Feedback Allocation For OFDMA Systems With Slow Frequency-domain Scheduling

We study the problem of allocating limited feedback resources across multiple users in an orthogonal-frequency-division-multiple-access downlink system with slow frequency-domain scheduling. Many flavors of slow frequency-domain scheduling (e.g., persistent scheduling, semi-persistent scheduling), that adapt user-sub-band assignments on a slower time-scale, are being considered in standards such as 3GPP Long-Term Evolution. In this paper, we develop a feedback allocation algorithm that operates in conjunction with any arbitrary slow frequency-domain scheduler with the goal of improving the throughput of the system. Given a user-sub-band assignment chosen by the scheduler, the feedback allocation algorithm involves solving a weighted sum-rate maximization at each (slow) scheduling instant. We first develop an optimal dynamic-programming-based algorithm to solve the feedback allocation problem with pseudo-polynomial complexity in the number of users and in the total feedback bit budget. We then propose two approximation algorithms with complexity further reduced, for scenarios where the problem exhibits additional structure.Comment: Accepted to IEEE Transactions on Signal Processin

Commentary: The carboxyl-terminal Crk SH3 domain: Regulatory strategies and new perspectives

AbstractSince their discovery as cellular counterparts of viral oncogenes more than two decades ago, enormous progress has been made in unraveling the complex regulatory pathways of signal transduction initiated by the Crk family of proteins. New structural and biochemical studies have uncovered novel insights into both negative and positive regulation of Crk mediated by its atypical carboxyl-terminal SH3 domain (SH3C). Moreover, SH3C is tyrosine phosphorylated by receptor tyrosine kinases and non-receptor tyrosine kinases, thereby permitting assemblages of other SH2/PTB domain containing proteins. Such non-canonical signaling by the Crk SH3C reveals new regulatory strategies for adaptor proteins

Treatment compliance in relation to source of referral and initial reaction to the diagnosis of tuberculosis

The source of referral and patient’s reaction to diagnosis were studied in relation to regularity of treatment in 107 patients attending Tuberculosis Research Centre (TRC), Chennai. In all, 29% of the patients were referred by family members, 27% by neighbours and friends, 11% attended on their own, private practitioners referred 18% and government facilities/NGOs referred 15%. The initial reactions to diagnosis of tuberculosis were anxiety, fear, worry and/or shock in 59%. Only 31% of the patients were hopeful of cure at the time. All those who attended on their own completed > 80% of treatment as did 90% of those who were hopeful of cure at the time of diagnosis. And, 86% of those who experienced a negative reaction (fear of death, anxiety and worry) completed > 80% of treatment

Learning Difficulties Among Dental Students- A Cross Sectional Study

Background: Learning difficulties also known as the learning disabilities are the conditions that impact on an individual’s ability to gain knowledge and skills. The common problem faced by dental students is learning subjects and doing practicals. Though many studies have been done on learning disabilities, this study gives detailed information on the problems faced by dental students. The main aim of this study is to create awareness on the difficulties faced by the dental students in learning the subjects and in doing practicals. An online survey was conducted among dental students to evaluate the learning difficulties. The study population are the 1st year dental students with a sample size of 100. 10 questions were circulated to the participants through an online survey link. Later the datas was analysed and made into pie charts. From this study, when asked about learning difficulties, the majority of the result shows that they have difficulty in learning that is nearly 75% and the rest felt easier. Nearly half of the students who feel difficulty in learning are trying to overcome their difficulty. From this survey, it was evident that most of the students have difficulty in learning dentistry. This study creates awareness among the students about the benefits and importance of overcoming the difficulty in learning

Awareness On Pterygoid Implant Among Dental Undergraduates

Introduction: Pterygoid implant has been defined as “implant placement through the maxillary tuberosity and into the pterygoid plate.” These implants were first introduced by Tulasne in 1989. The pterygoid implant originates in the tuberosity region and then follows an oblique mesiocranial direction proceeding posteriorly toward the pyramidal process; it subsequently proceeds upward between both wings of the pterygoid processes and finds its encroachment in the pterygoid or scaphoid fossa of the sphenoid bone. The length of these implants ranges from 15 to 20 mm, and they are generally placed at an angle of 45° to 50° to the horizontal planeThe success rates for all these different treatment possibilities seem to be similar. Therefore the need for engaging the implants at the level of the pterygoid plate is currently controversially discussed. Aim: To analyse the awareness of pterygoid implants among dental undergraduates. Materials And Methods: A questionnaire was prepared on google forms. It was distributed among 70 students. The data was transferred to excel and coding was done, the data was transferred to SPSS and statistical analysis was done. Results: Though 14% were still not aware when pterygoid implants can be used commonly. On doing the chi square test in regards to the awareness of pterygoid implant among undergraduates, along with a chi square value of 12.666, the p value was found to be 0.014, p<0.05, hence making the correlation statistically significant. The knowledge about the contraindications were also analysed and 60% of the participants who were aware of pterygoid implant were well aware of the contraindications. Conclusion: As future clinicians it is very important to know about the newer developments in the field of dentistry to provide a better treatment as well as for framing a fair treatment plan, the study shows that there still more than awareness needed in the respective topic of pterygoid implants

