Miguel Gutiérrez Gaitán

Luis Almeida

Thomas Watteyne
email: thomas.watteyne@inria.fr

Pedro M D'orey

Pedro M Santos

Diego Dujovne

Luís Almeida

Joint Scheduling, Routing and Gateway Designation in Real-Time TSCH Networks

Keywords: Centrality, Network design, Low-power wireless mesh networks, TSCH

niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Wireless networks are at the heart of Industry 4.0 and the Industrial Internet of Things (IIoT) [START_REF] Sisinni | Industrial internet of things: Challenges, opportunities, and directions[END_REF], offering more flexibility and scalability than their wired counterparts. Timesynchronized channel-hopping (TSCH) is widely regarded as the de-facto low-power wireless networking approach for demanding industrial applications, achieving ultra low-power and wire-like reliability [START_REF] Dujovne | 6TiSCH: deterministic IP-enabled industrial internet (of things)[END_REF]. Its core features are time-division multiple-access (TDMA) and frequency diversity, making it ideal for real-time communication, and therefore often applied to real-time monitoring and process control [START_REF] Lu | Real-time wireless sensor-actuator networks for industrial cyber-physical systems[END_REF].

Theoretical and empirical studies have analyzed the predictable and, thus, analyzable aspects of TSCH [START_REF] Gaitán | Multiprocessor scheduling meets the industrial wireless: A brief review[END_REF][START_REF] Lu | Real-time wireless sensor-actuator networks for industrial cyber-physical systems[END_REF]. These works typically focus on prioritized packet scheduling [START_REF] Saifullah | End-to-end communication delay analysis in industrial wireless networks[END_REF] and routing methods [START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF] for improved real-time network performance. Our previous work looks at gateway designa- * Corresponding author. tion [START_REF] Gaitán | Impact of network centrality on the gateway designation of real-time TSCH networks[END_REF], the convenient positioning/selection of the gateway within a given topology, for enhanced traffic schedulability.

Network Manager

In this work, we simultaneously deal with network design, routing and resource allocation to provide a joint configuration framework for improved real-time network performance in TSCH networks. We first look at joint minimal-overlap (MO) real-time routing and Earliest-Deadline-First (EDF) scheduling [START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF] then combine it with centrality-driven gateway designation [START_REF] Gaitán | Impact of network centrality on the gateway designation of real-time TSCH networks[END_REF]. The goal is to complement the benefits of the three approaches to further enhance the real-time properties of the network at the system design time. To the best of our knowledge, this paper proposes the first joint scheduling, routing and gateway designation framework for real-time TSCH-based networks.

PRELIMINARIES

We target low-power wireless sensor networks (WSNs) focused on industrial application in the broad sense (from smart farming to automotive). A typical network (see Fig. 1) is composed of several sensing nodes which have limited computation capabilities and energy. These nodes are interconnected wirelessly to more powerful networking equipment (e.g. access points) capable of hosting a gateway and/or a network manager. A gateway node is used to establish the connection between the sensor nodes and the host application. The specific application dictates the data collection process, i.e. the sampling rate at each sensor node.

Network Model

We assume TSCH as the underlying medium access control (MAC) layer adopted to build up highly reliable and low-power networks. TSCH supports multi-hop and multichannel communication over a globally synchronized TDMA scheme. Transmissions take place inside time slots of fixed duration allocated over up to m = 16 channels. A time slot allows transmitting a single packet and receiving its corresponding acknowledgement. A channel-hopping mechanism is used to improve reliability against multi-path fading and external interference. A global scheduler defines the channel and the time slot used by the different links. In this paper, we use a global EDF scheduling policy [START_REF] Liu | Scheduling algorithms for multiprogramming in a hard-real-time environment[END_REF].

We model the long-term connectivity between the nodes by a unidirected graph G = (V, E), where V is the set of vertices (or nodes), E the set of edges (or links) between those nodes. The number of vertices in G is denoted by |VG|; the number of edges, |EG|.

Flow Model

The global traffic flow pattern is assumed as convergecast, directed toward a single gateway. Packets are generated by a subset of n sensor nodes ∈ V ; the remaining |VG| -n -1 nodes act solely as relays. Sensor nodes also relay packets. Each sensor node transmits a periodic (and deadline-constrained) data flow over a single route. We call F = {f1, f2, ..., fn} the resulting set of n real-time network flows. Each flow is characterized by a 4-parameter tuple fi = (Ci, Di, Ti, φi). Ci is the effective transmission time between the source node si and the gateway, Di is the deadline, Ti is the period, φi is the multi-hop routing path. Note Ci does not consider interference from other flows. We assume a flow never stops, i.e. new packets are always generated. The γ th packet in flow i is denoted fi,γ; it is generated at time ri,γ such that ri,γ+1 -ri,γ = Ti. In accordance with EDF, fi,γ needs to reach the gateway before its absolute deadline [di,γ = ri,γ + Di].

