1,994 research outputs found
Application of Permutation Group Theory in Reversible Logic Synthesis
The paper discusses various applications of permutation group theory in the
synthesis of reversible logic circuits consisting of Toffoli gates with
negative control lines. An asymptotically optimal synthesis algorithm for
circuits consisting of gates from the NCT library is described. An algorithm
for gate complexity reduction, based on equivalent replacements of gates
compositions, is introduced. A new approach for combining a group-theory-based
synthesis algorithm with a Reed-Muller-spectra-based synthesis algorithm is
described. Experimental results are presented to show that the proposed
synthesis techniques allow a reduction in input lines count, gate complexity or
quantum cost of reversible circuits for various benchmark functions.Comment: In English, 15 pages, 2 figures, 7 tables. Proceeding of the RC 2016
conferenc
Transaction attributes and buyer-supplier relationships in AMT acquisition and implementation : the case of Malaysia.
This paper explores how transaction attributes of technology affect differences in the relationship between technology buyers and suppliers. It also examines the
impact on performance of different patterns of relationship between technology buyers and suppliers. Data obtained from 147 manufacturing firms in Malaysia are used to test several hypotheses, which were derived from a review of the
literature on technology, transaction cost theory and buyer–supplier relationships (BSR). The research results indicate that the higher the level of technological complexity, specificity and uncertainty, the more firms are likely to engage in a closer relationship with technology suppliers. Even though the majority of firms reported improvements in their performance, results indicate that firms
demonstrating a closer relationship with technology suppliers are more likely to achieve higher levels of performance than those that do not. It is also shown that
with high levels of transaction attribute, implementation performance suffers more when firms have weak relationships with technology suppliers than with moderate and low levels of transaction attribute
The precursors and impacts of BSR on AMT acquisition and implementation.
This paper reports on the results of research into the connections between transaction attributes and buyer-supplier relationships (BSRs) in advanced manufacturing technology (AMT) acquisition and implementation. The investigation began by examining the impact of the different patterns of BSR on the performance of the AMT acquisition. In understanding the phenomena, the study drew upon and integrated the literature of transaction cost economics theory, BSRs, and AMT, and used this as the basis for a theoretical framework and hypotheses development. This framework was then empirically tested using data that were gathered through a questionnaire survey with 147 companies and analyzed using a structural equation modeling technique. The results of the analysis indicated that the higher the level of technological specificity and uncertainty, the more firms are likely to engage in a stronger relationship with technology suppliers. However, the complexity of the technology being implemented was associated with BSR only indirectly through its association with the level of uncertainty (which has a direct impact upon BSR). The analysis also provided strong support for the premise that developing strong BSR could lead to an improved performance in acquiring and implementing AMT. The implications of the study are offered for both the academic and practitioner audience
Advanced manufacturing technology adoption in developing countries: the role of buyer‐supplier relationships
Purpose: Developing countries are heavily dependent on the resources and commitment of foreign providers to ensure successful adoption of advanced manufacturing technology (AMT). The purpose of this paper is to describe the important role of buyer‐supplier relationships (BSRs) in the process of technology selection, acquisition and implementation.
Design/methodology/approach: A survey of 147 Malaysian manufacturing firms is the main instrument used in the research investigations and data analysis is carried out by the structured equation modelling (SEM) technique. In particular, the authors examine the impact on performance of different patterns of relationship between technology buyers and suppliers.
Findings: Although the majority of the firms reported improvements in their performance since the acquisition of AMT, closer investigation reveals that those demonstrating a closer relationship with their suppliers are more likely to achieve higher levels of technology and implementation performance (IP) than those that do not.
Research limitations/implications: The paper only assesses the strength of BSR from the buyers' perspective and they may have limited experience of acquisition, whereas suppliers may have more experience of selling AMT. Also, the research is undertaken in Malaysia and the findings may be different in other countries, especially where the technology being acquired is not imported but sourced locally.
Practical implications: The findings relating to BSR, technology acquisition and IP have important implications both for customers and supplier firms as well as for industrial policy makers in developing countries.
Originality/value: The result of the research provides useful insights that are especially pertinent to an improved understanding of BSRs in the procurement of capital equipment, about which the current research literature is limited
On the Ionization of Luminous WMAP Sources in the Galaxy : Constraints from He Recombination Line Observations with the GBT
The Wilkinson Microwave Anisotropy Probe (WMAP) free-free foreground emission
map is used to identify diffuse ionized regions (DIR) in the Galaxy (Rahman &
Murray 2010). It has been found that the 18 most luminous WMAP sources produce
more than half of the total ionizing luminosity of the Galaxy. We observed
radio recombination lines (RRLs) toward the luminous WMAP source G49.75-0.45
with the Green Bank Telescope near 1.4 GHz. Hydrogen RRL is detected toward the
source but no helium line is detected, implying that n_He+/n_H+ < 0.024. This
limit puts severe constraint on the ionizing spectrum. The total ionizing
luminosity of G49 (3.05 x 10^51 s^-1) is ~ 2.8 times the luminosity of all
radio HII regions within this DIR and this is generally the case for other WMAP
sources. Murray & Rahman (2010) propose that the additional ionization is due
to massive clusters (~ 7.5 x10^3 Msun for G49) embedded in the WMAP sources.
