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Dengue infection is nowadays considered a re-emergent disease. It has a worldwide tropical and subtropical distribution. The dengue virus in a member of the flavivirus family composed by 4 different serotypes. The virus is transmitted by mosquitos of the Aedes genus. With the increment of travels to the endemic areas, dengue is now observed frequently in our country. We analyzed 57 patients, 30 with imported dengue (ID) and 27 with dengue fever suffered during the trip (DDT). This series is compared with other published ones and a review of the subject is presented. Patients with ID followed a protocol as a febril syndrome returning from the tropics. Dengue was diagnosed through a compatible clinico-epidemiological history, the absence of other ferbil illness and positivity of specific serology. All patients had travelled to endemic areas (Central America 28 cases, Indian subcontinent 15, South-East Asia 10, South America 2, West Africa one, and Pacific one). The following were the most important clinical characteristics: fever and asthenia (100%), headache (98%), mialgia (84%), arthralgia (72%), morbilliform rash (61%) and retroocular pain (65%). For ID cases, the most helpful analitical results were: leucopenia (70%), reactive lymphocytes in peripheral blood smear (70%), thrombocytopenia (70%), and increased hepatic enzymes ALAT (53%), ASAT (63%) and LDH (100% in the 7 patients tested for this enzyme). Dengue must be included in differential diagnosis of fever in patients coming back to travels to tropical areas.  相似文献   
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Currently, vertical partitioning has been used in multimedia databases in order to take advantage of its potential benefits in query optimization. Nevertheless, most vertical partitioning algorithms are static; this means that they optimize a vertical partitioning scheme (VPS) according to a workload, but if this workload suffers changes, the VPS may be degraded, which would result in long query response time. This paper presents a set of active rules to perform dynamic vertical partitioning in multimedia databases. First of all, these rules collect all the information that a vertical partitioning algorithm needs as input. Then, they evaluate this information in order to know if the database has experienced enough changes to trigger a performance evaluator. In this case, if the performance of the database falls below a threshold previously calculated by the rules, the vertical partitioning algorithm is triggered, which gets a new VPS. Finally, the rules materialize the new VPS. Our active rule base is implemented in the system DYMOND, which is an active rule-based system for dynamic vertical partitioning of multimedia databases. DYMOND’s architecture and workflow are presented in this paper. Moreover, a case study is used to clarify and evaluate the functionality of our active rule base. Additionally, authors of this paper performed a qualitative evaluation with the aim of comparing and evaluating DYMOND’s functionality. The results showed that DYMOND improved query performance in multimedia databases.  相似文献   
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Mexico has a free trade agreement with the United States of America (USA) and Canada which was signed in 1988. This agreement created the conditions for establishing many foreign companies in several Mexican cities along the border zone between Mexico and USA. This strategy takes advantage of the geographic proximity with one of the biggest markets in the world, qualified manpower, and low production cost. With the arrival of those companies, frequently called Maquiladoras, a lot of production approaches have been introduced, and one of those widely applied is the just-in-time (JIT) production strategy. Despite the benefits of JIT, the interrelationship among several industrial factors and their impact on results derived from the implementation of JIT are unknown in Mexico. This is the underlying reason of this article, which aims at illustrating the results of a survey applied to foreign companies established in the Mexican–USA border. On the one hand, the activities developed by these companies during the implementation process of JIT are investigated and grouped as latent independent variables. These variables include organizational commitment, communication channels in organization, empowerment granted to employees, education provided in different organizational levels, and the capacity to solve problems, among others. On the other hand, the obtained benefits investigated are grouped as latent dependent variables. These dependent variables involve inventory management, quality, and cost, among others. Those aspects in the activities and benefits of the companies were evaluated using the structural equations model (SEM), which is useful to identify and analyze causal relationships. Result obtained from SEM indicates that management commitment and education are the main critical success factors in the JIT implementation, and that success can be measured through inventory, quality, and cost performance indicators.  相似文献   
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The evaluation of a medical diagnosis system can depend on several external parameters, such as experts’ opinions/criteria or the gold standard used. In addition, there are other parameters that can be measured in a medical diagnosis system, and one of these parameters in particular is the sensitivity. Sensitivity allows knowing how sensible a system is to produce results in different environments. Hence, the aim of this paper is to provide researchers with an index able to estimate a parameter very similar to common sensitivity. This would permit to know an estimation of the results relying on the modeling of the knowledge base. It would be the mathematical justification of this index that would allow estimating the aforementioned parameter. Therefore, the index would in general allow an estimation of the sensitivity without the necessity of having external feedback from experts in the field, which is one of the main lacks within the classical sensitivity metric.  相似文献   
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A simple numerical method of multidimensional minimisation is applied in order to find the equilibrium configuration of N point charges confined to a given volume or surface. The method is applied to different geometric forms with both Coulomb and nonharmonic interacting potentials. The technique presented in this paper is very useful from a didactic point of view, as it allows the approximate configuration of charges on conductors to be visualised and stresses the importance of the inverse square law for the charge distribution. For this purpose, different three-dimensional and two-dimensional examples are presented  相似文献   
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Wireless Networks - This paper reports a structural equation model to relate three critical success factors for total quality management (TQM) (i.e. managerial commitment, role of quality...  相似文献   
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An Abaqus implementation of the extended finite element method   总被引:1,自引:0,他引:1  
In this paper, we introduce an implementation of the extended finite element method for fracture problems within the finite element software ABAQUSTM. User subroutine (UEL) in Abaqus is used to enable the incorporation of extended finite element capabilities. We provide details on the data input format together with the proposed user element subroutine, which constitutes the core of the finite element analysis; however, pre-processing tools that are necessary for an X-FEM implementation, but not directly related to Abaqus, are not provided. In addition to problems in linear elastic fracture mechanics, non-linear frictional contact analyses are also realized. Several numerical examples in fracture mechanics are presented to demonstrate the benefits of the proposed implementation.  相似文献   
40.
The design of a CMOS clamped‐clamped beam resonator along with a full custom integrated differential amplifier, monolithically fabricated with a commercial 0.35 μm CMOS technology, is presented. The implemented amplifier, which minimizes the negative effect of the parasitic capacitance, enhances the electrical MEMS characterization, obtaining a 48 × 108 resonant frequency‐quality factor product (Q×fres) in air conditions, which is quite competitive in comparison with existing CMOS‐MEMS resonators.  相似文献   
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