Optimal sampling strategies for multiscale stochastic processes

In this paper, we determine which non-random sampling of fixed size gives the best linear predictor of the sum of a finite spatial population. We employ different multiscale superpopulation models and use the minimum mean-squared error as our optimality criterion. In multiscale superpopulation tree models, the leaves represent the units of the population, interior nodes represent partial sums of the population, and the root node represents the total sum of the population. We prove that the optimal sampling pattern varies dramatically with the correlation structure of the tree nodes. While uniform sampling is optimal for trees with ``positive correlation progression'', it provides the worst possible sampling with ``negative correlation progression.'' As an analysis tool, we introduce and study a class of independent innovations trees that are of interest in their own right. We derive a fast water-filling algorithm to determine the optimal sampling of the leaves to estimate the root of an independent innovations tree.Comment: Published at http://dx.doi.org/10.1214/074921706000000509 in the IMS Lecture Notes--Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Optimal Energy Management Policies for Energy Harvesting Sensor Nodes

We study a sensor node with an energy harvesting source. The generated energy can be stored in a buffer. The sensor node periodically senses a random field and generates a packet. These packets are stored in a queue and transmitted using the energy available at that time. We obtain energy management policies that are throughput optimal, i.e., the data queue stays stable for the largest possible data rate. Next we obtain energy management policies which minimize the mean delay in the queue.We also compare performance of several easily implementable sub-optimal energy management policies. A greedy policy is identified which, in low SNR regime, is throughput optimal and also minimizes mean delay.Comment: Submitted to the IEEE Transactions on Wireless Communications; 22 pages with 10 figure

Optimizing Bandwidth Sharing for Real-time Traffic in Wireless Networks

We consider the problem of enhancing the delivery of real-time traffic in wireless networks using bandwidth sharing between operators. A key characteristic of real-time traffic is that a packet has to be delivered within a delay deadline for it to be useful. The abundance of real-time traffic is evident in the popularity of applications like video and audio conferencing, which increased significantly during the COVID-19 period. We propose a sharing and scheduling policy which involves dynamically sharing a portion of one operator's bandwidth with another operator. We provide strong theoretical guarantees for the policy. We also evaluate its performance via extensive simulations, which show significant improvements of up to 90% in the ability to carry real-time traffic when using the policy. We also explore how the improvements from bandwidth sharing depend on the amount of sharing, and on additional traffic characteristics

Abciximab induced severe thrombocytopenia in an elderly patient

Abciximab is a humanized monoclonal antibody which acts against αIIbβ3 receptor. The use of abciximab with percutaneous coronary interventions (PCI) has proven good results in patients. The drug has been notorious to cause bleeding and also decrease in the number of platelets. In this case the patient had normal platelet count but the count decreased significantly after abciximab was given. A number of cases have been reported but very few have been reported from India. Hence, we found it important to report and it is a valuable asset for scientific research.

Selective Laser Sintering of DuraForm Polyamide with Small-Scale Features

Selective Laser Sintering (SLS) has been used to make a fiber management module having very small feature size and ratios. Currently these modules are made out of Stereolithography using standard epoxy acrylate materials. SLS has been chosen to make these modules by the virtue of the material system it offers. The material system was chosen based on the flame retardant properties. The material used for this study is a DuraformTM Polyamide and Alumina-Ammonium Phosphate system. Ammonium Phosphate served as the binder in the Alumina-Ammonium Phosphate system. Experiments were done in order to find out the minimum feature size possible with the two material systems. Minimum hole diameters and maximum possible l/d ratios are determined by particle size, shape and processing conditions. Builds were made in different directions to understand the effect of the various processing parameters on the system. One particularly noteworthy observation was that part growth as a proportion of hole diameter became increasingly significant as hole size decreased. Optical microscopy was performed to measure the hole diameters and also to reveal the surface roughness. Results indicate material system determines the minimum diameter of micro-sized holes that can be effectively manufactured using Selective Laser Sintering.Mechanical Engineerin

Cancer burden and alarm signals: a community based study from Kerala, India

Background: Cancer is emerging as a major public health concern in many countries including India. Kerala state has the highest burden of cancer in the country. Objective of this study was to estimate the prevalence of diagnosed cancers, warning signs and selected risk factors of cancer in Kadapra Panchayath of Pathanamthitta district, Kerala.Methods: A total of 16,391 population was covered by door to door survey using a structured questionnaire. The questionnaire collected information on the sociodemographic variables of the residents, source of water supply, warning signs of cancer and details of diagnosed cancer cases.Results: The mean age of the population was 40.9+21 years. The prevalence of diagnosed cases of cancer in our study population was 776/100,000 population. Breast cancer was the most common cancer (43.5%) identified in the population. The prevalence of any warning sign among the study population was 220/100,000 population. Breast lump was the common warning sign identified. Increasing age and female gender were the factors found to be significantly associated with cancer.Conclusions: As prevalence of cancer was found to be high in this population, an active community based screening along with teaching self-breast examination to the women in the community are required. Improving community awareness could help in early diagnosis, treatment and prevention. Soil and water testing for carcinogens is recommended