Integrated wireless access and networking to support floating car data collection in vehicular networks

Collecting data from a large number of agents scattered over a region of interest is becoming an increasingly appealing paradigm to feed big data archives that lay the ground for a vast array of applications. Vehicular Floating Car Data (FCD) collection, a major representative of this paradigm, is a key enabler for a wide range of Intelligent Transportation Systems (ITS) services and applications aiming at enhancing safety, efficiency and sustainability. Obtaining real time, high spacial and temporal resolution vehicular FCD information is becoming a reality thanks to the variety of communication platforms that are being deployed. Dedicated Short-Range Communication (DSRC) and Long Term Evolution (LTE) are the most prominent communication technologies able to support periodic and persistent FCD collection. DSRC technology was mainly proposed for safety applications and is specifically tailored for Vehicular Ad Hoc Networks (VANETs). The first parts of this work are dedicated to assessing the suitability of DSRC to support FCD collection in real urban scenarios. We first study the basic communication paradigm that takes place in VANETs to populate vehicles’ local data bases with FCD information, named beaconing, and the trade-off between the beaconing frequency and the congestion induced in the wireless shared channel used to exchange these beacons. The primary metric to measure the information freshness inside every vehicle’s local data base is the Age-of-Information (AoI). We define an analytical model to evaluate the AoI of a VANET, given the connectivity graph of the vehicles, and validate the model by comparing it with realistic simulations of an urban area. Then, we propose an integrated DSRC-based protocol that disseminates queries and collects FCD messages from vehicles roaming in a quite large city area efficiently and timely by using a single network structure, i.e., a multi-hop backbone network made up of only vehicle nodes. The proposed solution is distributed and adaptive to different traffic conditions, i.e., to different levels of vehicular traffic density. One of the main protocol advantages is that for the dissemination of queries it exploits an existing standardized data dissemination algorithm, namely the GeoNetworking Contention-Based Forwarding (CBF). The proposed protocol is evaluated with reference to a real urban environment. The main parameters are dimensioned and an insight into the protocol operation is given. One of the main outcomes of this part of the thesis is the confirmation of the fact that DSRC is suitable to support not only safety applications, but also periodic FCD collection. The main issue with DSRC is the low penetration rate. LTE on the other hand is pervasive and has been identified as a good candidate technology for non-safety applications. However, a high number of vehicles intermittently reporting their information via LTE can introduce a very high load on the LTE access network. The second part of this work addresses the design and performance evaluation of heterogeneous LTE-DSRC networking solutions to yield significant offloading of LTE – here, DSRC technology can support local data aggregation. We propose distributed clustering algorithms that use both LTE and DSRC networks in the cluster head selection process. We target robustness, optimizing the amount of data and the value of the collection period, keeping in mind the goals of autonomous node operation and minimal coordination effort. Our results clearly indicate that it is crucial to consider parameters drawn from both networking platforms for selecting the right forwarders. We demonstrate that our solutions are able to significantly reduce the LTE channel utilization with respect to other state-of-the-art approaches. The impact of the proposed protocols on the DSRC channels’ load is evaluated and proved to be quite small, so that it does not interfere with other VANET-specific messages

