Stability and Performance Verification of Optimization-based Controllers

This paper presents a method to verify closed-loop properties of optimization-based controllers for deterministic and stochastic constrained polynomial discrete-time dynamical systems. The closed-loop properties amenable to the proposed technique include global and local stability, performance with respect to a given cost function (both in a deterministic and stochastic setting) and the $\mathcal{L}_2$ gain. The method applies to a wide range of practical control problems: For instance, a dynamical controller (e.g., a PID) plus input saturation, model predictive control with state estimation, inexact model and soft constraints, or a general optimization-based controller where the underlying problem is solved with a fixed number of iterations of a first-order method are all amenable to the proposed approach. The approach is based on the observation that the control input generated by an optimization-based controller satisfies the associated Karush-Kuhn-Tucker (KKT) conditions which, provided all data is polynomial, are a system of polynomial equalities and inequalities. The closed-loop properties can then be analyzed using sum-of-squares (SOS) programming

Politički sistem i institucionalni nered

The author analyses the situation of the key institutions of political system of Srbija as a result of transitional reforms in the period from 2000-2002. The institutions of political system are observed as institutes which should provide through reforms stable patterns of behaviour. As analytical matrix for the analysis, it is used Linz/Stephen pattern of consolidation of democracy in transition. The author points out the institutional chaos and problems in the foundation for a such analysis - existence of state, according the pattern of axiom for establishing democracy; degradation of parliament and legal authority; dominance of the executive; the selective respect and application of law, dominance of parties in power, but without real elected authorization; pushing out the civic sphere and its discreditation as a preparatory polygon for partizan actions; the consequences of shock-therapy in economy on the basis of confidence in the institutions of political system. The author makes conclusion that the transition has come to destruction of numbered institutions, that the new ones were not constituted, that such institutions create institutional chaos and that in political system begins to appear damaged consequences of a such institutional arrangement.Autor analizira stanje ključnih institucija političkog sistema Srbije kao posledice tranzicionih reformi u periodu 2000-2002. Institucije političkog sistema posmatraju se kao ustanove koje treba da kroz reforme obezbede stabilne obrasce ponašanja. Kao analitička matrica za analizu koristi se Linc/Stepanov model konsolidovanja demokratije u tranziciji. Autor ukazuje na institucionalni haos i probleme u osnovama za takvu analizu - postojanje države, prema navedenom modelu aksioma za uspostavljanje demokratije; degradaciju parlamenta i sudske vlasti, dominaciju egzekutive; selektivno poštovanje i primenjivanje zakona; dominaciju partija u vlasti bez realne izborne legitimacije; potiskivanje civilne sfere i njeno diskreditovanje kao pripremnog poligona za stranačke akcije; posledice šok terapije u ekonomiji na poverenje u institucije političkog sistema. Autor zaključuje da je tranzicija dovela do urušavanja brojnih institucija, da nove nisu uspostavljene, da takvo stanje stvara institucionalni haos i da se u političkom sistemu počinju reprodukovati štetne posledice takvog institucionalnog aranžmana

Horizontalna organizacija vlasti u predlozima za novi Ustav Srbije

During four years of intensive discussions and attempts of three governments to adopt a new Constitution of Serbia, ten constitutional projects have been accomplished. They all share the same agenda of theoretical concept of the power sharing. Special attention is paid to the relations between legislative and executive aspects of it. All projects call for bicefal executive power with various competencies of the head of the state included, in most of the cases in the role of the President of Republic except in the case of the proposition for establishment of the monarchy by Prof Dr. Pavle Nikolic. The proposed constitutional models thoroughly subsume the parliamentary system with classic warranties for the National Parliament, the president of Republic and the government. The proposed concepts are not very inventive when it comes to the control of the government's activity and domination of the executive regulation over the Parliament. According to these, in many regards, the key aspects of the content of the Constitution, there is no any controversial constitution proposal which could endanger the adoption of the new Constitution.Za četiri godine intenzivnih rasprava i pokušaja tri vlade da se donese novi Ustav Srbije sačinjeno je deset ustavnih projekata. Svi oni polaze od teorijskog koncepta podele vlasti. Posebna pažnja posvećena je odnosu legislative i egzekutive. Svi projekti plediraju za bicefalnu egzekutivu ali sa različitim ovlašćenjima šefa države, najčešće kao predsednika Republike, osim u jednom slučaju - predlogu za uspostavljanje monarhije prof. dr Pavla Nikolića. Ponuđeni ustavni modeli dosledno razrađuju parlamentarni sistem sa klasičnim ovlašćenjima Narodne skupštine predsednika Republike i Vlade. Predloženi koncepti ne odlikuju se inventivnošću kada je u pitanju kontrola rada vlade od strane zakonodavne vlasti i dominacija egzekutive nad parlamentom. Sudeći po ovim, po mnogo čemu ključnim aspektima ustavne materije, ne postoje predlozi koji bi pomogli predmet sporenja do tačke koja bi značila nemogućnost donošenja novog Ustava

