8,256 research outputs found
Gravitational Binding, Virialization and the Peculiar Velocity Distribution of the Galaxies
We examine the peculiar velocity distribution function of galaxies in
cosmological many-body gravitational clustering. Our statistical mechanical
approach derives a previous basic assumption and generalizes earlier results to
galaxies with haloes. Comparison with the observed peculiar velocity
distributions indicates that individual massive galaxies are usually surrounded
by their own haloes, rather than being embedded in common haloes. We then
derive the density of energy states, giving the probability that a randomly
chosen configuration of N galaxies in space is bound and virialized.
Gravitational clustering is very efficient. The results agree well with the
observed probabilities for finding nearby groups containing N galaxies. A
consequence is that our local relatively low mass group is quite typical, and
the observed small departures from the local Hubble flow beyond our group are
highly probable.Comment: Paper in aastex 5.0 format and 9 figures. Replace a new version with
figures and typos correcte
High-Performance Bioinstrumentation for Real-Time Neuroelectrochemical Traumatic Brain Injury Monitoring
Traumatic brain injury (TBI) has been identified as an important cause of death and severe disability in all age groups and particularly in children and young adults. Central to TBIs devastation is a delayed secondary injury that occurs in 30–40% of TBI patients each year, while they are in the hospital Intensive Care Unit (ICU). Secondary injuries reduce survival rate after TBI and usually occur within 7 days post-injury. State-of-art monitoring of secondary brain injuries benefits from the acquisition of high-quality and time-aligned electrical data i.e., ElectroCorticoGraphy (ECoG) recorded by means of strip electrodes placed on the brains surface, and neurochemical data obtained via rapid sampling microdialysis and microfluidics-based biosensors measuring brain tissue levels of glucose, lactate and potassium. This article progresses the field of multi-modal monitoring of the injured human brain by presenting the design and realization of a new, compact, medical-grade amperometry, potentiometry and ECoG recording bioinstrumentation. Our combined TBI instrument enables the high-precision, real-time neuroelectrochemical monitoring of TBI patients, who have undergone craniotomy neurosurgery and are treated sedated in the ICU. Electrical and neurochemical test measurements are presented, confirming the high-performance of the reported TBI bioinstrumentation
Malmquist Indices of Pre and Post-Deregulation Productivity, Efficiency and Technological Change in the Singaporean Banking Sector
By the end of the 1990s, the Singaporean government had recognised the need to open up its banking sector so as to remain competitive in the global economy. The Monetary Authority of Singapore thus began deregulation of the banking sector in 1999 to strengthening the competitiveness of local banks relative to their foreign competition through mergers. This paper employs a nonparametric Malmquist productivity index to provide measure of productivity, technological change and efficiency gains over the period 1995-2005. The findings reveal some total factor productivity growth associated with deregulation and scale efficiency improvement largely from mergers amongst the local banks.Efficiency, productivity; deregulation; Malmquist indices; banking
Testing Alternative Theories of the Property Price-Trading Volume Correlation
This article examines the correlation between the real housing price and trading volume. Contrary to the predictions of standard rational expectation models, a robust positive correlation between the two variables is identified. While no clear lead-lag relationship is found in the raw data, which is more consistent with the downpayment effect model, the medium-run component of the trading volume tends to lead (and Granger cause) the corresponding component of the property price, which is more consistent with the search theoretic model. An explanation for this difference in behavior is suggested and several future research directions are provided.
Entanglement convertibility by sweeping through the quantum phases of the alternating bonds chain
We study the entanglement structure and the topological edge states of the
ground state of the spin-1/2 XXZ model with bond alternation. We employ
parity-density matrix renormalization group with periodic boundary conditions.
The finite-size scaling of R\'enyi entropies and are used to
construct the phase diagram of the system. The phase diagram displays three
possible phases: Haldane type (an example of symmetry protected topological
ordered phases), Classical Dimer and N\'eel phases, the latter bounded by two
continuous quantum phase transitions. The entanglement and non-locality in the
ground state are studied and quantified by the entanglement convertibility. We
found that, at small spatial scales, the ground state is not convertible within
the topological Haldane dimer phase. The phenomenology we observe can be
described in terms of correlations between edge states. We found that the
entanglement spectrum also exhibits a distinctive response in the topological
phase: the effective rank of the reduced density matrix displays a specifically
large "susceptibility" in the topological phase. These findings support the
idea that although the topological order in the ground state cannot be detected
by local inspection, the ground state response at local scale can tell the
topological phases apart from the non-topological phases.Comment: Final versio
Fostering innovation through cultural change
Purpose: The paper aims to demonstrate a range of approaches to promoting innovative thought and action which can be applied in a variety of organisational contexts. Design/methodology/approach: The paper describes strategies adopted by one large academic library which sought to increase employee engagement and levels of innovation. Included is the background situation, a description of cultural change activities undertaken, information on provision of a suite of practical innovation process tools, and reference to relevant literature. Findings: The leadership framework of RMIT University, and associated developmental opportunities, benefit the library which also offers a tailored developmental programme for its leadership group. Specific purpose groups are used in the library to build capacity and promote cultural change. The library promotes involvement in professional associations and supports innovation through the provision of practical tools and techniques which can be used by staff at all levels. Building an innovative culture is challenging in a large organisation, but sustaining effort over time, utilising a variety of approaches and developing positive sub-cultures among motivated staff have been found to be beneficial. Originality/value: By describing strategies to promote an innovative organisational culture, the paper has originality. Most related library literature addresses specific innovations
Haze in the Klang Valley of Malaysia
Continuous measurements of dry aerosol light scattering (Bsp) were made at two sites in the Klang Valley of Malaysia between December 1998 and December 2000. In addition 24-h PM2.5 samples were collected on a one-day-in-six cycle and the chemical composition of the aerosol was determined. Periods of excessive haze were defined as 24-h average Bsp values greater than 150 Mm-1 and these occurred on a number of occasions, between May and September 1999, during May 2000, and between July and September 2000. The evidence for smoke being a significant contributor to aerosol during periods of excessive haze is discussed and includes features of the aerosol chemistry, the diurnal cycle of Bsp, and the coincidence of forest fires on Sumatra during the southwest (SW) monsoon period, as well as transport modelling for one week of the southwest Monsoon of 2000. The study highlights that whilst transboundary smoke is a major contributor to poor visibility in the Klang Valley, smoke from fires on Peninsular Malaysia is also a contributor, and at all times, the domestic source of secondary particle production is present
Full W-band MMIC medium power amplifier
A full W-band, MMIC amplifier has been tested on-wafer. The chip delivers 25-43 mW with 6.2±1.2 dB associated large-signal gain across 75-110 GHz when input power is held constant at 8 mW. This is the widest bandwidth MMIC amplifier ever published that delivers at least 25 mW over the entire W-band
Empirical load-line capacitance models for HEMT
Models for describing the gate-source and gate-drain capacitances' variation along a resistive load line have been proposed. They are charge conservative and consistent with the small-signal model at bias points along the load line. The extraction procedure for the models' parameters is fast and intuitive. The models can be implemented easily in most circuit simulator programs
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