is designed and robust pattern feature detection and decoding algorithms are proposed. • A DOE is manufactured based on the designed pattern, and an IR laser is used as light source for pattern projection. • Experimental results showed that higher accuracy can be obtained by the proposed approach and device in comparison with 3D sensors like Realsense etc. This paper presents a compact and accurate three-dimensional (3D) sensing system that employs a diffraction optical element as a projection device. Compared with the conventional laser speckle-based 3D sensing methods, a gridline pattern is utilized instead of a dot pattern. The proposed pattern is designed according to a pseudorandom coding scheme, and eight geometrical elements are embedded into the grid cells to form a unique codeword for each defined grid-point. By extracting the grid-points with the proposed feature detector, a topological graph is established to separate each pattern element. A convolutional neural network is trained for robust identification of the projected pattern elements. Finally, a codeword-correction procedure is applied to refine the decoding results. Using the proposed system-calibration method, accurate 3D reconstruction can be realized for the decoded grid-points. The measurement of the planarity and step distance has an absolute mean error of only 0.2–0.3 mm, indicating that it is far more accurate than the measurement using classical laser speckle-based 3D sensors. To demonstrate robustness of the proposed decoding algorithms, targets with plentiful color and texture are used. The results show that most of the grid-points can be robustly detected and that complex surfaces such as human faces and bodies can be precisely reconstructed. [ABSTRACT FROM AUTHOR]

Image, graphical abstract • We present a body model called symmetricSCAPE , which incorporates symmetry into the parametric model of 3D body. • SymmetricSCAPE imposes symmetry constraint on each symmetrically-related triangle pair of the body mesh. • symmetricSCAPE results in a better parametric model of 3D body than non-symmetry-aware representations. To realistically represent 3D human body shape in a mathematical way, the parametric model used should incorporate symmetry as displayed by real people. This paper proposes a symmetric parametric model called symmetricSCAPE. It successfully incorporates symmetry into a parametric model of the 3D body, formulating body geometric variations of both shape and pose using a triangular mesh representation. The symmetry constraint is imposed on each symmetrically-related triangle pair of the body mesh. Mathematically, symmetry-related constraint matrices are derived, and applied during shape and pose deformation of triangle pairs. By accurately registering a pre-designed symmetrization template mesh to the training dataset, we learn how the symmetricSCAPE model causes the body mesh to deform relative to the symmetry. Our experiments demonstrate that the symmetricSCAPE model results in a better, more parsimonious, and more accurate parametric model of the 3D human body than traditional non-symmetry-aware representations. [ABSTRACT FROM AUTHOR]

AWPPH is a newly discovered long non-coding (lnc)RNA that serves an oncogenic role in the development of several types of cancer; however, its involvement in non-small cell lung cancer (NSCLC) is unknown. Therefore, the aim of the present study was to investigate the function of AWPPH in NSCLC. The results demonstrated that AWPPH expression levels were significantly upregulated in the lung tissues and serum samples of patients with NSCLC compared with in healthy controls. High expression levels of AWPPH effectively distinguished NSCLC patients from healthy controls. In addition, patients with high expression levels of AWPPH had significantly shorter survival time. AWPPH overexpression in NSCLC cells promoted proliferation and inhibited apoptosis, and activated the Wnt/β-catenin signaling pathway, which is a classic signaling pathway involved in the development and progression of different types of cancers. Treatment with a Wnt/β-catenin signaling pathway activator produced no significant effect on AWPPH expression. Therefore, it was concluded that lcRNA AWPPH could promote the growth of NSCLCs by activating the Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Highlights • A reference-plane-based approach is applied to estimate the principle optical axis of LED light source as well as its principle energy. • An iterative process was proposed to optimize initial system parameters, and accurate 3D reconstruction results can be obtained for various objects. • Accurate 3D reconstruction results can be obtained based on the low-cost setup composed with some LEDs and a web-camera. Abstract This paper presents a complete computational framework for the photometric stereo system composed of some LED lamps and a single web-camera. To describe the lighting condition accurately, the angular and distance attenuation factors, as well as the LED radiance property, are considered in the modeling of the light source. The calibration of the system's parameters is a critical step for our setup, and a two-step calibration procedure is proposed in this work. A multiple-sphere-based approach is first used to estimate the light source positions. Then, a reference-plane-based approach is applied to estimate the principal optical axis of each light source and its principal energy. For each surface point on the target, the direction and intensity of its incidental light ray can be precisely determined by the calibration parameters and the quasi-point light model. Based on the initial 3D reconstruction result, an iterative procedure is applied to optimize the model's parameters for each surface point with respect to its initial estimated depth. In the experiments, both regular and free-form surfaces including a real human face are used. The results show that accurate 3D reconstruction results can be obtained by the proposed approach based on the low-cost setup. [ABSTRACT FROM AUTHOR]

Excavation in close proximity to the existing shield tunnel often leads to impacts on the stability of tunnel. However, interventions committed to mitigate the impacts may not be effective in preventing tunnel movement and/or deformation from occurring. This study presents a case history where two shield tunnels pass between two excavation pits belonging to the east square of the existing Zhengzhou East High Speed Rail (HSR) station. The centre down-top pit retained using a series of bored piles and three rows of tieback is first excavated in each excavation pit, followed by the periphery top-down pit retained by the diaphragm wall. The tunnels measured cumulative uplift and lateral deformation being equal to 22.9 mm and 77.9 mm, respectively, as the two excavations reached the final depth of 19.3 m. The tunnels also observed ballast separation, lining crack, and joint leakage. The contribution from each of the construction stages to the tunnel uplift and deformation is analysed. The effectiveness of the rectifications adopted is assessed and the lessons learnt are summarised preventing future similar incident from reoccurring. [ABSTRACT FROM AUTHOR]

Structured lighting (SL) scanning technology has been successfully applied to reconstruct personalized avatars, providing high-quality geometry for the face and body. However, previous white SL methods have typically been unable to capture and reconstruct hair geometry, preventing a complete, realistic avatar surface from being reconstructed. In this paper, we propose a novel hair capture system, producing a full-head manifold with complete hair, based on four white SL scanners made by ourselves. The key technical contribution is a robust strip-edge-based coding algorithm, using a projection pattern of 18 stripes; it allows geometric acquisition to an accuracy of 1 mm. Experiments are given to show that our system produces high-quality hair geometry, comparable to that captured by more expensive state-of-the-art multiview stereo systems. Our system is however easier to configure, and is more suited to real-world setups. [ABSTRACT FROM AUTHOR]

