scholarly journals Influences of Purline Stiffness on the Stability Performance of Portal Frame

2016 ◽  
Author(s):  
Gang Du ◽  
Feng Liu ◽  
Lehuan Xu
Keyword(s):  
Stability Performance ◽  
Portal Frame ◽  
The Stability

Experimental Study on the Stability Performance and Turning Motion of Multi-Connection VAWT

2021 ◽  
Author(s):  
Saika Iwamatsu ◽  
Yasunori Nihei ◽  
Kazuhiro Iijima ◽  
Tomoki Ikoma ◽  
Tomoki Komori
Keyword(s):  
Scaling Law ◽  
Type A ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Water Tank ◽  
Type B ◽  
Floating Bodies ◽  
Stability Performance ◽  
Turning Motion ◽  
The Stability

Abstract In this study, a series of dedicated water tank tests were conducted in wind and waves to investigate the stability performance and turning motion of Floating Offshore Wind Turbine (FOWT) equipped with two vertical axis wind turbines (VAWT). The FOWT targeted in this study is called Multi-connection VAWT, which is a new type of FOWT moored by Single-Point-Mooring (SPM) system. We designed and manufactured two types of semi-submersible floating bodies. One is a type in which VAWTs are mounted in two places of a right-angled isosceles triangle (Type-A) on a single floater, and the other is two independent units equipped with VAWTs on two separate floaters centered on a moored body. This is a type in which two semi-submersible floating bodies are lined up in a straight line (Type-B). The experimental conditions were determined by scaling down to 1/100 using Froude’s scaling law based on a wind thrust load of 320 kN (rated wind speed of 12 m/s) assuming an actual machine. In the free yawing test in waves, Type-A turned downwards, while Type-B was barely affected by the waves. Furthermore, in the free yawing test in wind, both Type-A and Type-B turned leeward and stabilized at a final point where the wind load was balanced.

scholarly journals Optimal Location and Design of TCSC controller For Improvement of Stability

2011 ◽  
pp. 210-215
Author(s):  
Swathi Kommamuri ◽  
P. Sureshbabu
Keyword(s):  
Power System ◽  
Optimization Problem ◽  
Low Frequency ◽  
System Stability ◽  
Simulation Environment ◽  
Swarm Optimization ◽  
Stability Performance ◽  
Low Frequency Oscillations ◽  
Simulation Results ◽  
The Stability

Power system stability improvement by a coordinate Design ofThyristor Controlled Series Compensator (TCSC) controller is addressed in this paper.Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.

scholarly journals PENGARUH GENOTIPE, LINGKUNGAN, DAN INTERAKSI KEDUANYA TERHADAP STABILITAS PENAMPILAN FENOTIPIK IKAN MAS

2019 ◽  
Vol 13 (4) ◽  
pp. 289
Author(s):  
Didik Ariyanto ◽  
Suharyanto Suharyanto ◽  
Flandrianto Sih Palimirmo ◽  
Yogi Himawan
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Environmental Conditions ◽  
Culture Systems ◽  
Stability Performance ◽  
Carp Cyprinus Carpio ◽  
Culture Environment ◽  
Net Cage ◽  
The Stability ◽  
Concrete Pond

