scholarly journals Sufficient conditions for compactness of the ∂-Neumann operator on high level forms

2021 ◽  
Vol 313 (1) ◽  
pp. 213-249
Author(s):  
Yue Zhang
2017 ◽  
Vol 29 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Seidali Kurtmollaiev

Despite its immense popularity, the dynamic capabilities framework faces fierce criticism because of the ambiguous and contradictory interpretations of dynamic capabilities. Especially challenging are the aspects related to the nature of dynamic capabilities and the issue of agency. In an attempt to avoid circular and overlapping definitions, I explicate dynamic capabilities as the regular actions of creating, extending, and modifying an organizational resource base. This implies that the individual’s intention to change the status quo in the organization and the individual’s high level of influence in the organization are necessary and sufficient conditions for dynamic capabilities. This approach overcomes challenges associated with current interpretations of dynamic capabilities, necessarily focusing on the actions and interactions of individuals in organizations. Following the micro-foundations movement, I present a multilevel approach for studying the individual-level causes and the firm-level effects of dynamic capabilities.


This paper is concerned with the existence of solutions of the Dirichlet problem for quasilinear elliptic partial differential equations of second order, the conclusions being in the form of necessary conditions and sufficient conditions for this problem to be solvable in a given domain with arbitrarily assigned smooth boundary data. A central position in the discussion is played by the concept of global barrier functions and by certain fundamental invariants of the equation. With the help of these invariants we are able to distinguish an important class of ‘ regularly elliptic5 equations which, as far as the Dirichlet problem is concerned, behave comparably to uniformly elliptic equations. For equations which are not regularly elliptic it is necessary to impose significant restrictions on the curvatures of the boundaries of the underlying domains in order for the Dirichlet problem to be generally solvable; the determination of the precise form of these restrictions constitutes a second primary aim of the paper. By maintaining a high level of generality throughout, we are able to treat as special examples the minimal surface equation, the equation for surfaces having prescribed mean curvature, and a number of other non-uniformly elliptic equations of classical interest.


Entropy ◽  
2021 ◽  
Vol 23 (10) ◽  
pp. 1291
Author(s):  
Zhuan Shen ◽  
Fan Yang ◽  
Jing Chen ◽  
Jingxiang Zhang ◽  
Aihua Hu ◽  
...  

This paper investigates the problem of adaptive event-triggered synchronization for uncertain FNNs subject to double deception attacks and time-varying delay. During network transmission, a practical deception attack phenomenon in FNNs should be considered; that is, we investigated the situation in which the attack occurs via both communication channels, from S-C and from C-A simultaneously, rather than considering only one, as in many papers; and the double attacks are described by high-level Markov processes rather than simple random variables. To further reduce network load, an advanced AETS with an adaptive threshold coefficient was first used in FNNs to deal with deception attacks. Moreover, given the engineering background, uncertain parameters and time-varying delay were also considered, and a feedback control scheme was adopted. Based on the above, a unique closed-loop synchronization error system was constructed. Sufficient conditions that guarantee the stability of the closed-loop system are ensured by the Lyapunov-Krasovskii functional method. Finally, a numerical example is presented to verify the effectiveness of the proposed method.


2019 ◽  
Vol 10 (1) ◽  
pp. 12-34
Author(s):  
Diego Ceccobelli

This article presents and adopts a new definition of the popularization of political communication, which is defined as a strategic communicative action through which political actors try to create new connections with those citizens who do not still know, follow and support them and to emotionally strengthen the political bond with their current sympathizers. Second, a comparative analysis of the Facebook pages of the main political leaders of 31 countries shows that the popularization of political communication is a relevant phenomenon on Facebook, while a qualitative comparative analysis (QCA) indicates that the presence of a presidential system, a high digitalization of the media system, and a high level of trust in political institutions are three sufficient conditions for a “pop” communication on Facebook. Finally, the article identifies and discusses its main properties and development under the current hybrid media system.


1980 ◽  
Vol 17 (02) ◽  
pp. 423-431 ◽  
Author(s):  
Richard Serfozo

The cumulative amount of time that a regenerative or semi-stationary process exceeds a high level and other measures of these exceedances are considered as special cases of a non-decreasing stochastic process of partial sums. We present necessary and sufficient conditions for these exceedance processes to converge in distribution to Poisson processes or processes with stationary independent non-negative increments as the level goes to infinity. We apply our results to random walks, M/M/s queues, and thinnings of point processes.