Tissue-engineered human anterior hemi-cornea (TE-aHC) is a promising equivalent for treating anterior lamellar keratopathy to surmount the severe shortage of donated corneas. This study was intended to construct a functional TE-aHC with nontransfected human corneal stromal (ntHCS) and epithelial (ntHCEP) cells using acellular porcine corneal stromata (aPCS) as a carrier scaffold, and evaluate its biological functions in a dog model. To construct a TE-aHC, ntHCS cells were injected into an aPCS scaffold and cultured for 3 days; then, ntHCEP cells were inoculated onto the Bowman's membrane of the scaffold and cultured for 5 days under air-liquid interface condition. After its morphology and histological structure were characterized, the constructed TE-aHC was transplanted into dog eyes via lamellar keratoplasty. The corneal transparency, thickness, intraocular pressure, epithelial integrity, and corneal regeneration were monitored in vivo, and the histological structure and histochemical property were examined ex vivo 360 days after surgery, respectively. The results showed that the constructed TE-aHC was highly transparent and composed of a corneal epithelium of 7-8 layer ntHCEP cells and a corneal stroma of regularly aligned collagen fibers and well-preserved glycosaminoglycans with sparsely distributed ntHCS cells, mimicking a normal anterior hemi-cornea (aHC). Moreover, both ntHCEP and ntHCS cells maintained positive expression of their marker and functional proteins. After transplantation into dog eyes, the constructed TE-aHC acted naturally in terms of morphology, structure and inherent property, and functioned well in maintaining corneal clarity, thickness, normal histological structure, and composition in dog models by reconstructing a normal aHC, which could be used as a promising aHC equivalent in corneal regenerative medicine and aHC disorder therapy. [ABSTRACT FROM AUTHOR]

This paper presents a novel structured light approach for the 3D reconstruction of specular surface. The binary shifting strip is adopted as structured light pattern instead of conventional sinusoidal pattern. Based on the framework of conventional High Dynamic Range (HDR) imaging technique, an efficient means is first introduced to estimate the camera response function. And then, dynamic range of the generated radiance map is compressed in the gradient domain by introducing an attenuation function. Subject to the change of lighting conditions caused by projecting different structured light patterns, the structure light image with middle exposure level is selected as the reference image and used for the slight adjustment of the primary fused image. Finally, the regenerated structured light images with well exposing condition are used for 3D reconstruction of the specular surface. To evaluate performance of the method, some stainless stamping parts with strong reflectivity are used for the experiments. And the results showed that, different specular targets with various shapes can be precisely reconstructed by the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, an integrated distributed fiber optic sensing technology, which includes Raman optical time-domain reflectometry (ROTDR), Brillouin optical time-domain analysis (BOTDA), and fiber Bragg grating (FBG) sensing technologies, is adopted to monitor the temperature and the stress/strain variations of a reinforced concrete pound lock structure during the construction process. The Raman optical time-domain reflectometry was used to monitor the internal temperature variation throughout the concrete curing process when concrete hydration heat was released in the base plate of the lock head. The FBG temperature sensors were adopted to measure the surface temperature of the concrete, and the temperature data were used to compensate the results that are measured by BOTDA sensing technology to get the real concrete strain of the base plate. To better understand the stress/strain state of the base plate before and after filling water in the lock, the BOTDA sensing cable and FBG temperature sensors monitoring continued throughout the whole construction process. The observation provided a positive indication that the proposed integrated distributed fiber optic sensing technology may have great potential in performance monitoring of hydraulic structures. [ABSTRACT FROM AUTHOR]

Based on the Shannon sampling theorem of multivariate functions, the upper bound of approximated error of homogeneous random field by local averages in the mean square sense is established. The main result is that the approximation of weak sense stochastic process from local averages is extended to the case of random field. It is expected that one can obtain more precise local average sampling in oceanography, meteorology, geology with this theory. [ABSTRACT FROM AUTHOR]

To study the tunnel stability at various static water pressures and determine the mechanical properties and deformation behavior of surrounding rock, a modified effective stress formula was introduced into a numerical integration algorithm of elastic-plastic constitutive equation, that is, closest point projection method (CPPM). Taking the effects of water pressure and seepage into account, a CPPM-based formula was derived and a CPPM algorithm based on Drucker-Prager yield criterion considering the effect of pore water pressure was provided. On this basis, a CPPM-based elastic-plastic numerical analysis program considering pore water pressure was developed, which can be applied in the engineering of tunnels and other underground structures. The algorithm can accurately take the effects of groundwater on stability of surrounding rock mass into account and it can show the more pronounced effect of pore water pressure on stress, deformation, and the plastic zone in a tunnel. The stability of water flooding in Fusong tunnel was systematically analyzed using the developed program. The analysis results showed that the existence of groundwater seepage under tunnel construction will give rise to stress redistribution in the surrounding rock mass. Pore water pressure has a significant effect on the surrounding rock mass. [ABSTRACT FROM AUTHOR]

Conventional Photometric Stereo (PS) techniques are usually based on the assumption that the light sources are assumed sufficiently far from the object that all incoming light can be modeled using parallel rays. Meanwhile, for near-field lighting conditions the light sources are close to the object so the parallel ray model cannot be used. To determine the surface normal for each point on the object more accurately, the incoming light direction should be calculated individually for each point. In this work, based on a simple PS setup consisting of LED lamps and one camera, we present a practical method for calibrating lighting directions. First, an optical model of an LED was introduced in the calibration procedure to represent the surface irradiance and image irradiance more accurately. A reference sphere was used for the calibration so that the LED optical axis could be estimated by extracting the specular points from the reference sphere. By introducing the LED emitting model, distance between the LED and the specular point along the optical axis can be calculated. Thus, the incident lighting directions for various image points can be estimated individually. To improve the estimation robustness, a non-linear fitting approach was also applied. Experiments were conducted using objects and the results are compared with traditional methods to demonstrate its feasibility and improvement. [ABSTRACT FROM AUTHOR]