Performance Model

We consider the supply/demand-bound based schedulability test proposed in [START_REF] Gaitán | -WIN: On the forced-forward demand-bound function analysis for wireless industrial networks[END_REF] to quantify the real-time performance of TSCH-based networks under EDF [START_REF] Gaitán | Work-in-progress: Assessing supply/demand-bound based schedulability tests for wireless sensor-actuator networks[END_REF]. This method evaluates if the supply-bound function (sbf) -the minimal transmission capacity offered by a network with m channels -is equal or larger than the forced-forward demand-bound function [START_REF] Baruah | Improved multiprocessor global schedulability analysis[END_REF] (ff-dbf-wsn) -the upper bound on the total network time demanded by a set of n time-sensitive flows in any interval of length .

Formally, the schedulability test can be presented by [START_REF] Baruah | Improved multiprocessor global schedulability analysis[END_REF].

ff-dbf-wsn( ) ≤ sbf( ), ∀ ≥ 0. ( 1
)
Where sbf( ) is a piecewise-linear function in all intervals [h, h + l] that satisfies [START_REF] Dujovne | 6TiSCH: deterministic IP-enabled industrial internet (of things)[END_REF].

sbf(0) = 0 ∧ sbf( + h) -sbf( ) ≤ m × h, ∀ , h ≥ 0; (2)
ff-dbf-wsn [START_REF] Gaitán | -WIN: On the forced-forward demand-bound function analysis for wireless industrial networks[END_REF] is composed of two main terms: (i) channel contention due to mutually exclusive scheduling on multiple channels, equivalent to ff-dbf for multiprocessors [START_REF] Baruah | Improved multiprocessor global schedulability analysis[END_REF], and (ii) transmission conflicts due to multiple flows encountering on a common half-duplex link.

ff-dbf-wsn( ) = channel contention 1 m n i=1 ff-dbf(fi, ) + n i,j=1 ∆i,j • max Ti , Tj transmission conflicts (3)
This results in [START_REF] Gaitán | Impact of network centrality on the gateway designation of real-time TSCH networks[END_REF], where ∆i,j is a factor representing the path overlapping degree between any pair of flows fi and fj ∈ F (with i = j) in a given network G, defined by [START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF].

∆ i,j = δ(ij) q=1 Lenq(ij) - δ (ij) q =1 (Len q (ij) -3) (4)
δ(ij) is the total number of overlaps between fi and fj of which δ (ij) are the ones larger than 3. The length of the q th and q th path overlap between fi and fj are called Lenq(ij) and Len q (ij), respectively, with q ∈ [1, δ(ij)] and q ∈ [1, δ (ij)]. In convergecast, the factor expression is simpler since all paths are directed to the same root: only one path of arbitrary length is shared between any pair of flows. This implies ∆(ij) = 3 for overlap paths larger than 3 hops.

A REAL-TIME TSCH FRAMEWORK

We consider the problem of co-designing the communication schedule, the routing topology and identifying the gateway to improve traffic schedulability. We build upon our prior research: the insights on joint EDF-MO scheduling and routing [START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF] and the centrality-driven network designation strategy [START_REF] Gaitán | Impact of network centrality on the gateway designation of real-time TSCH networks[END_REF]. While these works have already demonstrated -separately -their benefits, we show in this paper that combining the featured EDF-MO real-time scheduling and routing method with a judicious centrality-based gateway designation increases schedulability by up to 80% with respect to a naive real-time configuration.

Joint EDF-MO Scheduling and Routing

Minimal-overlap (MO) shortest-path routing is a greedy meta-heuristic search to find a suitable set of flow's paths that reduces the overall path overlapping degree in the network [START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF]. The overlaps -the set of nodes shared between two different flow paths -have a direct influence on the analysis of worst-case end-to-end delays for TSCH-based networks [START_REF] Saifullah | End-to-end communication delay analysis in industrial wireless networks[END_REF]. This, in turn, can be translated into an impact on network schedulability under a global EDF policy [START_REF] Xia | Resource analysis for wireless industrial networks[END_REF][START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF]. The joint EDF-MO configuration takes advantage of this inbred network relationship to provide a set of disjoint paths which minimizes the number of overlaps among flow paths, regardless of the node designated as a gateway.

