540 research outputs found
Boundary element method application to numerical solving of linear boundary-value problems in domains with strongly segmented boundary
В настоящей работе метод граничных элементов был применен к решению краевых задач для уравнения Лапласа в плоской области с сильно сегментированной границей. Особое внимание было уделено точности численного решения, которая исследовалась путем численного эксперимента на специально подобранных тестовых задачах, имеющих аналитические решения в квадратурах. Было реализовано два алгоритма метода граничных элементов: традиционный с решением системы линейных алгебраических уравнений методами гауссовского исключения, и итерационный, при этом в итерационном алгоритме использовались функции Грина или их вычислительные аналоги. Результаты работы могут быть использованы при создании специализированного программного обеспечения соответствующего назначения.One of the most serious problems of modern numerical analysis is boundary-value problem solution in domains of complex geometrical shapes. Such problems are proved especially difficult for the domains with strongly segmented boundary, which meansthat the boundary is divided into isolated pieces. Such situations are specific for heterogeneous media. In such situations local approximation methods have to deal with the insuperable difficulties such as constructing computational grid and subsequent solving rather sophisticated systems of linear algebraic equations. The methods of global approximations and, first of all, methods of computational potential theory do not have similar difficulties, nevertheless they have to overcome a lot of problems. Boundary element method is applied in thepresent work to solve boundary-value problems for Laplace equations in plane domain with strongly segmented boundary. Special attention in the work was paid to accuracy of numerical solutions. The accuracy is investigated by a numerical experiment using specially selected test problems, which have the known analytical solutions in quadrature. Two boundary element algorithms are implemented. The first one is the traditional approach with Gauss elimination algorithm for solving linear algebraic equation system. The second one is an iterative approach with possible using of Green’s functions or their computational analogs in the iterative procedure. The results obtained in the work can be applied for creating specialized software of corresponding purposes
Firm Competition and Cooperation with Norm-Based Preferences for Sustainability
We analyze firms’ incentives to coordinate on the introduction of a sustainable
product variant when consumers’ preferences for sustainability
depend on the perceived social norm, which in turn is shaped by average
consumption behavior.We show that such preferences could lead to
multiple equilibria. If the level of competition among potential adopters
is very low and adoption of the sustainable variant allows them to sufficiently
expand their aggregate market share, they will coordinate on
introducing the sustainable variant when a lenient legal regime makes
this feasible. If competition among them is intense and market expansion
under the sustainable variant is very limited, coordination can forestall
the adoption of the sustainable variant. Our analysis thus both
confirms and qualifies the notion of a sustainability “first-mover disadvantage”
as a justification for an agreement between competitors, which
has gained traction in antitrust.We also provide empirical evidence for
norm-based sustainability preferences
Access regulation and the transition from copper to fiber networks in telecoms
In this paper we study the impact of different forms of access obligations on firms' incentives to migrate from the legacy copper network to ultra-fast broadband infrastructures. We analyze three different kinds of regulatory interventions: geographical regulation of access to copper networks-where access prices are differentiated depending on whether or not an alternative fiber network has been deployed; access obligations on fiber networks and its interplay with wholesale copper prices; and, finally, a mandatory switch-off of the legacy copper network-to foster the transition to the higher quality fiber networks. Trading-off the different static and dynamic goals, the paper provides guidelines and suggestions for policy makers' decision
A Soft Budget Constraint Explanation for the Venture Capital Cycle
We explore why venture capital funds limit the amount of capital they raise and do not reinvest the proceeds. This structure is puzzling because it leads to a succession of several funds financing each new venture which multiplies the well known agency problems. We argue that an inside investor cannot provide a hard budget constraint while a less well informed outsider can. Therefore, the venture capitalist delegates the continuation decision to the outsider by ex ante restricting the amount of capital he has under management. The soft budget constraint problem becomes the more important the higher the entrepreneur’s private benefits are and the higher the probability of failure of a project is
Private Infrastructure Finance and Investment in Europe
This study discusses the structure and development of private infrastructure finance in Europe in a global context. It examines the contribution of private capital to the financing of infrastructure investment needs. A 'big picture' is created by putting the various financing instruments and investment vehicles into a simple frame, i.e. percentages of GDP. There is scope for the development of alternative financing arrangements (such as public-private partnerships) and investment vehicles (such as project bonds and suitable investment funds). However, the traditional ways of corporate (and public) capital expenditure as well bank lending, need to keep working in Europe. Institutional investors can play a bigger role as a source of finance but expectations should be realistic. There are a number of barriers in place, regulatory and otherwise, that need to be worked on
How Strong Buyers Spur Upstream Innovation
We challenge the view that the presence of powerful buyers stifles suppliers´ incentives to innovate. Following Katz (1987), we model buyer power as buyers´ ability to substitute away from a given supplier and isolate several effects that support the opposite view, namely that the presence of powerful buyers induces a supplier to invest more in cost reduction. In contrast in negotiations with smaller buyers, the outcome of negotiations with large buyers is fully determined by their more valuable alternative supply option. This increases the supplier´s incentives to reduce marginal costs, both as the supplier receives a larger fraction of the thereby generated incremental profits and as this makes buyers´ alternative supply option less valuable. The latter effect is due to downstraem competition between buyers and, as we show, is also stronger the larger and thus the more powerful buyers are
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