In order to investigate catalytic performance of bio-char on microwave-assisted CH4/CO2 reforming, different bio-chars were obtained through change of biomass material, adjustment of char-making temperature, and deashing of raw materials. And then various bio-chars were served as catalysts for CH4 reforming reaction in a fixed bed reactor,to study catalytic effect of different bio-chars on the conversions of reactant gases. The results show that the metal oxide contained in bio-char can not only impose catalytic effect on CH4/CO2 reforming, but also can affect the response of bio-char to microwave. As a result,the metal oxide content in bio-char is determinant for its catalytic activity. The conclusion reached above was confirmed by the catalytic effect of deliming bio-char on CH4/CO2 reforming. In addition, the surface area and pore characteristics of bio-char also play a role in the catalytic performance of bio-char. Bio-char was mixed evenly with different additives to examine the influence of additives on bio-char catalytic properties. The results reveal that the bio-chars mixed with Na2CO3 or K2CO3 can bring an increase in CO2 conversion as well as a decrease in CH4 conversion. An improvement in catalytic performance of char was observed because of the introduction of MgO,CaO oi NiO. Finally,the addition of SiO2 was demonstrated to be unfavorable for the reforming reaction. [ABSTRACT FROM AUTHOR]

Abstract: Two Zn2+ ion fluorescent probes based on a coumarin Schiff-base were designed and synthesized, which have highly selective sensing of Zn2+ ions over other metal ions in aqueous solution based on a C N isomerization mechanism. Both the X-ray crystal structure of the zinc complex and the Job’s plots showed a 1:1 probe-Zn2+ ion identification with high selectivity and sensitivity. The Cp1 probe was also used to image intracellular Zn2+ ions in MCF-7 cells with a good performance. [Copyright &y& Elsevier]

High-grade syngas can be produced from the reforming of CH4 with CO2. To achieve efficient conversion of reforming reaction into syngas production, the reforming of CH4 with CO2 for syngas production was conducted in this paper under microwave irradiation, with biomass char as catalyst and microwave absorbing medium. The influences of the conditions including reaction temperature, molar ratio of CO2 and CH4, addition amount of biomass char as well as the introduction of water vapor on the reforming reaction were investigated. The results reveal that an increase in the conversion of reactant gases into syngas production can be achieved through raising reaction temperature, enhancing molar ratio of CO2 and CH4 or increasing addition amount of biomass char. Raising reaction temperature results in a promotion in the ratio of H2 to CO, while enhancing molar ratio of CO2 to CH4 or increasing addition amount of biomass char bring about a decrease in the ratio of H2 to CO. And the introduction of water vapor is not only favorable for the reforming reaction, but also is responsible for an increase in the ratio of H4 to CO. [ABSTRACT FROM AUTHOR]

3D fingerprinting is an emerging technology with the distinct advantage of touchless operation. More important, 3D fingerprint models contain more biometric information than traditional 2D fingerprint images. However, current approaches to fingerprint feature detection usually must transform the 3D models to a 2D space through unwrapping or other methods, which might introduce distortions. A new approach directly extracts valley-ridge features from point-cloud-based 3D fingerprint models. It first applies the moving least-squares method to fit a local paraboloid surface and represent the local point cloud area. It then computes the local surface's curvatures and curvature tensors to facilitate detection of the potential valley and ridge points. The approach projects those points to the most likely valley-ridge lines, using statistical means such as covariance analysis and cross correlation. To finally extract the valley-ridge lines, it grows the polylines that approximate the projected feature points and removes the perturbations between the sampled points. Experiments with different 3D fingerprint models demonstrate this approach's feasibility and performance. [ABSTRACT FROM AUTHOR]

Three-dimensional measurement of shiny or reflective surface is a challenging issue for optical-based instrumentations. In this paper, we present a novel structured light approach for direct measurement of shiny target so as to skip the coating preprocedure. In comparison with traditional image-intensity-based structured light coding strategies like sinusoidal and line patterns, strip edges not raw image intensities are encoded in the illuminated patterns. With strip edges generally better preserved than individual image intensity in the image data in the presence of surface reflections, such a coding strategy is more robust. To remove the periodic ambiguity within strip patterns, traditional Gray code patterns are adopted. To localize the strip edges more precisely, both positive and negative strip patterns are used. An improved zero-crossing feature detector that has subpixel accuracy is proposed for strip-edge localization. The experimental setup is configured with merely an off-the-shelf pico-projector and a camera. Extensive experiments including accuracy evaluation, comparison with previous structured light algorithms, and the reconstruction of some real shiny objects are shown to demonstrate the system's accuracy and endurance against reflective nature of surfaces. [ABSTRACT FROM PUBLISHER]

Abstract: Semi-supervised learning has recently received considerable attention in machine learning. In this paper, we propose a novel diffusion maps based semi-supervised algorithm for dimensionality reduction, visualization and data representation. Unlike previous work which uses only geometric information for similarity metric construction, a distributional similarity metric is introduced to modify the geometric relationship of samples. This metric is defined using the posterior probability over the labels of each sample, which is learned through the Expectation–Maximization (EM) algorithm. The Euclidean distance between points on the intrinsic manifold learned by our proposed method is equal to the label-dependent “diffusion distance”, which is modified by the distributional similarity related metric, in the original space. Our algorithm preserves the local manifold structure in addition to separating samples in different classes, thus facilitates the classification. Encouraging experimental results on handwritten digits, Yale faces, UCI data sets and the Weizmann data set show that the algorithm can improve the classification accuracy significantly. [Copyright &y& Elsevier]

Non-uniform rational B-spline (NURBS) interpolator has been widely used in modern manufacturing systems to machine arbitrary geometries with great relief of the data flow bottleneck and feedrate fluctuation. However, in practice, real-time feedrate does not always meet the computer numerical control (CNC) command exactly subject to the system dynamics. To solve this problem, we present a real-time NURBS interpolator with feedrate optimization for CNC machining tools in this work. The parametric curve is first approximated with the Adams-Bashforth method which provides uniform feedrate in each sampling period in the interpolation process. And then, a feedback scheme is introduced to adjust the feedrate in real time so as to guarantee a specified deviation between the measured and the desired feedrate. The convergence condition for this closed-loop algorithm is presented and analyzed. Simulation and real experiments on an X- Y table are employed to verify its feasibility. And the comparisons with traditional interpolators based on Taylor's expansion are also provided to demonstrate its improvement in accuracy. [ABSTRACT FROM AUTHOR]