Ikan mas (Cyprinus carpio) merupakan komoditas budidaya yang mudah beradaptasi dengan berbagai kondisi lingkungan. Penelitian ini bertujuan mempelajari pengaruh genotipe, lingkungan, dan interaksi antara genotipe dengan lingkungan terhadap stabilitas penampilan fenotipik ikan mas dalam kegiatan budidaya. Rancangan percobaan menggunakan rancangan faktorial 3 x 5 dengan lima ulangan. Lima strain ikan mas, yaitu Rajadanu, Sutisna, Majalaya, Wildan, dan Sinyonya dipelihara secara komunal di dalam tiga model wadah budidaya, yaitu kolam beton, kolam jaring, dan kolam tanah, selama 90 hari. Hasil penelitian menunjukkan bahwa penampilan fenotipik ikan mas dipengaruhi oleh genotipe, lingkungan dan interaksi kedua faktor tersebut. Strain Sutisna dan Wildan mempunyai nilai sintasan yang paling baik di semua lingkungan dibanding tiga strain lainnya. Strain Sutisna mempunyai pertumbuhan terbaik di kolam tanah sedangkan strain Wildan di kolam jaring. Hal ini menyebabkan kedua strain tersebut menghasilkan biomassa panen terbaik pada lingkungan yang berbeda. Hasil analisis stabilitas menunjukkan bahwa kelima strain ikan mas dalam penelitian ini relatif tidak stabil dan mempunyai respons yang berbeda jika dipelihara pada lingkungan yang berbeda. Strain Wildan dan Rajadanu merupakan strain ikan mas yang mempunyai respons terhadap perbedaan lingkungan paling tinggi. Strain dengan karakteristik tersebut akan mempunyai performa terbaik pada lokasi dan kondisi pemeliharan yang sesuai dengan kebutuhannya, tetapi mempunyai penampilan fenotipik yang rendah jika kondisi lingkungan budidayanya tidak sesuai. Strain Sutisna, Sinyonya, dan Majalaya merupakan strain ikan mas dengan daya responsi terhadap lingkungan lebih rendah. Karakteristik ini menyebabkan penampilan fenotipik ketiga strain tersebut relatif stabil pada semua lokasi dan kondisi budidaya, meskipun tidak bisa mencapai hasil yang maksimal.Common carp (Cyprinus carpio) is known as fish species highly adaptable to various environmental conditions. This study aimed to evaluate the effect of genotype, environment, and their interaction in phenotypic performance stability of common carp. The experimental design used a 3 x 5 factorial design with five repetitions. Five strains of common carp, namely Rajadanu, Sutisna, Majalaya, Wildan, and Sinyonya were stocked communally for 90 days in three culture systems: concrete pond, net cage pond, and earthen pond. The result showed that the phenotypic performance of common carp was influenced by genotype, environment, and their interaction. Sutisna and Wildan strains have a higher survival rate compared to other strains in all culture systems. Sutisna and Wildan strains have the best growth performance in the earthen pond and net cage pond, respectively. Both strains also have the highest biomass production at harvest in all culture systems. Based on the stability performance analysis, Wildan and Rajadanu have the highest response to the different environmental conditions. Strains with this characteristic perform best in different locations or culture systems as long as the environmental conditions are suitable. However, these fish will likely perform poor in the unsuitable culture environment. Sutisna, Sinyonya, and Majalaya are carp strains with lower responsiveness to environmental change. Such characteristic causes the phenotypic performance of these three strains cannot achieve the maximum results, yet it is relatively stable in all locations.

scholarly journals Stability Anomalies of Some Jacobian-Free Iterative Methods of High Order of Convergence

Axioms ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 51
Author(s):  
Alicia Cordero ◽  
Javier G. Maimó ◽  
Juan R. Torregrosa ◽  
María P. Vassileva
Keyword(s):  
Difference Operator ◽  
Divided Difference ◽  
Polynomial System ◽  
Nonlinear Problems ◽  
Coefficient Matrix ◽  
Test Problems ◽  
Stability Performance ◽  
Need To Evaluate ◽  
The Stability ◽  
Theoretical Results

In this manuscript, we design two classes of parametric iterative schemes to solve nonlinear problems that do not need to evaluate Jacobian matrices and need to solve three linear systems per iteration with the same divided difference operator as the coefficient matrix. The stability performance of the classes is analyzed on a quadratic polynomial system, and it is shown that for many values of the parameter, only convergence to the roots of the problem exists. Finally, we check the performance of these methods on some test problems to confirm the theoretical results.

scholarly journals Stability Performance Analysis of Various Packaging Materials and Coating Strategies for Chronic Neural Implants under Accelerated, Reactive Aging Tests

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 810
Author(s):  
Yan Gong ◽  
Wentai Liu ◽  
Runyu Wang ◽  
Matthew Harris Brauer ◽  
Kristine Zheng ◽  
...  
Keyword(s):  
Packaging Materials ◽  
Neural Implants ◽  
Three Solutions ◽  
Parylene C ◽  
Prosthetic Devices ◽  
Neural Prosthetic ◽  
Stability Performance ◽  
Interface Delamination ◽  
The Stability ◽  
Phosphate Buffered Saline

Reliable packaging for implantable neural prosthetic devices in body fluids is a long-standing challenge for devices’ chronic applications. This work studied the stability of Parylene C (PA), SiO2, and Si3N4 packages and coating strategies on tungsten wires using accelerated, reactive aging tests in three solutions: pH 7.4 phosphate-buffered saline (PBS), PBS + 30 mM H2O2, and PBS + 150 mM H2O2. Different combinations of coating thicknesses and deposition methods were studied at various testing temperatures. Analysis of the preliminary data shows that the pinholes/defects, cracks, and interface delamination are the main attributes of metal erosion and degradation in reactive aging solutions. Failure at the interface of package and metal is the dominating factor in the wire samples with open tips.

