825 research outputs found
Single-Symbol ML Decodable Distributed STBCs for Partially-Coherent Cooperative Networks
Space-time block codes (STBCs) that are single-symbol decodable (SSD) in a
co-located multiple antenna setting need not be SSD in a distributed
cooperative communication setting. A relay network with N relays and a single
source-destination pair is called a partially-coherent relay channel (PCRC) if
the destination has perfect channel state information (CSI) of all the channels
and the relays have only the phase information of the source-to-relay channels.
In this paper, first, a new set of necessary and sufficient conditions for a
STBC to be SSD for co-located multiple antenna communication is obtained. Then,
this is extended to a set of necessary and sufficient conditions for a
distributed STBC (DSTBC) to be SSD for a PCRC, by identifying the additional
conditions. Using this, several SSD DSTBCs for PCRC are identified among the
known classes of STBCs. It is proved that even if a SSD STBC for a co-located
MIMO channel does not satisfy the additional conditions for the code to be SSD
for a PCRC, single-symbol decoding of it in a PCRC gives full-diversity and
only coding gain is lost. It is shown that when a DSTBC is SSD for a PCRC, then
arbitrary coordinate interleaving of the in-phase and quadrature-phase
components of the variables does not disturb its SSD property for PCRC.
Finally, it is shown that the possibility of {\em channel phase compensation}
operation at the relay nodes using partial CSI at the relays increases the
possible rate of SSD DSTBCs from when the relays do not have CSI
to 1/2, which is independent of N
Some New Developments in Semiconductor Structures
Some of the recent developments in the field of semiconductor devices are discussed. Two trends are apparent in this area of work. One is the continuous refinement of processes and instruments which enables us to design and fabricate devices in ever smaller dimensions. The second is the study of new structures which are now made possible by such advances in instrumentation and materials technology. New devices based on quantum well structures, superlattices and bandgap engineering are briefly discussed
Impact evaluation of international multidisciplinary tumor boards
Over the last 20 years, cancer clinicians have begun to improve the efficacy of cancer care through tumor boards, meetings of multidisciplinary patient care teams used to educate attendees and align treatment plans. In addition to the potential for collaboration between different disciplines, these meetings allow for the incorporation of information from peer-reviewed literature. Despite their use, very little research has been done on the effect of tumor boards on treatment efficacy. Within this small body of work, the indicators used are often inherently biased, and little concern is given to their confounding effects. This document will discuss alternative metrics that provide a less biased estimate of the impact of tumor boards.
Given their educational aspects, tumor boards are beginning to be used in an international context to support clinicians in developing nations. Despite the relative lack of evidence supporting use of tumor boards, they provide a low-cost method for improving clinician education in a setting where treatment protocols vary greatly. Moreover, international tumor boards provide a way for low-resource hospitals to tap into facilities of high-resource hospitals, receive resource-sensitive guidelines for future practice, and collaborate with clinicians from other hospitals. However, there are serious barriers to implementing international tumor boards, including technological, logistical, linguistic, and oversight issues. This document outlines potential issues and methods to circumvent them, as well as benefits of international tumor boards (including future collaboration)
Thermal Degradation Studies on PMMA–HET Acid Based Oligoesters Blends
Imparting thermal stability to polymethyl methacrylate (PMMA) without affecting its optical clarity is attempted by incorporating HET acid based oligoesters. Pure PMMA and PMMA containing five and 20 wt% of four different oligoesters are separately prepared using bulk polymerization. The thermal properties of the materials studied using DSC, TG, TG–FTIR and Pyr–GC–MS are presented. The main volatile degradation products identified are CO, HCl, CO2, H2O, hexachlorocyclopentadiene, hexachloroendomethylene tetrahydrophthalic acid/anhydride and methyl methacrylate. A detailed mechanism for the influence of the degradation products of HET acid based oligoesters on the thermal degradation of PMMA is also presented
On the Topological Origin of Entanglement in Ising Spin Glasses
The origin of thermal and quantum entanglement in a class of
three-dimensional spin models, at low momenta, is traced to purely topological
reasons. The establishment of the result is facilitated by the gauge principle
which, when used in conjunction with the duality mapping of the spin models,
enables us to recast them as lattice Chern-Simons gauge theories. The thermal
and quantum entanglement measures are expressed in terms of the expectation