The microwave-assisted heating apparatus was employed to study the reforming of CH4 with CO2 over activated carbon. The influences of microwave power and CH4/CO2 molar ratio on reforming reaction were investigated. Furthermore, catalytic activity of the activated carbon was tested. And specific surface area analysis and Bothem titration method were used to explore the possible reason for the deactivation of activated carbon. The results indicate that increasing microwave power or decreasing the CH4/CO2 molar ratio can result in an increase in the reactant gas conversions as well as in the content of syngas, together with a decrease in the molar ratio of H2 and CO. It is found that an encouraging catalytic activity is achieved at the beginning, followed by a sharp loss of catalytic activity after 40 min, which is mainly caused by the change of pore structure and the reduction of functional oxygen groups. [ABSTRACT FROM AUTHOR]

Abstract: Structured light-based sensing (SLS) requires the illumination to be coded either spatially or temporally in the illuminated pattern. However, while the former demands the use of uniquely coded spatial windows whose size grows with the reconstruction resolution and thereby demanding increasing smoothness on the imaged scene, the latter demands the use of multiple image captures. This article presents how the illumination of a very simple pattern plus a single image capture can also achieve 3D reconstruction. The illumination and imaging setting has the configuration of a typical SLS system, comprising a projector and a camera. The difference is, the illumination is not much more than a checkerboard-like pattern – a non-structured pattern in the language of SLS – that does not provide direct correspondence between the camera’s image plane and the projector’s display panel. The system works from the image progressively, first constructing the orientation map of the target object from the observed grid-lines, then inferring the depth map by the use of a few tricks related to interpolation. The system trades off little accuracy of the traditional SLSs with simplicity of its operation. Compared to temporally coded SLSs, the system has the essence that it requires only one image capture to operate; compared with spatially coded SLSs, it requires no use of spatial windows, and in turn a less degree of smoothness on the object surface; compared with methods like shape from shading and photometric stereo, owing to the use of artificial illumination it is less affected by the surface reflectance property of the target surface and the ambient lighting condition. [Copyright &y& Elsevier]

Abstract: Using the time-dependent Schrödinger equation, we present the analytical result of the expectation value of spin injected into a two-dimensional electron gas with respect to an arbitrarily spin-polarized electron state and monitor the spin time-evolution. We demonstrate that the expectation value of spin operator is the time-independent, and only the expectation values in the plane are time-dependent. A detailed study of spin precession in the spin-valve and spin-transistor geometry is presented, in which the initial spin-polarized electron state point perpendicular and parallel to the current direction, respectively. We put forward the possible reason that the resistance change is independent of gate voltage in the spin-valve geometry. Furthermore, it has been shown that the effective magnetic field generated by the spin–orbit interaction is not same with the truly magnetic field. The main effect of the truly magnetic field is to align the spin along the field direction, but the effective magnetic field generated by the spin–orbit interaction does not. [Copyright &y& Elsevier]

The acquisition of the geometry of general scenes is related to the interplay of surface geometry, material properties and illumination characteristics. Surface texture and non-Lambertian reflectance properties degrade the reconstruction results by structured light technique. Existing structured light techniques focus on different coding strategy and light sources to improve reconstruction accuracy. The hybrid system consisting of a structured light technique and photometric stereo combines the depth value with normal information to refine the reconstruction results. In this paper, we propose a novel hybrid system consisting of stripe-based structured light and photometric stereo. The effect of surface texture and non-Lambertian reflection on stripe detection is first concluded. Contrary to existing fusion strategy, we propose an improved method for stripe detection to reduce the above factor's effects on accuracy. The reconstruction problem for general scene comes down to using reflectance properties to improve the accuracy of stripe detection. Several objects, including checkerboard, metal-flat plane and free-form objects with complex reflectance properties, were reconstructed to validate our proposed method, which illustrates the effectiveness on improving the reconstruction accuracy of complex objects. The three-step phase-shifting algorithm was implemented and the reconstruction results were given and also compared with ours. In addition, our proposed framework provides a new feasible scheme for solving the ongoing problem of the reconstruction of complex objects with variant reflectance. The problem can be solved by subtracting the non-Lambertian components from the original grey values of stripe to improve the accuracy of stripe detection. In the future, based on stripe structured light technique, more general reflection models can be used to model different types of reflection properties of complex objects. [ABSTRACT FROM AUTHOR]

Structured light (SL) has a trade-off between acquisition time and spatial resolution. Temporally coded SL can produce a 3D reconstruction with high density, yet it is not applicable to dynamic reconstruction. On the contrary, spatially coded SL works with a single shot, but it can only achieve sparse reconstruction. This paper aims to achieve accurate 3D dense and dynamic reconstruction at the same time. A speckle-based SL sensor is presented, which consists of two cameras and a diffractive optical element (DOE) projector. The two cameras record images synchronously. First, a speckle pattern was elaborately designed and projected. Second, a high-accuracy calibration method was proposed to calibrate the system; meanwhile, the stereo images were accurately aligned by developing an optimized epipolar rectification algorithm. Then, an improved semi-global matching (SGM) algorithm was proposed to improve the correctness of the stereo matching, through which a high-quality depth map was achieved. Finally, dense point clouds could be recovered from the depth map. The DOE projector was designed with a size of 8 mm × 8 mm. The baseline between stereo cameras was controlled to be below 50 mm. Experimental results validated the effectiveness of the proposed algorithm. Compared with some other single-shot 3D systems, our system displayed a better performance. At close range, such as 0.4 m, our system could achieve submillimeter accuracy. [ABSTRACT FROM AUTHOR]

Summary: With the development of the vehicular ad hoc network, the security and privacy are now becoming vital concerns, especially when the attacker owns more and more resources. In order to address these concerns, a dynamic anonymous identity authentication scheme is proposed using Elliptic Curve Discrete Logarithm Problem and blockchain method, which guarantees the security and fast off‐line authentication for vehicle‐to‐infrastructure. Specifically, a dynamic pseudonym key is generated using tamper proof device (TPD) for off‐line authentication and anonymity when a vehicle roams among different roadside units' (RSUs) communication ranges. Even if all RSUs are compromised, vehicle's identity is still privacy. Moreover, two additional design goals are more suitable for the practical environment: (1) the reduced assumption of TPD; (2) certification authority can trace vehicle under the authorization by law. A dynamic anonymous identity authentication scheme is proposed for vehicular ad hoc network, which is more suitable for the practical situation. The analysis and the simulation show that the proposed scheme not only guarantees the offline update, traceable pseudonyms, and anonymous identity authentication, but also improves the efficiency for key pairs dynamically changement. [ABSTRACT FROM AUTHOR]