Algorithm 1 presents a pseudo-code of the MO routing based on its theoretical definitions in [START_REF] Gaitán | EDF scheduling and minimal-overlap shortest-path routing for real-time TSCH networks[END_REF]. The algorithm consists of three major procedures: EdgeUpdate (lines 1-4), CalcOverlaps (lines 5-7) and the main method MoGH (lines 8-21). The latter determines a new set of flow paths Φ k and its corresponding overall number of overlaps Ω k at each k th iteration to find the set of paths that provides minimal overlapping. This procedure stops when Ω k = 0, or after a kmax number of iterations. EdgeUpdate updates the weights of the link for the input topology Gin, returning Algorithm 1 Minimal-Overlap (MO) Routing

Input: G, F , kmax, ψ Output: Φopt, Ωopt 1: procedure EdgeUpdate(G in , Φ in ) 2: W k i,j (u, v) = 1 + δ (k-1) i,j e=1 ψ 3: G out ← -G in (V, E weighted )

4:

return G out 5: procedure CalcOverlaps(Φ in ) 6:

Ω k = n i,j ∆ ij 7:
return Ω out

G k ← EdgeUpdate(G k-1 , Φ k-1 )
14:

Φ k ← ShortestPath(G k , F ) Weight-based 15
:

Ω k = CalcOverlaps(Φ k )
16:

if Ω k < Ω min then 17:

Ω min k = Ω k 18: Φ min k = Φ k 19:
else 20:

Ω min k = Ω min k 21: k = k + 1 22: Φopt = Φ min k , Ωopt = Ω min k . Best Solution
a new weighted graph Gout over which new paths and overlaps are calculated. Cost function Wi,j(u, v) determines the weight of an edge (u, v) in Gout as function of δi,j and ψ. The former is the number of overlaps between the paths of flows fi and fj ∈ F at graph Gin; the latter a user-defined parameter used to control the speed of convergence of the algorithm. The ShortestPath procedure provides the shortest sequence of edges between two nodes in the graph, resorting to classical weighted or hop-count-based shortest-path mechanisms (e.g. Dijkstra). The CalcOverlaps procedure returns the total number of overlaps in the network by summing every ∆i,j factor (as defined in Section 2), and which represents the overlapping degree experienced by the paths of any pair of flows fi and fj ∈ F .

Centrality-Driven Gateway Designation

To further enhance network schedulability, we consider the centrality-driven network designation strategy proposed in [START_REF] Gaitán | Impact of network centrality on the gateway designation of real-time TSCH networks[END_REF]. We use network centrality from graph theory to provide convenient graph-based positions to designate the gateway in order to improve real-time network performance, by design. Specifically, it uses the four most common centrality metrics in social network analysis: degree, betweenness, closeness and eigenvector centrality, considered as near optimally correlated for the purposes of benchmarking.

Table 1 1 formally summarizes these four metrics.

1 Notation. DC: degree(vq) is the number of edges of node vq directly connected to any of the rest N -1 nodes in the graph G. BC: spr,s is the number of shortest paths between any pair of vertices vr and vs, and spr,s(vq) is the number of those paths passing through node vq; CC: distance(vp, vq) is the shortest-path (hop-count) distance between vertices vp and vq, with p = q, ∀ vp ∈ V . EC: λmax(A) is the largest eigenvalue of the adjacency matrix A = [aj,q]N , where aj,q is the matrix element at row j and column q, and xj is the jth value of the eigenvector x of graph G.

Eigenvector EC(vq) = 1 λmax(A) • N j=1 a j,q • x j 4. PERFORMANCE EVALUATION

Simulation Setup

Wireless network. We consider a set of 100 mesh topologies generated from synthetic graphs. Each topology is created using a sparse uniformly distributed random matrix of N × N of zeros and ones, with target density d. N represents the total number of nodes, including the gateway; d is the portion of other nodes each vertex is linked to. We assume N = 75 and d = 0.10 for all topologies. We assume the network is TSCH-based with m = 16 channels available, and 10 ms time slots.

