2,070 research outputs found
Smooth Inequalities and Equilibrium Inefficiency in Scheduling Games
We study coordination mechanisms for Scheduling Games (with unrelated
machines). In these games, each job represents a player, who needs to choose a
machine for its execution, and intends to complete earliest possible. Our goal
is to design scheduling policies that always admit a pure Nash equilibrium and
guarantee a small price of anarchy for the l_k-norm social cost --- the
objective balances overall quality of service and fairness. We consider
policies with different amount of knowledge about jobs: non-clairvoyant,
strongly-local and local. The analysis relies on the smooth argument together
with adequate inequalities, called smooth inequalities. With this unified
framework, we are able to prove the following results.
First, we study the inefficiency in l_k-norm social costs of a strongly-local
policy SPT and a non-clairvoyant policy EQUI. We show that the price of anarchy
of policy SPT is O(k). We also prove a lower bound of Omega(k/log k) for all
deterministic, non-preemptive, strongly-local and non-waiting policies
(non-waiting policies produce schedules without idle times). These results
ensure that SPT is close to optimal with respect to the class of l_k-norm
social costs. Moreover, we prove that the non-clairvoyant policy EQUI has price
of anarchy O(2^k).
Second, we consider the makespan (l_infty-norm) social cost by making
connection within the l_k-norm functions. We revisit some local policies and
provide simpler, unified proofs from the framework's point of view. With the
highlight of the approach, we derive a local policy Balance. This policy
guarantees a price of anarchy of O(log m), which makes it the currently best
known policy among the anonymous local policies that always admit a pure Nash
equilibrium.Comment: 25 pages, 1 figur
Genetic relatidness and In vitro antimicrobial activities of alkaloids isolated from Indian varieties of Catharanthus roseus (L.)
Catharanthus roseus (L.) is one of the most intensively studied for its anticancerous property but phytopathogenic activity of the plant has not been much studied. Callus induction from C. roseus was optimized by varying various harmone concentrations and the best result was obtanined in MS medium fortified with 2mgL-1 2, 4-D and 0.1 mgL-1 kinetin. Antimicrobial activity and minimum inhibitory concentration showed that the 20, 40, and 80% leaves, shoot, and root extract inhibits Gram positive B. subtilis and phytopathogenic fungus F. oxysporium, A. niger, Rhizoctonia solani, Colletotrichum falcatum, Cylindrocladium scoparium respectively. Genetic relatidness was determined by RAPD analysis revealed that, white and violet colored C.roseus flowered plant was closely related than rosy pink coloured flower
Precise time and frequency intercomparison between NPL, India and PTB, Federal Republic of Germany via satellite symphonie-1
A time and frequency intercomparison experiment conducted using Earth stations in New Delhi, India and Raisting, FRG is described. The NPL clock was placed at New Delhi Earth Station and the Raisting Clock was calibrated with PTB/Primary standard via LORAN-C and travelling clocks. The random uncertainity of time comparisons, represented by two sample Allan Variance sigma (30 seconds), was less than 10 nanoseconds. The relative frequency difference between the NPL and Raisting Clocks, SNPL, RAIS, as measured over the 44 days period was found to be -15.7 x 10 to the -13th power. The relative frequency difference between PTB Primary Standard and Raisting Clock, SPTB, RAIS, during this period, was measured to be -22.8 x 10 to the -13th power. The relative frequency difference between NPL clock and PTB Primary Standard, SNPL, PTB, thus, is +7.1 x 10 to the -13th power. The clock rate (UTC, India) of +7.1 + or - 0.5 x 10 to the -13th power, agrees well with that obtained via VLF phase measurements over one year period and with USNO travelling clock time comparisons made in September, 1980
Decoupling a Cooper-pair box to enhance the lifetime to 0.2 ms
We present a circuit QED experiment in which a separate transmission line is
used to address a quasi-lumped element superconducting microwave resonator
which is in turn coupled to an Al/AlO/Al Cooper-pair box (CPB) charge
qubit. In our measurements we find a strong correlation between the measured
lifetime of the CPB and the coupling between the qubit and the transmission
line. By monitoring perturbations of the resonator's 5.44 GHz resonant
frequency, we have measured the spectrum, lifetime (), Rabi, and Ramsey
oscillations of the CPB at the charge degeneracy point while the CPB was
detuned by up to 2.5 GHz . We find a maximum lifetime of the CPB was s for to 4.5 GHz. Our measured 's are consistent with
loss due to coupling to the transmission line, spurious microwave circuit
resonances, and a background decay rate on the order of
s of unknown origin, implying that the loss tangent in the AlO
junction barrier must be less than about at 4.5 GHz, about 4
orders of magnitude less than reported in larger area Al/AlO/Al tunnel
junctions
Intra- and inter-operator reproducibility of automated cloud-based carotid lumen diameter ultrasound measurement
Background: Common carotid artery lumen diameter (LD) ultrasound measurement systems are either manual or semi-automated and lack reproducibility and variability studies. This pilot study presents an automated and cloud-based LD measurements software system (AtheroCloud) and evaluates its: (i) intra/inter-operator reproducibility and (ii) intra/inter-observer variability. Methods: 100 patients (83 M, mean age: 68 ± 11 years), IRB approved, consisted of L/R CCA artery (200 ultrasound images), acquired using a 7.5-MHz linear transducer. The intra/inter-operator reproducibility was verified using three operator's readings. Near-wall and far carotid wall borders were manually traced by two observers for intra/inter-observer variability analysis. Results: The mean coefficient of correlation (CC) for intra- and inter-operator reproducibility between all the three automated reading pairs were: 0.99 (P < 0.0001) and 0.97 (P < 0.0001), respectively. The mean CC for intra- and inter-observer variability between both the manual reading pairs were 0.98 (P < 0.0001) and 0.98 (P < 0.0001), respectively. The Figure-of-Merit between the mean of the three automated readings against the four manuals were 98.32%, 99.50%, 98.94% and 98.49%, respectively. Conclusions: The AtheroCloud LD measurement system showed high intra/inter-operator reproducibility hence can be adapted for vascular screening mode or pharmaceutical clinical trial mode
- …