A weak solution for free vibration of multi-span beams with general elastic boundary and coupling conditions

A weak solution of free vibration is developed for multi-span beams, which can adapt general elastic boundary and coupling conditions. Firstly, create the energy functional of the multi-span beam system based on the small deformation theory. Then, adopt the modified Fourier series method to rewrite the displacement functions. Compared with the traditional Fourier series method, the present series representations provide a solution for general elastic restrains. Lastly, combined with the Rayleigh-Ritz technique, all the series expansion coefficients can be obtained as the generalized coordinates. Numerical results demonstrate that the current weak solution has good convergence and high accuracy compared with the existing results in literature and FEM results

Wind Pressures on 4∶12-Sloped Hip Roofs of L- and T-Shaped Low-Rise Buildings

A comprehensive wind tunnel experimental study for 4∶12-sloped hip roofs of L- and T-shaped low buildings was carried out in a simulated open terrain exposure to examine wind load characteristics and assess the applicability of wind provisions specified by the American wind load standard for such geometries. Results show that considering roof shape effects, hip roofs with rectangular or complex plans perform differently from rectangular gable roofs and incur smaller local and area-averaged suction. For L- and T-shaped hip roofs, distinctive pressure distributions occur, particularly along roof eaves near building re-entrant corners, where considerable suction appears for the wind blowing toward these building re-entrant corners. Furthermore, the building length-to-width aspect ratio effects are in most cases moderate. Generally, the wind load provisions of the American wind load standard are adequate for L- and T-shaped hip roofs, except for the edge zone along ridge and hip with large areas, for which measured values exceed the code-specified wind pressure coefficients. Finally, it was found more appropriate to utilize the entire L- or T-shaped roof dimensions, as opposed to the rectangular section only, to determine the least horizontal dimension of such nonrectangular hip roofs for the definition of roof zones

Highly stretchable conductor inspired by compliant mechanism

Flexible and stretchable conductors have invaluable applications in multiple domains, such as sensors, displays, and electronic skins. The stable conductance exhibited by conductors when subjected to diverse forms of deformation, such as tensile stress, curvature, or torsion, represents a fundamental characteristic. Attaining high conductivity and stretchability simultaneously in conductive materials is a formidable challenge, owing to inherent constraints in materials found in nature. To overcome this problem, an innovative approach of structurally designing conductors using existing materials to achieve high deformability and stretchability, i.e. stretchable conductors inspired by a compliant mechanism is proposed in this paper. Thus, a novel stretchable conductor inspired by flexible mechanisms is introduced. Unlike stretchable conductors based on Kirigami structures, the stretchable conductor based on flexible mechanisms can achieve large in‐plane deformation within the material's strength limit. The concept and design process of the highly deformable stretchable conductor inspired by flexible mechanisms are presented in this paper. Experimental results show that the resistance change ratio of the conductor remains within 0.05% during the 0–200% strain process. The consistency and durability of the conductor during stretching deformation are also confirmed through 500 repetitions of the test. Additionally, the experiments with the electric motor and light‐emitting diode (LED) light confirm the conductor's ability to maintain a stable current

Wind-induced cladding and structural loads on low-rise buildings with 4:12-sloped hip roofs

The characteristics of cladding and structural loads for 4:12-sloped hip-roofed low-rise buildings with rectangular, L- and T-shaped plans are examined, based on wind tunnel data and three-dimensional linear computational models. Regarding cladding loads, the rectangular gable roof incurs more considerable local suction, compared with the rectangular hip roof. However, due to building plan configurations, intense suction and positive pressure are distinctly distributed on roofs and walls around building re-entrant corners of hip-roofed non-rectangular buildings. Considering structural loads, very high pressures act on the gable-roofed end frame, compared with those on the corresponding hip-roofed frames. Furthermore, the building plan impact on structural load patterns varying with wind directions and on most critical values is clear. Particularly, the most critical structural loads acting on intermediate and penultimate frames of wings of L-shaped hip-roofed buildings and side wings of T-shaped cases, show a 25% maximum increase. However, regarding the central wings of T-shaped buildings, results generally fall within the same range with those of the rectangular and L-shaped buildings. In addition, the structural connections and boundary conditions significantly influence structural load magnitudes and distribution shapes. Finally, the effect of horizontal aspect ratios on both cladding and structural loads is found to be minimal

Segment and recognize expression phase by fusion of motion area and neutral divergence features