Network flows. A subset of n ∈ [START_REF] Baruah | Improved multiprocessor global schedulability analysis[END_REF]25] nodes is chosen randomly as sensor nodes which transmit periodically deadlineconstrained data toward a single gateway. The rest of nodes act as relay. Each period is randomly generated as 2 η , with η ∈ N ∈ [START_REF] Dujovne | 6TiSCH: deterministic IP-enabled industrial internet (of things)[END_REF][START_REF] Gaitán | -WIN: On the forced-forward demand-bound function analysis for wireless industrial networks[END_REF] slots. This implies a super-frame length of H = 1280 ms. Ci is computed directly from the number of hops in φi and Di = Ti.

Real-time performance assessment. We consider the performance model described in Section 2. We evaluate the schedulability over an interval equal to the super-frame length, = H, when all the channels are available. We further assume network management is centralized, scheduling uses a global EDF policy, and routing can be either a hopcount-based shortest-path routing (Dijkstra) or the featured MO routing described in Algorithm 1. For MO, we further consider the following: Ψ = 0.1 and kmax = 100.

Preliminary Results & Discussion

Fig. 2a (top) presents the schedulability ratio when a gateway is designated based on the degree centrality and a shortest path routing is assumed. Fig. 2b (top) shows equivalent results for a gateway designation based on the DC when the MO routing is considered. Both configurations also include the case when the gateway is designated randomly. The results show that a joint EDF-MO-DC framework can schedule up to 3 times more flows than a basic routing configuration, and up to twice more than the EDF-MO tuple. Notably, achieving up to 80% better schedulability than a naive real-time setting.

Figs. 2a (bottom) and 2b (bottom) presents the absolute deviation in terms of schedulability ratio of the other centrality metrics w.r.t. the DC. These results suggest none of the metrics dominates over the others, regardless of the routing used. We also observe the deviation among the metrics remains larger (up to ∼ 20%) for the shortest path routing, and almost marginal (< 3%) when MO is used.

Overall, the reported results highlight the relevance of applying a judicious gateway designation in real-time TSCH networks, even if a real-time routing scheme is considered.

CONCLUSIONS

This paper presents a novel framework towards joint scheduling, routing and gateway designation in real-time TSCH networks. By resorting to prior methods for joint routing and scheduling, and centrality-driven gateway designation, we show by simulation that a combined approach which takes into account all three dimensions can improve schedulability by ∼ 80%, scheduling up to three time more real-time flows than a basic configuration. We are working on further investigating the performance of the framework with a broader range of varying parameters (network density, number of channels, number of gateways) as well as to study its applicability in related real-time network domains (wireless TSN, 5G).

Figure 1 :

 1 Figure 1: A low-power wireless mesh network.

8 :

 8 procedure MoGH(G, F, kmax)

Figure 2 :

 2 Figure2: Top: The schedulability ratio under varying number of network flows n ∈[START_REF] Baruah | Improved multiprocessor global schedulability analysis[END_REF] 25] for both shortest path routing and minimal-overlap routing when using the degree centrality metric for gateway designation compared to a random benchmark. Bottom: The absolute deviation in terms of schedulability ratio of the other centrality metrics w.r.t. the degree centrality.

Table 1 :

 1 Network Centrality Metrics.

	Metric	Definition
	Degree	DC(vq) =	degree(vq ) N -1
	Betweenness	BC(vq) = q =r	spr,s(vq ) spr,s
	Closeness	CC(vq) =	1 p =q distance(vp,vq )

ACKNOWLEDGMENTS

This work was partially supported by National Funds through FCT/MCTES (Portuguese Foundation for Science and Technology), within the CISTER Research Unit (UIDB/04234/2020); by the Operational Competitiveness Programme and Internationalization (COMPETE 2020) under the PT2020 Agreement, through the European Regional Development Fund (ERDF); by FCT and the ESF (European Social Fund) through the Regional Operational Programme (ROP) Norte 2020, under PhD grant 2020.06685.BD.


Rodrigo Marçal
email: romgandia@gmail.com

The Quintuple Helix Model and the Future of Mobility: The role of Autonomous Vehicles in a Developing Country

Keywords: Quintuple Helix Model, Urban Mobility, Autonomous Vehicles

. Finally, QHM can corroborate to such needed improvement and, our proposed theoretical framework could explain how this dynamic works.

Introduction

In the 21 st century, mobility is understood as a major issue and is a focal topic of discussion worldwide. Autonomous vehicles (AVs) are considered an integral part of the future of mobility and have become a focus of many R&D projects in the automotive industry; in fact, they are considered the most popular application of R&D in the recent history of the industry (Fan & Chang, 2016).

