Multi-photon time-of-flight MLEM application for the positronium imaging in J-PET

We develop a positronium imaging method for the Jagiellonian PET (J-PET) scanners based on the time-of-flight maximum likelihood expectation maximisation (TOF MLEM). The system matrix elements are calculated on-the-fly for the coincidences comprising two annihilation and one de-excitation photons that originate from the ortho-positronium (o-Ps) decay. Using the Geant4 library, a Monte Carlo simulation was conducted for four cylindrical 22Na sources of beta plus decay with diverse o-Ps mean lifetimes, placed symmetrically inside the two JPET prototypes. The estimated time differences between the annihilation and the positron emission were aggregated into histograms (one per voxel), updated by the weights of the activities reconstructed by TOF MLEM. The simulations were restricted to include only the o-Ps decays into back-to-back photons, allowing a linear fitting model to be employed for the estimation of the mean lifetime from each histogram built in the log scale. To suppress the noise, the exclusion of voxels with activity below 2-10 percent of the peak was studied. The estimated o-Ps mean lifetimes were consistent with the simulation and distributed quasi-uniformly at high MLEM iterations. The proposed positronium imaging technique can be further upgraded to include various correction factors, as well as be modified according to realistic o-Ps decay models

Evaluation of Machine Learning Models for Breast Cancer Diagnosis Via Histogram of Oriented Gradients Method and Histopathology Images

Breast cancer is the main death rate from malignant growth worldwide and the most frequently diagnosed type of cancer in females. Machine learning systems have been developed to assist in the accurate detection of cancer. There are numerous methods for cancer detection. But histopathological images are thought to be more precise. In this study, we used the HOG features extractor to extract statistical features from histopathology images of invasive ductal carcinoma. We chose the following images at random from the histopathology images: 100, 200, 400, 1000, and 2000. These statistical features were then used to train several algorithms, including the decision tree, quadratic discriminant analysis, extra randomized trees, gradient boosting, gaussian process classifier, naive bayes, nearest centroid, multilayer perceptron, and support vector machine, to identify whether or not the images depict cancerous or noncancerous growth. The algorithms' performance was evaluated depending on the specificity, accuracy, sensitivity, precision, F1_score, and AUC. The algorithms used worked best when the number of images was set to 100. As the number of images went up, their effectiveness went down

Matrix approach for modeling of emission from multilayer spin-polarized light-emitting diodes and lasers

Spin-polarized light sources such as the spin-polarized light-emitting diodes (spin-LEDs) and spin-polarized lasers (spin-lasers) are prospective devices in which the radiative recombination of spin-polarized carriers results in emission of circularly polarized photons. The main goal of this article is to model emitted radiation and its polarization properties from spin-LED and spin-controlled vertical-cavity surface-emitting laser (spin-VCSEL) solid-state structures. A novel approach based on 4 × 4 transfer matrix formalism is derived for modeling of the interaction of light with matter in active media of resonant multilayer anisotropic structure and enables magneto-optical effects. Quantum transitions, which result in photon emission, are described using general Jones source vectors.Web of Science166art. no. 06500

Brain Image Segmentation Based on Fuzzy Clustering

The segmentation performance is topic to suitable initialization and best configuration of supervisory parameters. In medical image segmentation, the segmentation is very important when the diagnosing becomes very hard in medical images which are not properly illuminated. This paper proposes segmentation of brain tumour image of MRI images based on spatial fuzzy clustering and level set algorithm. After performance evaluation of the proposed algorithm was carried on brain tumour images, the results showed confirm its effectiveness for medical image segmentation, where the brain tumour is detected properly

Immobilization of cholesterol oxidase in a conducting copolymer of thiophene-3-yl acetic acid cholesteryl ester with pyrrole

Cholesterol oxidase has been immobilized in conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole (CM/PPy) and polypyrrole (PPy) via electropolymerization. p-Toluene sulphonic acid was used as the supporting electrolyte. Kinetic parameters (V-max and K-m) and operational stability of enzyme electrodes were investigated. Surface morphology of the films was examined by scanning electron microscope

Dephasing of a Qubit due to Quantum and Classical Noise

The qubit (or a system of two quantum dots) has become a standard paradigm for studying quantum information processes. Our focus is Decoherence due to interaction of the qubit with its environment, leading to noise. We consider quantum noise generated by a dissipative quantum bath. A detailed comparative study with the results for a classical noise source such as generated by a telegraph process, enables us to set limits on the applicability of this process vis a vis its quantum counterpart, as well as lend handle on the parameters that can be tuned for analyzing decoherence. Both Ohmic and non-Ohmic dissipations are treated and appropriate limits are analyzed for facilitating comparison with the telegraph process.Comment: 12 pages, 8 figure

Perencanaan Ulang Desain Parkir Pasar Bulu Kota Semarang

Nowadays the progress of Semarang city is getting rapid, many shop centers rises in Tugu Muda area. Most of people use their car or motorbike to do their activities through those streets. This condition caused the higher mobility each year and makes parking lots become important thing in transportation system. The necessary of parking lot should be available, The bigger traffic volume makes bigger necessary of parking lot. If it does not enough, cars may take the spaces beside of road to park, and this caused some disruptions to others. Redesigning the park design focused on one the biggest traditional market in Semarang one of them is Bulu market at Mgr Soegijapranoto street. The method used in this redesign is plat matching method for data retrieval parking , Linier regretion method and the queuing theory to data processing and the parking design. Primary data that is required in this analysis is parking duration, and service system. And for the secondary data required the amount of vehicles out – vehicles in at the market, the amount of traders at the market, the amount of resident at each subdistricts of Semarang city, and area of the market. The conclusion, the parking lot design, 117 SRP to car and 502 SRP to motorcycle, can provide the customers need in parking at the market. The design can be predicted that it will be resisted in five years based on growing ratio between city parking lot and Bulu market parking lot

THE SOURCE OF UNCERTAINTY IN 3D LASER SCANNER

3D laser scanner become popular in manufacturing field because of its capability in measuring various characteristics of part and reverse engineering. It is found that laser scanner which categorize under non-contact method is less accurate compared to the contact method. This is due to the output quality that depending on digitizing points captured during scanning. These digitizing points are affected from extrinsic and intrinsic parameters. Some of the parameters for commercial lasers are already calibrated prior to delivery. In this paper, extrinsic parameters are discussed based on LC15 laser scanner with Metris scan 4.1 software. A suggestion on model of uncertainty is suggested based on propagation of uncertainty method align with the understanding of extrinsic scanning parameters