Such clusters should produce enough photons with energy \geq 24.6 eV to fully
ionize helium in the DIR. Our observations rule out a simple model with G49
ionized by a massive cluster. We also considered 'leaky' HII region models for
the ionization of the DIR, suggested by Lockman and Anantharamaiah, but these
models also cannot explain our observations. We estimate that the helium
ionizing photons need to be attenuated by > ~10 times to explain the
observations. If selective absorption of He- ionizing photons by dust is
causing this additional attenuation, then the ratio of dust absorption cross
sections for He- and H- ionizing photons should be > ~6.Comment: Accepted for publication in the ApJ; 14 pages, 3 figure
The use of a mirror reduces isolation stress in horses being transported by trailer
Horse trailers are a common form of transportation for horses and ponies and often require the animal to travel alone or with a single companion. The current study investigated the effect of transporting horses alone, in company or with an acrylic safety mirror (measuring 81 x 61.5 cm) that provided surrogate companionship. The behavioural and physiological responses of twelve mature horses during a 30-minute journey by trailer under the three treatments were compared. Behaviour (vocalisation, eating, head-tossing, pawing, and head turning) was recorded. In order to assess circulatory changes that occur as part of the response to transport, heart rate (HR), rectal (Tr) and ear-pinna (Tp) temperatures were recorded. When travelling with a live companion significantly less time was spent vocalising (p<0.001), head turning (p<0.001), head-tossing (p<0.01) and pawing (p<0.01); eating behaviour increased (p<0.05). Physiological responses (increases in HR and Tr and decreases in Tp) were also significantly reduced when travelling with a live companion (p<0.01). Travelling with the mirror did not significantly affect physiological responses compared with travelling alone, but the rise in Tr and fall in Tp was reduced (p=0.052 and p=0.051 respectively) and can be considered a trend. When travelling with a mirror significantly less time was spent turning the head (p<0.01), vocalising (p<0.05) and head tossing (p<0.05); eating behaviour increased (p<0.05)
Massive Star Forming Regions in the Galaxy using the Spitzer GLIMPSE Survey
We examine the thirteen most luminous sources in the WMAP free-free map using
the Spitzer GLIMPSE and MSX surveys to identify massive star formation regions,
emitting one-third of the Galactic free-free luminosity. We identify star
forming regions by a combination of bubble morphology in 8 \micronm (PAH)
emission and radio recombination line radial velocities. We find 40 star
forming regions associated with our WMAP sources, and determine unique
distances to 31. We interpret the bubbles as evidence for radial expansion. The
radial velocity distribution for each source allows us to measure the intrinsic
speed of a region's expansion. This speed is consistent with the size and age
of the bubbles. The high free-free luminosities, combined with negligible
synchrotron emission, demonstrate that the bubbles are not driven by
supernovae. The kinetic energy of the largest bubbles is a substantial fraction
of that measured in the older superbubbles found by Heiles. We find that the
energy injected into the ISM by our bubbles is similar to that required to
maintain the turbulent motion in the gas disk inside 8 kpc. We report a number
of new star forming regions powered by massive (\textrm{M}_{*} > 10^4
\textrm{M}_\sun) star clusters. We measure the scale height of the Galactic O
stars to be h_{\textrm{*}} = 35 \pm 5 \pc. We determine an empirical
relationship between the PAH and free-free emission of the form
. Finally, we find that the bubble
geometry is more consistent with a spherical shell rather than a flattened
disk.Comment: Submitted to ApJ; 29 Pages, 17 Figures, 5 Table
Star Formation in Massive Clusters via the Wilkinson Microwave Anisotropy Probe and the Spitzer Glimpse Survey
We use the WMAP maximum entropy method foreground emission map combined with
previously determined distances to giant HII regions to measure the free-free
flux at Earth and the free-free luminosity of the galaxy. We find a total flux
f_\nu=54211 Jy and a flux from 88 sources of f_\nu=36043 Jy. The bulk of the
sources are at least marginally resolved, with mean radii ~60 pc, electron
density n_e ~ 9 cm^{-3}, and filling factor \phi_{HII}=0.005 (over the Galactic
gas disk). The total dust-corrected ionizing photon luminosity is Q=3.2x10^{53}
photons/s, in good agreement with previous estimates. We use GLIMPSE and MSX 8
micron images to show that the bulk of the free-free luminosity is associated
with bubbles having radii r~5-100 pc, with a mean ~20 pc. These bubbles are
leaky, so that ionizing photons from inside the bubble excite free-free
emission beyond the bubble walls, producing WMAP sources that are larger than
the 8 micron bubbles. We suggest that the WMAP sources are the counterparts of
the extended low density HII regions described by Mezger (1978). Half the
ionizing luminosity from the sources is emitted by the nine most luminous
objects, while the seventeen most luminous emit half the total Galactic
ionizing flux. These 17 sources have 4x10^{51} < Q <1.6x10^{52}, corresponding
to 6x10^4M_\odot < M_*< 2x10^5M_\odot; half to two thirds of this will be in
the central massive star cluster. We convert the measurement of Q to a Galactic
star formation rate dM/dt=1.3M_\odot/yr, but point out that this is highly
dependent on the exponent \Gamma~1.35 of the high mass end of the stellar
initial mass function.Comment: 19 pages, 8 figures, submitted to Ap
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