But What is the Driving Mechanism?

2022 ◽  
pp. 87-99
Author(s):  
Geoffrey F. Davies
Keyword(s):  
Driving Mechanism

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

Modelling a Multi-Dimensional Model of Memory Performance in Obsessive-Compulsive Disorder: A Multi-Level Meta-Analytic Review.

2020 ◽  
Author(s):  
Sofia Persson ◽  
Alan Yates ◽  
Klaus Kessler ◽  
Ben Harkin
Keyword(s):  
Executive Function ◽  
Obsessive Compulsive Disorder ◽  
Memory Load ◽  
Memory Performance ◽  
Effect Sizes ◽  
Driving Mechanism ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Analytic Review ◽  
Multi Level

Even though memory performance is a commonly researched aspect of Obsessive-Compulsive Disorder (OCD), a coherent and unified explanation of the role of specific cognitive factors has remained elusive. To address this, the present meta-analysis examined the predictive validity of Harkin and Kessler’s (2011) Executive Function (E), Binding Complexity (B) and Memory Load (L) Classification System with regards to affected vs. unaffected memory performance in OCD. We employed a multi-level meta-analytic approach (Viechtbauer, 2010) to accommodate the interdependent nature of the EBL model and interdependency of effect sizes (305 effect sizes from 144 studies, including 4424 OCD patients). Results revealed that the EBL model predicted memory performance, i.e., as EBL demand increases, those with OCD performed progressively worse on memory tasks. Executive function was the driving mechanism behind the EBL’s impact on OCD memory performance and negated effect size differences between visual and verbal tasks in those with OCD. Comparisons of sub-task effect sizes were also generally in accord with the cognitive parameters of the EBL taxonomy. We conclude that standardised coding of tasks along individual cognitive dimensions and multi-level meta-analyses provides a new approach to examine multi-dimensional models of memory and cognitive performance in OCD and other disorders.

The living organism: evolutionary design or an accident

2019 ◽  
Vol 15 (3) ◽  
Author(s):  
Roterman Irena ◽  
Konieczny Leszek
Keyword(s):  
Living Organism ◽  
Evolutionary Design ◽  
Driving Mechanism ◽  
Biological Mechanisms ◽  
Evolutionary Time ◽  
Evolutionary Progress ◽  
Biological Program

AbstractThe presented work discusses some evolutionary phenomena underlining the complexity of organism creation and surprisingly the short evolutionary time of this process in particular. Uncommonness of this process ensued from the necessary simultaneous combining of highly complicated biological mechanisms, of which some were generated independently before the direct evolutionary demand. This in conclusion points to still not fully understood biological program ensuring superiority of the permanent evolutionary progress over effects of purely random mutational changes as the driving mechanism in evolution.

scholarly journals Mathematical Modeling and Numerical Simulation of Atherosclerosis Based on a Novel Surgeon’s View

2021 ◽  
Author(s):  
Meisam Soleimani ◽  
Axel Haverich ◽  
Peter Wriggers
Keyword(s):  
Mathematical Modeling ◽  
Inflammatory Response ◽  
Phase Field ◽  
Mechanical Response ◽  
Type Equation ◽  
The Body ◽  
Vasa Vasorum ◽  
Diffusion Reaction ◽  
Dust Particles ◽  
Driving Mechanism

AbstractThis paper deals with the mathematical modeling of atherosclerosis based on a novel hypothesis proposed by a surgeon, Prof. Dr. Axel Haverich (Circulation 135(3):205–207, 2017). Atherosclerosis is referred as the thickening of the artery walls. Currently, there are two schools of thoughts for explaining the root of such phenomenon: thickening due to substance deposition and thickening as a result of inflammatory overgrowth. The hypothesis favored here is the second paradigm stating that the atherosclerosis is nothing else than the inflammatory response of of the wall tissues as a result of disruption in wall nourishment. It is known that a network of capillaries called vasa vasorum (VV) accounts for the nourishment of the wall in addition to the natural diffusion of nutrient from the blood passing through the lumen. Disruption of nutrient flow to the wall tissues may take place due to the occlusion of vasa vasorums with viruses, bacteria and very fine dust particles such as air pollutants referred to as PM 2.5. They can enter the body through the respiratory system at the first place and then reach the circulatory system. Hence in the new hypothesis, the root of atherosclerotic vessel is perceived as the malfunction of microvessels that nourish the vessel. A large number of clinical observation support this hypothesis. Recently and highly related to this work, and after the COVID-19 pandemic, one of the most prevalent disease in the lungs are attributed to the atherosclerotic pulmonary arteries, see Boyle and Haverich (Eur J Cardio Thorac Surg 58(6):1109–1110, 2020). In this work, a general framework is developed based on a multiphysics mathematical model to capture the wall deformation, nutrient availability and the inflammatory response. For the mechanical response an anisotropic constitutive relation is invoked in order to account for the presence of collagen fibers in the artery wall. A diffusion–reaction equation governs the transport of the nutrient within the wall. The inflammation (overgrowth) is described using a phase-field type equation with a double well potential which captures a sharp interface between two regions of the tissues, namely the healthy and the overgrowing part. The kinematics of the growth is treated by classical multiplicative decomposition of the gradient deformation. The inflammation is represented by means of a phase-field variable. A novel driving mechanism for the phase field is proposed for modeling the progression of the pathology. The model is 3D and fully based on the continuum description of the problem. The numerical implementation is carried out using FEM. Predictions of the model are compared with the clinical observations. The versatility and applicability of the model and the numerical tool allow.