values of Wilson lines, loops, and their generalisations. For continuous spins,
these are known to yield the topological invariants of knots and links. For
Ising-like models, they are expressible in terms of the topological invariants
of three-manifolds obtained from finite group cohomology -- the so-called
Dijkgraaf-Witten invariants.Comment: RevTex4, 6 page
The role of initial conditions in the ageing of the long-range spherical model
The kinetics of the long-range spherical model evolving from various initial
states is studied. In particular, the large-time auto-correlation and -response
functions are obtained, for classes of long-range correlated initial states,
and for magnetized initial states. The ageing exponents can depend on certain
qualitative features of initial states. We explicitly find the conditions for
the system to cross over from ageing classes that depend on initial conditions
to those that do not.Comment: 15 pages; corrected some typo
Trend of Hepatitis B Surface Antigen (HBsAg) among blood donors at the blood bank of a tertiary care referral teaching hospital in Southern India
Background: Blood is a scarce, but lifesaving resource; it is also the most efficient vehicle for the transmission of Hepatitis B virus (HBV). Hence there is a need for accurate screening of hepatitis B surface antigen (HBsAg) among blood donors. The present study was designed to assess the seroprevalence of HBsAg, among the voluntary and replacement blood donors in the blood bank of a tertiary care referral teaching hospital in Andhra Pradesh.Methods: This is a prospective cross sectional analytical study conducted over a period of one and a half year. A total of 9909 donor blood samples were screened for HBsAg status using enzyme linked immunosorbent assay (ELISA). The reactive samples have been tested in duplicate using different kit. The samples reactive in all three times were considered positive. The samples which were reactive only in first test were labeled as false positive.Results: Out of 9909 blood donors screened, 255 (2.6%) were initially reactive and 219 (2.2%) were reactive after triple testing.Conclusions: Our study showed similar HBsAg seroprevalence as that reported by World Health Organization (WHO) statistics in intermediate zone. But there was a mild increase in HBsAg seroprevalence among donors belonging to rural areas in our region compared to the urban donors.
Critical dynamics of nonconserved -vector model with anisotropic nonequilibrium perturbations
We study dynamic field theories for nonconserving -vector models that are
subject to spatial-anisotropic bias perturbations. We first investigate the
conditions under which these field theories can have a single length scale.
When N=2 or , it turns out that there are no such field theories, and,
hence, the corresponding models are pushed by the bias into the Ising class. We
further construct nontrivial field theories for N=3 case with certain bias
perturbations and analyze the renormalization-group flow equations. We find
that the three-component systems can exhibit rich critical behavior belonging
to two different universality classes.Comment: Included RG analysis and discussion on new universality classe
Improving water productivity, reducing poverty and enhancing equity in mixed crop-livestock systems in the Indo-Gangetic Basin: CPWF project report 68
Farming systems / Mixed farming / Water productivity / Feed production / Livestock / Energy consumption / Gender / Poverty / River basins / Case studies / India / Indo-Gangetic Basin / West Bengal / Haryana / Uttar Pradesh
SENSIBLE EXPANSION OF INTELLECTUAL DISPOSAL OF GARBAGE SYSTEM BY USING IOT
Many times, in our town we see that the rubbish boxes or dustbins located at public places are overloaded. It creates unhygienic conditions for human beings similarly to ugliness to that vicinity leaving unsightly smell. To keep away from all such conditions we're going to put into effect a venture referred to as IoT Based Intelligent disposal of rubbish. In this undertaking dustbins are interfaced with microcontroller based machine having Ultrasonic sensor and IR sensor at the side of big tool displaying contemporary-day fame of garbage, on cellular net browser with html page thru Wi-Fi. This tool additionally includes fuel sensor within it to avoid leakage of poisonous gases from the field. Hence the popularity might be updated directly to the html page. And the statistics detected can be dynamically despatched to all the stakeholders concerned within the system and it leads to the optimized series routes of rubbish bin. Here the admirable function present is that we deliberate to provide unfastened Wi-Fi for a person who is dumping the waste into the rubbish bin through shifting Wi-Fi code. It is probably used by a person in the precise distance from the garbage bin. Major part of our task relies upon the going for walks of the Wi-Fi module, essential for its implementation. The fundamental goal of this undertaking is to reduce human sources and efforts together with the enhancement of a smart metropolis imaginative and prescient
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