A multi-layered Bayesian network model for structured document retrieval

New standards in document representation, like for example SGML, XML, and MPEG-7, compel Information Retrieval to design and implement models and tools to index, retrieve and present documents according to the given document structure. The paper presents the design of an Information Retrieval system for multimedia structured documents, like for example journal articles, e-books, and MPEG-7 videos. The system is based on Bayesian Networks, since this class of mathematical models enable to represent and quantify the relations between the structural components of the document. Some preliminary results on the system implementation are also presented

Anisotropic brane gravity with a confining potential

We consider an anisotropic brane world with Bianchi type I and V geometries where the mechanism of confining the matter on the brane is through the use of a confining potential. The resulting equations on the anisotropic brane are modified by an extra term that may be interpreted as the x-matter, providing a possible phenomenological explanation for the accelerated expansion of the universe. We obtain the general solution of the field equations in an exact parametric form for both Bianchi type I and V space-times. In the special case of a Bianchi type I the solutions of the field equations are obtained in an exact analytic form. Finally, we study the behavior of the observationally important parameters.Comment: 14 pages, 3 figures, to appear in PL

Chemical control of the leprosis mite Brevipalpus phoenicis (Geuskes, 1939) in citrus

A field test was carried out to evaluate the performance of several pesticides for the control of the citrus leprosis mite Brevipalpus phoenicis. The treatments were as follows: A) propargite (0.05; 72% EC) + sulphur (1,0; 75% CS); B) peropal (0.1 kg 25% MP); C) quinomethionate (0.05 kg 70% MP) (standard treatment); D) dicofol + tetradifon (0.2; (16% + 6%) EC; E) propargite (0.075; 72% EC); F) check. The quantities of the products employed in the experiment were based on the commercial formulations for 100 liters of water. Each orange-tree received a single application of ten liters of spray. Five mite evaluations were made: 4 days before spray and 16, 31, 45 and 60 days after the application. All treatments resulted in real pest reduction, higher than 80%, except for A (16 days after the spray) and for treatment C (60 days after the application).Com o objetivo de combater o ácaro Brevipalpus phoenicis (Geijskes), transmissor do vírus da leprose, foi estudada a eficiência de diferentes defensivos químicos. Os tratamentos foram seis, cada um com quatro repetições. A) propargite (0,05; CE 72%) + enxofre (1,0; SC 75%); B) peropal (0,1 kg PM 25%); C) quinometionato (0,05 kg PM 70%) (padrão); D) dicofol + tetradifom (0,2; CE 16% + 6%); E) propargite (0,075; CE 72%); F) testemunha. Cada laranjeira recebeu dez litros de calda numa única aplicação; usou-se o espalhante-adesivo "Extravon", à razão de 20 cm³/l00 litros de calda. Foram feitas cinco avaliações de infestações de ácaro: uma 4 dias antes da aplicação e outras após 16, 31, 45 e 60 dias da pulverização. Com exceção dos tratamentos propargite + enxofre (aos 16 dias) e quinometionato (aos 60 dias), todos os produtos apresentaram porcentagem de redução real da praga acima de 80% nas diferentes épocas de avaliação

Controle da cochonilha (Orthezia praelonga Douglas, 1891) em laranjeira, com inseticidas granulados

Com o objetivo de se avaliar a eficiência de inseticidas granulados no controle da Orthezia praelonga em laranjeiras, foram empregados o aldicarbe 15% e o imidaclopride 5%, aplicados ao solo. Os tratamentos foram seis, com quatro repetições: A) testemunha; B) aldicarbe, 100g/pl; C) aldicarbe, 65g/pl; D) imidaclopride, 100g/pl; E) aldicarbe, 130g/pl; F) imidaclopride, 75g/pl. Foram feitas seis avaliações: uma prévia e outras cinco após 07, 20, 34, 49 e 70 dias da aplicação. Os melhores tratamentos foram: aldicarbe 100g/pl e aldicarbe, 130g/pl, aos 49 e 70 dias, respectivamente.The experiment was carried out on adult orange-trees in the county of Limeira, SP, Brazil. The objective was to evaluate the efficiency of insecticide granules with 15% aldicarb and 5% imidadoprid, applied to the soil, to control the citrus coccid Orthezia praelonga Douglas, 1891. Treatments were six: A) check; B) aldicarb, 100g/pl; C) aldicarb, 65g/pl; D) imidacloprid 100g/pl; E) aldicarb, 130g/pl; F) imidacloprid, 75g/pl of commercial insecticide granules. Six evaluations were made, one previous and other five 07, 20, 34, 49 and 70 days after application. The most efficient treatments were E and B at 49 and 70 days, respectively

Single-phase five-level multilevel inverter based on a transistors six-pack module

This article introduces a single-phase five-level multilevel inverter based on six switches and two transformers. The proposed converter requires a single dc input source with low voltage. The disposition of switches makes it possible to build the converter with a transistors six-pack module off-the-shelves, traditionally used to build three-phase inverters, which simplifies the manufacturing process. The converter increases the voltage with two transformers; for that reason, it does not require an auxiliary step-up converter. The use of transformers (with the transformer’s turns ratio) allows for using the same topology for several input voltage levels. To verify the operation of the proposed multilevel inverter, a computer-based simulation was performed with PSIM, a software that considers parasitic components. The results show that the proposed converter can work properly

A geometric approach to time evolution operators of Lie quantum systems

Lie systems in Quantum Mechanics are studied from a geometric point of view. In particular, we develop methods to obtain time evolution operators of time-dependent Schrodinger equations of Lie type and we show how these methods explain certain ad hoc methods used in previous papers in order to obtain exact solutions. Finally, several instances of time-dependent quadratic Hamiltonian are solved.Comment: Accepted for publication in the International Journal of Theoretical Physic

Ownership and control in a competitive industry

We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control