Background Objectives Materials and methods Results Discussion Conclusion Infertility is a prevalent global condition, and emerging reproductive technologies may enhance its evaluation and treatment. Understanding the current features of randomized clinical trials in infertility is crucial for improving study design and ensuring the translation of results for patient benefits.To investigate the primary characteristics of randomized clinical trials related to infertility and areas where require improvement.We conducted a search on the International Clinical Trials Registry platform for eligible infertility trials between 2003 and 2022. The distribution ratio of various characteristics uploaded by infertility‐related studies on the platform was analyzed and compared according to sex and registration year.Out of the total trials, 85.3% (1,906) included only women, 8.6% (192) included only men, and 6.1% (136) included couples. The majority of retrieved trials followed a parallel arm design (91.0%) and were non‐industry‐funded (92.2%), with a median planned sample size of 131 patients (interquartile range 75–270). Among these trials, 54.5% (1,217) were conducted in Asia. The most common primary purpose of infertility‐related trials was treatment (88.8%), with over half of the investigated interventions focusing on medication (57.9%).Asia is the leading region for research, and the drug therapy is still widely used and updated. However, support care for infertile couples has also received some preference. Areas that require improvement and promotion include addressing male infertility and focusing on underserved regions like Africa. The results also highlight deficiencies in trial registration and masking methods, emphasizing the need for better regulation and facilitation of infertility trials in the post‐COVID‐19 era.Based on the current status of infertility RCT studies, greater attention should be paid to infertile men and populations in underdeveloped regions like Africa in future studies, together with a standardized registration and implementation procedures. [ABSTRACT FROM AUTHOR]

Structured light is a widely employed approach for profile measurement in active stereo vision. Recent methods have developed learning-based single pattern structured light systems and unstructured light stereo vision systems. However, their methods require additional cameras or a diffractive optical element. In addition, the calibration methods of the learning-based structured light systems require a large number of images, while the stereo vision method cannot detect the blocked region. Classically, a digital projector is treated as a pseudocamera, and the stripe pattern is employed to measure the depth. However, an additional pattern is employed to calibrate the camera-projector system in the stripe-based method. In this paper, 24 reliable features and a novel calibration algorithm are proposed. With the proposed calibration algorithm, the stripe patterns are calibrated without additional patterns, and with the proposed RGB features, the number of encoded columns is enlarged significantly. Experiments demonstrate that the proposed method is accurate and robust. [ABSTRACT FROM AUTHOR]

Since the century discovery of cosmic ray, the origin of cosmic ray is always a mystery. The study on the origin of high-energy cosmic ray is in an interdiscipline between the very high-energy (VHE) gamma-ray astronomy and the cosmic ray physics. The Large High Altitude Air Shower Observatory (LHAASO) is a unique and new generation cosmic-ray station with the advantages of high altitude, all-weather, and large-scale. It takes the function of hybrid technology to detect cosmic rays and to upgrade greatly the resolving power between gamma rays and cosmic rays. The LHAASO is expected to make the full-sky survey to find new gamma-ray sources, to obtain the highest sensitivity of gamma-ray detection at the high energy band of > 30 TeV, and to make the very high precision measurement on the component energy spectra of cosmic rays in a broad energy range of 5 orders of magnitude, in order to provide the evidence for revealing the mystery of the origin of cosmic ray. This paper describes the detector structure, performance superiority and scientific motivation of the LHAASO. [ABSTRACT FROM AUTHOR]

We tackle the problem of dense reconstruction with a practical system, in which near point lighting (NPL) is employed. Different from the conventional formulation of photometric stereo (PS) that assumes parallel lighting, PS under the NPL condition is a nonlinear problem as the local surface normals are coupled with its distance to the camera as well as the light sources. After obtaining the locations of point lights by a calibration process, we develop a new framework to solve this nonlinear reconstruction problem via mesh deformation, in which each facet is corresponding to a pixel in the image captured by the camera. In our framework, mesh deformation is decoupled into an iteration of interlaced steps of local projection and global blending. Experimental results verify that our method can generate accurate estimation of surface shape under NPL in a few iterations. Besides, this approach is robust to errors on the positions of light sources and is easy to be implemented. [ABSTRACT FROM AUTHOR]

To improve the calibration efficiency of the structured light stereo vision system, a closed-form single-pose calibration method is proposed. Previous works calibrate the structured light stereo vision system via the planar-based method since the world coordinates of the projected pixels are easy to find. But the disadvantage of these methods is that multiple poses are required, so that the mechanical movement is necessary in these calibration methods. In this paper, the inherent geometry between the spheres and their image is exploited deeply. Thus, a sphere-based calibration method is proposed. The proposed method first calibrates the camera from the image of the absolute conic through an improved algorithm. Then, the three-dimensional coordinates of the projected pixels are found via the inherent geometrical relation. Next, the projector is calibrated using the direct linear method. Finally, the distortion of the projector is found through the nonlinear optimization method with an improved updating direction. Experiments demonstrate that not only the calibration efficiency is improved, but also the calibration accuracy is improved. [ABSTRACT FROM AUTHOR]

Benefiting from the small size and low driven voltage of the Micro Electro Mechanical Systems (MEMS) mirror, MEMS-based structured light (SL) 3D reconstruction has recently attracted much attention. In this paper, we propose a novel triangular stereo model for uniaxial MEMS-based 3D reconstruction. Existing SL methods based on MEMS mirrors often require the construction of a look-up table(LUT), but the proposed method only requires 34 parameters for accurate reconstruction. By analyzing the anatomy of the MEMS mirror, we put forward a transition function that allows the MEMS mirror to be regarded as an inverse camera model. Then, the triangular stereo principle can be directly employed to calculate 3D information. Furthermore, we present a calibration method to obtain the parameters of our model, since MEMS mirrors can only perform unidirectional fringe projection. Extensive experiments are performed to verify the feasibility and accuracy of our proposed mathematical model and calibration method. [ABSTRACT FROM AUTHOR]

