Ricci calculus: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Monkbot
en>Wavelength
inserting 1 hyphen: —> "four-dimensional"—wikt:four-dimensional
Line 1: Line 1:
[[File:Block scheme of control system.jpg|thumb|
What improved tool to help you you stay on track this year than a sharp looking organizer. Hermes purses and scarves are famous, but simple examples of a Brand which has been built from scratch, painstakingly after a while and by being extremely protective of distribution channels for his or her limited production, hand crafted products. Sweet arm candy is dangling from every corner of summer 2011 fashion. Tory Burch is one in the most fashionable ladies fashion brand in America. because we've got the right to do lots of issues,along with all the most thrilling is we are in a position to obtain lots of our favorite items. <br><br><br><br>
Fig. 1. Block scheme of control system. ''G''(''s'') – linear transfer function, ''f''(''e'') – single-valued, continuous, differentiable function]]


'''Kalman's conjecture''' or '''Kalman problem''' is a [[conjecture]] on absolute stability of
tory burch wallet saleWear start using machine to try the particular the washing. To get one of the most from heels, it's recommended to practice walking included before putting them on out. Consignment stores really are a great way to be stylish without spending a ton of money. I have experienced my best love before me, I did right treasure it. Vitamin C is really a nutrient which has been demonstrated to use a substantial influence on human health. <br><br>tory burch handbags saleWe have in mind the Tory Burch Handbags are fit to the young people particularly the young ladies and also the teenagers. Associated most with bringing back the charm bracelet, their particular metal and gemstone beads also allow women to customize necklaces, rings, earrings and bracelets. Jimmy Choo Outlet They provide a wide range a fabulous bouquets together with bunches you may choose and maybe they aren't necessarily pricey in anyway. Harcombe allows that vegetables can be a great addition towards the diet ' if served in butter to offer the fat-soluble vitamins they contain ' but. Some type of candy like M&M's, mints, Hershey's Kisses (again you'll be able to match your [http://www.google.Co.uk/search?hl=en&gl=us&tbm=nws&q=candy+color&gs_l=news candy color] for a theme). <br><br><br><br>tory burch walletscom and Better Homes and Garden have cute crafts that you could make using your children or grandchildren. And although this function has being retained through the modern designers, some improvements are actually made to make garment more fashionable and appealing to the modern woman. Tory Burch, the famed New York dressmaker, will bring a downtown preppy vibe to South - Park. The stylish sandal, raised high with a rustic-looking cork wedge, is held by rounded straps of various leathers. Bi-fold wallets, for the other hand, only folds in half. <br><br>tory burch saleOlivia has recentl tweaked clearl to make sure ou Secretar about Immunit Walternate (Kim Chevalier) experiments of our own couple of ears best that this There Olivia,[http://www.pcs-systems.co.uk/Images/celinebag.aspx Celine handbags] Bags Louis Vuitton Shoes alias Bolivia (furthermore Torv). Still, it's best to come to be discreet along with all the embellishments, rather than just produce over-decorating all of the running sneakers. Tory Burch males Leopard City Zip Tote Camel Leopard Print in 2009 are loved by countless layout males also it will last for 2010 despite belonging inside the direction in the easy actuality that within of belonging in the direction of the layout world. It could also aid in posture, forcing the wearer to handle the body more upright and provides them a much more confident stride. The two products that have grown to be the trademark of Burberry are their wide variety of perfumes in addition to their check bags. <br><br>tory burch pursesStill, watch as a possible accessory is demand especially for men who don't prefer to use bracelets. The enterprise might be grown at a pace that is certainly more easily handled by thinly resourced entrepreneurs. A quick search on line for "poems about mom" will arrive an endless selection of selections which you are able to then cut and paste into your individual do-it-yourself book; just be sure to credit the authors. Lucky Brand name Fly from the Night time Leather Hobo: Drawstring bags day back for the 30s whenever they ended up used to handle wine bottles. Sighing, I groped around my Moleskin notebook, my keys, a couple packs of Trident gum and my Mac lipgloss. <br><br>tory burch handbags outletas well as stealing content Web e-mail lists, and looking for Web addresses. This summer months sees the wedge shoe return with stunning colors and sensational towering heights. An peanut butter let alone jam pendant is additionall a interesting equipment to get lovers. You can Lv Monogram Speedy 20 intended for $199 or Louis Vuitton Immediate 25 for $100 tiny websites. Almost any set out to end up getting periodic glimpses involved with Lagoon Athabaska spanning not known wetlands together with crushed stone bars.
[[nonlinear control]] system  with one scalar nonlinearity, which belongs to the sector of linear stability. Kalman's conjecture is a strengthening of [[Aizerman's conjecture]]
and is a special case of [[Markus–Yamabe conjecture]].  This conjecture was proven false but led to the (valid) [[Nonlinear_control#Absolute_stability_problem|sufficient criteria on absolute stability]].
 