scholarly journals Spatio-Temporal Coupling Characteristics and the Driving Mechanism of Population-Land-Industry Urbanization in the Yangtze River Economic Belt

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 400
Author(s):  
Liejia Huang ◽  
Peng Yang ◽  
Boqing Zhang ◽  
Weiyan Hu
Keyword(s):  
Economic Development ◽  
Spatial Correlation ◽  
Yangtze River ◽  
Three Dimensional ◽  
Driving Mechanism ◽  
The Yangtze River ◽  
Central Cities ◽  
Urban Agglomerations ◽  
Development Level ◽  
Coordination Degree

The purpose of this paper is to probe into the coupled coordination of urbanization in population, land, and industry to improve urbanization quality. A coupled coordination degree model, spatial analysis method and spatial metering model are employed. The study area is 110 prefecture-level cities in the Yangtze River Economic Belt. The study shows that: (1) the coupling degree of the population-land-industry urbanization grew very slowly between 2006 and 2016. On the whole, the three-dimensional urbanization is in a running-in period, and land-based urbanization dominates, while population-based urbanization and industry-based urbanization are relatively lagging behind. (2) The three major urban agglomerations, the Chengdu-Chongqing, the middle reaches of the Yangtze River and the Yangtze River Delta, are parallel to the whole area in terms of the coupling degree of the three dimensional urbanization with a well-ordered structure, especially in the central cities of the three major urban agglomerations. (3) There is significant spatial correlation in the coupling degree and coordination degree of the three-dimensional urbanization. The high value of coupling degree and coordination degree are clustered continuously in developed cities, provincial capitals, and central cities of the downstream reaches of the Yangtze River. (4) The coordinated degree has significant positive spatial autocorrelation, showing obvious spatial agglomeration characteristics: H-H agglomeration areas are concentrated in the downstream developed areas such as Jiangsu, Zhejiang, and Shanghai. L-L agglomeration areas are mainly concentrated in upstream undeveloped areas, but the number of their cities shows a decreasing trend. (5) The coordination degree of the three-dimensional urbanization is the result of the comprehensive effect of economic development level, the government’s decision-making behavior, and urban location. Among them, the economic development level, urbanization investment, traffic condition, and urban geographical location play a decisive role. This paper contributes to the existing literatures by exploring urbanization quality, spatial correlation and influencing factors from the perspectives of the three-dimensional urbanization in the Yangtze River Economic Belt. The conclusion might be helpful to promote the coupling and coordinated development of urbanization in population-land-industry, and ultimately to improve urbanization quality in the Yangtze River Economic Belt.

scholarly journals Driving Mechanism of Farmers’ Utilization Behaviors of Straw Resources—An Empirical Study in Jilin Province, the Main Grain Producing Region in the Northeast Part of China

2021 ◽  
Vol 13 (5) ◽  
pp. 2506
Author(s):  
Hongpeng Guo ◽  
Shuang Xu ◽  
Xiaotong Wang ◽  
Wen Shu ◽  
Jia Chen ◽  
...  
Keyword(s):  
Structural Equation ◽  
Positive Impact ◽  
Agricultural Waste ◽  
Equation Model ◽  
Subjective Norms ◽  
Jilin Province ◽  
Policy Implications ◽  
Driving Mechanism ◽  
Perceived Behavior Control

In recent years, the unsustainable behaviors of straw utilization have led to waste straw being one of the sources of agricultural non-point source pollution. Studying the resource utilization of crop straw is conducive to expediate the development of ecological and green agriculture. More importantly, it has long-term significance for the recycling of agricultural waste, improving the quality of rural life, and the employment of farmers. Based on the theory of planned behavior (TPB), taking the representative survey questionnaire of farmers in Jilin Province, China as the sample, the structural equation model (SEM) was constructed to study the main factors that drive the utilization behaviors of straw resources of farmers and to explore the driving mechanism of the farmers behaviors in Jilin Province. The results show that the behavioral attitude and subjective norms of farmers in Jilin Province not only indirectly affect their actual behaviors through behavioral willingness, but also has significant direct effects on their behaviors. The most critical factors that affect the willingness of farmers to utilize the straw resources in Jilin Province are subjective norms and moral responsibilities. The subjective norms of farmers have a direct and significant positive impact on their willingness and behaviors. Behavioral attitude and perceived behavior control have a significant positive impact on their willingness. The behavioral willingness has a significant positive impact on their actual behaviors. This study provides guidance for the utilization of straw resources policy implications.

