Theory of photon coincidence statistics in photon-correlated beams

The statistics of photon coincidence counting in photon-correlated beams is thoroughly investigated considering the effect of the finite coincidence resolving time. The correlated beams are assumed to be generated using parametric downconversion, and the photon streams in the correlated beams are modeled by two partially correlated Poisson point processes. An exact expression for the mean rate of coincidence registration is developed using techniques from renewal theory. It is shown that the use of the traditional approximate rate, in certain situations, leads to the overestimation of the actual rate. The error between the exact and approximate coincidence rates increases as the coincidence-noise parameter, defined as the mean number of uncorrelated photons detected per coincidence resolving time, increases. The use of the exact statistics of the coincidence becomes crucial when the background noise is high or in cases when high precision measurement of coincidence is required. Such cases arise whenever the coincidence-noise parameter is even slightly in excess of zero. It is also shown that the probability distribution function of the time between consecutive coincidence registration can be well approximated by an exponential distribution function. The well-known and experimentally verified Poissonian model of the coincidence registration process is therefore theoretically justified. The theory is applied to an on-off keying communication system proposed by Mandel which has been shown to perform well in extremely noisy conditions. It is shown that the bit-error rate (BER) predicted by the approximate coincidence-rate theory can be significantly lower than the actual BER obtained using the exact theory

Gambaran Perilaku Menyimpang Mahasiswa Indekost dan Upaya Pencegahannya

Para siswa yang indekost kebanyakan berasal dari daerah yang jauh, seperti mengakses film negatif, hingga jatuh ke dalam hubungan negatif dengan para mitranya, dampaknya adalah untuk menjangkau orang tua, pemilik rumah kost, dan pengembangan media dari media telekomunikasi yang disalahgunakan, ini harus dicegah pendekatan oleh semua pihak

Statistical algorithm for nonuniformity correction in focal-plane arrays

A statistical algorithm has been developed to compensate for the fixed-pattern noise associated with spatial nonuniformity and temporal drift in the response of focal-plane array infrared imaging systems. The algorithm uses initial scene data to generate initial estimates of the gain, the offset, and the variance of the additive electronic noise of each detector element. The algorithm then updates these parameters by use of subsequent frames and uses the updated parameters to restore the true image by use of a least-mean-square error finite-impulse-response filter. The algorithm is applied to infrared data, and the restored images compare favorably with those restored by use of a multiple-point calibration technique

Implementasi Sistem Penjualan Toko Online Pada Verici Sport Dengan Menggunakan Pemrograman Php

Saat ini Toko Verici Sport dalam sistem penjualan masih secara manual. Ini menunjukkan bahwa sistem yang dipakai tidak efektif dan efisien. Untuk itu dibutuhkan suatu sistem yang dapat memberikan kemudahan bagi konsumen dalam hal mendapatkan informasi mengenai produk-produk melalui website. Sebelum pembuatan website terlebih dahulu dilakukan penganalisisan data dengan menggunakan alat bantu perancangan sistem, kemudian dirancang desain input, desain output, desain file, dan aliran program dari sistem yang baru. Hasil dari analisis tersebut diterapkan ke dalam suatu program aplikasi website penjualan yang didukung oleh PHP-MySQL. Dengan adanya sistem yang baru diharapkan konsumen mendapatkan informasi mengenai produk  lebih cepat dan akurat dan pemesanan lebih mudah. Bagi Toko Verici Sport penjualan produk diupayakanlebih meningkat sehingga dapat memberikan keuntungan bagi Perusahaan

Taxonomic significance of leaf epidermal anatomy of selected Persicaria Mill. species of family Polygonaceae from Pakistan

Leaf epidermal anatomy of selected Persicaria Mill. species of the family Polygonaceae revealed variation in size and shape of epidermal cells, stomata, glandular and non glandular trichomes. This study proves to be taxonomically important tool in the delimitation of taxa. Epidermal cell shapes are variable but mostly polygonal. Five different stomatal patterns are reported for Persicaria Mill. Two types of non glandular trichomes are observed only in P. barbata, P. stagnina and P. orientalis which serve as their distinguishing characters. Glandular trichomes are 1, 2 and 4-celled peltate, capitate and spheroidal. Cluster analyses elucidate relationship among different taxa by utilization of leaf epidermal characters

Gastrointestinal symptoms in acromegaly: A case control study

BACKGROUND Acromegaly is a chronic disease caused by a pituitary somatotroph adenoma resulting in excess secretion of growth hormone, which leads to excess secretion of Insulin like growth factor 1 from the liver, causing abnormal soft tissue growth. There is increasing awareness that diseases affecting connective tissue are associated with an increase in functional gastrointestinal symptoms. Data was collected from patients with a confirmed diagnosis of acromegaly to evaluate the intensity, variety and impact of abdominal symptoms in comparison with a control group who were healthy participants recruited from the local fracture clinic. AIM To evaluate the frequency type and burden of abdominal symptoms in acromegaly in comparison with a control group. METHODS Medical documentation of patients with a diagnosis of acromegaly treated in one tertiary medical centre between 2010 and 2017 has been analysed. Data was collected from patients with confirmed acromegaly, using the Short Form Health Survey (SF36) and Rome IV Diagnostic questionnaire for Functional Gastrointestinal Disorders in Adults (R4DQ) and compared to a sex- and age-matched control group, to assess the burden of abdominal symptoms. Microsoft Excel and IBM SPSS v 25 were used for data analysis. RESULTS Fifty patients with acromegaly (24 male and 26 females; age range 23-64 years, mean 43) and 200 controls (96 male and 104 females; age range 18-84, mean 42.4) were recruited. 92% (46 out of 50) of patients with acromegaly reported abdominal symptoms and 78% (39 out of 50) had at least one functional gastrointestinal disorder according to the Rome IV diagnostic criteria, compared to 16% of controls (OR > 1, P 1, P 1, P < 0.001) as compared to the control group. CONCLUSION Upper and lower functional gastrointestinal tract disorders (defined by Rome IV diagnostic criteria) are significantly more prevalent in patients with acromegaly compared with healthy age and sex matched controls in our study. Functional constipation is the most commonly reported problem. Poorer quality of life may in part be attributable to the increased prevalence of abdominal symptoms

Scene-based nonuniformity correction for focal plane arrays by the method of the inverse covariance form

What is to our knowledge a new scene-based algorithm for nonuniformity correction in infrared focal-plane array sensors has been developed. The technique is based on the inverse covariance form of the Kalman filter (KF), which has been reported previously and used in estimating the gain and bias of each detector in the array from scene data. The gain and the bias of each detector in the focal-plane array are assumed constant within a given sequence of frames, corresponding to a certain time and operational conditions, but they are allowed to randomly drift from one sequence to another following a discrete-time Gauss-Markov process. The inverse covariance form filter estimates the gain and the bias of each detector in the focal-plane array and optimally updates them as they drift in time. The estimation is performed with considerably higher computational efficiency than the equivalent KF. The ability of the algorithm in compensating for fixed-pattern noise in infrared imagery and in reducing the computational complexity is demonstrated by use of both simulated and real data