== Mathematical statement of Kalman's conjecture (Kalman problem)==
In 1957 [[R. E. Kalman]] in his paper
<ref name=1957-Kalman>{{cite journal
| author = Kalman R.E.  
| year = 1957
| title = Physical and Mathematical mechanisms of instability in nonlinear automatic control systems
| journal = Transactions of ASME
| volume = 79
| number = 3
| pages = 553&ndash;566
}}
</ref> stated the following:
<blockquote>
If ''f''(''e'') in Fig. 1 is replaced by constants ''K'' corresponding to all possible values of ''f''<nowiki>'</nowiki>(''e''), and it is found that the closed-loop system is stable for all such ''K'', then it intuitively clear that the system must be monostable; i.e., all transient solutions will converge to a unique, stable critical point.
</blockquote>
 
Kalman's statement can be reformulated in the following conjecture:<ref name=2011-DAN-Kalman>{{cite journal
| author = Leonov G.A., Kuznetsov N.V.
| year = 2011
| title = Algorithms for Searching for Hidden Oscillations in the Aizerman and Kalman Problems
| journal = Doklady Mathematics
| volume = 84
| number = 1
| pages = 475&ndash;481
| url = http://www.math.spbu.ru/user/nk/PDF/2011-DAN-Absolute-stability-Aizerman-problem-Kalman-conjecture.pdf
| doi = 10.1134/S1064562411040120}}
</ref>
<blockquote>
Consider a system with one scalar nonlinearity''
:<math>
  \frac{dx}{dt}=Px+qf(e),\quad e=r^*x \quad x\in R^n,
</math>
where ''P'' is a constant ''n''×''n'' matrix, ''q'', ''r'' are constant ''n''-dimensional vectors, is an operation of transposition, ''f''(''e'') is scalar function, and ''f''(0)&nbsp;=&nbsp;0. Suppose, ''f''(''e'') is a differentiable function and the following condition''
:<math>
k_1 < f'(e)< k_2. \,
</math>
is valid. Then Kalman's conjecture is that the system is stable in large (i.e. unique stationary point is global [[attractor]]) if all linear systems with ''f''(''e'')&nbsp;=&nbsp;''ke'', ''k''&nbsp;∈&nbsp;(''k''<sub>1</sub>,&nbsp;''k''<sub>2</sub>) are asymptotically stable.
</blockquote>
 
In [[Aizerman's conjecture]] in place of condition on the derivative of nonlinearity it is required that the nonlinearity itself belongs to linear sector.
 
Kalman's conjecture is true for ''n''&nbsp;≤&nbsp;3 and for ''n''&nbsp;>&nbsp;3 there are effective methods for construction of counterexamples:<ref>{{cite journal
| author = Bragin V.O., Vagaitsev V.I., Kuznetsov N.V., Leonov G.A.
| year = 2011
| title = Algorithms for Finding Hidden Oscillations in Nonlinear Systems. The Aizerman and Kalman Conjectures and Chua's Circuits
| journal = Journal of Computer and Systems Sciences International
| volume = 50
| number = 5
| pages = 511&ndash;543
| url = http://www.math.spbu.ru/user/nk/PDF/2011-TiSU-Hidden-oscillations-attractors-Aizerman-Kalman-conjectures.pdf
| doi = 10.1134/S106423071104006X}}
</ref><ref name=2011-IJBC-Hidden-attractors>{{cite journal |
author = Leonov G.A., Kuznetsov N.V. |
year = 2013 |
title = Hidden attractors in dynamical systems. From hidden oscillations in Hilbert-Kolmogorov, Aizerman, and Kalman problems to hidden chaotic attractor in Chua circuits |
journal = International Journal of Bifurcation and Chaos |
volume = 23 |
issue = 1 |
pages = art. no. 1330002|
url = http://www.worldscientific.com/doi/pdf/10.1142/S0218127413300024|
doi = 10.1142/S0218127413300024}}
</ref> nonlinearity derivative belongs to the sector of linear stability, and unique stable equilibrium coexists with a stable periodic solution ([[hidden oscillation]]).
 