Spatial structured light (SL) can achieve three-dimensional measurements with a single shot. As an important branch in the field of dynamic reconstruction, its accuracy, robustness, and density are of vital importance. Currently, there is a wide performance gap of spatial SL between dense reconstruction (but less accurate, e.g., speckle-based SL) and accurate reconstruction (but often sparser, e.g., shape-coded SL). The central problem lies in the coding strategy and the designed coding features. This paper aims to improve the density and quantity of reconstructed point clouds by spatial SL whilst also maintaining a high accuracy. Firstly, a new pseudo-2D pattern generation strategy was developed, which can improve the coding capacity of shape-coded SL greatly. Then, to extract the dense feature points robustly and accurately, an end-to-end corner detection method based on deep learning was developed. Finally, the pseudo-2D pattern was decoded with the aid of the epipolar constraint. Experimental results validated the effectiveness of the proposed system. [ABSTRACT FROM AUTHOR]

Decoding is a challenging and complex problem in a coded structured light system. In this paper, a robust pattern decoding method is proposed for the shape-coded structured light in which the pattern is designed as grid shape with embedded geometrical shapes. In our decoding method, advancements are made at three steps. First, a multi-template feature detection algorithm is introduced to detect the feature point which is the intersection of each two orthogonal grid-lines. Second, pattern element identification is modelled as a supervised classification problem and the deep neural network technique is applied for the accurate classification of pattern elements. Before that, a training dataset is established, which contains a mass of pattern elements with various blurring and distortions. Third, an error correction mechanism based on epipolar constraint, coplanarity constraint and topological constraint is presented to reduce the false matches. In the experiments, several complex objects including human hand are chosen to test the accuracy and robustness of the proposed method. The experimental results show that our decoding method not only has high decoding accuracy, but also owns strong robustness to surface color and complex textures. [ABSTRACT FROM AUTHOR]

Purpose: To clarify the ambiguity of the function of CMTM3 in the development of hepatocellular carcinoma (HCC) and explore its molecular mechanism. Methods: The Cmtm3-KO C57BL/6 mouse strain was established using CRISPR-Cas9. Acute liver damage and HCC models were induced by peritoneal injection of 100 or 25 mg/kg.BW N-Nitrosodiethylamine (DEN) to male mice. Liver function and histology were evaluated by blood serum levels of AST and ALT, and HE staining. Gene and protein expression in liver tissues was investigated by RNA-seq, RT-qPCR, Western blotting, immunohistochemistry, and immunofluorescence. Protein–protein interactions were studied by STRING and topological measures. The mRNA expression of CMTM3 and PPARs and patient survival were analyzed using the UALCAN database. Results: Global knockout of Cmtm3 in KO mice was successfully confirmed. Cmtm3 knockout alleviated DEN-induced acute damage to liver histological integrity and liver function, reduced DNA damage and apoptosis, and also caused a significantly reduced number (WT: 8.7 ± 5.5 vs. KO: 2.7 ± 3.1, P = 0.0394) and total size of tumors (WT: 130.9 ± 181.8 mm2vs. KO: 9.3 ± 11.5 mm2, P = 0.026) in the liver. Mechanistically, Cmtm3 knockout resulted in reduced expression and inactivation of Pparγ and its downstream lipid metabolism genes (e.g. Adipoq) upon DEN intoxication. CMTM3 and PPARγ were both overexpressed in HCC, and higher levels of both genes were associated with worse overall survival of HCC patients. Conclusion: This study clarified the pro-tumorigenesis role of CMTM3 in HCC in vivo, possibly through the upregulation of PPARγ and activation of the PPAR pathway. [ABSTRACT FROM AUTHOR]

A structured light system simplifies three-dimensional reconstruction by illuminating a specially designed pattern to the target object, thereby generating a distinct texture on it for imaging and further processing. Success of the system hinges upon what features are to be coded in the projected pattern, extracted in the captured image, and matched between the projector's display panel and the camera's image plane. The codes have to be such that they are largely preserved in the image data upon illumination from the projector, reflection from the target object, and projective distortion in the imaging process. The features also need to be reliably extracted in the image domain. In this article, a two-dimensional pseudorandom pattern consisting of rhombic color elements is proposed, and the grid points between the pattern elements are chosen as the feature points. We describe how a type classification of the grid points plus the pseudorandomness of the projected pattern can equip each grid point with a unique label that is preserved in the captured image. We also present a grid point detector that extracts the grid points without the need of segmenting the pattern elements, and that localizes the grid points in subpixel accuracy. Extensive experiments are presented to illustrate that, with the proposed pattern feature definition and feature detector, more features points in higher accuracy can be reconstructed in comparison with the existing pseudorandomly encoded structured light systems. [ABSTRACT FROM AUTHOR]

Using the perturbation method, we theoretically study the spin current and its heat effect in a multichannel quantum wire with Rashba spin--orbit coupling. The heat generated by the spin current is calculated. With the increase of the width of the quantum wire, the spin current and the heat generated both exhibit period oscillations with equal amplitudes. When the quantum-channel number is doubled, the oscillation periods of the spin current and of the heat generated both decrease by a factor of 2. For the spin current js,xy, the amplitude increases with the decrease of the quantum channel; while the amplitude of the spin current js,yx remains the same. Therefore we conclude that the effect of the quantum-channel number on the spin current js,xy is greater than that on the spin current js,yx. The strength of the Rashba spin--orbit coupling is tunable by the gate voltage, and the gate voltage can be varied experimentally, which implies a new method of detecting the spin current. In addition, we can control the amplitude and the oscillation period of the spin current by controlling the number of the quantum channels. All these characteristics of the spin current will be very important for detecting and controlling the spin current, and especially for designing new spintronic devices in the future. [ABSTRACT FROM AUTHOR]

