C. Srinivasa Murthy and K. Sridevi
In this paper, the authors present different methods for reconfigurable finite impulse response (RFIR) filter design. Distributed arithmetic (DA)-based reconfigurable FIR filter…
Abstract
Purpose
In this paper, the authors present different methods for reconfigurable finite impulse response (RFIR) filter design. Distributed arithmetic (DA)-based reconfigurable FIR filter design is suitable for software-defined radio (SDR) applications. The main contribution of reconfiguration is reuse of registers, multipliers, adders and to optimize various parameters such as area, power dissipation, speed, throughput, latency and hardware utilizations of flip-flops and slices. Therefore, effective design of building blocks will be optimized for RFIR filter with all the above parameters.
Design/methodology/approach
The modified, direct form register structure of FIR filter contributes the reuse concept and allows utilization of less number of registers and parallel computation operations. The disadvantage of DA and other conventional methods is delay increases proportionally with filter length. This is due to different partial products generated by adders. The usage of adder and multipliers in DA-FIR filter restricts the area and power dissipation because of their complexity of generation of sum and carry bits. The hardware implementation time of an adder can be reduced by parallel prefix adder (PPA) usage based on Ling equation. PPA uses shift-add multiplication, which is a repetitive process of addition, and this process is known as Bypass Zero feed multiplicand in direct multiplication, and the proposed technique optimizes area-power product efficiently. The modified DA (MDA)-based RFIR filter is designed for 64 taps filter length (N). The design is developed by using Verilog hardware description language and implemented on field-programmable gate array. Also, this design validates SDR channel equalizer.
Findings
Both RFIR and SDR are integrated as single system and implemented on Artix-7 development board of XC7A100tCSG324 and exploited the advantages in area-delay, power-speed products and energy efficiency. The theoretical and practical comparisons have been carried out, and the results are compared with existing DA-RFIR designs in terms of throughput, latency, area-delay, power-speed products and energy efficiency, which are improved by 14.5%, 23%, 6.5%, 34.2% and 21%, respectively.
Originality/value
The DA-based RFIR filter is validated using Chipscope Pro software tool on Artix-7 FPGA in Xilinx ISE design suite and compared constraint parameters with existing state-of-art results. It is also tested the filtering operation by applying the RFIR filter on Audio signals for removal of noisy signals and it is found that 95% of noise signals are filtered effectively.
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Y. Srinivasa Rao and M. Satyam
The effects of material parameters and processing conditions on the resistance drop by high voltage discharge in PVC – graphite thick film resistors are studied in this paper. The…
Abstract
The effects of material parameters and processing conditions on the resistance drop by high voltage discharge in PVC – graphite thick film resistors are studied in this paper. The resistance drop increased upon an increase in graphite aggregate size, which is a function of material parameters and processing conditions. The resistance drop has been attributed to the dielectrophoretic motion of graphite particles in PVC by the application of high voltages to polymer thick film resistors.
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Busi Rambabu and Y. Srinivasa Rao
The purpose of this paper is to study high-voltage interactions in polymer thick-film resistors, namely, polyvinyl chloride (PVC)-graphite thick-film resistors, and their…
Abstract
Purpose
The purpose of this paper is to study high-voltage interactions in polymer thick-film resistors, namely, polyvinyl chloride (PVC)-graphite thick-film resistors, and their applications in universal trimming of these resistors.
Design/methodology/approach
The authors applied high voltages in the form of pulses and impulses of various pulse durations and with different amplitudes to polymer thick-film resistors and observed the variation of resistance of these resistors with high voltages.
Findings
The paper finds that high voltages can be used for trimming of polymer thick-film resistors in both directions, i.e. upwards and downwards.
Research limitations/implications
The research implication of this paper is that polymer thick-film resistors can be trimmed downwards or upwards practically using this method.
Practical implications
The practical implications of this paper is that one can trim the polymer thick-film resistors, namely, PVC–graphite thick-film resistors, in both directions, i.e. upwards and downwards, by using this method.