Measurement of frequency characteristics of disturbance torque in the process of satellite antenna rotation

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1563-1569
Author(s):  
Bo Gao ◽  
Minglong Xu
Keyword(s):  
Real Time ◽  
Signal Transmission ◽  
Frequency Characteristics ◽  
Structural Vibration ◽  
Driving Mechanism ◽  
Satellite Antenna ◽  
Satellite Applications ◽  
Study Characteristics ◽  
Satellite Signal ◽  
Disturbance Torque

As an important equipment for satellite signal reception and transmission, the satellite antenna needs to be rotated in real time to achieve real-time tracking of the target and complete signal transmission during applications. Antenna driving mechanism is generally composed of motor and other components, which will cause some structural vibration during rotation. For high-stability satellite applications, the vibration disturbance torque is a major factor affecting the satellite stability. In order to study characteristics of the disturbance torque, the disturbance data from the antenna under different rotation conditions should be measured. In this paper, the frequency characteristics of disturbance torque of a rotating satellite antenna using stepper motor as driving motor is tested and discussed.

scholarly journals Landscape pattern and economic factors’ effect on prediction accuracy of cellular automata-Markov chain model on county scale

2020 ◽  
Vol 12 (1) ◽  
pp. 626-636
Author(s):  
Wang Song ◽  
Zhao Yunlin ◽  
Xu Zhenggang ◽  
Yang Guiyan ◽  
Huang Tian ◽  
...  
Keyword(s):  
Land Use ◽  
Markov Chain ◽  
Cellular Automata ◽  
Markov Model ◽  
Prediction Accuracy ◽  
Driving Mechanism ◽  
Economic Factors ◽  
Chain Model ◽  
The Impact ◽  
County Scale

AbstractUnderstanding and modeling of land use change is of great significance to environmental protection and land use planning. The cellular automata-Markov chain (CA-Markov) model is a powerful tool to predict the change of land use, and the prediction accuracy is limited by many factors. To explore the impact of land use and socio-economic factors on the prediction of CA-Markov model on county scale, this paper uses the CA-Markov model to simulate the land use of Anren County in 2016, based on the land use of 1996 and 2006. Then, the correlation between the land use, socio-economic data and the prediction accuracy was analyzed. The results show that Shannon’s evenness index and population density having an important impact on the accuracy of model predictions, negatively correlate with kappa coefficient. The research not only provides a reference for correct use of the model but also helps us to understand the driving mechanism of landscape changes.

scholarly journals Research and Test of Three-Pulley Noncircular Synchronous Pulley Transmission Mechanism with Minimum Slack

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jianneng Chen ◽  
Xincheng Sun ◽  
Chuanyu Wu ◽  
Dadu Xiao ◽  
Jun Ye
Keyword(s):  
Optimization Design ◽  
Simulation Analysis ◽  
Transmission Mechanism ◽  
Driving Mechanism ◽  
Belt Drive ◽  
Drive Mechanism ◽  
Automatic Optimization ◽  
Pitch Curve ◽  
Synchronous Belt Drive ◽  
Belt Transmission

AbstractThe noncircular synchronous belt drive mechanism has demonstrated certain achievements and has been used in special fields. Research regarding noncircular synchronous belt drive mechanisms has focused on optimization design and kinematic analysis in China, whereas two pulley noncircular synchronous belt transmissions have been developed overseas. However, owing to the noncircular characteristics of the belt pulley, the real-time variation in the belt length slack during the transmission of the noncircular synchronous belt is significant, resulting in high probabilities of skipping and vibration. In this study, a noncircular tensioning pulley is added to create a stable three-pulley noncircular synchronous belt driving mechanism and a good synchronous belt tensioning, with no skipping; hence, the non-uniform output characteristic of the driven pulley is consistent with the theoretical value. In the circular noncircular noncircular three-pulley noncircular synchronous belt mechanism, the pitch curve of the driving synchronous belt pulley is circular, whereas those of the driven synchronous belt and tensioning pulleys are noncircular. To minimize the slack of the belt length of the synchronous belt and the constraint of the concavity and circumference of the tensioning pulley, an automatic optimization model of the tensioning pulley pitch curve is established. The motion simulation, analysis, and optimization code for a three-belt-pulley noncircular synchronous belt drive mechanism is written, and the variation in belt length slack under different speed ratios is analyzed based on several examples. The testbed for a circular–noncircular–noncircular three-pulley noncircular synchronous belt transmission mechanism is developed. The test shows that the three-pulley noncircular synchronous belt drives well. This study proposes an automatic optimization algorithm for the tensioning pulley pitch curve of a noncircular synchronous belt transmission mechanism; it yields a stable transmission of the noncircular synchronous belt transmission mechanism as well as non-uniform output characteristics.

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