Consumul de pește în rândul populației Republicii Moldova

Organizația pentru Agricultură și Alimentație a Națiunilor Unite, Agenția Națională pentru Sănătate Publică, Chișinău, Republica Moldova, Catedra de igienă generală, USMF „Nicolae Testemiţanu”, Congresul consacrat aniversării a 75-a de la fondarea Universității de Stat de Medicină și Farmacie „Nicolae Testemițanu” din Republica Moldova, Ziua internațională a științei pentru pace și dezvoltareBackground. At present, very little is known about the consumption of different fish species at national level. The elucidation of this topic would be useful both for assessing the risk of exposure of the population to various chemical contaminants and for assessing the associated benefits. Objective of the study. The purpose of this study was to identify which fish species are consumed by the population of the Republic of Moldova. Material and Methods. FishStatJ v4.00.9 software was used to estimate fish species consumed nationally. The data extracted, per species, (annual series) for the period 2005-2017, in tons per year were converted into grams per day per capita. To exclude the inedible component conversion factors were applied. Results. The application of conversion factors decreased the average consumption by 34.7%. In the period 2005-2017 there was an increasing trend (y=0.4016x+16.88; R²=0.4036x) from 17.8g/day (2005) to 23.6g/day (2017), on average per capita was consumed 19.68g/day. 97.3% of the average consumption are: herring/sardines - 6.46g/day (32.8%), carp - 4.14g/day (21.0%), unspecified species - 3.09g/day (15.7%), mackerel - 1.61g/day (8.17% ), hake - 1.10g/day (5.6%), blue whiting - 0.953g/day (4.84%), salmon - 0.824g/day (4.19%), cod - 0.745g/day (3.78%), polak - 0.22g/day (1.14%), tuna - 0.09g/day (0.47%). During the analyzed period, 26 species of fish were consumed. Conclusion. The population consumes 26 different species of fish. Herring/sardines and carp are the most consumed species with a share of 32.8% and 21.0% respectively. Another 15.7% of average consumption remains uncertain because the species could not be identified. Introducere. La momentul actual, se cunoaște foarte puțin despre consumul diferitor specii de pești la nivel național. Elucidarea acestui subiect ar fi utilă atât pentru evaluarea riscului expunerii populației la diferiți contaminanți chimici, cât și pentru aprecierea beneficiilor asociate. Scopul lucrării. Scopul acestui studiu a fost de a identifica care sunt speciile de pești consumate de către populația din Republica Moldova. Material și Metode. Pentru estimarea speciilor de pești consumate la nivel național s-a utilizat softul FishStatJ v4.00.9. Datele extrase per specie (serii anuale) pentru perioada 2005-2017, în tone pe an s-au transformat în grame pe zi per capita. Pentru a exclude componenta necomestibilă s-au aplicat factori de conversie. Rezultate. Aplicarea factorilor de conversie a micșorat consumul în mediu cu 34.7%. În perioada 2005-2017 s-a înregistrat o tendință de creștere (y=0.4016x+16.88; R²=0.4036x) de la 17.8g/zi (2005) la 23.6g/zi (2017), în mediu per capita s-a consumat 19.68g/zi. 97.3% din consumul mediu constituie: hering/sardine - 6.46g/zi (32.8%), crap - 4.14g/zi (21.0%), specii nespecificate – 3.09g/zi (15.7%), macrou – 1.61g/zi (8.17%), merluciu – 1.10g/zi (5.6%), putasu – 0.953g/zi (4.84%), somon – 0.824g/zi (4.19%), batog – 0.745g/zi (3.78%), polac - 0.22g/zi (1.14%), ton – 0.09g/zi (0.47%). În perioada analizată s-au consumat 26 specii de pești. Concluzii. Populația consumă 26 specii diferite de pești. Hering/ sardinele și crapul sunt cele mai consumate specii cu o pondere de 32.8% și 21.0%, respectiv. Alte 15.7% din consumul mediu rămân a fi incerte deoarece nu s-a putut identifica speciile

Age of Information of One-Hop Broadcast Communications in a CSMA Network

We consider a network of agents that send periodic updates to their neighbors. A trade-off between load on the shared communication channel and data timeliness is obtained by looking at the Age of Information (AoI) metric. We develop a model of a Carrier-Sense Multiple Access (CSMA) network with partial sensing, to calculate the AoI of one-hop broadcast messages exchanged among the agents. The model is applied to beacon messages in a vehicular network to gain insight into the impact of system parameters

A Multi-Hop Broadcast Wave Approach for Floating Car Data Collection in Vehicular Networks

Inter-Vehicle Communication (IVC) is bringing connected and cooperative mobility closer to reality. Vehicles today are able to produce huge amounts of information, known in the literature as Floating Car Data (FCD), containing status information gathered from sensing the internal condition of the vehicle and the external environment. Adding networking capabilities to vehicles allows them to share this information among themselves and with the infrastructure. Collecting real-time FCD information from vehicles opens up the possibility of having access to an enormous amount of useful information that can boost the development of innovative services and applications in the domain of Intelligent Transportation System (ITS). In this paper we propose several solutions to efficiently collect real-time FCD information in Dedicated Short-Range Communication (DSRC)-enabled Vehicular Ad Hoc Networks (VANETs). The goal is to improve the efficiency of the FCD collection operation while keeping the impact on the DSRC communication channel as low as possible. We do this by exploiting a slightly modified version of a standardized data dissemination protocol to create a backbone of relaying vehicles that, by following local rules, generate a multi-hop broadcast wave of collected FCD messages. The proposed protocols are evaluated via realistic simulations under different vehicular densities and urban scenarios

Microscopical Methods for the In Situ Investigation of Biodegradation on Cultural Heritage