scholarly journals Stability Tests of Agricultural and Operating Machines by Means of an Installation Composed by a Rotating Platform (the “Turntable”) with Four Weighting Quadrants

2020 ◽  
Vol 10 (11) ◽  
pp. 3786
Author(s):  
Marco Bietresato ◽  
Fabrizio Mazzetto
Keyword(s):  
Degrees Of Freedom ◽  
Structural Integrity ◽  
Support Surface ◽  
Rotating Platform ◽  
Technical Standards ◽  
Stability Tests ◽  
Support Plane ◽  
Stability Performance ◽  
Inclination Angles ◽  
The Stability

The stability of agricultural machines, earth-moving machines, snow-compaction machines and, in general, of all vehicles that may operate on sloping terrains is a very important technical feature and should not be underestimated. In fact, it is correlated, above all, to the safety of the operators, but also to the preservation of the structural integrity of these vehicles, to the prosecution of the activities and to the preservation of the economic investment. Although these facts are well-known, the international legislation and technical standards do not yet have a sufficient level of detail to give an all-inclusive quantification of the stability of the vehicle under examination in all its working conditions, e.g., at different inclination angles of the support surface, at different climbing angles of the vehicle on the slope, with different tires and inflating pressures, and on different terrains. Actual standards limit the stability tests to the experimental measurement of the lateral rollover angle only. Furthermore, the realization of unconventional test equipment able to widen the usually-tested scenarios could not be simple, due to the necessary size that such equipment should have (to perform tests not in scale) and to the related difficulties of handling full-scale vehicles. This work illustrates the applications of a new rig for testing the stability of vehicles, able to address all the above-illustrated issues and of possible future adoption to certify the stability performance of machines and perform homologations. This installation, named “rotating platform” or “turntable”, has the peculiarity of being able to move the machine positioned on it according to two rotational degrees of freedom: (1) overall inclination of the support plane, (2) rotation of the support plane around an axis perpendicular to the plane. The same installation is also designed to record the weight supported by each wheel of the machine placed on it (by means of four sensorized quadrants), both when the platform is motionless and while the above-described movements of tilt and rotation are being carried out, thus locating precisely the spatial position of the vehicle center of gravity. The presented physical-mathematical models highlight the great potential of this facility, anticipate the outcomes of the recordings that the experimenters will have at disposal when the test rig will be effectively active, and help the future understanding of trends of data, thus maximizing the available information content.

scholarly journals Characteristics of BeiDou-3 Experimental Satellite Clocks

2018 ◽  
Vol 10 (11) ◽  
pp. 1847 ◽  
Author(s):  
Yifei Lv ◽  
Tao Geng ◽  
Qile Zhao ◽  
Jingnan Liu
Keyword(s):  
Global Positioning System ◽  
Precise Orbit Determination ◽  
Frequency Standard ◽  
Step Method ◽  
Stability Performance ◽  
Global Positioning ◽  
Clock Prediction ◽  
Block Iif ◽  
The Stability ◽  
Gps Block Iif

The characteristics of the improved Atomic Frequency Standard (AFS) operated on the latest BeiDou-3 experimental satellites are analyzed from day-of-year (DOY) 254 to 281, of the year 2017, considering the following three aspects: stability, periodicity, and prediction precision. The two-step method of Precise Orbit Determination (POD) is used to obtain the precise clock offsets. We presented the stability of such new clocks and studied the influence of the uneven distribution of the ground stations on the stability performance of the clock. The results show that the orbit influence on the Medium Earth Orbit (MEO) clock offsets is the largest of three satellite types, especially from 3 × 10 3 s to 8.64 × 10 4 s. Considering this orbit influence, the analysis shows that the Passive Hydrogen Maser (PHM) clock carried on C32 is approximately 2.6 × 10 − 14 at an interval of 10 4 , and has the best stability for any averaging intervals among the BeiDou satellite clocks, which currently achieves a level comparable to that of the PHM clock of Galileo, and the rubidium (Rb) clocks of Global Positioning System (GPS) Block IIF. The stability of the improved Rb AFS on BeiDou-3 is also superior to that of BeiDou-2 from 3 × 10 2 s to 3 × 10 3 s, and comparable to that of Rb AFS on the Galileo. Moreover, the periodicity of the PHM clock and the improved Rb clock are presented. For the PHM clock, the amplitudes are obviously reduced, while the new Rb clocks did not show a visible improvement, which will need further analysis in the future. As expected, the precision of the short-term clock prediction is improved because of the better characteristics of AFS. The Root Mean Square (RMS) of 1-h clock prediction is less than 0.16 ns.

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