A framework for working with digitized cultural heritage artefacts

In this paper, we present our work in designing, implementing, and evaluating a set of 3D interactive spatial measurement tools in the context of Cultural Heritage Toolbox (CH Toolbox), a framework for computer-aided cultural heritage research. Our application utilizes a bi-manual, spaceball and mouse driven user interface to help the user manage visualized 3D models digitized from real artifacts. We have developed a virtual radius estimator, useful for analyzing incomplete pieces of radial artifacts, and a virtual tape measure, useful in measurement of geodesic distances between two points on the surface of an artifact. We tested the tools on the special case of pottery analysis

Comparison of longitudinal changes in resting state functional magnetic resonance imaging between alzheimer’s and healthy controls

Resting State Functional Magnetic Resonance Imaging (rs-fMRI) is a technique that is widely used for analyzing brain function using different approaches and methods. This study involves rs-fMRI analysis of Blood Oxygenation Level Dependent (BOLD) signals acquired from Alzheimer’s disease (AD) Patients and Healthy Controls (HC). Each subject in the study had both functional and anatomical images with at least one rs-fMRI scan with their Anatomical (T1) scans. Previous rs-fMRI studies have demonstrated that AD shows differences in Amplitude of Low Frequency (\u3c0.1 Hz) Fluctuations (ALFF), and Regional Homogeneity (ReHo) measures according to HCs. The aim of the study is to investigate individual and group level differences using ReHo and mALFF related measures in a longitudinal analysis. The hypothesis is that with the age and group (AD or HC) of the subject, it is possible to separate AD and HC subjects from each other using 3 different ROIs (DMN – MT – MV), These regions are known to show abnormalities in AD patients but clinical wise never been identified as neuroimaging biomarkers. This study tries to check these ROIs to see if there are significant differences between the AD patients and HCs using 3 different features

Polarization Beam Splitter Based on Self-Collimation of a Hybrid Photonic Crystal

A photonic crystal polarization beam splitter based on photonic band gap and self-collimation effects is designed for optical communication wavelengths. The photonic crystal structure consists of a polarization-insensitive self-collimation region and a splitting region. TM- and TE-polarized waves propagate without diffraction in the self-collimation region, whereas they split by 90 degrees in the splitting region. Efficiency of more than 75% for TM- and TE-polarized light is obtained for a polarization beam splitter size of only 17 μm x 17 μm in a wavelength interval of 60 nm including 1.55 μm

Determination of the Change in Electrical Conductivity of Single, Bimetallic and Trimetallic Cylindrical Billets with Plastic Deformation Induced by Upsetting Process

In this study, measurement of the effect of singular, bimetallic and multimetallic materials exposed to cold plastic deformation on electrical conductivity properties was investigated. The main subject of this research is plastic deformation occurring in the upsetting process and changing the conductivity properties of the parts. In the experiments, steel, aluminium, copper, brass, bimetallic and multimetallic materials designed with different combinations of these materials were used as test materials. Experimental upsetting tests were performed as a height reduction ratio 10%, 20% and 30%. The electrical conductivity measurement results of the deformed samples were obtained with a conductivity measuring device. The results obtained from the experiments are presented in graphs with electrical conductivity axis that change due to deformation. As a result of the experiments and measurements, it was concluded that the electrical conductivity of the deformed materials generally decreased slightly due to the plastic deformation of the deformed materials, and the bimetallic and multimetallic materials were similar to the properties of the majority material

The performance of multiple imputations for different number of imputations

Multiple imputation method is a widely used method in missing data analysis. The method consists of a three-stage process including imputation, analyzing and pooling. The number of imputations to be selected in the imputation step in the first stage is important. Hence, this study aimed to examine the performance of multiple imputation method at different numbers of imputations. Monotone missing data pattern was created in the study by deleting approximately 24% of the observations from the continuous result variable with complete data. At the first stage of the multiple imputation method, monotone regression imputation at different numbers of imputations (m=3, 5, 10 and 50) was performed. In the second stage, parameter estimations and their standard errors were obtained by applying general linear model to each of the complete data sets obtained. In the final stage, the obtained results were pooled and the effect of the numbers of imputations on parameter estimations and their standard errors were evaluated on the basis of these results. In conclusion, efficiency of parameter estimations at the number of imputation m=50 was determined as about 99%. Hence, at the determined missing observation rate, increase was determined in efficiency and performance of the multiple imputation method as the number of imputations increased

Distributed Deep Joint Source-Channel Coding over a Multiple Access Channel

We consider distributed image transmission over a noisy multiple access channel (MAC) using deep joint source-channel coding (DeepJSCC). It is known that Shannon's separation theorem holds when transmitting independent sources over a MAC in the asymptotic infinite block length regime. However, we are interested in the practical finite block length regime, in which case separate source and channel coding is known to be suboptimal. We introduce a novel joint image compression and transmission scheme, where the devices send their compressed image representations in a non-orthogonal manner. While non-orthogonal multiple access (NOMA) is known to achieve the capacity region, to the best of our knowledge, non-orthogonal joint source channel coding (JSCC) scheme for practical systems has not been studied before. Through extensive experiments, we show significant improvements in terms of the quality of the reconstructed images compared to orthogonal transmission employing current DeepJSCC approaches particularly for low bandwidth ratios. We publicly share source code to facilitate further research and reproducibility.Comment: To appear in IEEE International Conference on Communications (ICC) 202