Determination of the refractive index profile and surface topography of optically smooth objects using interference of optical vortices

In this paper, we present the results of the propagational dynamics of vortex beams in the scope of their possible applications for interferometric non-contact robust and precision optical surface profilometry with nanoscale longitudinal resolution. The result of coaxial superposition of the reference plane wave with singly charged vortex beams represents a dynamically changing intensity distribution. The nature of this changes, namely, rotational effects of intensity zeros, allows to determine directly the optical path difference which is introduced by the surfaces and internal structure of test object. We have proposed the experimental setup for examination of reflecting and transmitting objects.

A novel algorithm of the digital nervous tissue phantom creation based on 3D Voronoi diagram application

The essential part of mathematical modelling of nutrients convectional reaction-diffusion is creation of a digital phantom of considered biological object. This process becomes an especial problem which needs to be solved before numerical calculations of the concentration gradients will be done. There are two principal ways to get the solution in this case. The first approach is the reconstruction of a digital phantom on the base of the experimental data directly. The second one is the creation of a virtual object according to the experimental evidence and the known principals de novo. The main advantage of the created phantom is a high adaptability to modelling demands and a physical problem formulation. In the present study a new algorithm of a digital phantom creation has been established. The principles of the claimed procedures are demonstrated by the example of a nervous tissue. Initially, one needs to create N 3D objects according to Voronoi diagrams. Each object has 144 edges and 69 boundaries on average. Having chosen M rear objects, a long 3D structure mimicking neurons axons is created according to a loft procedure from the start boundaries to the end ones. Then, the set of Boolean operations has been applied to form continuous smooth objects. The remain (N-(M+s)) objects are combined into several whole bodies using the loft procedures between the closet neighbours. The final structure has a good conformity with a nervous tissue architecture. Furthermore, the obtained phantom is correct to the mesh application and further numerical calculations.

Foreign body ingestion by children: an analysis of age and types at a tertiary hospital in Bangladesh

Foreign body (FB) ingestion is common in children worldwide. Type of FB ingestion varies among cultures and countries. We retrospectively reviewed all patients of foreign body ingestion who were admitted in Department of Pediatric Surgery, Chittagong Medical College Hospital from January 2017 to December 2019 (total 3 years). Age, Sex, type of foreign body, hospital stay, management and outcome were analyzed. A total of 91 children were admitted with ingestion of FB during this period; male 61, female 30 (male to female ratio 2:1). Age ranged from 3 months to 12 years (median 3.5 ± 3.8 years). Fifty eight percent were less than 5 years old. Children ingested 21 different types of FB; however ingestion of coin was most common (24 patients, 26.37%) followed by different types of pins (19 patients, 20.88%), nail (6 patients, 6.59%), battery (5 patients, 5.49%), screw (5 patients, 5.49%), needle (4 patients, 4.40%), ring (4 patients, 4.40%) and others (18 patients). Sharp object ingestion is higher in older (>5 year) age group. Hospital stay ranged from 0 day to 19 days (mean 1.6 ± 2.1 day). Endoscopic removal needed in 4 patients (coin-2, chain 2), bronchoscopic removal in 1 (pin) and one patient needed laparotomy (open hair pin). There was no mortality. The pattern of FB ingestion is similar to many other countries. Small, smooth objects pass spontaneously. Endoscopic or surgical intervention is sometimes needed if significant symptoms develop or if the object fails to progress through the gastrointestinal tract. Asian J. Med. Biol. Res. June 2020, 6(2): 299-304

Segmentasi Citra Medis untuk Deteksi Objek FAM pada Payudara Menggunakan Metode Sobel

Fibroa Adenoma Mammae (FAM) or called a benign tumor is the most common tumor found in the breast, often this disease is considered as breast cancer by some laymen, but this disease is different from cancer because Fibroadenoma (FAM) can grow in all parts of the breast, In identifying FAM, doctors or radiologists usually have to analyze carefully the images of Magnetic Resonance stored in the format of Digital Imaging Communication In Medicine (DICOM). This process is certainly quite time consuming. Thus the author feels the need to create a digital image processing application to help doctors or radiologists identify FAM in the breast by utilizing the segmentation process in medical images of USG results using the Sobel method. This method performs the original image segmentation process by detecting the edges of the image then the segmentation results are converted into binary images so the system can determine the FAM area. Medical image segmentation using the Sobel method is good for determining the edges of FAM objects because the edges can be clearly seen but for some image images with less resolution as previously tested, edge detection will be difficult to determine the edges of smooth objects and only form lines rough edges.

AROUND THE NEARBY CYCLE FUNCTOR FOR ARITHMETIC -MODULES

We will establish a nearby and vanishing cycle formalism for the arithmetic $\mathscr{D}$-module theory following Beilinson’s philosophy. As an application, we define smooth objects in the framework of arithmetic $\mathscr{D}$-modules whose category is equivalent to the category of overconvergent isocrystals.

Force and Contact Location Shading Methods for Use Within Two- and Three-Dimensional Polygonal Environments

Current state-of-the-art haptic interfaces only provide kinesthetic (force) feedback, yet studies have shown that providing tactile feedback in concert with kinesthetic information can dramatically improve a person's ability to dexterously interact with and explore virtual environments. In this research, tactile feedback was provided by a device, called a contact location display (CLD), which is capable of rendering the center of contact to a user. The chief goal of the present work was to develop algorithms that allow the CLD to be used with polygonal geometric models, and to do this without the resulting contact location feedback being overwhelmed by the perception of polygonal edges and vertices. Two haptic shading algorithms were developed to address this issue and successfully extend the use of the CLD to 2D and 3D polygonal environments. Two experiments were run to evaluate these haptic shading algorithms. The first measured perception thresholds for rendering faceted objects as smooth objects. It was found that the addition of contact location feedback significantly increased user sensitivity to edges and that the use of shading algorithms was able to significantly reduce the number of polygons needed for objects to feel smooth. The second experiment explored the CLD device's ability to facilitate exploration and shape recognition within a 3D environment. While this study provided a validation of our 3D algorithm, as people were able to identify the rendered objects with reasonable accuracy, this study underscored the need for improvements in the CLD device design in order to be effectively used in general 3D environments.

Mammographic Feature Enhancement by Curvelet Transform

This paper presents an approach for digital mammograms enhancement using curvelet transform. The curvelet transform breaks the limitation of the wavelet transform and provides efficient representation of smooth objects with discontinuities along curves. It has special micro-local features which make them especially adapted to the contrast enhancement of mammographic features. A kind of nonlinear enhancing function is applied to enhance the details of mammogram according to the importance of the curvelet coefficients from different scales and angles. Results show the technique is potential to improve the accuracy of cancer breast detection.