Considering the rapid change in the automotive industry and the new players that are ready to shape the automotive industry of tomorrow, there are still a number of legal, ethical, social, environmental and market barriers to overcome. The industry has entered a new era in which value creation relies entirely on dynamic relations in an open ecosystem of innovation, with moving boundaries to be addressed in the long run [START_REF] Attias | The Autonomous Car, a Disruptive Business Model?[END_REF].

AVs are bound to change the future of urban mobility, and this transformation will not only affect means of transport but also society as a whole. Nevertheless, there are many issues that still need to be addressed in the development of AVs, such as the possible impacts of autonomous driving on mobility behaviors and human-machine interactions, as well as related aspects of protection and safety [START_REF] Schreurs | Autonomous Driving-Political, Legal, Social, and Sustainability Dimensions[END_REF]. AVs will change the structures of our cities [START_REF] Zakharenko | Self-driving cars will change cities[END_REF], and we do not fully understand how our lives will be affected by this automobile revolution.

Although technical developments should be stimulated for the purpose of consolidating this technology, there are several non-technical aspects that have not yet received adequate attention, such as the societal implications of this technology's advancement [START_REF] Schreurs | Autonomous Driving-Political, Legal, Social, and Sustainability Dimensions[END_REF]. The timing, scale, and direction of AVs' impacts are uncertain, and the opportunities to influence investment decisions are limited [START_REF] Guerra | Planning for cars that drive themselves: Metropolitan Planning Organizations, regional transportation plans, and autonomous vehicles[END_REF]. In regard to technology and innovation models, one that is very influential among academics is the triple helix. Created by [START_REF] Etzkowitz | The dynamics of innovation: from National Systems and "Mode 2" to a Triple Helix of university-industry-government relations[END_REF], this model describes the innovation process via government-university-business cooperation. Although widely used, the concept has evolved to include two other main players: society and the environment. Therefore, the concepts of the Quadruple Helix and Quintuple Helix created by [START_REF] Carayannis | Mode 3'and'Quadruple Helix': toward a 21st century fractal innovation ecosystem[END_REF] have also emerged. In these new theories, the three original helices operate in a complex urban environment, where market demand, governance, civil involvement and citizens' characteristics, along with cultural and social capital endowments, shape the relationships among the traditional helices of university, industry and government (Lombard et al, 2012).

The most important element of the Quintuple Helix is the "knowledge" feature, which encompasses the entire system. This model, which can be used both in theory and practice, highlights the exchange of knowledge resources based on five social subsystems in order to promote the sustainable development of society (Carayannis, Barth & Campbell, 2012).

The quest to reduce uncertainties has motivated a number of countries to take significant steps to be at the forefront of AV research [START_REF] Cavazza | Management and Business of Autonomous Vehicles: A Systematic Integrative Bibliographic Review[END_REF]. Universities, industries and governments worldwide (especially in the USA, China and the European Union) are studying AVs to determine how this innovation may affect cities and be implemented as part of urban mobility solutions.

Currently, the concept has evolved, and the triad of university-industry-government has been strengthened by new models of knowledge generation that include society (Quadruple Helix) and the environment (Quintuple Helix) as important aspects of innovation dynamics. According to Lombardi et al. (2012), the Quintuple Helix operates in a complex urban environment, where market demand, governance, civic involvement and citizens' characteristics, along with cultural and social capital endowments, shape the relationships among the traditional helices of university, industry and government.

A key reason for policymakers to consider AVs now is that the spatial planning and infrastructure investment decisions that we make today will determine the development of our countries and cities for decades [START_REF] Kpmg | Autonomous Vehicles Readiness Index: Assessing countries' openness and preparedness for autonomous vehicles[END_REF]. Thus, adopting this perspective, other countries, especially in Europe, have already begun to design and plan AV-related actions, anticipating the future of mobility by thinking about policies that favor the propagation of this new technology. However, this is far from the reality in Brazil. We realize that there is still a lack of coordination among companies, government, universities and even societycoordination that would enable AVs to promote economic, social and sustainable development for all. In this sense, the QHM can fill the gap among the abovementioned agents. Thus, it remains to be seen "when" and, most importantly "how", this innovation will be disseminated.

