The aim of the paper is to draw attention to the possibility of improving the transmission properties of telecommunication networks by subordinating the capacity of individual links to the frequency of their occurrence in a set of minimum length paths. The defined unevenness coefficient was used to divide the global transmission resources of the network in order to make the traffic carried by this network as large as possible. The article presents the results of the simulation tests to which tree topology network was subjected.
This paper presents the components of a sleep apnea analysis device that have been evaluated for diagnosis suitability and expected difficulties. The medical background and statistics of sleep apnea are presented. Work related to the topic is then discussed. A description of the system components follows: ECG, respiratory effort, nasal flow and pulse oximetry. Problems expected with all of these measurements are then outlined both from the methodological and electronic perspective. The main difficulties identified are the necessity to maintain the exact location of the sensors on the patient’s body and vulnerability of the sensors to variations of the environmental conditions. Challenges on the electronic aspect are then discussed, which are mainly caused by the need of measuring small signals (noise, interference) and compensation of the sensors’ nonlinearity. Power supply design in the context of the measurement accuracy is also considered followed by an evaluation of the impact of telemedical function presence. The paper ends with a summary and conclusions.
This work reports the measurement results of long-terms tests obtained in real smart street lighting LV networks and in lab test bed. The measurements results are presented in the form of PER vs. SNR characteristics for BPSK coded and BPSK coded with peak noise avoidance algorithm. The surprising results obtained from real LV networks prompted the Authors to carry out detailed lab tests. The setup for lab tests is also presented in this work. To carry out lab tests a suitable software was prepared, it allowed to obtain results in 72 times shorter time comparing to real conditions; it is why this work can present characteristics of PER vs. SNR even for the values of PER at the level of 10−9. The work concludes with disadvantages of using the peak noise avoidance algorithm in PLC communication for smart street lighting.
This work shows transmission parameters of specific power line, which is control cable used for supplying a railway sign. Two transmission parameters are considered, namely: attenuation and characteristic impedance, these two secondary parameters are calculated from primary parameters i.e. R, L and C. Primary parameters and their components were calculated if they depended on the frequency or were taken from producers notes. Analysis was done for the frequency in range from 50 kHz up to 100 kHz. Two types of cables were analysed, as extreme cases, first with the 1 mm2 solid conductors cable and second with the 1.5 mm2 19 strands conductors. Knowing the PLC modem transmission parameters together with the transmission parameters of the railway sign power line it is possible to calculate the capabilities of the communication system e. g. distance or maximum bit rate.
The paper presents a web application for navigation through the university campus, which is based on Global Positioning System GPS and OpenStreetMap. The application has a multilayer structure and multi-labelling support. The proposed solution ensures better management of visual data and more efficient image processing comparing to the other known methods. With the new search system, users can place a lot of information on one layer without losing the legibility of displayed data. All the information that was displayed on the map was grouped and assigned to the appropriate categories.Therefore a map contains a lot of related information that needs to be linked to each other. The system has been divided into modules that ensure the integrity of the displayed things. Presenting so much information at the same time is managed by modules. Their main job is to provide results that is then segregated and grouped. The system presented in this paper was applied for Lodz University of Technology.
Recently, optical coherence tomography (OCT) has been tested as a contactless technique helpful for damaged or spoofed fingerprint recovery. Three dimensional OCT images cover the range from the skin surface to papillary region in upper dermis. The proposed method extracts from cross-sections of volumetric images (B-scans) high intensity ridges in both air-epidermis and dermis-epidermis interfaces. The extraction is based on the localisation of two OCT signal peaks corresponding to these edges. The borders are spline smoothed in two orthogonal planes of the image space. The result images are presented and compared with camera views.
The paper provides a comparison of three variants of algorithms for automatic assessment of some examination tasks involving sketching a function graph based on image processing. Three types of functions have been considered: linear, quadratic, and trigonometric. The assumption adopted in the design of the algorithm is to map the way the examiner assesses the solutions and to achieve the evaluation quality close to the one obtained in manual evaluation. In particular, the algorithm should not reject a partly correct solution and also extract the correct solution from other lines, deletions and corrections made by a student. Essential subproblems to solve in our scheme concern image segmentation, object identification and automatic understanding. We consider several techniques based on Hough Transform, least square fitting and nearest neighbor based classification. The most reliable solution is an algorithm combining least square fitting and Hough Transform.
Internet of Things (IoT) devices are big part of concept, which is called by electronic producers and many others Smart Home. Authors of this paper have decided to take a look at it and as a result of this analysis propose and implement (in a form of working prototype) a system that could manage different kinds of devices.
The main objective of the project presented in this paper is a device that looks like a mirror and it is known to most people also is an interactive center, a place to obtain information of the devices that surround us and various parameters coming from sensors. Authors have prepared a prototype, that will be the central point of the apartment and will allow users to control all devices connected to this main system. Prototype allows to connect external sensors over GPIO (general purpose input/output) interface or Internet connection. There is also a possibility to add another communication interfaces such as 433MHz radio module, which is very cheap and works great in small areas or bluetooth module.
The control of dense phase pneumatic convening process is not a trivial task. The control of bulk solids flow phenomena requires detailed knowledge about the temporal and spatial changes of material concentration during flow. This paper describes application of electrical capacitance tomography for the characterization of the pneumatic conveying of solids. The level of concentration changes obtained with the aid of tomography imaging and calculated flow velocity allows monitoring flow behaviour during the granular material transport process. The cross-correlation technique applied for image processing as well as the calculated pixels-based flow velocity profile together with the proposed visualisation method of tomography images sequence provide information about flow conditions. The study of flow characterization, based on ECT data, was conducted for measurements gathered with different flow conditions, including flow blockage.
We present TomoTable—a research prototype of a position sensing device hidden inside an ordinary table. While the Human-Computer Interaction (HCI) field has extensively explored possibilities for spatially-aware multi-device interactions, the sensing methods that would enable such systems are still complex and hard to deploy in the wild. TomoTable presents a possibility of easily deployable invisible positional sensing that uses electrical capacitance tomography (ECT). Electrodes are embedded inside the table structure and provide accurate imaging of what is placed on the table. The entire system is invisible to the user. Objects can be identified based on their electrical properties. Our work creates opportunities for in-the-wild studies using multi-device systems. In this paper, we share the technical concept of TomoTable, preliminary insights on its use and perspectives for future studies.