Análise espectral de reflectarrays com substratos de duas camadas dielétricas anisotrópicas uniaxiais

Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters

Desenvolvimento de antenas de microfita com aberturas nos patches condutores através do método da segmentação

Microstrip antennas are widely used in modern telecommunication systems. This is particularly due to the great variety of geometries and because they are easily built and integrated to other high frequency devices and circuits. This work presents a study of the properties of the microstrip antenna with an aperture impressed in the conducting patch. Besides, the analysis is performed for isotropic and anisotropic dielectric substrates. The Multiport Network Model MNM is used in combination with the Segmentation Method and the Greens function technique in the analysis of the considered microstrip antenna geometries. The numerical analysis is performed by using the boundary value problem solution, by considering separately the impedance matrix of the structure segments. The analysis for the complete structure is implemented by choosing properly the number and location of the neighboor element ports. The numerial analysis is performed for the following antenna geometries: resonant cavity, microstrip rectangular patch antenna, and microstrip rectangular patch antenna with aperture. The analysis is firstly developed for microstrip antennas on isotropic substrates, and then extended to the case of microstrip antennas on anisotropic substrates by using a Mapping Method. The experimental work is described and related to the development of several prototypes of rectangular microstrip patch antennas wtih and without rectangular apertures. A good agreement was observed between the simulated and measured results. Thereafter, a good agreement was also observed between the results of this work and those shown in literature for microstrip antennas on isotropic substrates. Furthermore, results are proposed for rectangular microstrip patch antennas wtih rectangular apertures in the conducting patch

Análise espectral de reflectarrays com substrato de duas camadas dielétricas anisotrópicas uniaxiais

Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters

Métodos numéricos para resolução de equações diferenciais ordinárias lineares baseados em interpolação por spline

In this work we have elaborated a spline-based method of solution of inicial value problems involving ordinary differential equations, with emphasis on linear equations. The method can be seen as an alternative for the traditional solvers such as Runge-Kutta, and avoids root calculations in the linear time invariant case. The method is then applied on a central problem of control theory, namely, the step response problem for linear EDOs with possibly varying coefficients, where root calculations do not apply. We have implemented an efficient algorithm which uses exclusively matrix-vector operations. The working interval (till the settling time) was determined through a calculation of the least stable mode using a modified power method. Several variants of the method have been compared by simulation. For general linear problems with fine grid, the proposed method compares favorably with the Euler method. In the time invariant case, where the alternative is root calculation, we have indications that the proposed method is competitive for equations of sifficiently high order.

Geração de casos de teste a partir de especificações B

With the increasing complexity of software systems, there is also an increased concern about its faults. These faults can cause financial losses and even loss of life. Therefore, we propose in this paper the minimization of faults in software by using formally specified tests. The combination of testing and formal specifications is gaining strength in searches mainly through the MBT (Model-Based Testing). The development of software from formal specifications, when the whole process of refinement is done rigorously, ensures that what is specified in the application will be implemented. Thus, the implementation generated from these specifications would accurately depict what was specified. But not always the specification is refined to the level of implementation and code generation, and in these cases the tests generated from the specification tend to find fault. Additionally, the generation of so-called "invalid tests", ie tests that exercise the application scenarios that were not addressed in the specification, complements more significantly the formal development process. Therefore, this paper proposes a method for generating tests from B formal specifications. This method was structured in pseudo-code. The method is based on the systematization of the techniques of black box testing of boundary value analysis, equivalence partitioning, as well as the technique of orthogonal pairs. The method was applied to a B specification and B test machines that generate test cases independent of implementation language were generated. Aiming to validate the method, test cases were transformed manually in JUnit test cases and the application, created from the B specification and developed in Java, was tested. Faults were found with the execution of the JUnit test cases

Beta: uma ferramenta para geração de testes de unidade a partir de especificações B

