Engineering Quantum Jump Superoperators for Single Photon Detectors

We study the back-action of a single photon detector on the electromagnetic field upon a photodetection by considering a microscopic model in which the detector is constituted of a sensor and an amplification mechanism. Using the quantum trajectories approach we determine the Quantum Jump Superoperator (QJS) that describes the action of the detector on the field state immediately after the photocount. The resulting QJS consists of two parts: the bright counts term, representing the real photoabsorptions, and the dark counts term, representing the amplification of intrinsic excitations inside the detector. First we compare our results for the counting rates to experimental data, showing a good agreement. Then we point out that by modifying the field frequency one can engineer the form of QJS, obtaining the QJS's proposed previously in an ad hoc manner

Non-local quantum correlations and detection processes in QFT

Quantum detection processes in QFT must play a key role in the description of quantum field correlations, such as the appearance of entanglement, and of causal effects. We consider the detection in the case of a simple QFT model with a suitable interaction to exact treatment, consisting of a quantum scalar field coupled linearly to a classical scalar source. We then evaluate the response function to the field quanta of two-level point-like quantum model detectors, and analyze the effects of the approximation adopted in standard detection theory. We show that the use of the RWA, that characterizes the Glauber detection model, leads in the detector response to non-local terms corresponding to an instantaneously spreading of source effects over the whole space. Other detector models, obtained with non-standard or the no-application of RWA, give instead local responses to field quanta, apart from source independent vacuum contribution linked to preexisting correlations of zero-point field.Comment: 23 page

Analysis of risk factors of hypertension: a cross-sectional study in a rural area

Background: Hypertension (high blood pressure) is when the pressure in your blood vessels is too high (140/90 mmHg or higher). It is common but can be serious if not treated. Methods: The present study was conducted at medicine department of Adichunchanagiri Institute of Medical Sciences, Mandya from February to July 2023. Total 100 study subjects in the age group of 30–60 years were included by simple random sampling technique in the present study. Pre-designed, pre-tested proforma was used to collect data regarding demographic characteristics and different risk factors i.e. smoking and alcoholism through house-to-house visits. Results: In the present study the overall prevalence of hypertension was found to be 18%. Similar findings have also been reported in other studies. Comparable prevalence (15%) was found in the study conducted at squatter settlement of Karachi (Pakistan). Similar prevalence of hypertension (16.9%) has also been reported in the study conducted among labour population of Gujarat. Conclusions: Cardiovascular risk factors and lifestyle behaviors are amenable to modification and may therefore be relevant targets in the prevention of hypertension. For some modifiable risk factors, it is unclear whether they are causally related to hypertension. This study found that, BMI, alcohol dependence, insomnia, and educational level are causal risk factors of hypertension. This improved understanding of the pathophysiology of hypertension can be used to identify additional targets for the prevention of hypertension and its association diseases.

Multi-way Cloud-Side Access Control for Encrypted Cloud Storage

Individuals support the incredible intensity of cloud computing, however can't completely believe the cloud providers to have protection delicate data, because of the nonattendance of client to-cloud controllability. To guarantee confidentiality, data administrators redistribute scrambled data rather than plaintexts. To impart the scrambled files to different clients, ciphertext-strategy attribute-based encryption can be used to direct fine-grained and administrator driven access control. Yet, this doesn't adequately get secure against different assaults. Numerous past schemes didn't concede the cloud supplier the capacity to check whether a downloader can decode. Along these lines, these files ought to be accessible to everybody open to the cloud storage. A noxious aggressor can download a great many files to dispatch monetary refusal of supportability assaults, which will to a great extent expend the cloud asset. The payer of the cloud service bears the cost. These worries ought to be settled in true open cloud storage. In this paper, we propose an answer for secure encoded cloud storages from EDoS assaults and give asset utilization responsibility. We present two conventions for various settings, trailed by execution and security examination. Furthermore, attribute-based control in the framework additionally empowers the cloud server to confine the entrance to those clients with a similar arrangement of attributes while protecting client security, i.e., the cloud server just realizes that the client satisfies the necessary predicate, however has no clue on the specific identity of the client

Multi-task Image Classification via Collaborative, Hierarchical Spike-and-Slab Priors

Promising results have been achieved in image classification problems by exploiting the discriminative power of sparse representations for classification (SRC). Recently, it has been shown that the use of \emph{class-specific} spike-and-slab priors in conjunction with the class-specific dictionaries from SRC is particularly effective in low training scenarios. As a logical extension, we build on this framework for multitask scenarios, wherein multiple representations of the same physical phenomena are available. We experimentally demonstrate the benefits of mining joint information from different camera views for multi-view face recognition.Comment: Accepted to International Conference in Image Processing (ICIP) 201

The use of remote sensing data for drought assessment and monitoring in southwest Asia

Drought / Monitoring / Indicators / Assessment / Remote sensing / Asia

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.