998 resultados para design and build


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An important problem in designing RFIC in CMOS technology is the parasitic elements of passive and active devices that complicate design calculations. This article presents three LNA topologies including cascode, folded cascade, and differential cascode and then introduces image rejection filters for low-side and high-side injection. Then, a new method for design and optimization of the circuits based on a Pareto-based multiobjective genetic algorithm is proposed. A set of optimum device values and dimensions that best match design specifications are obtained. The optimization method is layout aware, parasitic aware, and simulation based. Circuit simulations are carried out based on TSMC 0.18 um CMOS technology by using Hspice.

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A central obstacle to the design of a global HIV vaccine is viral diversity. Antigenic differences in envelope proteins result in distinct HIV serotypes, operationally defined such that antibodies raised against envelope molecules from one serotype will not bind envelope molecules from a different serotype. The existence of serotypes has presented a similar challenge to vaccine development against other pathogens. In such cases, antigenic diversity has been addressed by vaccine design. For example, the poliovirus vaccine includes three serotypes of poliovirus, and Pneumovax® presents a cocktail of 23 pneumococcal variants to the immune system. It is likely that a successful vaccine for HIV must also comprise a cocktail of antigens. Here, data relevant to the development of cocktail vaccines, designed to harness diverse, envelope-specific Bcell and T-cell responses, are reviewed.

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Information technology has become the core tool of business organisations’. External and internal threats as well as legal, regulatory and contractual compliance requirements are all combining to make effective information security a key information technology management challenges. This paper describes an undergraduate information technology security management course that provides comprehensive knowledge and skills necessary to manage both strategic and operational aspects of information security. The course covers a broad range of managerial topics in information technology security and makes use of a number of security tools and techniques to complement the theory taught. In this paper, we describe our approach, our experiences and lessons learned for teaching information technology security management course. The paper details the content of the course and outlines how it is taught and assessed.

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This paper reports on three approaches to the translation of Gaussian surface models into scaled physical prototype models. Using the geometry of Eladio Dieste's Gaussian Vaults, the paper reports on the aspects encountered in the process of digital to physical prototype fabrication. The primary focus of the paper is on exploring the design geometry, investigating methods for preparing the geometry for fabrication and constructing physical prototypes. Three different approaches in the translation from digital to physical models are investigated: rapid prototyping, two dimensional surface models in paper and structural component models using Computer Numerical Controlled (CNC) fabrication. The three approaches identify a body of knowledge in the design and prototyping of Gaussian vaults. Finally the paper discusses the digital to. fabrication translation processes with regards to the characteristics, benefits and limitations of the three approaches of prototyping the ruled surface geometry of Gaussian Vaults.

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This paper presents design of an electrostatic wide band shunt capacitive coupling RF MEMS switch with low actuation voltage. The key factors of the RF MEMS switch design are the proper scattering parameters, low actuation voltage, and the cost of the fabrication process. An overview of the recent low actuation voltage RFMEMS switches has been presented. These designs still suffer from the complexity of process, lack of reliability, limitation of frequency band, and process cost. RF characteristics of a shunt RF MEMS switches are specified mostly by coupling capacitor in upstate position of the membrane Cu. This capacitor is in trade-off with actuation voltage. In this work, the capacitor is eliminated by using two short high impedance transmission lines, at the input and output of the switch. The simulation results demonstrate an improvement in the RF characteristic of the switch.

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This paper presents a new architecture for a high quality tunable MEMS filter that can be used in wireless biomedical signal transceivers. It consists of a π match circuit with two shunt capacitive coupling switches separated by a piece of high impedance short transmission line, and also a series switch placed at the quarter wavelength distance away from the π match circuit. The low actuation voltage and also tunability are important features of the design objective. All portions of the filter can be realized simultaneously. Thus, the filter docs not require any extra steps during its fabrication, and is not costly. The simulation results confirm the good performance of the filter.

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RF MEMS plays an important role in microwave switching. The high performance of RF MEMS shunt such as high bandwidth, low insertion loss, and high isolation have made these switches well suitable for high performing microwave and millimeter wave circuits. This paper presents a RF MEMS shunt capacitive switch for Ka and V band application. This paper investigates the effect of various geometrical parameters on RF characteristics of the switch. The simulation results are presented and discussed.

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This paper presents design, construction, and evaluation of a micropump for drug delivery applications. The proposed micropump consists of three components: fluidics, electronics, and software. The fluidics component includes a silicone elastic diaphragm, a microservo, housing and two check valves. The diaphragm is modeled and simulated to establish its geometrical specifications. The housing is built using a rapid prototype machine. The electronics component consists of a microcontroller, a microswitch array, a simple display and a power unit. The software component is written in C and receives inputs from user, controls the microservo speed and displays the programmed speed. A number of experiments are conducted to evaluate the performance and capabilities of the micropump. The experiments focus on measurement of flow rate, dosage and duration of operation. A discussion of the performance and capabilities of the developed micropump is also given.

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Background
There is an urgent need for more carefully developed public health measures in order to curb the obesity epidemic among youth. The overall aim of the "EuropeaN Energy balance Research to prevent excessive weight Gain among Youth" (ENERGY)-project is the development and formative evaluation of a theory-informed and evidence-based multi-component school-based and family-involved intervention program ready to be implemented and evaluated for effectiveness across Europe. This program aims at promoting the adoption or continuation of health behaviors that contribute to a healthy energy balance among school-aged children. Earlier studies have indicated that school and family environments are key determinants of energy-balance behaviors in schoolchildren. Schools are an important setting for health promotion in this age group, but school-based interventions mostly fail to target and involve the family environment.

Methods

Led by a multidisciplinary team of researchers from eleven European countries and supported by a team of Australian experts, the ENERGY-project is informed by the Environmental Research Framework for Weight gain Prevention, and comprises a comprehensive epidemiological analysis including 1) systematic reviews of the literature, 2) secondary analyses of existing data, 3) focus group research, and 4) a cross European school-based survey.

Results and discussion
The theoretical framework and the epidemiological analysis will subsequently inform stepwise intervention development targeting the most relevant energy balance-related behaviors and their personal, family-environmental and school-environmental determinants applying the Intervention Mapping protocol. The intervention scheme will undergo formative and pilot evaluation in five countries. The results of ENERGY will be disseminated among key stakeholders including researchers, policy makers and the general population.

Conclusions
The ENERGY-project is an international, multidisciplinary effort to develop and test an evidence-based and theory-informed intervention program for obesity prevention among school-aged children.

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In this paper, we introduce a single-walled boron nitride nanotube (SWBNNT)-based cantilever biosensor, and investigate its bending deformation. The BNNT-based cantilever is modelled by accounting that the surface of the cantilever beam is coated with the antibody molecule. We have considered two main approaches for the mechanical deformation of the BNNT beam. The first one is differential surface stress produced by the binding of biomolecules onto its surface, and the second one is the charge released from the biomolecular interaction. In addition, other parameters including length of beam, variation of beam’s location and chiralities of the BNNT have been taken into consideration to design the cantilever biosensor. The computed results are in good agreement with the well known electrostatic equations that govern the deformation of the cantilever.