Vibration control of pedestrian-bridge vertical dynamic coupling interaction based on biodynamic model

The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper（MMSD） biodynamic model, and the mass damper（TMD） with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.

Biodynamic Practices, Eco-label Wines and Millennial Consumers

Abstract： The objective of this study was to provide insights on the motivations behind the decision of biodynamic producers in the United States to shift to biodynamic practices in the vineyard and winemaking process. The second objective of the study was to evaluate the perceptions of the consumers regarding eco-label wines, with a direct focus on the attitudes of millennial generation. Two surveys, one directed to biodynamic producers in the United States and the other to a group of Californian wine consumers were distributed during spring and fall of 2010. Findings from the first survey reveal that biodynamic producers are engaged in biodynamic practices out of socially motivated reasons rather than economic factors. Results from the consumer survey suggest a generally uninformed generation of consumers about eco-label wines and particularly about the practices associated with these products. This lack of information heavily influences their behavioral decisions and attitudes and points out to the critical need for consumer education.

Optimization of Biodynamic Seated Human Models Using Genetic Algorithms

Many biodynamic models have been derived using trial and error curve-fitting technique, such that the error between the computed and measured biodynamic response functions is minimum. This study developed a biomechanical model of the human body in a sitting posture without backrest for evaluating the vibration transmissibility and dynamic response to vertical vibration direction. In describing the human body motion, a three biomechanical models are discussed (two models are 4-DOF and one model 7-DOF). Optimization software based on stochastic techniques search methods, Genetic Algorithms (GAs), is employed to determine the human model parameters imposing some limit constraints on the model parameters. In addition, an objective function is formulated comprising the sum of errors between the computed and actual values (experimental data). The studied functions are the driving-point mechanical impedance, apparent mass and seat- to-head transmissibility functions. The optimization process increased the average goodness of fit and the results of studied functions became much closer to the target values (Experimental data). From the optimized model, the resonant frequencies of the driver parts computed on the basis of biodynamic response functions are found to be within close bounds to that expected for the human body.

Metabonomic Investigation by 1H-NMR to Discriminate between Red Wines from Organic and Biodynamic Grapes

This study aimed to discriminate red wines obtained from organic and biodynamic management by means of proton nuclear magnetic resonance (1H-NMR) and metabonomic investigation. Red wines were produced from Sangiovese grapes over the three harvests 2010-2012 from two parcels of a vineyard, managed according to organic (ORG) or biodynamic (BIO) protocol, respectively. Every year the vinifications were performed with commercial selected yeasts (CSY) according to the organic protocol. Moreover, in 2012, CSY vinification was flanked by a spontaneous vinification (SPO) carried out by microorganisms naturally present on the grapes. To gain information about the effects of production year, vineyard management, vinification protocol and vines site in the field on the wine characteristics, proton nuclear magnetic resonance spectra were registered by means of a spectrometer operating at 600 MHz and multivariate analysis was carried out. Production year and vinification protocol were found to be the factors affecting most the characteristics of wine metabolome. Vineyard management seemed to have more limited consequences on the wine composition, with effects on some aminoacids (proline, aspartic acid and valine), alcohols and some polyphenols. The latter observation could not be considered as certain, as vines site in the field acted, in this respect, as a confounding element.

Phenolic Acids Content and Nutritional Quality of Conventional, Organic and Biodynamic Cultivations of the Tomato CXD271BIO Breeding Line (Solanum lycopersicum L.)

This study was undertaken to evaluate the influence of growing systems (conventional, organic and biodynamic performed with two types of manuring) on some nutritional traits of the tomato breeding line CXD271BIO (Solanum lycopersicum L.). Experimental fields were in the same geographical area and the cultivations were performed over five years. The content of macronutrients, minerals (Ca, K, Mg, P, Na), trace elements (Fe, Zn, Cu, Mn) and phenolic acids (chlorogenic, caffeic, p-coumaric and ferulic acids) was determined. The biodynamic A growing system showed the highest protein and carbohydrates content compared to the other growing systems. Data on minerals and trace elements content showed significant differences (mainly in Ca, Na, Fe and Zn content) between conventional and biodynamic tomatoes, whereas no major impact of the fertilization among organic and the two biodynamic growing systems was observed. Appreciable differences in phenolic acids biosynthesis were observed, with the year of harvest showing a marked effect especially on chlorogenic, p-cumaric and ferulic acids content. Conversely, the cultivation system did not show major influence. Principal Components Analysis (PCA), performed on mineral and phenolic acids content, substantiated the large effect of the year of harvest, also suggesting an effect of the conventional cultivation system.