Author(s):  
PERESLEGIN SERGEY B. ◽  

The fundamental instability of the global world, associated with the technological limitation as a marker of globalization, precedes the crisis. Mankind is currently facing a succession of crises, in which the Covid-19 pandemic being only an outward representation, a media "face". The crisis of globalization can follow two paths: First, a transformation through chaos, a "savannah world", "grey zones" where no laws except the law of force apply. Second, transformation through the creation of macro-regions. Both options imply a high risk of military conflicts throughout the space of globalization and, above all, in Southeast Asia, which will lead to an arc of instability affecting Russian interests. The key area determining the behavior of the arc of instability is the Caspian Sea region. At present, of the four possible versions of the post-global world (as of 2015: infrastructure colonialism, cosmocolonialism, ecological capitalism, macro-regionalization) two remain. Ecological capitalism has been transformed into inclusive capitalism, and macro-regionalisation turned out to be the only alternative to the initiative of K. Schwab. Currently, the macro-region is understood in three senses - geopolitical, geographical and administrative. Geographically linked 'blocks', which are the basis of geoplanetary macro-regions, can be called meso-regions. The article considers six versions of the Caspian Sea mesoregionalization: "Transcaucasia", "Anatolia", SENTO, "Pre-Caspian", "Iranian-speaking Oikumene" and "Pyatimorye". It is stated that only the strategically grounded inertial "Anatolian mesoregion" scenario and the geographically grounded realistic "Pre-Caspian" scenario have a notable probability of implementation. Of these, only the second meets Russia's interests. The military, political and economic alliance between Russia and Iran could become the core of such a region. The Caspian Sea mesoregion is economically and logistically based on the meridional North- South transport corridor. It is shown that this corridor should be connected not only to the latitudinal routes, but also to the ring infrastructure, uniting the Transcaucasus in a single whole. hus, the transition from the necessary conditions for the formation of a mesoregion (geographical connectivity, broadly understood security, common interests) to sufficient conditions is carried out. These sufficient conditions include the transition from geographical connectivity to infrastructural and economic connectivity, the creation of a "ring economy" and a "ring identity". However, in addition to transport and economic connectivity and overall military and political security, the core of a mesoregion should also have a high level of social and socio-ethnic cohesion and a common goal setting, which would allow it to be stable against external cultural and semantic manipulation. In other words, one of the sufficient conditions for the existence of a mesoregion is the unity or, at least, the compatibility of the cultural codes of the ethnic groups comprising the region. The article gives a definition of the cultural code and a sketchy way of its calculation, briefly describes the cultural codes of the Caspian countries and draws a conclusion about their compatibility and the possibility of constructing a common cultural code of the region around the interaction of Russian and Persian/Iranian cultures. Such a cultural code can be transmitted through a geoplanetary educational canon.


1980 ◽  
Vol 17 (2) ◽  
pp. 423-431 ◽  
Author(s):  
Richard Serfozo

The cumulative amount of time that a regenerative or semi-stationary process exceeds a high level and other measures of these exceedances are considered as special cases of a non-decreasing stochastic process of partial sums. We present necessary and sufficient conditions for these exceedance processes to converge in distribution to Poisson processes or processes with stationary independent non-negative increments as the level goes to infinity. We apply our results to random walks, M/M/s queues, and thinnings of point processes.


2007 ◽  
Vol 44 (02) ◽  
pp. 492-505
Author(s):  
M. Molina ◽  
M. Mota ◽  
A. Ramos

We investigate the probabilistic evolution of a near-critical bisexual branching process with mating depending on the number of couples in the population. We determine sufficient conditions which guarantee either the almost sure extinction of such a process or its survival with positive probability. We also establish some limiting results concerning the sequences of couples, females, and males, suitably normalized. In particular, gamma, normal, and degenerate distributions are proved to be limit laws. The results also hold for bisexual Bienaymé–Galton–Watson processes, and can be adapted to other classes of near-critical bisexual branching processes.


1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.


1986 ◽  
Vol 23 (04) ◽  
pp. 1013-1018
Author(s):  
B. G. Quinn ◽  
H. L. MacGillivray

Sufficient conditions are presented for the limiting normality of sequences of discrete random variables possessing unimodal distributions. The conditions are applied to obtain normal approximations directly for the hypergeometric distribution and the stationary distribution of a special birth-death process.


Sign in / Sign up

Export Citation Format

Share Document