Computational and Mathematical Methods in Medicine

This paper introduces a review article on indoor localization techniques and technologies. The paper starts with current localization systems and summarizes comparisons between these systems in terms of accuracy, cost, advantages, and disadvantages. Also, the paper presents different detection techniques and compare them in terms of accuracy and cost. Finally, localization methods and algorithms, including angle of arrival (AOA), time of arrival (TOA), and recived signal strength (RSS) are introduced. The study contains concepts, requirements, and specifications for each category of methods presents pros and cons for investigated methods, and conducts comparisons between them.

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A Review of Indoor Localization Techniques and Wireless Technologies

Assisting traffic control is one of the most important applications on the Internet of Vehicles (IoVs). Traffic information provided by vehicles is desired since drivers or vehicle sensors are sensitive in perceiving or detecting nuances on roads. However, the availability and privacy preservation of this information are critical while conflicted with each other in the vehicular communication. In this paper, we propose a semicentralized mode with attribute-based blockchain in IoVs to balance the tradeoff between the availability and the privacy preservation. In this mode, a method of control-by-vehicles is used to control signals of traffic lights to increase traffic efficiency. Users are grouped their attributes such as locations and directions before starting the communication. The users reach an agreement on determining a temporary signal timing by interacting with each other without leaking privacy. Final decisions are verifiable to all users, even if they have no a priori agreement and processes of consensus. The mode not only achieves the aim of privacy preservation but also supports responsibility investigation for historical agreements via ciphertext-policy attribute-based encryption (CP-ABE) and blockchain technology. Extensive experimental results demonstrated that our mode is efficient and practical.

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SCTSC: A Semicentralized Traffic Signal Control Mode With Attribute-Based Blockchain in IoVs

This paper presents a comprehensive review of retinal blood vessel segmentation based on deep learning. The geometric characteristics of retinal vessels reflect the health status of patients and help to diagnose some diseases such as diabetes and hypertension. The accurate diagnosis and timing treatment of these diseases can prevent global blindness of patients. Recently, deep learning algorithms have been rapidly applied to retinal vessel segmentation due to their higher efficiency and accuracy, when compared with manual segmentation and other computer-aided diagnosis techniques. In this work, we reviewed recent publications for retinal vessel segmentation based on deep learning. We surveyed these proposed methods especially the network architectures and figured out the trend of models. We summarized obstacles and key aspects for applying deep learning to retinal vessel segmentation and indicated future research directions. This article will help researchers to construct more advanced and robust models.

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Retinal Vessel Segmentation Using Deep Learning: A Review

Fast and efficient retinal blood vessel segmentation method based on deep learning network.

The visual exploration of retinal blood vessels assists ophthalmologists in the diagnoses of different abnormalities of the eyes such as diabetic retinopathy, glaucoma, cardiovascular ailment, high blood pressure, arteriosclerosis, and age-related macular degeneration. The manual inspection of retinal vasculature is an extremely challenging and tedious task for medical experts due to the complex structure of an eye, tiny blood vessels, and variation in vessels width. Several automatic retinal vessels extraction techniques have been proposed in contemporary literature, which assist ophthalmologists in the timely identification of an eye disorders. However, due to the fast evolution of such techniques, a comprehensive survey is needed. This survey presents a comprehensive review of such techniques, strategies, and algorithms presented to date. The techniques are classified into logical groups based on the underlying methodology employed for retinal vessel extraction. The performance of existing techniques is reported on the publicly accessible datasets in term of various performance measures, providing a valuable comparison among the techniques. Thus, this survey presents a valuable resource for researchers working toward automatic extraction of retinal vessels.

A review of retinal blood vessels extraction techniques: challenges, taxonomy, and future trends

Security mechanisms recommended by VANET standardization bodies are not sufficient to stop authorized vehicles from sending bogus or fake messages that in the worst cases could put people's life at risk. There are efforts in evaluating the behaviour of the vehicles in VANETs, based on reputation mechanisms. However, the most of them compromise the privacy, the messages are linkable and no anonymous. Our proposal ARS: Anonymous Reputation System for VANET focuses on a centralized reputation system privacy-preserving using pseudonyms and giving reputation level to different behavioral aspects of the vehicle. A reputation server collects feedback from the vehicles through a Road-Side Unit or vehicles with LTE/4G/5G connection and updates the vehicles reputation level by matching the pseudoidentities with its real identity. Considering the amount of negative feedback, ARS defines two security states to adapt the applications to the real security risk. We implement and evaluate the performance of ARS through a set of simulation experiments, based on an opportunistic message forwarding application. Results showed that the calculating reputation level of vehicles could help reduce the dissemination of fake messages.

