2,370 research outputs found
Smooth quantum-classical transition in photon subtraction and addition processes
Recently Parigi et al. [Science 317, 1890 (2007)] implemented experimentally
the photon subtraction and addition processes from/to a light field in a
conditional way, when the required operations were produced successfully only
upon the positive outcome of a separate measurement. It was verified that for a
low intensity beam (quantum regime) the bosonic annihilation operator does
indeed describe a single photon subtraction, while the creation operator
describes a photon addition. Nonetheless, the exact formal expressions for
these operations do not always reduce to these simple identifications, and in
this connection here we deduce the general superoperators for multiple photons
subtraction and addition processes and analyze the statistics of the resulting
states for classical field states having an arbitrary intensity. We obtain
closed analytical expressions and verify that for classical fields with high
intensity (classical regime) the operators that describe photon subtraction and
addition processes deviate significantly from simply annihilation and creation
operators. Complementarily, we analyze in details such a smooth
quantum-classical transition as function of beam intensity for both processes.Comment: 7 pages, 5 figures. To appear in Phys. Rev.
Microscopic models of quantum jump super-operators
We discuss the quantum jump operation in an open system, and show that jump
super-operators related to a system under measurement can be derived from the
interaction of that system with a quantum measurement apparatus. We give two
examples for the interaction of a monochromatic electromagnetic field in a
cavity (the system) with 2-level atoms and with a harmonic oscillator
(representing two different kinds of detectors). We show that derived quantum
jump super-operators have `nonlinear' form which depends on assumptions made
about the interaction between the system and the detector. A continuous
transition to the standard Srinivas--Davies form of the quantum jump
super-operatoris shown
Yield and Quality of Passion Fruit in Relation to Training Systems
Four different training systems, viz., Kniffin, High trellis, Tatura and Bower were evaluated in passion fruit cv. Kaveri. Kniffin system with 4 arms recorded highest cumulative yield of 67.22 t/ha with a cost:benefit ratio of 1:4.25, followed by Kniffin 2 arm and 6 arm, respectively. Kniffin system was also the most ideal system of training for passion fruit, facilitating easy cultural operations. Although Tatura system recorded highest cumulative yield/vine (43.57kg), it registered lowest yield/ha, largely due to lower plant population/ha (1250 vines/ha). Fruit quality parameters like TSS, Vit. C, carotene content and titrable acidity were not significantly influenced by different training systems. Similarly, interception of Photosynthetically Active Radiation (PAR) by the canopy did not differ significantly among training systems. Though photosynthetic rate did not differ significantly, shaded leaves in the canopy did not contribute photosynthates and were parasitic on the vine
Rhodovulum visakhapatnamense sp. nov.
A Gram-negative, rod-shaped, phototrophic bacterium (JA181T) was isolated from a tidal water sample. On the basis of 16S rRNA gene sequence similarity, strain JA181T was shown to belong to the class Alphaproteobacteria, most closely related to Rhodovulum sulfidophilum (97.8 % similarity to the type strain), Rhodovulum adriaticum (93 %), Rhodovulum robiginosum (93 %), Rhodovulum iodosum (94 %), Rhodovulum imhoffii (94 %), Rhodovulum strictum (95 %), Rhodovulum euryhalinum (94.6 %) and Rhodovulum marinum (94.6 %). DNA–DNA hybridization with Rdv. sulfidophilum DSM 1374T (relatedness of 39 % with strain JA181T) and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain JA181T from the eight Rhodovulum species with validly published names. Strain JA181T therefore represents a novel species, for which the name Rhodovulum visakhapatnamense sp. nov. is proposed (type strain JA181T =JCM 13531T =ATCC BAA-1274T =DSM 17937T)
A k-out-of-n reliability system with an unreliable server and phase type repairs and services: the (N, T) policy
In this paper we study a k-out-of-n reliability system in which a single unreliable server maintains n identical components. The reliability system is studied under the (N,T) policy. An idle server takes a vacation for a random amount of time T and then attends to any failed component waiting in line upon completion of the vacation. The vacationing server is recalled instantaneously upon the failure of the Nth component. The failure times of the components are assumed to follow an exponential distribution. The server is subject to failure with failure times exponentially distributed. Repair times of the component, fixing times of the server, and vacationing times of the server are assumed to be of phase type. Using matrix-analytic methods we perform steady state analysis of this model. Time spent by a failed component in service, total time in the repair facility, vacation time of the server, non-vacation time of the server, and time until failure of the system are all shown to be of phase type. Several performance measures are evaluated. Illustrative numerical examples are presented
On Discrete Wrapped Cauchy Model