Design of a real-time inspection system for NDE of reactor vessels and piping components

Progress in the development of a special-purpose system for use in a real-time in-service inspection system for reactor vessels and piping components is described in this report. An analysis of the synthetic aperture processing algorithm is presented and new methods of speedup are described. A number of special purpose processor architectures are presented and two of the more promising ones are described in detail and are compared and evaluated. Proposed specifications for an initial field inspection system are presented. A brief description of the capabilities of a laboratory prototype processor (to be fabricated) is given.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25794/1/0000356.pd

Review on Sparse-Based Multipath Estimation and Mitigation: Intense Solution to Counteract the Effects in Software GPS Receivers

Multipath is the major concern in GPS receivers that fade the actual GPS signal causes positioning error up to 10 m so special care need to be taken to mitigate the multipath effects. Numerous methods like hardware based antenna arrays technique, receiver based narrow correlator receiver, double -delta discriminator, Adaptive Multipath Estimator, Wavelet Transformation and Particle filter, Kalman filter based post receiver methods etc. used to resolve the problem. But some of the methods can only reduce code multipath error but not effective in eliminating carrier multipath error. Most of these techniques are based on the assumption that the Line-of-Sight (LOS) signal is stronger than the Non-Line of-Sight (NLOS) signals. However, in the scenarios where the LOS signal is weaker than the composite multipath signal, this approach may result in a bias in code tracking. In this chapter, different types of multipath mitigation and its limitation are described. The recent development in sparse signal processing based blind channel estimation is investigated to compensate the multipath error. The Rayleigh and Rician fading model with different multipath parameters are simulated to test the urban scenario. The inverse problem of finding the GPS signal is addressed based on the deconvolution approach. To solve linear inverse problems, the suitable kind of appropriate objective function has been formulated to find the signal of interest. By exploiting this methods, the signal is observed and the carrier and code tracking loop parameters are computed with minimal error

Transport of N-acetylaspartate via murine sodium/dicarboxylate cotransporter NaDC3 and expression of this transporter and aspartoacylase II in ocular tissues in mouse

AbstractCanavan disease is a genetic disorder associated with optic neuropathy and the metabolism of N-acetylaspartate is defective in this disorder due to mutations in the gene coding for the enzyme aspartoacylase II. Here we show that the plasma membrane transporter NaDC3, a Na+-coupled transporter for dicarboxylates, is able to transport N-acetylaspartate, suggesting that the transporter may function in concert with aspartoacylase II in the metabolism of N-acetylaspartate. Since Canavan disease is associated with ocular complications, we investigated the expression pattern of NaDC3 and aspartoacylase II in ocular tissues in mouse by in situ hybridization. These studies show that NaDC3 mRNA is expressed in the optic nerve, most layers of the retina, retinal pigment epithelium, ciliary body, iris, and lens. Aspartoacylase II mRNA is coexpressed in most of these cell types. We conclude that transport of N-acetylaspartate into ocular tissues via NaDC3 and its subsequent hydrolysis by aspartoacylase II play an essential role in the maintenance of visual function

Extensible Component Based Architecture for FLASH, A Massively Parallel, Multiphysics Simulation Code

FLASH is a publicly available high performance application code which has evolved into a modular, extensible software system from a collection of unconnected legacy codes. FLASH has been successful because its capabilities have been driven by the needs of scientific applications, without compromising maintainability, performance, and usability. In its newest incarnation, FLASH3 consists of inter-operable modules that can be combined to generate different applications. The FLASH architecture allows arbitrarily many alternative implementations of its components to co-exist and interchange with each other, resulting in greater flexibility. Further, a simple and elegant mechanism exists for customization of code functionality without the need to modify the core implementation of the source. A built-in unit test framework providing verifiability, combined with a rigorous software maintenance process, allow the code to operate simultaneously in the dual mode of production and development. In this paper we describe the FLASH3 architecture, with emphasis on solutions to the more challenging conflicts arising from solver complexity, portable performance requirements, and legacy codes. We also include results from user surveys conducted in 2005 and 2007, which highlight the success of the code.Comment: 33 pages, 7 figures; revised paper submitted to Parallel Computin