Experimental constraints on fluid-rock reactions during incipient serpentinization of harzburgite
Klein, Frieder
2014-10-20
Search results
1,869 records were found.
Our goal in this paper is to study the problem of the interaction among databases in a peer-to-peer (P2P) network. We propose a new approach, that we call “data (base) coordination”, that rejects the assumption, made for instance in data integration, that the involved databases act as if they were a single (virtual) database, modeled as a global schema. From an operational point of view, the distinguishing feature of data coordination is that many of the parameters (metadata) influencing the interaction among peer databases are decided at run time. For any given query, the involved databases interact using the most “appropriate” (virtual) schema. This is crucial for dealing with the strong dynamics of a P2P network. We provide four basic architectural notions and hint how they are the building blocks of a possible distributed implement...
Rassegna bibliografica di studi dedicati al fenomeno della delinquenza minorile, secondo diversi tagli (criminologico, sociologico, psicologico)
A general equilibrium model is proposed which assumes that firms hire both official and unregistered workers as imperfect substitutes, that entrepreneurs differ in their ability to increase the efficiency of official labour, and that this ability is due to heterogeneous original ability and to Marshallian (non-linear) externalities. In equilibrium, smaller firms hire fewer official workers and are less efficient. If externalities increase sufficiently when firms are numerous, two stable equilibria exist where the number and the size of firms, the proportion of official employment, overall output and efficiency are, respectively, small (the trap) and large. The increase of individual ability due to, e.g., educational policies, has positive effects on the equilibrium number of firms, overall output, and labour regularisation. High and ev...
Multi- and hyper-spectral data pose severe problems in terms of storage capacity and transmission bandwidth. Although recommendable, compression techniques require efficient approaches to guarantee an adequate fidelity level. In particular, depending on the final destination of the data, it could be necessary to maximize several parameters, as for instance the visual quality of the rendered data, the correctness of their interpretation, or the performance of their classification. Based on the idea of Spectral Vector Quantization, the approach proposed in this paper aims at combining a compression and a classification methodology into a single scheme, in which visual distortion and classification accuracy can be balanced a- priori according to the requirements of the target application. Experimental results demonstrate that the proposed...
We use a propositional language of qualitative rectangle relations to detect the reading order from document images. To this end, we define the notion of a document encoding rule and we analyze possible formalisms to express document encoding rules such as LATEX and SGML. Document encoding rules expressed in the propositional language of rectangles are used to build a reading order detector for document images. In order to achieve robustness and avoid brittleness when applying the system to real life document images, the notion of a thick boundary interpretation for a qualitative relation is introduced. The framework is tested on a collection of heterogeneous document images showing recall rates up to 89%.
We motivate special database problems introduced by peer-to-peer computing and propose the Local Relational Model (LRM) to solve some of them. As well, we summarize a formalization of LRM, present an architecture for a prototype implementation, and discuss open research questions.
A simple graph is P_4-indifferent if it admits a total order < on its nodes such that every chordless path with nodes a,b,c,d and edges ab,bc,cd has ab>c>d. P_4-indifferent graphs generalize indifferent graphs and are perfectly orderable. Recently, Hoang, Maffray and Noy gave a characterization of P_4-indifferent graphs in terms of forbidden induced subgraphs. We clarify their proof and describe a linear time algorithm to recognize P_4-indifferent graphs. When the input is a P_4-indifferent graph, then the algorithm computes an order < as above.
Our thesis is that an agent1 is autonomous only if he is capable, within a non predictable environment, to balance two forms of rationality: one that, given goals and preferences, enables him to select the best course of action (means-ends), the other, given current achievements and capabilities, enables him to adapt preferences and future goals. We will propose the basic elements of an economic model that should explain how and why this balance is achieved: in particular we underline that an agent’s capabilities can often be considered as partially sunk investments. This leads an agent, while choosing, to consider not just the value generated by the achievement of a goal, but also the lost value generated by the non use of existing capabilities.We will propose that, under particular conditions, an agent, in order to be rational, could...
A wide band voltage to current converter capable of compensating for parasitic impedances is presented. The circuit is analyzed and the transfer function is calculated and optimized. Output impedance calculation and noise analysis are also given for the best choice of circuit parameters. An application example is proposed and analyzed, full SPICE simulations and a breadboard proof of concept circuit are employed to exemplify the validity of the technique.
Mader proved that every loopless undirected graph contains a pair (u,v) of nodes such that the star of v is a minimum cut separating u and v. Nagamochi and Ibaraki showed that the last two nodes of a "max-back order" form such a pair and used this fact to develop an elegant min-cut algorithm. M. Queyranne extended this approach to minimize symmetric submodular functions. With the help of a short and simple proof, here we show that the same algorithm works for an even more general class of set functions.
