Scheduling Policies in Time and Frequency Domains for LTE Downlink Channel: A Performance Comparison

A key feature of the Long-Term Evolution (LTE) system is that the packet scheduler can make use of the channel quality information (CQI), which is periodically reported by user equipment either in an aggregate form for the whole downlink channel or distinguished for each available subchannel. This mechanism allows for wide discretion in resource allocation, thus promoting the flourishing of several scheduling algorithms, with different purposes. It is therefore of great interest to compare the performance of such algorithms under different scenarios. Here, we carry out a thorough performance analysis of different scheduling algorithms for saturated User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) traffic sources, as well as consider both the time- and frequency-domain versions of the schedulers and for both flat and frequency-selective channels. The analysis makes it possible to appreciate the difference among the scheduling algorithms and to assess the performance gain, in terms of cell capacity, users' fairness, and packet service time, obtained by exploiting the richer, but heavier, information carried by subchannel CQI. An important part of this analysis is a throughput guarantee scheduler, which we propose in this paper. The analysis reveals that the proposed scheduler provides a good tradeoff between cell capacity and fairness both for TCP and UDP traffic sources

Emergence of hexatic and long-range herringbone order in two-dimensional smectic liquid crystals : A Monte Carlo study

Using a high resolution Monte Carlo simulation technique based on multi-histogram method and cluster-algorithm, we have investigated critical properties of a coupled XY model, consists of a six-fold symmetric hexatic and a three-fold symmetric herringbone field, in two dimensions. The simulation results demonstrate a series of novel continues transitions, in which both long-range hexatic and herringbone orderings are established simultaneously. It is found that the specific-heat anomaly exponents for some regions in coupling constants space are in excellent agreement with the experimentally measured exponents extracted from heat-capacity data near the smecticA-hexaticB transition of two-layer free standing film

Mathematical Model for Image Restoration Based on Fractional Order Total Variation

This paper addresses mathematical model for signal restoration based on fractional order total variation (FOTV) for multiplicative noise. In alternating minimization algorithm the Newton method is coupled with time-marching scheme for the solutions of the corresponding PDEs related to the minimization of the denoising model. Results obtained from experiments show that our model can not only reduce the staircase effect of the restored images but also better improve the PSNR as compare to other existed methods

Precarious rock methodology for seismic hazard: Physical testing, numerical modeling and coherence studies

This report covers the following projects: Shake table tests of precarious rock methodology, field tests of precarious rocks at Yucca Mountain and comparison of the results with PSHA predictions, study of the coherence of the wave field in the ESF, and a limited survey of precarious rocks south of the proposed repository footprint. A series of shake table experiments have been carried out at the University of Nevada, Reno Large Scale Structures Laboratory. The bulk of the experiments involved scaling acceleration time histories (uniaxial forcing) from 0.1g to the point where the objects on the shake table overturned a specified number of times. The results of these experiments have been compared with numerical overturning predictions. Numerical predictions for toppling of large objects with simple contact conditions (e.g., I-beams with sharp basal edges) agree well with shake-table results. The numerical model slightly underpredicts the overturning of small rectangular blocks. It overpredicts the overturning PGA for asymmetric granite boulders with complex basal contact conditions. In general the results confirm the approximate predictions of previous studies. Field testing of several rocks at Yucca Mountain has approximately confirmed the preliminary results from previous studies, suggesting that the PSHA predictions are too high, possibly because the uncertainty in the mean of the attenuation relations. Study of the coherence of wavefields in the ESF has provided results which will be very important in design of the canisters distribution, in particular a preliminary estimate of the wavelengths at which the wavefields become incoherent. No evidence was found for extreme focusing by lens-like inhomogeneities. A limited survey for precarious rocks confirmed that they extend south of the repository, and one of these has been field tested

Cancer Patterns in Quetta (1998-1999)

Introduction: Quetta, the capital of Baluchistan, is located at latitude 30,25; longitude 67.00. It has a population of 759,245; 425,474 males (56%) and 333,771 females (44%); Census 1998. The majority of residents are Persian or Baluchi speaking Baluchs. Methodology: The cancer cases from Quetta reported to the Karachi Cancer Registry were reviewed. The data included cases from the Aga Khan University Hospital (AKUH), Pathology Department (Quetta collection point) and health care facilities in Karachi. The residents of Baluchistan were ascertained and cancer cases residents of Quetta identified with the help of recorded addresses and retraceable telephone numbers. Results: During a 2-year period, 1st January 1998 to 31st December 1999 the Karachi Cancer Registry received 1077 cancer notifications from Quetta. Approximately half the cases were registered from the AKUH Quetta collection point. Others were the referral patterns in Karachi. The age-standardized incidence rate (ASR) of cancer, all sites (1998-99) was 137.0 for males and 92.8/100,000 for females. The commonest cancer in the males and females was cancer of the esophagus (lCD­10 categories C15; males- ASR 25.5, 17.2 %; females- ASR 23.4, 23.1%). One of the highest in the world, for both genders. Incidence of cancer breast in the females (lCD-10 categories C50; ASR 11.8, 13.3%) was low, Conclusion: The cancer data from Quetta is quite distinct from the cancer pattern of Karachi. It represents only a part of the cancer burden of Quetta; nonetheless it gives a glimpse into the cancer profile of Baluchistan. The high incidence of esophageal cancer indicates an extension of the geographical limits of the esophageal cancer belt

Current Management Strategies in Breast Cancer by Targeting Key Altered Molecular Players

Breast Cancer is second largest disease affecting women worldwide. It remains the most frequently reported and leading cause of death among women in both developed and developing countries. Chemoprevention is one the promising approaches which reduces breast cancer. Tamoxifen and raloxifene are commonly used for treatment of breast cancer in women with high risk, although resistance occurs by tamoxifen after five years of therapy and both drugs cause uterine cancer and thromboembolic events. Aromatase inhibitors are coming up as potential option for prevention in treatment with adjuvant trials in practice. The combination of aromatase inhibitors along with tamoxifen can also be beneficial. For this, clinical trials based on large number of patients with optimal dose and lesser side effects have to be more in practice. Despite the clinical trials going on, there is need of better molecular models which can identify high risk population and new agents with better benefit having less side effects and improved biomarkers for treating breast cancer