Deterministic Consistency: A Programming Model for Shared Memory Parallelism

The difficulty of developing reliable parallel software is generating interest in deterministic environments, where a given program and input can yield only one possible result. Languages or type systems can enforce determinism in new code, and runtime systems can impose synthetic schedules on legacy parallel code. To parallelize existing serial code, however, we would like a programming model that is naturally deterministic without language restrictions or artificial scheduling. We propose "deterministic consistency", a parallel programming model as easy to understand as the "parallel assignment" construct in sequential languages such as Perl and JavaScript, where concurrent threads always read their inputs before writing shared outputs. DC supports common data- and task-parallel synchronization abstractions such as fork/join and barriers, as well as non-hierarchical structures such as producer/consumer pipelines and futures. A preliminary prototype suggests that software-only implementations of DC can run applications written for popular parallel environments such as OpenMP with low (<10%) overhead for some applications.Comment: 7 pages, 3 figure

Financial structure and the transmission of monetary shocks: preliminary evidence for the Czech Republic, Hungary and Poland

The paper analyses the financial structure of the private sector in the Czech Republic, Hungary and Poland and assesses its implications for the monetary transmission mechanism. The financial accounts of these countries provide a picture of a private sector which is predictably financially less mature than the EU average: the corporate sector relies significantly on non-market financial liabilities (such as trade credits and non-traded shares) and bears a substantial exchange rate risk; the household sector is less sophisticated both in terms of financial assets, whose composition is tilted towards bank deposits, and liabilities, the volume of which is still negligible. VAR system estimates conducted separately on each acceding country suggest that, despite the inferior financial development of these countries, the co-movement of macroeconomic variables conditional on a monetary policy shock is similar across countries and not dissimilar to what is found in the more advanced economies.Financial structure, identified VAR, monetary policy shock, price puzzle.

Applying Multi-Hour Traffic Assignment to Estimate Trips Distribution between Hours and the Intrinsic Value of Hour of the Day

Recent analysis regarding the patterns and composition of trips in morning peak hour revealed that an increasing part of these trips correspond to non-work related trips. In general, these trips are not specifically associated with morning peak. Other studies show that price elasticity of leisure trips is considerably higher than that of commuting and business trips. According to Wardrop's first principle, if the transportation network maintains equilibrium, then no user could improve his situation by selecting alternative travel route. Expanding on that principle, the fact that non-work related trips (such as shopping, family visits, tourism) take place in the morning peak hour, under congestion conditions, means that the specific hour, not only the duration of time and trip purpose, is important to the user. Hence, each hour of the day has its own intrinsic value, named "Intrinsic Hourly Value” (IHV). In order to estimate this value, calibration of a multi-hour equilibrium assignment is suggested to determine the magnitude and characteristics of the IHV. Several hypotheses have been tested with regard to the IHV. For example, significant positive values were estimated for morning IHV. The methodology was applied using the demand and data from the Haifa Metropolitan Area. Commonly used models were employed for the multi-hour traffic assignment. Consequently, a clear methodology to estimate the IHV is presented. The results can assist public authorities to decide on policies such as activities time rescheduling or the application of congestion tolls

Vibrating Superconducting Island in a Josephson Junction

We consider a combined nanomechanical-supercondcuting device that allows the Cooper pair tunneling to interfere with the mechanical motion of the middle superconducting island. Coupling of mechanical oscillations of a superconducting island between two superconducting leads to the electronic tunneling generate a supercurrent which is modulated by the oscillatory motion of the island. This coupling produces alternating finite and vanishing supercurrent as function of the superconducting phases. Current peaks are sensitive to the superconducting phase shifts relative to each other. The proposed device may be used to study the nanoelectromechanical coupling in case of superconducting electronics.Comment: 4 pages, 3 figures, to appear in Phys. Rev. Let

Le rythme, pratique du ravissement ; la poésie, pontifex

L'intérêt de la théorie récente pour le rythme peut répondre à la perte du « réel » dans le constructionnisme radical postmoderne. Mais Kristeva et Meschonnic, en redéfinissant le rythme en le liant à la subjectivité et au discours, répètent la perte du corps et la perte moderne de la spécificité de la poésie par rapport à la prose. En retenant le sens traditionnel, musical, du « rythme », nous retrouvons le rythme dans la poésie comme dans la politique. Le rythme est cet élément du langage sans signifiance. Il crée une communauté en effaçant le sens institué, la subjectivité individuelle, les hiérarchies et les préjugés. Une lecture d'un poème de Wallace Stevens montre que la poésie « fait un pont » (pontifex) entre le sens et le rythme, si on la lit comme une allégorie du pouvoir extatique du rythme, donc de l'effort vain du langage à représenter sa source rythmique.A focus on rhythm in recent theory may respond to the loss of the "real" in postmodern, radical constructionism. But Kristeva and Meschonnic, redefining; rhythm by connecting it to, subjectivity and discourse, repeat the loss of the real body and the modernist loss of poetry's difference from prose. Rather, keeping the traditional, musical meaning of "rhythm", we can rediscover rhythm both in poetry and in political life. Rhythm is the nonmeaning element in language, creating a community while effacing normal meaning, individual subjectivity, hierarchies, and prejudice. Poetry "bridges" (as pontifex) the gap between meaning and rhythm, if it is read as an allegory for ecstatic power of rhythm, and thus of the impossible effort of language to represent its rhythmic source as exemplified in a reading of a Wallace Stevens lyric