A Research of Damping Characteristic of Hydro-Pneumatic Suspension

2014 ◽  
Vol 1030-1032 ◽  
pp. 1129-1132 ◽  
Author(s):  
Bin Yang ◽  
A Lei Du

A simplified mathematic model of hydro-pneumatic suspension was set up and the damping characteristic curve of hydro-pneumatic suspension was obtained accordingly. A analysis of the effect of diameter of hydraulic jar, velocity of piston, diameter of damping hole and check valve diameter on damping characteristic of hydro-pneumatic suspension was made. It showed that the major influence factors includes moving speed of piston, diameter of hydraulic jar and diameter of damping hole.

2019 ◽  
Vol 16 (3) ◽  
pp. 193-208 ◽  
Author(s):  
Yan Hu ◽  
Guangya Zhou ◽  
Chi Zhang ◽  
Mengying Zhang ◽  
Qin Chen ◽  
...  

Background: Alzheimer's disease swept every corner of the globe and the number of patients worldwide has been rising. At present, there are as many as 30 million people with Alzheimer's disease in the world, and it is expected to exceed 80 million people by 2050. Consequently, the study of Alzheimer’s drugs has become one of the most popular medical topics. Methods: In this study, in order to build a predicting model for Alzheimer’s drugs and targets, the attribute discriminators CfsSubsetEval, ConsistencySubsetEval and FilteredSubsetEval are combined with search methods such as BestFirst, GeneticSearch and Greedystepwise to filter the molecular descriptors. Then the machine learning algorithms such as BayesNet, SVM, KNN and C4.5 are used to construct the 2D-Structure Activity Relationship(2D-SAR) model. Its modeling results are utilized for Receiver Operating Characteristic curve(ROC) analysis. Results: The prediction rates of correctness using Randomforest for AChE, BChE, MAO-B, BACE1, Tau protein and Non-inhibitor are 77.0%, 79.1%, 100.0%, 94.2%, 93.2% and 94.9%, respectively, which are overwhelming as compared to those of BayesNet, BP, SVM, KNN, AdaBoost and C4.5. Conclusion: In this paper, we conclude that Random Forest is the best learner model for the prediction of Alzheimer’s drugs and targets. Besides, we set up an online server to predict whether a small molecule is the inhibitor of Alzheimer's target at http://47.106.158.30:8080/AD/. Furthermore, it can distinguish the target protein of a small molecule.


2019 ◽  
Vol 35 (4) ◽  
pp. 714-721 ◽  
Author(s):  
Els M Gielis ◽  
Kristien J Ledeganck ◽  
Amélie Dendooven ◽  
Pieter Meysman ◽  
Charlie Beirnaert ◽  
...  

Abstract Background After transplantation, cell-free deoxyribonucleic acid (DNA) derived from the donor organ (ddcfDNA) can be detected in the recipient’s circulation. We aimed to investigate the role of plasma ddcfDNA as biomarker for acute kidney rejection. Methods From 107 kidney transplant recipients, plasma samples were collected longitudinally after transplantation (Day 1 to 3 months) within a multicentre set-up. Cell-free DNA from the donor was quantified in plasma as a fraction of the total cell-free DNA by next generation sequencing using a targeted, multiplex polymerase chain reaction-based method for the analysis of single nucleotide polymorphisms. Results Increases of the ddcfDNA% above a threshold value of 0.88% were significantly associated with the occurrence of episodes of acute rejection (P = 0.017), acute tubular necrosis (P = 0.011) and acute pyelonephritis (P = 0.032). A receiver operating characteristic curve analysis revealed an equal area under the curve of the ddcfDNA% and serum creatinine of 0.64 for the diagnosis of acute rejection. Conclusions Although increases in plasma ddcfDNA% are associated with graft injury, plasma ddcfDNA does not outperform the diagnostic capacity of the serum creatinine in the diagnosis of acute rejection.


