Strength Analysis of Single-Symmetry Ratio for Single-Symmetry I-Beam

2021 ◽  
Vol 1047 ◽  
pp. 202-206
Author(s):  
Wei Ting Hsu ◽  
Kun Ze Ho ◽  
Yu Xin Liu ◽  
Shu Ti Chung
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Strength Analysis ◽  
Cross Sectional ◽  
Demand Characteristics ◽  
Cultural Standards ◽  
Bridge Type ◽  
Material Economy ◽  
Double Symmetry

Double-symmetry I-beams are the most common beam cross-sections in structural building. Because that is simpler to design and analyze steel profiles than single-symmetry I-beams. However, with the advancement of economy, the improvement of the quality of life and the cultural standards, large-scale emergence of various large span bridges, special bridge-type landscapes and viaducts. Single symmetrical I-section is better than Double-symmetry I-section to fairly in line with demand characteristics and material economy. This study chooses different Iyc/Iy ratio sections, 0.229, 0.23, 0.3 and 0.5. Iyc/Iy =0.23 is the change point of the sudden drop of the strength of the compressed airfoil. In study, the section is divided into three sections of plasticity, inelasticity and elasticity for analysis and comparison. Considering the different section sizes. If the value of Lb for a small non-elastic interval is too large, the section with a smaller cross-section will reach the elastic interval. Taking all section conditions Lb into consideration, taking 1.4m as a section will reach the non-elastic interval, if the value of the longer Lb is too small, the section with the larger section does not reach the elastic interval. In study, 10m is taken as the section to reach the elastic interval, orientation the AISC ( 2017 ) specification is used to analyze the I-beam. Symmetrical wing plate cross-sections were increased and reduced. The strength of the cross-sections between the compressed side and the tensioned side was discussed, and a single-symmetric I-section with the best cross-sectional efficiency was proposed.

Constraint-Based Reverse Engineering From Ultrasound Cross-Sections

1997 ◽  
Author(s):  
Jai Menon ◽  
Ranjit Desai ◽  
Jay Buckey
Keyword(s):  
Reverse Engineering ◽  
Cross Sections ◽  
Biomedical Applications ◽  
Engineering Application ◽  
Volume Data ◽  
Cross Sectional ◽  
Reverse Engineer ◽  
Network Bandwidth ◽  
Complex Topology

Abstract This paper extends the “cross-sectional” approach for reverse engineering, used abundantly in biomedical applications, to the mechanical domain. We propose a combination of “projective” and cross-sectional algorithms for handling physical artifacts with complex topology and geometry. In addition, the paper introduces the concept of constraint-based reverse engineering, where the constraint parameters could include one or more of the following: time, storage (memory, disk-space), network bandwidth, Quality of Service (output-resolution), and so forth. We describe a specific reverse-engineering application which uses ultrasound (tilt-echo) imaging to reverse engineer spatial enumeration (volume) representations from cross-sectional data. The constraint here is time, and we summarize how our implementation can satisfy real-time reconstruction for distribution of the volume data on the internet. We present results that show volume representations computed from static objects. Since the algorithms are tuned to satisfy time constraints, this method is extendable to reverse engineer temporally-varying (elastic) objects. The current reverse engineering processing time is constrained by the data-acquisition (tilt-echo imaging) process, and the entire reverse engineering pipeline has been optimized to compute incremental volume representations in the order of 3 seconds on a network of four processors.

Simulation of Flow Field on a Large Scale Wind Turbine

2008 ◽  
Author(s):  
I. Janajreh ◽  
C. Ghenai
Keyword(s):  
Flow Field ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Cross Sections ◽  
Large Scale ◽  
Wind Farms ◽  
Operating Characteristics ◽  
Cross Sectional ◽  
Capital Costs

Large scale wind turbines and wind farms continue to evolve mounting 94.1GW of the electrical grid capacity in 2007 and expected to reach 160.0GW in 2010 according to World Wind Energy Association. They commence to play a vital role in the quest for renewable and sustainable energy. They are impressive structures of human responsiveness to, and awareness of, the depleting fossil fuel resources. Early generation wind turbines (windmills) were used as kinetic energy transformers and today generate 1/5 of the Denmark’s electricity and planned to double the current German grid capacity by reaching 12.5% by year 2010. Wind energy is plentiful (72 TW is estimated to be commercially viable) and clean while their intensive capital costs and maintenance fees still bar their widespread deployment in the developing world. Additionally, there are technological challenges in the rotor operating characteristics, fatigue load, and noise in meeting reliability and safety standards. Newer inventions, e.g., downstream wind turbines and flapping rotor blades, are sought to absorb a larger portion of the cost attributable to unrestrained lower cost yaw mechanisms, reduction in the moving parts, and noise reduction thereby reducing maintenance. In this work, numerical analysis of the downstream wind turbine blade is conducted. In particular, the interaction between the tower and the rotor passage is investigated. Circular cross sectional tower and aerofoil shapes are considered in a staggered configuration and under cross-stream motion. The resulting blade static pressure and aerodynamic forces are investigated at different incident wind angles and wind speeds. Comparison of the flow field results against the conventional upstream wind turbine is also conducted. The wind flow is considered to be transient, incompressible, viscous Navier-Stokes and turbulent. The k-ε model is utilized as the turbulence closure. The passage of the rotor blade is governed by ALE and is represented numerically as a sliding mesh against the upstream fixed tower domain. Both the blade and tower cross sections are padded with a boundary layer mesh to accurately capture the viscous forces while several levels of refinement were implemented throughout the domain to assess and avoid the mesh dependence.