In this sense, the inquiries that guided this research are as follows: How can the QHM positively support the implementation of AVs to advance urban mobility? What are the dynamics between the QHM and the Brazilian context? Therefore, this paper aims to understand whether the QHM can positively foster advancements in urban mobility via the insertion of AVs into society. Furthermore, we seek to discuss the dynamics of the QHM in the Brazilian context.

The mobility systems of the future are likely to be very different from what exists in most of the world today. It is therefore important to understand that people are at the center of this evolution [START_REF] Mckerracher | An integrated perspective on the future of mobility[END_REF]. In addition to thinking about safety aspects, other issues should be discussed in a coordinated way [START_REF] Schoitsch | Autonomous Vehicles and Automated Driving Status, Perspectives and Societal Impact[END_REF] because increased AV availability increases workers' well-being, displacement distances and the sizes of cities, while also improving traffic coverage and collective transportation [START_REF] Zakharenko | Self-driving cars will change cities[END_REF].

Theoretical Background

Urban mobility and autonomous vehicles

Considered part of the lifeblood of our cities, mobility is what keeps our urban centers running [START_REF] Mckerracher | An integrated perspective on the future of mobility[END_REF]. The concept of urban mobility is considered to encompass the characteristics of all transport modes and their relationships with land use, environmental quality and urban planning (Oliveira et al., 2017). Issues related to sustainability and overpopulation, among others, make mobility one of the main concerns of our contemporary society, making it a central topic that is discussed worldwide.

Among the currently available providers of transportation, the automotive industry plays a fundamental role in mobility. In recent years, this industry has been witnessing a transformative evolution into a new ecosystem, known as "intelligent mobility", into which AVs are being inserted. Consequently, this new ecosystem presents several possibilities for new scenarios [START_REF] Attias | Extending the Scope of Partnerships in the Automotive Industry Between Competition and Cooperation[END_REF]. In this sense, it is understood that AVs' development is a disruptive innovation that promises to have a substantial impact on issues of urban mobility.

Hodson (2016) notes that AVs are only a part of a major revolution in urban transport, as there are simultaneous expansions of autonomous technology to other modes of public transport (e.g., metro lines that already operate without drivers in major cities worldwide). Corroborating this, [START_REF] Attias | The Autonomous Car, a Disruptive Business Model?[END_REF] proposes that in a mid-term perspective, this evolution will not stop with AVs and will open the field for the design of similar technical objects (e.g., trucks, buses) and even boats and autonomous planes.

The convergence process of such dynamic movements between the traditional transport model and intelligent mobility culminates with consumers being even more connected and seeking more accessible mobility solutions at more competitive prices. In this sense, [START_REF] Enoch | How a rapid modal convergence into a universal automated taxi service could be the future for local passenger transport[END_REF] proposes that traditional transport models (cars, buses and taxis) will converge to intermediate transport models (centered on sharing), and the author goes further in stating that AVs will accelerate this convergence process due to their various advantages, such as increased mobility, better usage of urban spaces, reduction in congestion costs, increased road safety, user comfort, and reduction in fuel consumption and pollutant emissions [START_REF] Schoitsch | Autonomous Vehicles and Automated Driving Status, Perspectives and Societal Impact[END_REF]U.K. Department for Transport, 2015).

However, negative impacts still surround the development of AV, such as social risks (rebound effects); personal data protection (e.g., hacking attacks); increased insurance costs; loss of revenues related to the reduction in individual traffic (e.g., reduction in parking, speeding and infraction tickets); attraction of passengers from public transport systems, resulting in job losses (e.g., taxi drivers, truck drivers and bus drivers may lose their livelihoods and occupations); possible investments in infrastructure; and rules and regulations, among others [START_REF] Schoitsch | Autonomous Vehicles and Automated Driving Status, Perspectives and Societal Impact[END_REF].

In this sense, it is understood that any positive or negative impacts of this innovation go beyond organizational and governmental limits, affecting many other spheres of our modern society. Therefore, it is important and necessary that the building and execution of this technology contemplate all these spheres (government, companies, society, academy, environment) synergistically to optimize this dynamic process of transformation in contemporary urban mobility.

From the triple helix to the quintuple helix

Countries' innovation systems have been gaining strength given that knowledgeproducing institutions are essential to fighting the issues faced by our modern society. Thus, companies, governments, universities and even the population must work together on trying to curb, or minimize, the negative social consequences of the economic development that has occurred so far.

The main difference between the traditional triple helix model and the newer quintuple helix is in the "innovation ecosystem", which combines and integrates social systems and environments, emphasizing the importance of the diversity of actors and organizations, such as universities, small and medium-sized enterprises, and large corporations, government innovation networks and knowledge clusters (Carayannis & Campbell, 2011).

