Program ‘Ziarah Ihsan Ramadan @ WAZAN di Hati’ santuni pelajar asnaf

SERDANG - Program ‘Ziarah Ihsan Ramadan @ WAZAN di Hati’ anjuran Pusat Pengurusan Wakaf, Zakat dan Endowmen (WAZAN) kali ini berbeza dan lebih meriah daripada sebelum ini, dengan beberapa entiti lain turut dijemput menyertainya

Introduction: Advances and trends in image formation in X-ray computed tomography

Introduction to articles in a special focus series on CT imaging

On efficient assessment of image-quality metrics based on linear model observers

pre-printThis paper is motivated by the problem of image-quality assessment using model observers for the purpose of development and optimization of medical imaging systems. Specifically, we present a study regarding the estimation of the receiver operating characteristic (ROC) curve for the observer and associated summary measures. This study evaluates the statistical advantage that may be gained in ROC estimates of observer performance by assuming that the difference of the class means for the observer ratings is known. Such knowledge is frequently available in image-quality studies employing known-location lesion detection tasks together with linear model observers. The study is carried out by introducing parametric point and confidence interval estimators that incorporate a known difference of class means. An evaluation of the new estimators for the area under the ROC curve establishes that a large reduction in statistical variability can be achieved through incorporation of knowledge of the difference of class means. Namely, the mean 95% AUC confidence interval length can be as much as seven times smaller in some cases. We also examine how knowledge of the difference of class means can be advantageously used to compare the areas under two correlated ROC curves, and observe similar gains

A nonparametric procedure for comparing the areas under correlated LROC curves

pre-printIn contrast to the receiver operating characteristic (ROC) assessment paradigm, localization ROC (LROC) analysis provides a means to jointly assess the accuracy of localization and detection in an observer study. In a typical multireader, multicase (MRMC) evaluation, the data sets are paired so that correlations arise in observer performance both between readers and across the imaging conditions (e.g., reconstruction methods or scanning parameters) being compared. Therefore, MRMC evaluations motivate the need for a statistical methodology to compare correlated LROC curves. In this paper, we suggest a nonparametric strategy for this purpose. Specifically, we find that seminal work of Sen on U-statistics can be applied to estimate the covariance matrix for a vector of LROC area estimates. The resulting covariance estimator is the LROC analog of the covariance estimator given by DeLong et al. for ROC analysis. Once the covariance matrix is estimated, it can be used to construct confidence intervals and/or confidence regions for purposes of comparing observer performance across imaging conditions. In addition, given the results of a small-scale pilot study, the covariance estimator may be used to estimate the number of images and observers needed to achieve a desired confidence interval size in a full-scale observer study. The utility of our methodology is illustrated with a human-observer LROC evaluation of three image reconstruction strategies for fan-beam X-ray computed tomography

Estimation of channelized hotelling observer performance with known class means or known difference of class means

Journal ArticleThis paper concerns task-based image quality assessment for the task of discriminating between two classes of images. We address the problem of estimating two widely-used detection performance measures, SNR and AUC, from a finite number of images, assuming that the class discrimination is performed with a channelized Hotelling observer. In particular, we investigate the advantage that can be gained when either 1) the means of the signal-absent and signal-present classes are both known, or 2) when the difference of class means is known. For these two scenarios, we propose uniformly minimum variance unbiased estimators of S N R?, derive the corresponding sampling distributions and provide variance expressions. In addition, we demonstrate how the bias and variance for the related AUC estimators may be calculated numerically by using the sampling distributions for the S N R? estimators. We find that for both S N R? and AUC, the new estimators have significantly lower bias and mean-square error than the traditional estimator, which assumes that the class means, and their difference, are unknown

Image Reconstruction from Truncated Data in Single-Photon Emission Computed Tomomgraphy with Uniform Attenuation

International audienceWe present a mathematical analysis of the problem of image reconstruction from truncated data in two-dimensional (2D) single-photon emission computed tomography (SPECT). Recent results in classical tomography have shown that accurate reconstruction of some parts of the object is possible in the presence of truncation. We have investigated how these results extend to 2D parallel-beam SPECT, assuming that the attenuation map is known and constant in a convex region $\Omega$ that includes all activity sources. Our main result is a proof that, just like in classical tomography accurate SPECT reconstruction at a given location x ∈ $\Omega$,does not require the data on all lines passing through $\Omega$; some amount of truncation can be tolerated. Experimental reconstruction results based on computer-simulated data are given in support of the theory

APLIKASI PENERIMAAN SISWA BARU STUDI KASUS SDI OEBUFU KUPANG MENGGUNAKAN VB 6.0

Penerapan aplikasi penerimaan siswa baru adalah sebuah aplikasi komputer yang dibangun untuk memberikan kemudahan dalam penerimaan siswa baru yang pencatatan dan pendataannya menggunakan sebuah aplikasi khusus yang dianggap penulis lebih efektif. Aplikasi tersebut diatas dapat memberikan manfaat bagi pengguna maupun lembaga sekolah dengan menyediakan banyak informasi berupa laporan-laporan dari system yang secara garis besar berupa laporan data calon siswa baru dan laporan pemasukan keuangan pendaftaran siswa. Selain itu pengguna dapat melakukan pengaksesan data dengan mudah dan cepat sehingga tidak memerlukan waktu yang lama dan dapat meringankan beban serta meningkatkan kinerja kerja dari panitia penerimaan siswa baru. Metode penelitian yang digunakan pada aplikasi ini adalah metode waterfall . Dari permasalahan diatas dapat disimpulkan bahwa dengan adanya “Aplikasi Penerimaan Siswa Baru Dengan Menggunakan Visual Basic 6.0 (Studi Kasus SDI Oebufu Kupang)†dapat membantu memperlancar tugas dari pihak pengolahan data siswa dalam mendata dan menyajikan informasi yang lengkap dan terupdate setiap saat, serta lebih menjamin kualitas penyimpanan dan pengolahan data dibandingkan dengan penyimpanan dan pengolahan data pada sistem yang lama