A Method of Form Selection for Large Scale Structures

2002 ◽  
Author(s):  
Damiano Pasini ◽  
S. C. Burgess ◽  
D. J. Smith
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Design Parameters ◽  
Cross Sectional ◽  
Geometrical Properties ◽  
Large Scale Structures ◽  
Shape Selection ◽  
Efficiency Parameter ◽  
Sectional Shape ◽  
Selection Of

This paper presents a new method for modelling the efficiency of large-scale structural forms. Parametric equations, which include all design parameters and also the effect of buckling, are developed. Shape transformers, envelope efficiency parameter and scaling factor are introduced to describe the geometrical properties of cross-sections and to allow interaction between form and cross-sectional shape selection. Design charts provide insight and understanding and assist the selection of different structural concepts at the preliminary stage of design.

scholarly journals Quality of life during the epidemic of COVID-19 and its associated factors among enterprise workers in East China

2020 ◽  
Author(s):  
Xiaoxiao Chen ◽  
Qian Xu ◽  
Haijiang Lin ◽  
Jianfu Zhu ◽  
Yue Chen ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Associated Factors ◽  
Large Scale ◽  
Life Quality ◽  
Cross Sectional Study ◽  
Related Factors ◽  
Cross Sectional ◽  
Home Ventilation ◽  
The Impact

Abstract Background: The COVID-19 related lockdown and home confinement might have an important impact on the quality of life in enterprise workers. We investigated the quality of life during the epidemic in enterprise workers who just returned to work, and assessed its potential influencing factors to have a better understanding of the impact of COVID-19 epidemic lockdown and home confinement. Methods: This was a cross-sectional study of enterprise workers conducted in Deqing and Taizhou, Zhejiang Province, China. The Chinese version of EQ5D was used to assess life quality, and information about general characteristics and COVID-19 related factors was collected by a structured questionnaire, which was distributed through the social application “WeChat”. Results: A total of 2,435 participants were enrolled, 59.5% of which worked in Deqing. About 50% of the participants reported worries about the COVID-2019 epidemic and 40.1% had a centralized or home quarantine during the epidemic. The mean EQ-5D score and VAS were 0.990 and 93.5. Multiple logistic regression showed that the quality of life measures was related to physical activities (ORad=0.46) and keeping home ventilation (ORad=0.04) in Deqing, and were related to wearing a mask when going out (ORad=0.35), keeping home ventilation (ORad=0.16), unmarried status (ORad=2.38) and having a centralized or home quarantine (ORad=1.64) in Taizhou,Conclusions: The quality of life for returning enterprise workers in areas with different risks of COVID-19 was affected by different factors. Associated factors identified from this study would help develop proper intervention measures for enterprise workers to reduce the impact of large-scale public health events like the COVID-19 on their quality of life.

scholarly journals Quality of life during the epidemic of COVID-19 and its associated factors among enterprise workers in East China

2020 ◽  
Author(s):  
Xiaoxiao Chen ◽  
Qian Xu ◽  
Haijiang Lin ◽  
Jianfu Zhu ◽  
Yue Chen ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Associated Factors ◽  
Large Scale ◽  
Life Quality ◽  
Cross Sectional Study ◽  
Related Factors ◽  
Cross Sectional ◽  
Home Ventilation ◽  
The Impact

Abstract Background: The COVID-19 related lockdown and home confinement might have an important impact on the quality of life in enterprise workers. We investigated the quality of life during the epidemic in enterprise workers who just returned to work, and assessed its potential influencing factors to have a better understanding of the impact of COVID-19 epidemic lockdown and home confinement.Methods: This was a cross-sectional study of enterprise workers conducted in Deqing and Taizhou, Zhejiang Province, China. The Chinese version of EQ5D was used to assess life quality, and information about general characteristics and COVID-19 related factors was collected by a structured questionnaire, which was distributed through the social application “WeChat”.Results: A total of 2,435 participants were enrolled, 59.5% of which worked in Deqing. About 50% of the participants reported worries about the COVID-2019 epidemic and 40.1% had a centralized or home quarantine during the epidemic. The mean EQ-5D score and VAS were 0.990 and 93.5. Multiple logistic regression showed that the quality of life measures was related to physical activities (ORad=0.46) and keeping home ventilation (ORad=0.04) in Deqing, and were related to wearing a mask when going out (ORad=0.35), keeping home ventilation (ORad=0.16), unmarried status (ORad=2.38) and having a centralized or home quarantine (ORad=1.64) in Taizhou,Conclusions: The quality of life for returning enterprise workers in areas with different risks of COVID-19 was affected by different factors. Associated factors identified from this study would help develop proper intervention measures for enterprise workers to reduce the impact of large-scale public health events like the COVID-19 on their quality of life.