2012 ◽  
Vol 195-196 ◽  
pp. 673-677
Author(s):  
Yuan Li ◽  
Li An Bian ◽  
Jia Go

In this paper, we set up the model of downlink for Time Division synchronous Code Division Multiple Access (TD-SCDMA), and present link level simulation to TD-SCDMA mobile terminal smart antenna system. By carrying on performance simulation in system bit error rate between dual-unit antenna and single-unit antenna, we can validate the advantage of dual-unit smart antenna. Besides, we analysis the mobile terminal smart antenna may influenced by many factors, such as distance of two antenna, moving speed, the number of multi-path and user and so on, solve the contradiction between miniaturization of mobile terminal smart antenna and independence between antenna, and provide a valuable design reference to commercialize the limited frequency spectrum resource.


2014 ◽  
Vol 707 ◽  
pp. 259-262 ◽  
Author(s):  
Ming Song Wu ◽  
Xin Yang Xu ◽  
Xun Xu ◽  
Yue Ting Zeng ◽  
Jing Nan Zhang ◽  
...  

Algae and bacteria blooms in eutrophication in summer have made the quality of landscape water degradation. Treatment efficiency of potassium monopersulfate compound, a new kind of oxidation reagent, on killing algae and bacteria has been valued and the effect of influence factors, such as dosage, contact time and temperature are also discussed. The results indicated that potassium monopersulfate is appropriate for killing algae and bacteria in landscape water, dosage and contact time are the major influence factors. The contact time should be longer than 20min and the algicidal rate is higher when the temperature is above 20°C.


Author(s):  
Longyun Wang ◽  
Zhi Tao ◽  
Jianqin Zhu ◽  
Haiwang Li ◽  
Zeyuan Cheng

A new empirical correlation for upward flowing supercritical aviation kerosene RP-3 in the vertical tubes is proposed. In order to obtain the database, numerical simulation with a four-component surrogate model on RP-3 and LS low Reynolds turbulence model in vertical circular tube has been performed. Tubes of diameter 2mm to 10mm are studied and operating conditions cover pressure from 3MPa to 6MPa. Heat flux is 500KW/m2, mass flow rate is 700kg/(m2·s). The numerical results on wall temperature distribution under various conditions are compared with experimental data and a good agreement is achieved. The existing correlations are summarized and classified into three categories. Three representative correlations of each category are selected out to evaluate the applicability in heat transfer of supercritical RP-3. The result shows that correlations concluded from water and carbon-dioxide do not perform well in predicting heat transfer of hydrocarbon fuel. The mean absolute deviation of them is up to 20% and predict about 80% of the entire database within 30% error bands. So a new correlation which is applicable to different working conditions for supercritical RP-3 is put forward. Gnielinski type has been adapted as the basis of the new correlation for its higher accuracy. In consideration of major influence factors of supercritical heat transfer, correction terms of density and buoyancy effect are added in. The new correlation has a MAD of 9.26%, predicting 90.6% of the entire database within ±15% error bands. The comparisons validate the applicability of the new correlation.


1998 ◽  
Vol 74 (4) ◽  
pp. 606-616 ◽  
Author(s):  
Darwin Burgess ◽  
Craig Robinson