Vertical vibration characteristics of seated human bodies and a biodynamic model with two degrees of freedom

Understanding the vibration characteristics of a seated human body is critical for evaluation and improvement of ride comfort of various passenger vehicles. There have been very little publications about the vibration characteristics of a seated Chinese human body. By using wide-band white noise excitations and a homemade seat sensor, vertical vibration tests were carried out on 28 volunteers. Apparent masses were obtained for each volunteer at a frequency range of 1-20 Hz for various excitation le-vels. A biodynamic model, which has two degrees of freedom in parallel and includes a frame mass, was chosen to describe the vertical vibration characteristics of the seated human body. The model parameters were identified by means of a Gauss-Newton method with an error function defined in terms of both real and imaginary parts of the apparent mass against frequency. Based on the averaged data of the mass-normalized apparent mass from experiments, the model parameters and corresponding modal parameters were obtained for seated Chinese people at ages of 20-25 with standard weight. The apparent masses predicted by the biodynamic model with identified parameters agree very well with those obtained from experiments. Statistical analysis demonstrates the influence of volunteer’s height and weight on the model parameters for a seated human body.

Optimal Seat and Suspension Design for a Half-Car with Driver Model Using Genetic Algorithm

This paper presents an optimal vehicle and seat suspension design for a half-car vehicle model to reduce human-body vibration (whole-body vibration). A genetic algorithm is applied to search for the optimal parameters of the seat and vehicle suspension. The desired objective is proposed as the minimization of a multi-objective function formed by the combination of seat suspension working space (seat suspension deflection), head acceleration, and seat mass acceleration to achieve the best comfort of the driver. With the aid of Matlab/Simulink software, a simulation model is achieved. In solving this problem, the genetic algorithms have consistently found near-optimal solutions within specified parameters ranges for several independent runs. For validation, the solution obtained by GA was compared to the ones of the passive suspensions through sinusoidal excitation of the seat suspension system for the currently used suspension systems.

Optimal Seat Suspension Design Using Genetic Algorithms

The linear seat suspension is considered due to the low cost consideration therefore, the optimal linear seat suspension design method can be used for this purpose. In this paper, the design of a passive vehicle seat suspension system was handled in the framework of linear optimization. The variance of the dynamic load resulting from the vibrating vehicle operating at a constant speed was used as the performance measure of a suspension system. Using 4-DOF human body model developed by Abbas et al., with linear seat suspension and coupled with half car model. A genetic algorithm is applied to solve the linear optimization problem. The optimal design parameters of the seat suspension systems obtained are kse = 3 012.5 N/m and cse = 1 210.4 N.s/m, respectively.

Study on Virtual Human Skeleton System

A solution of virtual human skeleton system is proposed. Some issues on integration of anatomical geometry, biodynamics and computer animation are studied. The detailed skeleton system model that incorporates the biodynamic and geometric characteristics of a human skeleton system allows some performance studies in greater detail than that performed before. It may provide an effective and convenient way to analyze and evaluate the movement performance of a human body when the personalized anatomical data are used in the models. An example shows that the proposed solution is effective for the stated problems.

The making of an agricultural classic: farmers of forty centuries or permanent agriculture in China, Korea and Japan, 1911-2011

Few agriculture books achieve the status of ‘classic’. F. H. King’s book Farmers of Forty Centuries or Permanent Agriculture in China, Korea and Japan was privately published in Wisconsin, USA, in 1911. The book had an inauspicious start, and the longevity and acclaim that this book has since achieved must have been, then, barely conceivable. The author was dead, the book was incomplete, and there was no commercial publisher. Yet through a combination of perhaps luck and circumstance the book was ‘resurrected’ in 1927 by a London publisher, Jonathan Cape, who then kept it in print for more than two decades. The London issue of King’s book was favourably cited in the 1930s and 1940s by leading agriculture and organic agriculture writers including: Lord North- bourne, Eve Balfour, Viscount Lymington, Albert and Louise Howard in Britain;Ehrenfried Pfeiffer in Switzerland;Jerome Rodale in the USA;and Stanton Hicks in Australia. These endorsements served to entrench King’s book as a ‘classic’. Jerome Rodale reintroduced the book to a US audience with an edition published by his Organic Gardening Press, c.1949. King’s book arose out of his discontent with the views promulgated by the US Department of Agriculture (USDA), he differentiated the Asian agriculture he encountered as ‘permanent agriculture’, he provided a detailed account of the ancien régime organic agriculture of China, Korea and Japan, he called for a “world movement” for agricultural reform, and his book was been taken as a validation of the principles of organic agriculture. At least twenty six impressions of Farmers of Forty Centuries have been published in the past century, ten of these appeared during the first nine decades, while 16 have appeared in the past decade.

Novel Quantitative Approach for Predicting mRNA/Protein Counts in Living Cells

One of the most complex questions in quantitative biology is how to manage noise sources and the subsequent consequences for cell functions. Noise in genetic networks is inevitable, as chemical reactions are probabilistic and often, genes, mRNAs and proteins are present in variable numbers per cell. Previous research has focused on counting these numbers using experimental methods such as complex fluorescent techniques or theoretical methods by characterizing the probability distribution of mRNAs and proteins numbers in cells. In this work, we propose a modeling based approach;we build a mathematical model that is used to predict the number of mRNAs and proteins over time, and develop a computational method to extract the noise-related information in such a biological system. Our approach contributes to answering the question of how the number of mRNA and proteins change in living cells over time and how these changes induce noise. Moreover, we calculate the entropy of the system;this turns out to be important information for prediction which could allow us to understand how noise information is generated and expanded.