Organizacija vlasti u predlozima za novi ustav Srbije

All proposed projects within the discussion round on new Constitution of Serbia emphasize the principle of authority division. The division on legislative and executive authority has been thoroughly implemented, even into the proposal of P. Nikolić, whose concept of authority division is related to the model of parliament monarchy. Differences between proposed projects on the authority organization in the new Constitution are results of the level and model of decentralization, not of the authority of the government body. Nor they are, as the polemics may lead to wrong conclusion results of the role and authority of the president of Republic. In all the projects the function of the head of the state is standard for the system of double centered executive authority dominated by the government, while the role of the head of the state is of protocol character only. Direct selection of president of the state, as proposed by the project of Serbian Democratic Party, is not sufficient to secure the moderator role, as envisioned by the propose.U raspravama o novom ustavu Srbije svi predloženi projekti insistiraju na načelu podele vlasti. Podela na zakonodavnu i izvršnu vlast dosledno je izvedena po parlamentarnom modelu organizacije vlasti čak i u predlogu P. Nikolića čiji koncept počiva na parlamentarnoj monarhiji. Razlike među predloženim projektima novog ustava posmatrane kroz organizaciju vlasti proizilaze prvenstveno iz stepeni i oblika decentralizacije, a ne iz nadležnosti organa ili, kako bi se iz polemika moglo pogrešno zaključiti, iz položaja i uloge predsednika Republike. Šef države u svim projektima ima funkcije standardne za sistem bicefalne egzekutive u kojem dominira vlada, a šef države ima protokolarnu ulogu. Neposredan izbor predsednika države koji se predlaže u projektu Demokratske stranke Srbije nije dovoljan da obezbedi moderatornu ulogu za koju se predlagač zalaže

A World of Difference: Soviet Antisubmarine Warfarein 1991

The final years of the existence of the Soviet Union-a period that encompassed also the dissolution of the Warsaw Treaty Organization were, notwithstanding, years of substantial development of antisubmarine warfare thought and capability in the Soviet navy. Some of this progress was readily visible to the West, particularly in the introduction of highly capable general-purpose nuclear submarines (SSNs)

Izborna jedinica, izborni prag i stranački sistem

The author analyzed influence of the limit issue in allocation clause largeness of electoral unit and D'Onte formula for parliamentarian party system in Serbia in five electoral cycles from 1992 to 2003. Through analysis of the allocation clause of inclusivity and exclusivity, the author noted that lower allocation clause would significantly increase number of parliamentarian parties and caused fragmentation of parliamentarian party system. In contrast to calls for lowering the limit in the allocation clause the author pointed out danger of further fractionalization of the parties unstable parliamentarian majority and weak government, and urged for integral electoral reform.Autor analizira uticaj visine izbornog praga, veličine izborne jedinice i D' Ontove formule na parlamentarni stranački sistem u Srbiji u pet izbornih ciklusa od 1992. do 2003. godine. Kroz analizu izbornog praga inkluzivnosti i ekskluzivnosti, autor pokazuje da bi niži izborni prag znatno povećao broj parlamentarnih stranaka i uslovio fragmentaciju parlamentarnog stranačkog sistema. Protiveći se idejama za snižavanje izbornog praga, autor ukazuje na opasnosti dalje frakcionalizacije stranaka, nestabilne parlamentarne većine i slabe vlade, i pledira za celovitu izbornu reformu

Strong impact of light induced conical intersections on the spectrum of diatomic molecules

We show that dressing of diatomic molecules by running laser waves gives rise to conical intersections (CIs). Due to presence of such CIs, the rovibronic molecular motions are strongly coupled. A pronounced impact of the CI on the spectrum of $Na_2$ molecule is demonstrated via numerical calculation for weak and moderate laser intensity, and an experiment is suggested on this basis. The position of the light induced CI and the strength of its non-adiabatic couplings can be chosen by changing the frequency and intensity of the used running laser wave. This offers new possibilities to control the photo-induced rovibronic molecular dynamics.Comment: 4 pages, 7 figure

Comment on "Spatial optical solitons in highly nonlocal media" and related papers

In a recent paper [A. Alberucci, C. Jisha, N. Smyth, and G. Assanto, Phys. Rev. A 91, 013841 (2015)], Alberucci et al. have studied the propagation of bright spatial solitary waves in highly nonlocal media. We find that the main results in that and related papers, concerning soliton shape and dynamics, based on the accessible soliton (AS) approximation, are incorrect; the correct results have already been published by others. These and other inconsistencies in the paper follow from the problems in applying the AS approximation in earlier papers by the group that propagated to the later papers. The accessible soliton theory cannot describe accurately the features and dynamics of solitons in highly nonlocal media.Comment: 2 page