The processes of cultural heritage sites’ degradation reveal interactions between the chemical characteristics of the substrates, the underlying substrate penetration, and the microbiota systems. Microorganisms penetrate the stone, causing extensive disaggregation of the materials. This chapter reveals comparative studies between the usual research approaches applied in biodegradation studies, especially optical microscopy, epifluorescence, and electron microscopy (SEM). These in situ microscopy techniques propose some complex analyses for the evaluation of the relationship between the microorganism’s cells and the stone surfaces (adherence, interactions), and also for the evaluation of the level of health or balance of the niche complex, from mesoscale to microscale. The stages of the exact monitorization and evaluation of lithotypes and deterioration phenomena are periodical sampling and monument mapping. The aim of this chapter is to identify microscopical methods used in biodegradation studies, especially the facilities provided by these methods. Our in situ analysis (light microscopy, epifluorescence, and scanning electron microscopy) performed for the first time on the painted Matia-Fresco Loggia (Corvin Castle, Romania) highlighted several aspects, such as mixtures of mineral elements with different chromatic appearance and porosity, shredding degradation, depigmented areas, cracked portions, and highly biota activity (bacterial and fungal) on painted surface

Experimental Evaluation of Floating Car Data Collection Protocols in Vehicular Networks

The main objectives of the Intelligent Transportation Systems (ITS) vision is to improve road safety, traffic management, and mobility by enabling cooperative communication among participants. This vision requires the knowledge of the current state of the road traffic, which can be obtained by collecting Floating Car Data (FCD) information using Dedicated Short-Range Communication (DSRC) based on the IEEE 802.11p standard. Most of the existing FCD collection protocols have been evaluated via simulations and mathematical models, while the real-world implications have not been thoroughly investigated. This paper presents an open-source implementation of two state-of-the-art FCD collection algorithms, namely BASELINE and DISCOVER. These algorithms are implemented in an open-source vehicular prototyping platform and validated in a real-world experimental setup

Age of Information in CSMA-Based Networks With Bursty Update Traffic

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Churches Heating: The Optimum Balance Between Cost Management and Thermal Comfort

AbstractIn this paper is presented a numerical and cost benefit approach of the indoor climate environment created inside of a historical Roman-Catholic church that will be subjected to restoration in the near future. The heating system used in present is with static heaters. The numerical model has as proposes to subject to comparison another heat system: floor heating and mechanical ventilation system in order to have a better understanding of the differences between them and the economical implication of this changes. Historical buildings and churches constitute a problem because they have enormous volumes and the envelope has a low efficiency. From the economical point of view, the solution must the feasible. The comparative results showed that the existing heating system is inefficient and has a lot of damage for the artworks and the painting inside the church

Traffic Management and Networking for Autonomous Vehicular Highway Systems

We develop traffic management and data networking mechanisms and study their integrated design for an autonomous transportation system. The traffic management model involves a multi-lane multi-segment highway. Ramp managers regulate admission of vehicles into the highway and their routing to designated lanes. Vehicles moving across each lane are organized into platoons. A Platoon Leader (PL) is elected in each platoon and is used to manage its members and their communications with the infrastructure and with vehicles in other platoons. We develop new methods that are employed to determine the structural formations of platoons and their mobility processes in each lane, aiming to maximize the realized flow rate under vehicular end-to-end delay constraints. We set a limit on the vehicular on-ramp queueing delay and on the (per unit distance) transit time incurred along the highway. We make use of the platoon formations to develop new Vehicle-to-Vehicle (V2V) wireless networking cross-layer schemes that are used to disseminate messages among vehicles traveling within a specified neighborhood. For this purpose, we develop algorithms that configure a hierarchical networking architecture for the autonomous system. Certain platoon leaders are dynamically assigned to act as Backbone Nodes (BNs). The latter are interconnected by communications links to form a Backbone Network (Bnet). Each BN serves as an access point for its Access Network (Anet), which consists of its mobile clients. We study the delay-throughput performance behavior of the network system and determine the optimal setting of its parameters, assuming both TDMA and IEEE 802.11p oriented wireless channel sharing (MAC) schemes. Integrating these traffic management and data networking mechanisms, we demonstrate the performance tradeoffs available to the system designer and manager when aiming to synthesize an autonomous transportation system operation that achieves targeted vehicular flow rates and transit delays while also setting the data communications network system to meet targeted message throughput and delay objectives