Formal methods and software testing are tools to obtain and control software quality. When used together, they provide mechanisms for software specification, verification and error detection. Even though formal methods allow software to be mathematically verified, they are not enough to assure that a system is free of faults, thus, software testing techniques are necessary to complement the process of verification and validation of a system. Model Based Testing techniques allow tests to be generated from other software artifacts such as specifications and abstract models. Using formal specifications as basis for test creation, we can generate better quality tests, because these specifications are usually precise and free of ambiguity. Fernanda Souza (2009) proposed a method to define test cases from B Method specifications. This method used information from the machine s invariant and the operation s precondition to define positive and negative test cases for an operation, using equivalent class partitioning and boundary value analysis based techniques. However, the method proposed in 2009 was not automated and had conceptual deficiencies like, for instance, it did not fit in a well defined coverage criteria classification. We started our work with a case study that applied the method in an example of B specification from the industry. Based in this case study we ve obtained subsidies to improve it. In our work we evolved the proposed method, rewriting it and adding characteristics to make it compatible with a test classification used by the community. We also improved the method to support specifications structured in different components, to use information from the operation s behavior on the test case generation process and to use new coverage criterias. Besides, we have implemented a tool to automate the method and we have submitted it to more complex case studies

Unicidade e discretização para problemas de valor inicial

This paper has two objectives: (i) conducting a literature search on the criteria of uniqueness of solution for initial value problems of ordinary differential equations. (ii) a modification of the method of Euler that seems to be able to converge to a solution of the problem, if the solution is not unique

A teoria de Callista Roy, a nanda-i e o cuidado ao paciente prostatectomizado

Trata-se de um estudo descritivo de caso clínico, com abordagem qualitativa, o qual possui como objetivo estabelecer relações entre os diagnósticos de enfermagem da NANDA-I e os problemas de adaptação segundo o Modelo Teórico de Roy em um paciente prostatectomizado. A coleta de dados ocorreu em um hospital universitário localizado na cidade de Natal-RN, no mês de janeiro de 2011, por meio de um roteiro de entrevista e exame físico. Os diagnósticos que apresentaram relações entre a NANDA-I e o Modelo de Roy foram: dor, ansiedade, constipação, sono, atividade, volume de líquido e infecção. Conclui-se que grande parte dos problemas adaptativos segundo o Modelo de Roy, manifestados pelos pacientes no pós-operatório de prostatectomia, possuem semelhança com os diagnósticos da NANDA-I

Iniqüidade em saúde: uma extensão das desigualdades sociais no sistema público de saúde do Brasil (2003-2006)

This issue analises the unevenness in the brazilian system of public health care as an extension of socials inequities. It is a theoretical study based in a historical method, using empirical camp from academic, corporation and institution researchs, along the period 2002-2006. Equality and effectiveness in health systems are analitical basic cathegories grap in the root of the doctrine, principles and organization of the Unique Health System, in which sectorial actions are inserted. Discuss the estructural prodution and determined those inequalities through some social determiners of health system: income, land, food securitiy, nutritional situation, basic sanitation, epidemiological inequities and public management policy. Carry out a thematic review over health social production, it formlation and the goals of social policies, as well as the insertion of the equality principle in the assistance system, in the frame of the running public health regulations. It uses reflections that enlighted the correlation between the process of political-institutional actions and equity on health assistance. Analized the pertinency of sectorial reorganizational strategies on basic attendance, confronting the hipothesis that those strategies reinforce social inequities in health system, because it organize diferential assistance levels over not equal baselines. The results show up that social inequalities, even remaining, have had a small decrease; that the selectiviness of actual public policies and the duplication of the health system, increases the differences within and between the social classes and configures the assistance as inequal. The basic care system has great shortages that also appeares in middle and complex assistance levels. As conclusion, it remarks that the health assintance system, even with it integrality has limits; structural problems on material conditions of living and health system could not be reversed only with institutional legal arragements; by the contrary, in border conditions, these strategies produce policies that reinforce inequities, neglecting the equity principle of the system in which frame, they work. One patina of this tim

Representações sociais de discentes sobre universidade: um estudo psicossocial entre ingressantes do vestibular e da seleção ProUni