Modeling angular data throws many challenges in practical situations. Good number of circular / semicircular models are developed for modeling continuous circular / angular data. Scant attention was paid in analysis of discrete angular data, in particular, construction of discrete angular models for fitting angular data is not touched so far. Hence an attempt is made to develop method for constructing Discrete l - axial models and study their population characteristics.Keywords: China insurance industry, Foreign fund, Challenge DOI: 10.7176/MTM/9-4-02 Publication date: April 30th 2019
Climate change adaptation and mitigation strategies for sustainable crop production
Climate change is the main environmental problem facing humanity. Evidences over the past few decades show that significant changes in climate are taking place all over the world as a result of enhanced human activities through deforestation emission of various greenhouse gases and indiscriminate use of fossil fuels. Carbon dioxide (CO2) Methane and Nitrous Oxide are the major greenhouse gases. CO2 enters the atmosphere mostly through burning fossil fuels. Methane emissions also result from livestock and other agricultural practices and Nitrous Oxide is emitted during agricultural and industrial activities. Global atmospheric concentration of CO2 has increased from pre-industrial level of 280 parts per million (ppm) to 408 ppm in Feb 2018. Global projections indicate higher temperature of 1.5 to 4.5°C by the year 2050 as a result of enhanced greenhouse gases. There is medium confidence in that the Indian summer monsoon circulation weakens but this is compensated by increased atmospheric moisture content leading to more rainfall. There is medium confidence in an increase of Indian summer monsoon rainfall and its extremes throughout the 21st century under all RCP (Representative Concentration Pathways) scenarios
Effects of Daily News Sentiment on Stock Price Forecasting
Predicting future prices of a stock is an arduous task to perform. However,
incorporating additional elements can significantly improve our predictions,
rather than relying solely on a stock's historical price data to forecast its
future price. Studies have demonstrated that investor sentiment, which is
impacted by daily news about the company, can have a significant impact on
stock price swings. There are numerous sources from which we can get this
information, but they are cluttered with a lot of noise, making it difficult to
accurately extract the sentiments from them. Hence the focus of our research is
to design an efficient system to capture the sentiments from the news about the
NITY50 stocks and investigate how much the financial news sentiment of these
stocks are affecting their prices over a period of time. This paper presents a
robust data collection and preprocessing framework to create a news database
for a timeline of around 3.7 years, consisting of almost half a million news
articles. We also capture the stock price information for this timeline and
create multiple time series data, that include the sentiment scores from
various sections of the article, calculated using different sentiment
libraries. Based on this, we fit several LSTM models to forecast the stock
prices, with and without using the sentiment scores as features and compare
their performances.Comment: 9th ICBAI conference on December'2022 at IIM Bangalor
A security suite for wireless body area networks
Wireless Body Area Networks (WBANs) have gained a lot of research attention
in recent years since they offer tremendous benefits for remote health
monitoring and continuous, real-time patient care. However, as with any
wireless communication, data security in WBANs is a challenging design issue.
Since such networks consist of small sensors placed on the human body, they
impose resource and computational restrictions, thereby making the use of
sophisticated and advanced encryption algorithms infeasible. This calls for the
design of algorithms with a robust key generation / management scheme, which
are reasonably resource optimal. This paper presents a security suite for
WBANs, comprised of IAMKeys, an independent and adaptive key management scheme
for improving the security of WBANs, and KEMESIS, a key management scheme for
security in inter-sensor communication. The novelty of these schemes lies in
the use of a randomly generated key for encrypting each data frame that is
generated independently at both the sender and the receiver, eliminating the
need for any key exchange. The simplicity of the encryption scheme, combined
with the adaptability in key management makes the schemes simple, yet secure.
The proposed algorithms are validated by performance analysis.Comment: 20 pages, 10 figures, 3 tables, International Journal of Network
Security & its Applications (IJNSA
Observation of direct and indirect magnetoelectricity in lead free ferroelectric (Na 0.5Bi 0.5TiO 3)-magnetostrictive (CoFe 2O 4) particulate composite
A particulate composite consisting of 65 mol. % Na 0.5Bi 0.5TiO 3 and 35 mol. % CoFe 2O 4 was synthesized, and it's structure, microstructure, ferroelectric, magnetostrictive, magnetic, and direct/indirect magnetoelectric properties were studied. The composite showed different magnetization behaviour under electrically poled and un-poled conditions. The percentage change in magnetization as a result of poling is approximately -15% at 500 Oe magnetic field. Magnetostriction measurements displayed a value of λ 11 = -57 × 10 -6 and piezomagnetic coefficient δλ 11/δH = 0.022 × 10 -6 kOe -1 at 2.2 kOe for the composite. The maximum magnetoelectric output varied from 1350 mV/cm to 2000 mV/cm with change in the electrical poling condition
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