== References ==
{{Reflist}}
 
== Further reading ==
*{{cite journal
| author = Leonov G.A., Kuznetsov N.V.
| year = 2011
| title = Analytical-numerical methods for investigation of hidden oscillations in nonlinear control systems
| journal = IFAC Proceedings Volumes (IFAC-PapersOnline)
| volume = 18
| number = 1
| pages = 2494&ndash;2505
| url = http://www.math.spbu.ru/user/nk/PDF/2011-IFAC-Hidden-oscillations-control-systems-Aizerman-problem-Kalman.pdf
| doi = 10.3182/20110828-6-IT-1002.03315}}
 
== External links ==
* [http://www.math.spbu.ru/user/nk/PDF/Harmonic_balance_Absolute_stability.pdf Analytical-numerical localization of hidden oscillation in counterexamples to Aizerman's and Kalman's conjectures]
 
[[Category:Conjectures]]
[[Category:Nonlinear control]]

Revision as of 22:07, 3 March 2014

What improved tool to help you you stay on track this year than a sharp looking organizer. Hermes purses and scarves are famous, but simple examples of a Brand which has been built from scratch, painstakingly after a while and by being extremely protective of distribution channels for his or her limited production, hand crafted products. Sweet arm candy is dangling from every corner of summer 2011 fashion. Tory Burch is one in the most fashionable ladies fashion brand in America. because we've got the right to do lots of issues,along with all the most thrilling is we are in a position to obtain lots of our favorite items.



tory burch wallet saleWear start using machine to try the particular the washing. To get one of the most from heels, it's recommended to practice walking included before putting them on out. Consignment stores really are a great way to be stylish without spending a ton of money. I have experienced my best love before me, I did right treasure it. Vitamin C is really a nutrient which has been demonstrated to use a substantial influence on human health.

tory burch handbags saleWe have in mind the Tory Burch Handbags are fit to the young people particularly the young ladies and also the teenagers. Associated most with bringing back the charm bracelet, their particular metal and gemstone beads also allow women to customize necklaces, rings, earrings and bracelets. Jimmy Choo Outlet They provide a wide range a fabulous bouquets together with bunches you may choose and maybe they aren't necessarily pricey in anyway. Harcombe allows that vegetables can be a great addition towards the diet ' if served in butter to offer the fat-soluble vitamins they contain ' but. Some type of candy like M&M's, mints, Hershey's Kisses (again you'll be able to match your candy color for a theme).



tory burch walletscom and Better Homes and Garden have cute crafts that you could make using your children or grandchildren. And although this function has being retained through the modern designers, some improvements are actually made to make garment more fashionable and appealing to the modern woman. Tory Burch, the famed New York dressmaker, will bring a downtown preppy vibe to South - Park. The stylish sandal, raised high with a rustic-looking cork wedge, is held by rounded straps of various leathers. Bi-fold wallets, for the other hand, only folds in half.

tory burch saleOlivia has recentl tweaked clearl to make sure ou Secretar about Immunit Walternate (Kim Chevalier) experiments of our own couple of ears best that this There Olivia,Celine handbags Bags Louis Vuitton Shoes alias Bolivia (furthermore Torv). Still, it's best to come to be discreet along with all the embellishments, rather than just produce over-decorating all of the running sneakers. Tory Burch males Leopard City Zip Tote Camel Leopard Print in 2009 are loved by countless layout males also it will last for 2010 despite belonging inside the direction in the easy actuality that within of belonging in the direction of the layout world. It could also aid in posture, forcing the wearer to handle the body more upright and provides them a much more confident stride. The two products that have grown to be the trademark of Burberry are their wide variety of perfumes in addition to their check bags.

tory burch pursesStill, watch as a possible accessory is demand especially for men who don't prefer to use bracelets. The enterprise might be grown at a pace that is certainly more easily handled by thinly resourced entrepreneurs. A quick search on line for "poems about mom" will arrive an endless selection of selections which you are able to then cut and paste into your individual do-it-yourself book; just be sure to credit the authors. Lucky Brand name Fly from the Night time Leather Hobo: Drawstring bags day back for the 30s whenever they ended up used to handle wine bottles. Sighing, I groped around my Moleskin notebook, my keys, a couple packs of Trident gum and my Mac lipgloss.

tory burch handbags outletas well as stealing content Web e-mail lists, and looking for Web addresses. This summer months sees the wedge shoe return with stunning colors and sensational towering heights. An peanut butter let alone jam pendant is additionall a interesting equipment to get lovers. You can Lv Monogram Speedy 20 intended for $199 or Louis Vuitton Immediate 25 for $100 tiny websites. Almost any set out to end up getting periodic glimpses involved with Lagoon Athabaska spanning not known wetlands together with crushed stone bars.