Demand for access to higher education to put in test the education Brazilian system in view of the surplus of selective processes of public universities, people without option to pay their studies at this education level. In this context, it has arisen the University for All(Universidade para Todos)Program, the ProUni, from Ministry of Education - MEC, created by the Federal Government in 2004, and that it aims the granting of full and partial scholarships in private higher education institutions, graduate courses in sequential specific training, low-income Brazilians students who do not have higher-level degree. Created by the Provisional Measure No 213/2004 and institutionalized by Law No. 11096 of January 13, 2005, the ProUni offers, however, the exemption of some taxes to those institutions that join the program. This is one of the privileged time for the study of Social Representations by offering the researcher, a living laboratory, natural environment, the confrontation between the established and new. In time like this people are challenged to incorporate the new system to the pre-existing one, aiming it through a strangeness of what was so familiar. It is through this game of social forces that we developed the present study with 196 entering higher education, of these are 116 of selective vestibular system and 80 of the ProUni selective system. We opt by the procedures for data collection in order to have access to the circulating senses, in addition to the streamlined responses. With foundation in Abric, we perform the test the Free Association of Words, then analysed by the software and by EVOC Content of the type theme as Bardin. Besides, we require of the subjects, a writing on the study object university later analysed by the software ALCESTE. The results point out to a representation strongly rooted in social factors such as more traditional socio-cultural elements: the beliefs, values, the symbols. It is unique in both groups of subjects: among those entering by the selective ProUni system, there was a stronger anchor in that it does not make inquiries about the program. At the same time, there is a stronger presence of objectivation, entering the selective vestibular system in order that they explained with a value judgement on the programme. It is suggested further studies considering the embryonic state of social representation, as recent as the social purpose that triggered. It would be relevant even the replication of the same research with other people in order to strengthen the power of the theorising of empiria available

A migração do cuidado em saúde: do hospital para o domicílio

This study is an analysis of opportunities and challenges of health assistance migration from hospitals to home care from the approach of the Domiciliary Internment Program (PID) in Natal / RN. The research aims to identify the ways that the multidisciplinary team act and know the stories of these professionals about the situation experienced in the transition between the instituting and instituted on home care modalities. PID has as a prior focus the elderly person in stable medical conditions, not to replace the hospital care, but to offer a therapeutic support turned to the exercise of their autonomy and coexistence with the situation of diseases. The home in their internal coexistence rules preserves own customs. As the hospital care migrates to the home care, it happens in the confrontation and rationality negotiation and becomes something new, that is going to be directed by an instituting dimension. In the view of New History, that suggests an interdisciplinary approach and interprets the problems on its time and from the technique of thematic oral history, it can be seen that working in interdisciplinary team is able to incorporate new values in the way of healthcare assistance, it longs for maintaining the maximum functional capacity of patients, it presents results as the prevention of diseases, costs reduction in connection with the Hospital Service, empowers and expands the possibilities for the patient recovery by aligning with the daily life and the opportunity of the patient being assisted by a multiprofessional team, interacting on the concrete reality. Therefore, PID is in line with the contemporary demands and as an instrument to be considered in the review of a wider concept of the health-disease process

Um estudo algorítmico de problemas logísticos na indústria de petróleo e gás natural

This work consists on the study of two important problems arising from the operations of petroleum and natural gas industries. The first problem the pipe dimensioning problem on constrained gas distribution networks consists in finding the least cost combination of diameters from a discrete set of commercially available ones for the pipes of a given gas network, such that it respects minimum pressure requirements at each demand node and upstream pipe conditions. On its turn, the second problem the piston pump unit routing problem comes from the need of defining the piston pump unit routes for visiting a number of non-emergent wells in on-shore fields, i.e., wells which don t have enough pressure to make the oil emerge to surface. The periodic version of this problem takes into account the wells re-filling equation to provide a more accurate planning in the long term. Besides the mathematical formulation of both problems, an exact algorithm and a taboo search were developed for the solution of the first problem and a theoretical limit and a ProtoGene transgenetic algorithm were developed for the solution of the second problem. The main concepts of the metaheuristics are presented along with the details of their application to the cited problems. The obtained results for both applications are promising when compared to theoretical limits and alternate solutions, either relative to the quality of the solutions or to associated running time

A teoria de Callista Roy, a nanda-i e o cuidado ao paciente prostatectomizado

Trata-se de um estudo descritivo de caso clínico, com abordagem qualitativa, o qual possui como objetivo estabelecer relações entre os diagnósticos de enfermagem da NANDA-I e os problemas de adaptação segundo o Modelo Teórico de Roy em um paciente prostatectomizado. A coleta de dados ocorreu em um hospital universitário localizado na cidade de Natal-RN, no mês de janeiro de 2011, por meio de um roteiro de entrevista e exame físico. Os diagnósticos que apresentaram relações entre a NANDA-I e o Modelo de Roy foram: dor, ansiedade, constipação, sono, atividade, volume de líquido e infecção. Conclui-se que grande parte dos problemas adaptativos segundo o Modelo de Roy, manifestados pelos pacientes no pós-operatório de prostatectomia, possuem semelhança com os diagnósticos da NANDA-I