Two of the oldest permanent sample plots (PSPs) in Canada were set up at Petawawa, Ontario (45° 57′ N, 77° 34′ W) to examine the effect of thinning on the development of natural white (Pinus strobus L.) and red pine (Pinus resinosa Ait). Field data were collected periodically, starting in 1918 when the stand was 40 years old and continuing for 71 years. Six thinning treatments were completed, beginning in 1918, and then in 1933, 1941, 1959, 1969 and 1989. The intensity of thinning varied through time with 14, 27, 38, 8, 30, and 7% of the basal area removed. The sawlog volume mean annual increment for the thinned plot remained stable at about five m3 ha−1 yr−1, but the sawlog volume periodic annual increment for the control declined markedly during the last 10-year measurement period to less than 2 m3 ha−1 yr−1. The residual volume was higher in the control; but, if the harvested sawlog volume (264.5 m3 ha−1) was added to the residual sawlog volume (301.3 m3 ha−1) for PSP one, then the sawlog production on the thinned plot has been about the same and its residual volume concentrated on fewer, larger and more valuable trees. The level of natural mortality in the control plot (129.7 m3 ha−1 of sawlog volume) was greater than 10 times that in the thinned plot, thereby adding more coarse woody debris to improve wildlife habitat. These two approaches had a major influence on stand development. The approach used will depend on specific stand-level management objectives. Key words: white pine, red pine, natural stand management, shelterwood system, permanent sample plots.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Antonio Peña-García ◽  
Luisa-María Gil-Martín ◽  
Roberto Escribano ◽  
Antonio Espín-Estrella

Shifting the threshold zone of road tunnels with semitransparent tension structures has shown itself to be an effective way of saving energy in regards to electricity consumption, maintenance, and construction materials used in the electrical lighting, thus lessening negative environmental impacts. Even though the shape of the tension structure has a major influence on energy savings, the optimal type of structure for each tunnel is often difficult to determine, because experiments using real tunnels are extremely expensive. It is thus necessary to find methods of doing this that are both reliable as well as economical. In this research study, three candidate structures were set up at the portal of a scale model of a real tunnel. The energy savings in each case were analyzed and compared. As a result, it was possible to formulate a new equation that calculates the energy savings in the threshold zone.


Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 56 ◽  
Author(s):  
Jianhai Zhang ◽  
Zhiyong Feng ◽  
Yong Su ◽  
Meng Xing ◽  
Wanli Xue

Individual recognition based on skeletal sequence is a challenging computer vision task with multiple important applications, such as public security, human–computer interaction, and surveillance. However, much of the existing work usually fails to provide any explicit quantitative differences between different individuals. In this paper, we propose a novel 3D spatio-temporal geometric feature representation of locomotion on Riemannian manifold, which explicitly reveals the intrinsic differences between individuals. To this end, we construct mean sequence by aligning related motion sequences on the Riemannian manifold. The differences in respect to this mean sequence are modeled as spatial state descriptors. Subsequently, a temporal hierarchy of covariance are imposed on the state descriptors, making it a higher-order statistical spatio-temporal feature representation, showing unique biometric characteristics for individuals. Finally, we introduce a kernel metric learning method to improve the classification accuracy. We evaluated our method on two public databases: the CMU Mocap database and the UPCV Gait database. Furthermore, we also constructed a new database for evaluating running and analyzing two major influence factors of walking. As a result, the proposed approach achieves promising results in all experiments.


2013 ◽  
Vol 385-386 ◽  
pp. 89-92 ◽  
Author(s):  
Ya Jun Shao ◽  
Qin He Gao ◽  
Hong Jie Cheng

Taking a special vehicle vibration system as the research object, according to the actual structure of the chassis, the spring damping and stiffness of the nonlinear characteristics and the tire vertical elastic accounted, a nonlinear vibration model of special vehicle based on dual-mass-system is set up. The tire radial stiffness value is analyzed in Ansys, a simulation is performed by leading the mathematical model of suspension system into Adams, a characteristic curve of stiffness and damping of suspension system is obtained.


2011 ◽  
Vol 368-373 ◽  
pp. 829-833
Author(s):  
Fang Wei Liao ◽  
Xiao Liu ◽  
Ping Liu

Debris flow is one of the usual mountain geological disasters, and it is significant to assess and forecast its risk degree. The paper bases on statistical analysis of influence factors of debris flow risk degree, establishing 15 indexes to accurately assess debris flow risk degree. Furthermore, the evaluation index system is constructed by using analytic hierarchy process. And after combining the linkages between indexes, calculating each weight, and amending repeatedly with examples, finally the comprehensive mathematical evaluation on risk of debris flow is set up.


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