ARS: Anonymous reputation system for vehicular ad hoc networks

Vehicular Ad hoc Network (VANET) is an auspicious technology for the future Intelligent Transportation System (ITS). A large number of safety applications are envisioned for VANET. Nonetheless, non-safety applications, more specifically advertisement of roadside commercial services, still need a great deal of attention. The classical methods of advertisements (e.g., billboards) are not adequate for the business owners (for instance: hotel, restaurant, supermarket and gas station) to promote their commercial services to the nearby travellers (drivers or passengers) on highways. We address this problem by proposing SADP—a lightweight beaconing-based commercial services advertisement protocol for VANET. Our solution is based on the Wireless Access in Vehicular Environments (WAVE) architecture. SADP performance was evaluated in a congested multi-lane highway scenario, by an extensive set of experiments. Simulation results conclude that: (a) the Road Side Unit (RSU) broadcast frequency and vehicles speed affect the reception of advertisement beacon packets; (b) a frequency of 10 advertisement beacon packets per second assures 100 % reception of all the advertised services by all vehicles and could be the basis for a premium-like type of service advertisement plan for the business owners.

SADP: A Lightweight Beaconing-Based Commercial Services Advertisement Protocol for Vehicular Ad Hoc Network

ULLAH, K.. On the use of opportunistic vehicular communication for roadside services advertisement and discovery. 2016. 104 f. Doctoral dissertation (Doctorate Candidate Program in Computer Science and Computational Mathematics) – Instituto de Ciências Matemáticas e de Computação (ICMC/USP), São Carlos – SP. Vehicular Ad hoc Network (VANET) is a special kind of Mobile Ad hoc Network (MANET) and is a key enabling technology for Intelligent Transportation Systems (ITS). It plays an important role in the deployment of a large scale of both safety and non-safety applications. Among non-safety applications, an important and challenging area is the provision of roadside services advertisement and discovery. In this work, we adopted the beaconing strategy and opportunistic vehicular communications to address the problem of roadside services advertisement and discovery on the highways. Our approach offers several advantages over the traditional billboard method, e.g., low cost, targeting a large number of customers in a real time, more control over the advertisement campaign, dynamic content updating, and discovery of services far ahead of the business region. For advertising roadside services, we followed the push-based advertisement strategy and relied on Infrastructure-to-Vehicle (I2V) communications only. On the other hand, for discovering these services by the drivers, we used pull-based advertisement strategy and opportunistic Vehicle-to-Vehicle (V2V) communications. In order to contribute to the advertisement campaign, we used the store-carry-and-forward mechanism. Our first contribution is the Extended Opportunistic Service Discovery Protocol (EOSDP). EOSDP implements the original version of Opportunistic Service Discovery Protocol (OSDP) via simulation experiments. We used Simulation of Urban Mobility (SUMO), Objective Modular Network Testbed in C++ (OMNET++), and Vehicles in network simulation (Veins) simulators. Our second contribution is Service Advertisement Protocol (SADP). SADP is a lightweight beaconing-based services advertisement protocol for VANETs. It does not require the Internet connection for advertising the roadside services. Moreover, SADP modeling is based on VANETs standard protocols. The performance of SADP was evaluated in a congested highway scenario with varying speed of vehicles and under different broadcast frequencies. Finally, we present our last protocol called Commercial Services Discovery Protocol (CSDP). Like the previous protocol, CSDP is a lightweight beaconing-based services discovery protocol for VANETs. CSDP is infrastructureless protocol which only depends on opportunistic V2V communications for roadside services discovery. The protocol was implemented in congested highway scenario and extensive set of simulation experiments were performed to evaluate its performance under different parameters, e.g., Query Interval (QI), Query Attempts (QA), and Time to Live (TTL).

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On the use of opportunistic vehicular communication for roadside services advertisement and discovery

Due to widespread availability of WiFi networks in buildings, indoor location based systems become a reality. To provide indoor location based services (LBS), finding the current location of a human, a computer, a mobile device or equipment such as a small UAV (like Quad copter) is of great interest. The most prominent method for this purpose is the received signal strength (RSS)-based location from WiFi Access Points (APs) inside a building. Considerable amount of research is carried out in estimating current location and providing different services based on different wireless technologies. On the other hand, little attention has been paid to study and analyze the behavior of the received signal strength itself. It is challenging because the intensity of signal can change very frequently due to environmental features like topology, temperature, interaction with objects etc. In this paper, we study the behavior of WiFi signals in an indoor environment for RSS based localization by analyzing signals from three different access points by using triangulation technique. Our method is based on fingerprinting method. The experimental results reveal that the behavior of signal changes very frequently. The results lead us to the conclusion that understanding signals behavior is important before estimating current location and providing different LBS.

Kifayat Ullah

Papers

A review of retinal blood vessels extraction techniques: challenges, taxonomy, and future trends

ARS: Anonymous reputation system for vehicular ad hoc networks

SADP: A Lightweight Beaconing-Based Commercial Services Advertisement Protocol for Vehicular Ad Hoc Network

On the use of opportunistic vehicular communication for roadside services advertisement and discovery

An Experimental Study on the Behavior of Received Signal Strength in Indoor Environment