A Graph Model for Imperative Computation

Scott's graph model is a lambda-algebra based on the observation that continuous endofunctions on the lattice of sets of natural numbers can be represented via their graphs. A graph is a relation mapping finite sets of input values to output values. We consider a similar model based on relations whose input values are finite sequences rather than sets. This alteration means that we are taking into account the order in which observations are made. This new notion of graph gives rise to a model of affine lambda-calculus that admits an interpretation of imperative constructs including variable assignment, dereferencing and allocation. Extending this untyped model, we construct a category that provides a model of typed higher-order imperative computation with an affine type system. An appropriate language of this kind is Reynolds's Syntactic Control of Interference. Our model turns out to be fully abstract for this language. At a concrete level, it is the same as Reddy's object spaces model, which was the first "state-free" model of a higher-order imperative programming language and an important precursor of games models. The graph model can therefore be seen as a universal domain for Reddy's model

BER degradation of MC-CDMA at high SNR with MMSE equalization and residual frequency offset

Multicarrier Code Division Multiple Access (MC-CDMA) is an attractive technique for high speed wireless data transmission in view of its advantages over orthogonal frequency division multiplexing. In this paper, we analyze the performance of fully loaded downlink MC-CDMA systems with minimum mean square error (MMSE) equalizer in the presence of residual frequency offset (RFO) in multipath Rayleigh fading channels. We first show that as the SNR is increased beyond a value, referred as threshold SNR, the performance degrades. We then analyze the cause for this behavior and propose a remedy to prevent the degradation by regularizing the coefficient(s) of the equalizer, and use the regularized equalizer for SNRs beyond the threshold value. We suggest two methods for estimating this SNR, one gives close to the true value but requires the knowledge of RFO and the channel state information (CSI), while the other gives an approximate value but requires only CSI. We show that the regularization based on the approximate value also prevents the degradation, but the performance at higher SNRs is slightly poorer compared to that with the better estimate. Numerical and simulation results are provided to support the analysis

Seismic Analysis And Design Of Rc Skeleton Framework

Using time date analysis, evaluation of the framework response is subject to earthquakes of high, low and medium content. There are three types of violations such as group violations, rigid violations, and vertical engineering violations. According to our observations, the ground shear strength has been found to be the maximum for the first floor and in all cases is lower than the upper floor. Collective irregular structures have been observed to experiment with larger base shears than normal structures. The rigid structural structure saw scissors with a low base and had large barriers between the floors. The complete displacement obtained from the analysis of the chronological history of the irregular structure in the relevant nodes was found to be greater in the case of normal structures of the upper stories, but gradually as we transformed the structure of the lower layers into lower structures. Reduced rigidity increases the high dispersion of stories in the event of a large irregular structure, time history analysis provides slightly higher displacements of stories higher than normal structures, while when we reduce the following stories, regular structures are compared to the height of structures. When the history of time was analyzed in search of rigidly structured and structured structures, he found that higher story displacements were not completely different from each other, but we moved on to the following stories, in the case of light warehouses. Displacement was higher in comparison

Perceptions of Educators of Reading Literacy; A Case Study of the Intermediate Phase in South African Primary Schools

The achievement of worldwide participation in education is essentially determined by the quality of education available. How well learners are instructed and how much they learn determines how regularly learners attend schools. Sound education is further affected by the following factors: time spent learning by learners, assessment methods for monitoring learner progress, styles of teaching, education spending, the language of instruction, and classroom organisation strategies (EFA Global Monitoring Report, 2005). However, the development of learners’ literacy in South Africa as a developing country is accentuated by several challenges. Many learners in South Africa have difficulty understanding the language in which they are taught which is English, as they are not taught in their mother tongue. However, the language of instruction is not solely responsible for the poor performance in international reading tests and schooling in general. Learners are also faced with socio-economic issues, very little or hardly any parental supervision and educators are faced with the challenge of finding reading methods and strategies suitable to improving reading. Learners in the foundation phase are explicitly taught reading skills. In the intermediate phase, learners are expected to apply the skills acquired in the foundation phase to access the curriculum. In reality, this is difficult to achieve. The purpose of this article is to determine educator perceptions of reading literacy in the intermediate phase with the aim of enhancing reading literacy in the intermediate phase

Flotation of Low Grade Copper ore from Kallur, Raichur District, Karnataka

Copper, an important non-ferrous metal, is in great demand in India, resulting in a continuous important of large quantities. The total copper ore reserves in India(Raghunandan et. al.1981) have been estimated to be 497 million tons of which an average of 2 million tons are being processed at present. In this c ontext the deve-lopment and exploitation of new reserves assumes impor-tance in order to meet the increasing demand from inter-nal production rather than through imports of the metal. Out of 19.4 million tons of reserves of the ore in Kar-nataka, 4.5 million tons are at present commercially exploited at Ingaldhal and Kalyadi. New ore reserves have been found at Tintini, Kailur, Machanur and Aladahalli and exploratory drilling for copper in these areas have been started by the Department of Mines and Geology. In this paper a detailed account of the beneficiation studies carried out on the low grade copper ore from Kallur, Raichur District, Karnataka are described for possible commercial exploitation in future

FORMULATION AND EVALUATION OF CHITOSAN NANOPARTICLES FOR IMPROVED EFFICACY OF ITRACONAZOLE ANTIFUNGAL DRUG

Objective: The main objective of the study was to formulate and evaluate the chitosan nanoparticles to improve the therapeutic efficacy of itraconazole by loading in nanoparticle drug delivery system. Designing the formulation of the drug itraconazole prolongs the therapeutic concentration of the drug in the blood and which will lower the frequency of dosing and also improves the efficacy of the drug. Methods: Itraconazole nanoparticles are prepared by ionic gelation method; here, chitosan is used as polymer. The formulated nanoparticles are evaluated for external morphological studies by scanning electron microscope (SEM), drug content, in vitro drug release studies, as well as infrared (IR) spectral analysis. Results: The Fourier transform IR spectra show that there was no interaction between drug and polymers; hence, they are compatible. Percentage entrapment efficiency, drug content, and percentage yield were higher for F3 formulation. The particle size analysis shows that every particle in the formulations gave the range of 148–227 nm, respectively; increasing in the particle size observed with varying concentration of polymer. SEM analysis of the nanoparticles shows that all the formulations were spherical and smooth with ideal surface morphology. As the concentration of polymer, the drug release decreased proportionally. The stability studies were carried out on the optimized formulation for 2 months at 30±2°C and 60±5% RH and 40±2°C and 75±5% RH; finally, it was observed that there was no change in drug content and in vitro drug release profile even after storage at 30±2°C and 60±5% RH and 40±2°C and 75±5% RH for 2 months. Conclusion: Itraconazole is one among the most widely used antifungal drugs. Designing the formulation of drug itraconazole prolongs therapeutic drug concentration in the blood and decreases dosage frequency and also enhances the efficacy of drug