In the triple helix model, the relationships are overlapping, creating hybrid environments, leading to dilution of barriers and enabling greater cooperation [START_REF] Silva | Mapeamento da atuação dos Núcleos de Inovação Tecnológica dos Institutos Federais de Educação, Ciência e Tecnologia[END_REF]. For this, the government has the role of elaborating public policies that foster innovation processes, and the government is also responsible for regulating and normalizing economic activity. Companies must concentrate on their productive activities in a cooperative sense, and the production, dissemination and transfer of knowledge are reserved for universities [START_REF] Vieira | Triple Helix e Inovação: A Relação com os Vales da Uva Goethe. Anais da Altec[END_REF].

The above actors are pressured by the accelerating pace of change and innovation in both scientific and technological environments. Thus, in the process of manufacturing autonomous cars, even cutting-edge companies are facing ethical, moral, technological, and urban mobility challenges because evidence of the long-run impact of AVs is not yet clear and well mapped.

The first step to be stimulated within this innovation system begins with the introduction of education inputs. Because more investments flowing into the helix of the education system means the production of new equipment, new locations for scientists and teachers, and greater opportunities for research, a greater outlet for innovations in science and research can be created (Carayannis, Barth & Campbell, 2012).

For this to happen in an integrated way, the other helices must be interconnected via the input of knowledge. The second step begins with human capital in the helix of the economic system, represented by companies. Any investment in knowledge and in promoting the production of knowledge brings new impulses crucial to innovation, know-how and the advancement of society (Carayannis, Barth & Campbell, 2012). Leydesdorff (2012) argued that to go further -i.e., towards the fourth or fifth helixwould require greater specification, operationalization in terms of potentially relevant data, and sometimes additional development of relevant indicators. To do this, companies must focus on their productive activities in a cooperative sense, and the university reserves its role in constructing, disseminating and transferring knowledge [START_REF] Vieira | Triple Helix e Inovação: A Relação com os Vales da Uva Goethe. Anais da Altec[END_REF].

The "fourth helix" of the model refers to the culture and values of society. In this way, innovation policies and strategies must recognize the important role culture plays in promoting a knowledge-based economy. The politics of knowledge and innovation should be inclined to reflect the dynamics of "media-based democracy" and their role in the elaboration of strategies. The goal is to develop a policy of innovation to generate economic performance and thus link the whole system of innovation in a country [START_REF] Carayannis | Mode 3'and'Quadruple Helix': toward a 21st century fractal innovation ecosystem[END_REF].

By adding the fifth helix to the model, the model becomes more comprehensive because, in addition to the analytical and explanatory approach it already possessed, the "natural environments of society" are added in the macro analysis (Carayannis & Campbell 2010). Now, the socio-ecological environment is taken into account, that is, the Quintuple Helix's innovation system is ecologically reliable because it is based on the understanding of the production of knowledge (research) and the application of knowledge (innovation), both of which consider environmental issues (Carayannis, Campbel & Rehman, 2016).

We believe that the model has the advantage of aggregating new knowledge, helping in the creation and development of creative innovations and new learning methods. At the same time, innovation in AVs is still characterized by lack of coordination among OEMs, governments, universities and even society; such coordination is necessary if these vehicles are to effectively support economic, social and sustainable development overall.

Methodological Approach

With the dual aim of understanding whether the QHM can positively foster advancements in urban mobility as a result of AV insertion into society and discussing the dynamics of the model in the Brazilian context, the adopted research design (Figure 01) was characterized as a qualitative approach of a descriptive and exploratory nature. First, we proceeded with data collection in both academic and grey literature by using the saturation criteria as a stopping point [START_REF] Fontanella | Amostragem por saturação em pesquisas qualitativas em saúde: contribuições teóricas[END_REF][START_REF] Fontanella | Amostragem por saturação em pesquisas qualitativas em saúde: contribuições teóricas[END_REF][START_REF] Fontanella | Amostragem por saturação em pesquisas qualitativas em saúde: contribuições teóricas[END_REF][START_REF] Guerra | Pesquisa qualitativa e análise de conteúdo: sentidos e formas de uso. São João do Estoril[END_REF]. Next, we created five propositions based on QHM that could positively impact AVs. In the sequence, we used categorical content analysis and descriptive qualitative analysis [START_REF] Bardin | Análise de conteúdo[END_REF][START_REF] Vergara | Métodos de pesquisa em administração[END_REF] to discuss and analyze the results. Finally, we created a theoretical framework aiming to bring the results and practical implications together to illustrate the theoretical contribution of the QHM to urban mobility.