Color encoded structured light is an important means for single-shot 3D reconstruction. In this article, we present a pseudorandom array-based structured light method. The proposed pattern is composed with four colors, and one geometric shape is inlaid to the color elements to extend the coding element from four to eight. As a result, a relatively small coding window with the size of 2×2 can be obtained. Grid-point between each two adjacent pattern elements is defined as the pattern feature. And an improved feature detector is proposed for the robust and accurate grid-point localization. The grid-points are divided into two types and represented by a topological structure. The decoding procedure is performed in two steps, the shape decoding and color decoding. Finally, the epipolar constraint and neighboring constraint are introduced to improve the decoding reliability. Accuracy and robustness of the proposed method are evaluated in the experiments. Some real objects including human face are reconstructed to demonstrate the 3D reconstruction quality of the proposed structured light method. [ABSTRACT FROM AUTHOR]

Turntable-based 3D scanners are popular but require calibration of the turntable axis. Existing methods for turntable calibration typically make use of specially designed tools, such as a chessboard or criterion sphere, which users must manually install and dismount. In this article, the authors propose an automatic method to calibrate the turntable axis without any calibration tools. Given a scan sequence of the input object, they first recover the initial rotation axis from an automatic registration step. Then they apply an iterative procedure to obtain the optimized turntable axis. This iterative procedure alternates between two steps: refining the initial pose of the input scans and approximating the rotation matrix. The performance of the proposed method was evaluated on a structured light-based scanning system. [ABSTRACT FROM AUTHOR]

In this study, the effects of electrolyzed oxidizing water (EOW) on the prevention of enzymatic browning of fresh-cut 'Jiu Jinhuang' Chinese yam were investigated. The yams were immersed in the inhibitors for 25 min at 20 °C. Compared with the tap water (TW) treatment, the chromatic attributes were significantly different after 72 h of storage ( P < 0.05). The activities of polyphenol oxidase (PPO, EC 1.10.3.1), peroxidase (POD, EC 1.11.1.7), and L-phenylalanine ammonia lyase (PAL, EC 4.3.1.5) were inhibited when measured at 24 h. The contents of phenolic acids, including gallic and chlorogenic acid, in the group treated with the slightly acidic electrolyzed water (SAEW) were higher than those treated with TW and neutral electrolyzed water (NEW). The group treated with NEW had the highest total phenol content ( P < 0.05, at 24 h), while the group treated with SAEW had the highest flavonoid content ( P < 0.05) during storage. Without being treated with inhibitors, the Km and Vmax values of yam PPO were 0.0044 mol/L and 0.02627 U/min, respectively, and the Ki of samples treated with SAEW and citric acid (CA) were 15.6607 and 2.3969 μmol/L, respectively. These results indicate that EOW is beneficial as a browning inhibitor. [ABSTRACT FROM AUTHOR]

• The curved LCD is first applied to the PMD, which increases the measurable curvature than the planar LCD. • A calibration method is proposed for the system based on the 3D fiducials on the curved LCD rather than the 2D fiducials on the planar one. • Different from the traditional stereo-PMD in which only areas that has common FOV with phase information of two cameras can be reconstructed, the proposed stereo-PMD reconstruction and registration algorithm can reconstruct the surface in FOV of each camera, respectively, and then register together. • The reconstructed error of RMS is less than 100 nm for the concave mirror of ROC 1000 mm. Phase measuring deflectometry (PMD) technique is widely used to measure the specular surface. However, the Current PMD methods are generally based on the planar LCD for the measurement, which limits the measurable curvature of the surface under test (SUT). To increase the measurable range of curvature, this paper proposes a novel PMD method by using a curved LCD monitor. A calibration method based on the cylindrical coordinate system is introduced for the proposed system calibration. To extend the measurable range further, the curved LCD is applied in stereoscopic PMD. The partial surface of SUT in the field of view (FOV) of each camera and curved LCD are reconstructed with iterative algorithm respectively, the calibration parameters as well as the seed point are used for point cloud registration. Simulations show the advantage of a curved LCD over a planar one and the feasibility of the proposed method. The actual performance is demonstrated in the experiments for specular optics and a phone touchscreen. [ABSTRACT FROM AUTHOR]

3-Chloro-2-hydroxypropyl dimethyl dehydroabietyl ammonium chloride (CHPDMDHA) was synthesized from dehydroabietylamine (DHA) and epichlorodrin. The synthesis was done in three steps. First, DHA was transformed into N, N-dimethyl dehydroabietyl amine (DMDHA) through Eschweiler-Clarke Reaction. Second, the DMDHA was reacted with hydrochloric acid and translated into DMDHA hydrochloride. Third, the CHPDMDHA was obtained after the DMDHA hydrochloride had reacted with epichlorodrin and recrystallized using a solvent composed of ethyl acetate and ethanol. The critical micelle concentrations (CMC) of CHPDMDHA at 25 °C was found to be 2.56 × 10 mol L, and its surface tension at the CMC (γ) was determined to be 27.4 mN m; these data suggest that the surface activities of CHPDMDHA are better than those of benzalkonium chloride (BC), so that CHPDMDHA could be used as a good alternative to BC. [ABSTRACT FROM AUTHOR]

Low desalination efficiency and water production efficiency limit the commercial application of freeze desalination (FD) technology. In this study, three freezing temperatures were set to carry out single-stage progressive freezing desalination of brackish water in southern Xinjiang, China. The ice were melted using conventional methods and gravity-induced desalination (GD), and the salt migration law during the icing and melting process was studied. The effect of GD technology on the improvement of the output of frozen desalinated produced water was quantitatively analyzed using scenario simulation. Experimental results showed that salts accumulated towards concentrated water during FD process. The ice total dissolved solids (TDS) increased with decreasing freezing temperature, which was linearly and positively correlated with the raw water TDS. GD efficiency was significantly affected by the salt concentration of ice crystals. In the first stage (the first 450 mL), ice-melt water was salt explosive dissolution, with salt drained mass accounted for more than 85% of the total salt mass. During GD process, exponential decay of ice-melt water TDS (TDS I) was observed with increasing ice-melt water amount. Through the simulation of the two exponential equation scenarios, it was found that Scenario II (mixed water TDS I as the target value) had significantly higher water yield and production rate than Scenario I (TDS I as the target value), with an increase of more than 23%. The algebraic relationship between TDS I of mixed water and the amount of ice-melt water was derived. GD technology can effectively improve the freshwater output efficiency of the FD process, which is manifested by the fact that the ice crystals of the FD process cannot produce freshwater using conventional melting. Scenario II can produce freshwater as high as 69.83% of the total amount of the GD ice-melt water. The GD technology performed increased multiplicatively in WPdv (decrease in water production) and WPRdv (decrease in water production rate) when the TDS I of the mixed water demanded by the user was low. When FD and GD are combined to desalinate salt water, lowering the freezing temperature can significantly increase the freshwater yield, breaking the limitation of freezing temperature for FD. Therefore, an automated, energy-saving freeze desalination-gravity desalination device capable of realizing the collection of the product water according to the users' needs was conceptualized. This study provides new ideas and algorithms for accurately assessing the efficiency of water production in the combined desalination of saltwater by FD and GD. [Display omitted] • TDS: total dissolved solid; GD/FD: gravity-induced & freeze desalination. • A calculation method for mixed ice-melt water TDS of GD was proposed. • Gradual freezing process significantly increases water production. • An equation between mixed ice-melt water TDS and amount in GD is derived. • Lowering the freezing temperature significantly increases the freshwater yield. • An automated energy-saving FD/GD device was constructed. [ABSTRACT FROM AUTHOR]