Originality/value
The value of the paper is in showing that high voltages can be used to trim downwards and also upwards in the case of polymer thick-film resistors. This type of trimming is called universal trimming, developed first time for polymer thick-film resistors.
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K.S. Sujatha, A. Mani and S. Srinivasa Murthy
Develops a fine element method employing Galerkin’s approach for the analysis of a vertical tubular bubble absorber working with R22‐DMF as working fluid. Aims to provide an…
Abstract
Develops a fine element method employing Galerkin’s approach for the analysis of a vertical tubular bubble absorber working with R22‐DMF as working fluid. Aims to provide an understanding of the absorption process which helps in the design of bubble absorbers. Numerical experiments have also been carried out with ammonia‐water combination for the sake of comparison with the results in the literature and the agreement is found to be good. Suggests a correlation for mass transfer coefficient for vertical tubular bubble absorbers working with R22‐DMF. The use of the correlation can either be in estimating the mass transfer rates, or in fixing up the major design parameters such as diameter and length required for complete absorption.
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The paper aims to study the variation of electrical properties like electrical resistivity and current noise of a polymer thick film resistor, namely, PVC‐graphite thick film…
Abstract
Purpose
The paper aims to study the variation of electrical properties like electrical resistivity and current noise of a polymer thick film resistor, namely, PVC‐graphite thick film resistor, with parameters such as volume fraction, grain size, temperature and high voltage.
Design/methodology/approach
A model is proposed to explain the observed variations, which assumes that the texture of the polymer thick film resistor consists of insulator granules coated with conducting particles and also having cavities. The resistivity of these resistors is controlled mainly by the contact resistance between the conducting particles and the number of contacts each particle with its neighbors.
Findings
The variation of resistivity with temperature and high voltage is explained with the help of the model and it is attributed to the change in contact area and number of contacts. The current noise of these resistors is controlled mainly by the average relative resistance fluctuations between the conducting particles and the number of contacts each particle with its neighbors.
Originality/value
The variation of current noise with high voltage has also been explained with the help of this model and it is attributed to the change in number of conducting particles and conducting layers.
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Kandagaddla Venkatasubrahmanayam, Busi Ram Babu, Billa Poornaiah and Yarravarapu Srinivasa Rao
The purpose of this paper is to study the microwave interactions in polymer thick film resistors, namely, polyvinyl chloride (PVC)-graphite thick film resistors, and its…
Abstract
Purpose
The purpose of this paper is to study the microwave interactions in polymer thick film resistors, namely, polyvinyl chloride (PVC)-graphite thick film resistors, and its applications in trimming of these resistors.
Design/methodology/approach
We applied microwave radiation in the form of pulses of various pulse durations and with different powers to polymer thick film resistors and observed the variation of resistance of these resistors with microwave radiation.
Findings
The paper finds that microwave radiation can be used for trimming of polymer thick film resistors.
Research limitations/implications
The research implication of this paper is that polymer thick film resistors can be trimmed practically using this method.
Practical implications
The practical implication of this paper is that we can trim the polymer thick film resistors, namely, PVC-graphite thick film resistor, by using this method.
Originality/value
The value of the paper is in showing that microwave radiation can be used to trim downwards in the case of high-value resistors and trim upwards in the case of low-value resistors.
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Y. Srinivasa Rao and M. Satyam
The effect of high voltage pulses on the resistance of polymer thick film resistors (PTFR) is studied. It is found that the resistance decreases with both the amplitude and…
Abstract
The effect of high voltage pulses on the resistance of polymer thick film resistors (PTFR) is studied. It is found that the resistance decreases with both the amplitude and duration of the high voltage pulses and with the number of pulses. The change in resistance is attributed to the dielectrophoretic motion of graphite granules in the PVC medium when high voltage pulses are applied to PTFR. A model has been proposed through which the percentage change in resistance can be estimated in terms of the number of pulses, duration of pulses etc. Based on these investigations, we suggest a downward trimming method for PTFR through the application of high voltage pulses. This method of trimming is a clean process and trimmed resistors are free from hot spots.