Abstract—An expression can be approximated by a sequence of temporal segments called neutral, onset, offset and apex. However, it is not easy to accurately detect such temporal segments only based on facial features. Some researchers try to temporally segment expression phases with the help of body gesture analysis. The problem of this approach is that the expression temporal phases from face and gesture channels are not synchronized. Additionally, most previous work adopted facial key points tracking or body tracking to extract motion information, which is unreliable in practice due to illumination variations and occlusions. In this paper, we present a novel algorithm to overcome the above issues, in which two simple and robust features are designed to describe face and gesture information, i.e., motion area and neutral divergence features. Both features do not depend on motion tracking, and they can be easily calculated too. Moreover, it is different from previous work in that we integrate face and body gesture together in modeling the temporal dynamics through a single channel of sensorial source, so it avoids the unsynchronized issue between face and gesture channels. Extensive experimental results demonstrate the effectiveness of the proposed algorithm. Keywords-temporal segment; motion area; neutral divergence; I

Multi-Objective Parameter Optimization Dynamic Model of Grinding Processes for Promoting Low-Carbon and Low-Cost Production

Grinding is widely used in mechanical manufacturing to obtain both precision and part requirements. In order to achieve carbon efficiency improvement and save costs, carbon emission and processing cost models of the grinding process are established in this study. In the modeling process, a speed-change-based adjustment function was introduced to dynamically derive the change of the target model. The carbon emission model was derived from the grinding force using regression. Considering the constraints of machine tool equipment performance and processing quality requirements, the grinding wheel’s linear velocity, cutting feed rate, and the rotation speed of the workpiece were selected as the optimization variables, and the improved NSGA-II algorithm was applied to solve the optimization model. Finally, fuzzy matter element analysis was used to evaluate the most optimal processing plan

The Stability of U(VI) and As(V) under the Influence of pH and Inorganic Ligands

Uranium and arsenic are two pollutants commonly found in groundwater near uranium mines. However, the reactivity of U(VI) and As(V) need to be carefully investigated to better understand their fate and transport in the environment. In this study, the reactivity of U(VI) and As(V) were studied under various pH, bicarbonate, and Ca2+ levels. In air-equilibrated systems, the reactivity of U(VI) and As(V) generally decreased with the increase in pH, as evidenced by the solubility of U(VI) and As(V) increasing along with the elevation of pH. At pH = 8, 44.70% and 37.81% of initially added U(VI) and As(V) remained soluble. The addition of 1 mM of bicarbonate increased the reactivity of U(VI) and As(V) at mild acidic to neutral pH; however, the presence of bicarbonate significantly increased the solubility of U(VI) at mild alkaline condition, as nearly all U(VI) remained soluble at pH values of 8 and 9. After the addition of Ca2+, the solubility of both U(VI) and As(V) decreased at mild acidic to neutral pH ranges; however, the addition of Ca2+ markedly increased the soluble percentages of U(VI) at neutral pH, in which the condition 97.81 ± 2.95% of U(VI) remained soluble. Comparatively, only 36.13 ± 4.98% and 1.69 ± 1.08% of U(VI) were soluble at the same pH in air-equilibrated and bicarbonate systems. Our study demonstrated that U(VI) and As(V) are less reactive at neutral to alkaline conditions. Furthermore, the addition of bicarbonate and Ca2+ can further reduce the reactivity of U(VI) and As(V) at neutral to alkaline conditions. The findings of this study contribute to a deeper understanding of the fate and transport of U(VI) and As(V) in groundwater and could aid in better designing of U(VI) and As(V) removal processes

MGOGP: a gene module-based heuristic algorithm for cancer-related gene prioritization

Abstract Background Prioritizing genes according to their associations with a cancer allows researchers to explore genes in more informed ways. By far, Gene-centric or network-centric gene prioritization methods are predominated. Genes and their protein products carry out cellular processes in the context of functional modules. Dysfunctional gene modules have been previously reported to have associations with cancer. However, gene module information has seldom been considered in cancer-related gene prioritization. Results In this study, we propose a novel method, MGOGP (Module and Gene Ontology-based Gene Prioritization), for cancer-related gene prioritization. Different from other methods, MGOGP ranks genes considering information of both individual genes and their affiliated modules, and utilize Gene Ontology (GO) based fuzzy measure value as well as known cancer-related genes as heuristics. The performance of the proposed method is comprehensively validated by using both breast cancer and prostate cancer datasets, and by comparison with other methods. Results show that MGOGP outperforms other methods, and successfully prioritizes more genes with literature confirmed evidence. Conclusions This work will aid researchers in the understanding of the genetic architecture of complex diseases, and improve the accuracy of diagnosis and the effectiveness of therapy