Comparison of different algorithms used for creating river terrain model based on the cross-sections.

2020 ◽  
Author(s):  
Luděk Bureš ◽  
Radek Roub ◽  
Petra Sychová
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Hydrodynamic Model ◽  
Linear Interpolation ◽  
Cross Sectional ◽  
Terrain Model ◽  
Model Based ◽  
Interpolation Techniques ◽  
The Cross

<p>Various techniques can be used to create a river terrain model. The most common technique uses 3D bathymetric points distributed across the main channel. The terrain model is then created using common interpolation techniques. The quality of this terrain depends on the number of the measured points and their location.</p><p>An alternative method may be an application of a set of cross-sections. Special interpolation algorithms are used for this purpose. These algorithms create new bathymetric points between two adjacent cross-sections that are located in a composite bathymetric network (CBN). Common interpolation techniques can be used to create a river terrain model. The advantage of this approach is a necessity of smaller dataset.</p><p>We present a comparison of four different algorithms for creating a river terrain model based on measured cross-sections. The first algorithm (A1) adopts a method of linear interpolation to create CBN [1]. The second algorithm (A2) reshapes the cross-sections and then applies linear interpolation. This reshaping allows better take into the account the thalweg line [2]. The third algorithm (A3) uses cross-sectional reshaping and uses cubic hermit splines to create CBN [3]. The last algorithm (A4)  implies the channel boundary and the thalweg line as additional inputs. Additional inputs define the shape of the newly created river channel [4].</p><p>Three different distances among individual cross-sections were used for the performance tests (50, 100 and 200 meters). The quality of topographic schematization and its impact on hydrodynamic model results were evaluated. Preliminary results show that there is almost no difference in the performance of the algorithms at cross-section distance of 50 m. The A4 algorithm outperforms/surpass its competitors in the case that input data (the cross-section distance is) are in 200 m spacing.</p><p>This research was supported by the Operational Programme Prague – Growth Pole of the Czech Republic, project No. CZ.07.1.02/0.0/0.0/17_049/0000842, Tools for effective and safe management of rainwater in Prague city – RainPRAGUE.</p><p>[1]       Vetter, M., Höfle, B., Mandelburger, G., Rutzinger, M. Estimating changes of riverine landscapes and riverbeds by using airborne LiDAR data and river cross-sections. Zeitschrift für Geomorphologie, Supplementary Issues, 2011, 55.2: 51-65.</p><p>[2]       Chen, W., Liu, W. Modeling the influence of river cross-section data on a river stage using a two-dimensional /three-dimensional hydrodynamic model. Water, 2017, 9.3: 203.</p><p>[3]       Caviedes-Voullième, D.; Morales-Hernández, M.; López-Marijuan, I.; García-Navarro, P. Reconstruction of 2D river beds by appropriate interpolation of 1D cross-sectional information for flood simulation. Environ. Model. Softw., 2014, 61, 206–228.</p><p>[4]       Merwade, V.; Cook, A.; Coonrod, J. GIS techniques for creating river terrain models for hydrodynamic modeling and flood inundation mapping. Environ. Model. Softw., 2008, 23, 1300–1311.</p>

scholarly journals Skindex-29 to Determine Quality of Life and Emotional Factors in Dermatological Conditions

2017 ◽  
Vol 53 (01) ◽  
pp. 041-050
Author(s):  
Desiree Saimbi ◽  
MSVK Raju ◽  
Vaibhav Dubey ◽  
Vivek Kumar Dey
Keyword(s):  
Quality Of Life ◽  
Large Scale ◽  
Skin Diseases ◽  
Psychiatric Morbidity ◽  
Cross Sectional ◽  
Severe Impairment ◽  
Related Quality ◽  
Health Related ◽  
Moderate Range

