Noise in optical synthesis images. I. Ideal Michelson interferometer

We study the distribution of noise in optical images produced by the aperture synthesis technique, in which the principal source of noise is the intrinsic shot noise of photoelectric detection. The results of our analysis are directly applicable to any space-based optical interferometer. We show that the signal-to-noise ratio of images synthesized by such an ideal interferometric array is essentially independent of the details of the beam-combination geometry, the degree of array redundancy, and whether zero-spatial-frequency components are included in image synthesis. However, the distribution of noise does depend on the beam-combination geometry. A highly desirable distribution, one of uniform noise across the entire image, is obtained only when the beams from the n primary apertures are subdivided and combined pairwise on n(n - 1)/2 detectors

Noise in optical synthesis images. II. Sensitivity of an ^nC_2 interferometer with bispectrum imaging

We study the imaging sensitivity of a ground-based optical array of n apertures in which the beams are combined pairwise, as in radio-interferometric arrays, onto n(n - 1)/2 detectors, the so-called ^nC_2 interferometer. Groundbased operation forces the use of the fringe power and the bispectrum phasor as the primary observables rather than the simpler and superior observable, the Michelson fringe phasor. At high photon rates we find that bispectral imaging suffers no loss of sensitivity compared with an ideal array (space based) that directly uses the Michelson fringe phasor. In the opposite limit, when the number of photons per spatial coherence area per coherence time drops below unity, the sensitivity of the array drops rapidly relative to an ideal array. In this regime the sensitivity is independent of n, and hence it may be efficient to have many smaller arrays, each operating separately and simultaneously

Parameter Selection for Experimental Investigation of Machining Parameters of Inconel -718 for Turning Operation for Green Machining Using AHP

The most important part in experimental investigation is Parameter selection. The parameter plays crucial role in type of investigation or the performance evaluation. There are many methods to select the parameters. In this research we proposed Analytical Hierarchy Process (AHP) to select the parameter for the experimental investigation of machining parameters of Inconel-718 for turning operation. It will include the structural investigation and questionarie. The Sattey scale is used for the pairwise comparison. There are various parameters we are considering for experimental investigations .These are like Cutting Speed , Feed, Depth of cut, Material removal rate (MRR),surface roughness, tool wear, helix angle etc

Changing Contexts of Customer Service in the Social Media Era: Challenges and Opportunities for Indian e-tail Industry

The research aims to analyse the impact of social media on customer service provided by the E-tailing companies in India. The analysis depicted that antecedent variables of customer service such as personal greetings, idea generation, loyalty benefits, and feedback mechanisms have a positive impact but they fail to create an impression on the consequence variables such as loyalty development, time efficiency, and knowledge creation. Researchers conclude that the lack of clarity in media vehicles communication, proliferation of e-tailing, and their rivalry create issues among the consumers of E-tail companies

ESTABLISHMENT OF AGE VS STRENGTH CURVE FOR SET OF MATERIALS

This study was directed toward performance of concrete under varying water to cementitious materials ratio. The influence of constituent materials and various mix proportions on compressive strength of concrete was studied experimentally and reported. At each water/cement ratio varied from .25 to .55 at constant increment of 0.05. For all the concrete mixes,the compressive strength of concrete was determined at ages of 1,3,7,28,90 and 180 days. The experiment was carried out at the same ambient temperature and the compressive strengths of concrete mixes were found to increase with age but decrease as water - cement ratio increases. From the experimental test results,it was observed that the important parameter affecting the strength of concrete is the water/cement ratio and Abrams' generalization law is applicable to concrete in compression for our set of materials. Graphical model is proposed to predict the compressive strength of concrete using Water/Cement ratio. https://www.ijiert.org/paper-details?paper_id=14101

Comparison of dexamethasone and clonidine as an adjunct to bupivacaine in transversus abdominis plane block in patients undergoing lower segment caesarean section

Background: A lower segment caesarean section (LSCS) commonly induces moderate to severe postoperative pain for 48 hours. Aim of the study was to compare 0.25% bupivacaine with dexamethasone and 0.25% bupivacaine with clonidine for transversus abdominis plane (TAP) block as post-operative analgesia in patients undergoing lower segment caesarean section (LSCS).Methods: A randomized prospective controlled clinical study was conducted in 104 patients undergoing LSCS. Participants were divided into two groups in which group TAP-D (n=54) received 0.25% Bupivacaine with Dexamethasone 4mg and those in group TAP-C (n=50) received 0.25% Bupivacaine with Clonidine 75mcg as TAP block at the end of surgery. The postoperative pain was evaluated by visual analog scale (VAS) for pain scoring at every 2 hours for 12 hours postoperatively. Subjective assessment of duration of analgesia was done.Results: The average duration of analgesia with TAP bock for the overall study population was 316.15 minutes. The average VAS score in patients who received TAP with dexamethasone was 1.50 which is significantly lower than those who received clonidine (1.95) (P value-0.0001). Further the duration of analgesia was 151 minutes longer in the first group who received dexamethasone TAP. In majority of the patients (84%) who received clonidine TAP, the analgesia persisted for 2-4 hours. While in patients who received dexamethasone addition, the analgesia persisted for 6-8 hours in 37%.Conclusions: TAP block is a safe and effective way of relieving postoperative pain in LSCS patients. Addition of dexamethasone to bupivacaine significantly enhances its effect in terms of block quality and analgesia duration as compared to clonidine addition

Source-to-Source Refactoring and Elimination of Global Variables in C Programs

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.A global variable in C/C++ is one that is declared outside a function, and whose scope extends the lifetime of the entire program. Global variables cause problems for program dependability, maintainability, extensibility, verification, and thread-safety. However, global variables can also make co ding more convenient and improve program performance. We have found the use of global variables to remain unabated and extensive in real-world software. In this paper we present a source-to-source refactoring tool to au tomatically detect and localize global variables in a program. We implement a compiler based transformation to find the best location to redefine each global va riable as a local. For each global, our algorithm initializes the corresponding new local variable, pa sses it as an argument to necessary functions, and updates the source lines that used the global to now instead use th e corresponding local or argumen t. We also characterize the use of global variables in standard benchmark programs. We study the effect of our transformation on static program properties, such as change in the number of function ar guments and program state visibility. Additionally, we quantify dynamic program features, including memory and runtime performance, before and after our localizing transformation

Flux pump for HTS rotating machinery applications

High Temperature Superconducting (HTS) machines offer several benefits over the conventional machines. With the advent of YBCO materials, research and development in HTS applications has gained significant impetus. The application of flux pump has its own advantages over the conventional mechanism for magnetic field generation in superconductors. This paper reviews few relevant works and presents preliminary results from experiments carried out to provide justification on the application of flux pump for generating magnetic flux in a rotating machine