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Michelle Funk, Natalie Drew and Martin Knapp
This paper, which builds on the findings of WHO's Report on Mental Health and Development, aims to highlight the health, social, economic, and human rights effects of unaddressed…
Abstract
Purpose
This paper, which builds on the findings of WHO's Report on Mental Health and Development, aims to highlight the health, social, economic, and human rights effects of unaddressed mental disorders in low and middle income countries (LMICs) and to propose effective strategies to address mental disorders and their impacts as part of an overall development strategy.
Design/methodology/approach
The paper first reviews the findings of relevant research on mental disorders and poverty and then proposes solutions that can be adopted by countries to promote development.
Findings
This evidence of strong links between poverty and mental disorder supports the argument that mental disorders should be an important concern for development strategies. Mental disorders have diverse and far‐reaching social impacts, including homelessness, higher rates of imprisonment, poor educational opportunities and outcomes, lack of employment and reduced income. Targeted poverty alleviation programmes are needed to break the cycle between mental illness and poverty. These must include measures specifically addressing the needs of people with mental health conditions, such as the provision of accessible and effective services and support, facilitation of education, employment opportunities and housing, and enforcement of human rights protection.
Originality/value
The paper highlights that four out of every five people suffering from mental disorders are living in LMICs. Many LMICs have identified mental health as an important issue, yet lack the finances and technical expertise to address the problem. Having mental health on the agenda of development organizations will be a critical step for overcoming the negative development consequences of mental disorders.
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Loganathan Appaia, Padmanaban Muthu Krishnan and Sankaran Kalaiselvi
– The purpose of this paper is the determination of reliability sampling plans in the Bayesian approach assuming that the lifetime distribution is exponential.
Abstract
Purpose
The purpose of this paper is the determination of reliability sampling plans in the Bayesian approach assuming that the lifetime distribution is exponential.
Design/methodology/approach
Sampling plans are used in manufacturing companies as a tool for carrying out sampling inspections, in order to make decisions about the disposition of many finished products. If the quality characteristic is considered as the lifetime of the products, the plan is known as a reliability sampling plan. In life testing, censoring schemes are adopted in order to save time and cost of life test. The inverted gamma distribution is employed as the natural conjugate prior to the average lifetime of the products. The sampling plans are developed assuming various probability distributions to the lifetime of the products.
Findings
The optimum plans n and c are obtained for some sets of values of (p1, a, p2, ß). The selection of sampling plans is illustrated through numerical examples.
Originality/value
Results obtained in this paper are original and the study has been done for the first time in this regard. Reliability sampling plans are essential for making decisions either to accept or reject based on the inspection of the sample.
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The purpose of this paper is to study the variation of the temperature coefficient of resistance (TCR) of polymer thick film resistors, namely, PVC‐graphite thick film resistors…
Abstract
Purpose
The purpose of this paper is to study the variation of the temperature coefficient of resistance (TCR) of polymer thick film resistors, namely, PVC‐graphite thick film resistors, with parameters such as volume fraction, grain size, and high voltage.
Design/methodology/approach
A model is proposed to explain the observed variations, which assumes that the texture of the thick film resistors consists of insulator granules coated with conducting particles.
Findings
The paper finds that the TCR of these materials is controlled mainly by the contact resistance fluctuations between the conducting particles and the number of contacts each particle has with it neighbours. The variation of TCR with high voltage has also been explained with the help of this model and it is attributed to the changes in contact area and the number of contacts.
Originality/value
The value of the paper is in showing that apparently the TCR of polymer thick film resistors can be controlled by the expansion properties of the insulating medium. The variation of TCR with high voltage is also due to change in number of contacts between the conducting particles. These types of material may find applications in thermal sensors or as temperature control elements.