This paper experimentally investigates the mechanical properties of 1860 MPa twisted wire strands and the load capacity of hot casting sockets at elevated temperatures. The stress-strain curves of the strands at the temperature in 20 °C to 600 °C range are reported, and the elastic modulus, yield strength, ultimate strength, ultimate strain and rupture strain are obtained and compared to EC2 and other existing studies. The failure mode, load capacity, failure displacement and critical temperature of the sockets at the temperature in 20 °C to 440 °C range are acquired. The test results show that 1860 MPa twisted wire strands have significantly improved ductility in necking stage after 200 °C, which is underestimated in EC2. The strands with hot casting sockets rupture before 180 °C, and are pulled out from the sockets after 230.5 °C. The load capacity drops after 150 °C, and the failure displacement dropped after 300 °C, indicating significant influence of the sockets on the fire resistance. Based on thick-walled cylinder model, calculation methods are proposed to determine the bonding strength and load capacity of the strand with hot casting sockets. The prediction of the failure modes and load capacity agrees well with test results. The parametrical analysis by the calculation methods shows that the load capacity of the strands with sockets increases as the embedded length or internal diameter of socket increases, or the diameter of the strands decreases in a limited range. For fire protection, it is recommended to keep the socket temperature under the critical temperature in accordance with load ratio. • Mechanical properties of 1860 MPa twisted wire strands at elevated temperatures are presented. • A novel stress-strain model of high-strength twisted wire strands is proposed. • The load capacity of hot casting sockets at elevated temperatures is presented. • The critical temperature of hot casting socket as a function of load ratio is proposed. • An analytical method is proposed to determine the bonding strength of the strand with hot casting sockets. [ABSTRACT FROM AUTHOR]

Recognizing actions from a monocular video is a very hot topic in computer vision recently. In this paper, we propose a new representation of actions, the co-occurrence matrices descriptor, on the intrinsic shape manifold learned by graph embedding. The co-occurrence matrices descriptor captures more temporal information than the bag of words (histogram) descriptor which only considers the spatial information, thus boosting the classification accuracy. In addition, we compare the performance of the co-occurrence matrices descriptor on different manifolds learned by various graph-embedding methods. Graph-embedding methods preserve as much of the significant structure of the high-dimensional data as possible in the low-dimensional map. The results show that nonlinear algorithms are more robust than linear ones. Furthermore, we conclude that the label information plays a critical role in learning more discriminating manifolds. [ABSTRACT FROM AUTHOR]

Calibration is a critical step for the phase measuring deflectometry system. Existing calibration methods are mainly optimizing the calibration parameters with respect to the 2D re-projection error criterion. However, such a procedure cannot reduce metric errors in the practical application. Therefore, an accurate and practical calibration method is proposed. In which, conventional calibration means is first applied for the primary calibration. Then, a precise square planar mirror is used for the optimization of system calibration parameters. All the intrinsic and extrinsic parameters are considered as a global multi-objective optimization problem. Three metric error criteria are introduced to evaluate the 3D reconstruction accuracy of the reference mirror. Compared with classical calibration means, which apply the parameter optimization in 2D image space to minimize the re-projection errors, the proposed optimization approach is executed in 3D space directly. An experiment and comparison are conducted to verify that the proposed optimal calibration approach can effectively reduce the system deviation and to improve the system measurement accuracy. [ABSTRACT FROM AUTHOR]

• The thermal strain and thermal expansion coefficient were proposed for 1860 MPa steel wires at elevated temperature, higher than the value recommended in Eurocode 2. • A fitting formula of the final prestress loss of strands with common prestress level as a function of highest temperature was proposed. • Finite element analysis and analytical method were proposed to determine the thermo-structural behaviour and prestress loss of strands at elevated temperatures. • The improved analytical method can be applied on practical engineering, such as large span cables exposed to localised fire. High-strength prestressing cables exposed to high temperature result in the prestress loss, potentially leading to failure and even collapse of prestressing structures. This paper experimentally investigates thermal expansion of 1860 MPa steel wires and prestress loss of 1860 MPa twisted wire strands and parallel wire strands at elevated temperatures initially. Strands are localised heated in prestress loss tests. Different highest temperatures and initial prestress levels are considered. The test results show that EC2 underestimates the thermal strain of 1860 MPa steel wire at more than 450 °C. Prestress loss of the prestressing strand increases as the temperature increases. Cable types have little influence on the final prestress loss ratio. The strand with higher initial prestress level results in less final prestress loss ratio at less than 400 °C. A series fitting formulas of thermal strain, thermal expansion coefficient and final prestress loss ratio of prestressing strands are proposed. In addition, the finite element model of prestressing strand at elevated temperatures is established and validated. The numerical analysis shows that the temperature of the strand in non-heated region is significant, and the stress of the strand rises and then fall during heating stage, due to the balance between thermal expansion and degradation of mechanical properties. Finally, the analytical model of the prestress loss of the strands at elevated temperatures is proposed. The effect of thermal expansion, degradation of the mechanical properties and high-temperature creep of the strand in the heated region and non-heated region is considered respectively. Simplified method is obtained for more efficient computation. The analytical results have great agreement with the test results. The application of analytical method on practical engineering is discussed, and improved calculation equation is proposed for large span cables exposed to localised fire. [ABSTRACT FROM AUTHOR]