Channel Estimation for MIMO MC-CDMA Systems

The concepts of MIMO MC-CDMA are not new but the new technologies to improve their functioning are an emerging area of research. In general, most mobile communication systems transmit bits of information in the radio space to the receiver. The radio channels in mobile radio systems are usually multipath fading channels, which cause inter-symbol interference (ISI) in the received signal. To remove ISI from the signal, there is a need of strong equalizer. In this thesis we have focused on simulating the MIMO MC-CDMA systems in MATLAB and designed the channel estimation for them

Workload Characterization of AFS File Servers

This paper describes the workload characterization of AFS file servers, based on traces collected by the file servers at CITI over a 2-4 week period. These workload characteristics have been used to compare the performance of servers running on different hardware. There are two parts to this paper. In the first part, we describe a server model that will be used to drive a synthetic workload. In the second part, we build a client model consisting of the requests made by different user types. We show that the user community can be broken into distinct types, where all the users of a specific type exhibit similar request patterns. This clustering information is used in conjunction with the workload characteristics at the server to predict loads on servers, given the community that needs to be served. Finally, we give an example to show how this can be done.http://deepblue.lib.umich.edu/bitstream/2027.42/107962/1/citi-tr-92-6.pd

Using the Medical Research Council framework for the development and evaluation of complex interventions in a theory-based infant feeding intervention to prevent childhood obesity:The baby milk intervention and trial

Introduction. We describe our experience of using the Medical Research Council framework on complex interventions to guide the development and evaluation of an intervention to prevent obesity by modifying infant feeding behaviours. Methods. We reviewed the epidemiological evidence on early life risk factors for obesity and interventions to prevent obesity in this age group. The review suggested prevention of excess weight gain in bottle-fed babies and appropriate weaning as intervention targets; hence we undertook systematic reviews to further our understanding of these behaviours. We chose theory and behaviour change techniques that demonstrated evidence of effectiveness in altering dietary behaviours. We subsequently developed intervention materials and evaluation tools and conducted qualitative studies with mothers (intervention recipients) and healthcare professionals (intervention deliverers) to refine them. We developed a questionnaire to assess maternal attitudes and feeding practices to understand the mechanism of any intervention effects. Conclusions. In addition to informing development of our specific intervention and evaluation materials, use of the Medical Research Council framework has helped to build a generalisable evidence base for early life nutritional interventions. However, the process is resource intensive and prolonged, and this should be taken into account by public health research funders. This trial is registered with ISRTCN: 20814693 Baby Milk Trial

Ethnomedicinal Plants Survey and Documentation Related to Paliyar Community

The present study is mainly focused on the ethnomedico botany of the tribe Paliyars a dominant ethnic group inhabiting the Western Ghats (Off Shoots) of Sirumalai Hills, Dindigul district. Tamil Nadu. In the present study the focus is on survey, documentation and enumeration of the medicinal plants practiced by the tribal Paliyars, As an outcome of the present investigations 30 plants have been identified and documented. The life style of the Paliyar was also studied

Effect of Relay Nodes on End-To-End Delay in Multi-Hop Wireless Ad-Hoc Networks

Channel access delay in a wireless adhoc network is the major source of delay while considering the total end to-end delay. Channel access delays experienced by different relay nodes are different in multi-hop adhoc network scenario. These delays in multi-hop network are analysed in the literature assuming channel access delays are independent and are of same magnitude at all the nodes in the network. In this work, the end to-end delay in a multi-hop adhoc network is analysed taking into account the silent relay nodes. Along with silent relay node effect, Channel access probability (p), transmission radius (r) analogous to transmit power, network throughput and density of nodes arête other factors considered for the end-to-end delay analysis. Effect of network parameters along with silent relay nodes on end-to-end delay is found to be considerably high compared to the previous literature results. Given a bound on end-to-end delay with percentage of silent relay nodes, throughput, node density requirements for a multi-hop adhoc network, optimal ranges of transmission radius and channel access probability can be obtained from the proposed analysis. End-to-end delay increases with silent relay nodes along with transmission radius(r), channel access probability(p), node density and throughput. It is clear from the analysis, that the effect of silent relay nodes on end to-end delay cannot be ignored to maintain certain Quality of service (QoS) metrics for the multi-hop wireless adhoc networ