ABSTRACTThough rarely fatal, skin diseases are known to be associated with increased psychiatric morbidity and considerable impairment of quality of life (QoL). Health Related Quality of Life (HRQoL) in skin diseases can be assessed by generic or skin specific instruments. One hundred sixty patients with a range of dermatological diagnoses were studied on a cross sectional observational paradigm. Skindex29, a skin specific instrument, was used to assess QoL, while anxiety and depression were assessed by Anxiety Status Inventory (ASI) and Depression Status Inventory (DSI), respectively. Sixty two patients (39%) had impaired QoL out of which 37(60%) had severe impairment. 11 patients (7%) had anxiety and 22(14%) had depression in the mild to moderate range. Gender, anxiety, depression and effect on appearance seem to be not related to impaired QoL. Further large scale studies are needed to ascertain the factors impinging on the QoL of dermatologically ill patients.

scholarly journals A Superellipse with Deformation and Its Application in Describing the Cross-Sectional Shapes of a Square Bamboo

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2073
Author(s):  
Weiwei Huang ◽  
Yueyi Li ◽  
Karl J. Niklas ◽  
Johan Gielis ◽  
Yongyan Ding ◽  
...  
Keyword(s):  
Cross Sections ◽  
Large Scale ◽  
Deformation Parameter ◽  
Rotational Symmetry ◽  
Cross Sectional ◽  
Future Studies ◽  
Initial Application ◽  
Stem Development ◽  
The Cross ◽  
The Difference

Many cross-sectional shapes of plants have been found to approximate a superellipse rather than an ellipse. Square bamboos, belonging to the genus Chimonobambusa (Poaceae), are a group of plants with round-edged square-like culm cross sections. The initial application of superellipses to model these culm cross sections has focused on Chimonobambusa quadrangularis (Franceschi) Makino. However, there is a need for large scale empirical data to confirm this hypothesis. In this study, approximately 750 cross sections from 30 culms of C. utilis were scanned to obtain cross-sectional boundary coordinates. A superellipse exhibits a centrosymmetry, but in nature the cross sections of culms usually deviate from a standard circle, ellipse, or superellipse because of the influences of the environment and terrain, resulting in different bending and torsion forces during growth. Thus, more natural cross-sectional shapes appear to have the form of a deformed superellipse. The superellipse equation with a deformation parameter (SEDP) was used to fit boundary data. We find that the cross-sectional shapes (including outer and inner rings) of C. utilis can be well described by SEDP. The adjusted root-mean-square error of SEDP is smaller than that of the superellipse equation without a deformation parameter. A major finding is that the cross-sectional shapes can be divided into two types of superellipse curves: hyperellipses and hypoellipses, even for cross sections from the same culm. There are two proportional relationships between ring area and the product of ring length and width for both the outer and inner rings. The proportionality coefficients are significantly different, as a consequence of the two different superellipse types (i.e., hyperellipses and hypoellipses). The difference in the proportionality coefficients between hyperellipses and hypoellipses for outer rings is greater than that for inner rings. This work informs our understanding and quantifying of the longitudinal deformation of plant stems for future studies to assess the influences of the environment on stem development. This work is also informative for understanding the deviation of natural shapes from a strict rotational symmetry.

scholarly journals Quality of life during the epidemic of COVID-19 and its associated factors among enterprise workers in East China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaoxiao Chen ◽  
Qian Xu ◽  
Haijiang Lin ◽  
Jianfu Zhu ◽  
Yue Chen ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Influencing Factors ◽  
Associated Factors ◽  
Large Scale ◽  
Life Quality ◽  
Related Factors ◽  
Cross Sectional ◽  
Home Ventilation ◽  
The Impact

Abstract Background The COVID-19 related lockdown and home confinement might have an important impact on the quality of life in enterprise workers. We investigated the quality of life during the epidemic in enterprise workers who just returned to work, and assessed its potential influencing factors to have a better understanding of the impact of COVID-19 epidemic lockdown and home confinement. Methods This was a cross-sectional study of enterprise workers conducted in Deqing and Taizhou, Zhejiang Province, China. The Chinese version of EQ5D was used to assess life quality, and information about general characteristics and COVID-19 related factors was collected by a structured questionnaire, which was distributed through the social application “WeChat”. Multiple liner regression was used to investigate potential influencing factors. Results A total of 2420 participants were enrolled, 59.5% of which worked in Deqing. About 50% of the participants reported worries about the COVID-2019 epidemic and 40.2% had a centralized or home quarantine during the epidemic. The mean EQ-5D score and VAS were 0.990 and 93.5. Multiple liner regression showed that the quality of life measures was related to physical activities (β = 0.006) and keeping home ventilation (β = 0.063) in Deqing, and were related to wearing a mask when going out (β = 0.014), keeping home ventilation (β = 0.061), other marital status (β = − 0.011), worry about the epidemic (β = − 0.005) and having a centralized or home quarantine (β = − 0.005) in Taizhou. Conclusions The quality of life for returning enterprise workers in areas with different risks of COVID-19 was affected by different factors. Associated factors identified from this study would help develop proper intervention measures for enterprise workers to reduce the impact of large-scale public health events like the COVID-19 on their quality of life.

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