Results and Discussion

Automotive companies, suppliers, government, regulators, legal authorities, rating agencies, road operators, and the general public have been prepared for what is the greatest inflection point for the automotive industry since the introduction of the assembly line [START_REF] Mosquet | Revolution in the driver's seat: The road to autonomous vehicles[END_REF]. In this session, we tried to show the impact that the Quintuple Helix could have on AVs and the impact on each of the 05 helices: (P1) government; (P2) companies; (P3) academy; (P4) society and; (P5) environment.

(P1) Governments can positively impact autonomous vehicles

The relations among the institutional spheres of university, industry, and government can help generate solid strategies for economic growth and societal transformation. From a political perspective, national innovation systems can be defined as a relevant reference framework for governmental interventions, which are aimed at the economic growth of different industries [START_REF] Etzkowitz | The dynamics of innovation: from National Systems and "Mode 2" to a Triple Helix of university-industry-government relations[END_REF]. In this sense, the organization of the political system is of crucial importance because it formulates the "will" of the state, that is, where the state is directed both in the present and the future and how it organizes the general conditions of the nation. Therefore, this helix has active political and legal capital through incentives, ideas, laws, plans, and partnerships that can benefit companies and the population, as well as emerging sectors (Carayannis, Barth, & Campbell, 2012).

An issue that is already on the agenda in some European governments concerns AVs' regulation and encouragement of the motor vehicle industry. Regulation should ensure safety and accompany the development of the emerging AV industry, avoiding any market failures. Different countries have created rules on prototypes allowing testing, licensing and operation of this technology on public roads [START_REF] Frisoni | Self-piloted cars: The future of road transport[END_REF].

For instance, in Germany in 2015, the federal government started a round table on vehicular automation where industry, academia and government met to define specific areas of action to support the introduction of autonomous driving in the country. Discussions included topics such as infrastructure, legislation, innovation, and interconnectivity [START_REF] Frisoni | Self-piloted cars: The future of road transport[END_REF].

Sweden is supporting a national program to promote alliances among the various stakeholders. In 2009, the country established a partnership with the automotive industry, called "Strategic Vehicle Research and Innovation", with the aim of investigating innovative solutions for the climate, environment and safety. This report involves R&D activities worth approximately €100 million per year (half of this amount is publicly funded), including research in AVs and connected transport systems [START_REF] Frisoni | Self-piloted cars: The future of road transport[END_REF].

France is encouraging a new strategic alliance among the main French automotive companies to favor the development of AVs in the country. This industrial strategy is called "La Nouvelle France Industrielle" and was promoted by the Ministry of Economy and Finance beginning in 2014. AVs are mentioned as a key point of technological development in France.

Based on the above reports, we see that the discussions between government and industry in the aforementioned European countries are moving towards partnerships. Despite the progress initiated by some countries, there seems to be little coordination of the actions taken by different jurisdictions; the jurisdictions are restricted to targeting their own individual actions [START_REF] Frisoni | Self-piloted cars: The future of road transport[END_REF].

The analysis of the Brazilian context points to the Government helix as the weakest link. Undoubtedly, the Brazilian government has several issues and problems that need to be overcome so that the implementation of AVs can be made feasible. According to the KPMG (2018) report "Autonomous Vehicles Readiness Index," which seeks to access countries' openness and readiness for AVs, Brazil "has the weakest scores of the 20 surveyed countries for policy and legislation".

According to Mauricio Endo -Head of Government & Infrastructure, Advisory, KPMG in Brazil:

In terms of specific regulation, we haven't seen discussions on AVs but there is a new automotive sector regulation called 'Rota 2030' being discussed by the government, which may include some initial related topics. AV discussions are starting in forums and events related to the automotive and telecom industries, but we still haven't seen city authorities or governments planning around it. (KPMG, 2018, p.33).

These results clearly state the deficiency of the Brazilian government concerning the legislation and incentives surrounding AV technology. Thus, there is still a large chasm to be overcome so that Brazil can really be ready for the imminent arrival of AVs.

(P2) Companies can positively impact autonomous vehicles

We observed that the governments of some countries offer tax support and create public policies to strengthen their relationships with universities and industries. For example, some European countries are already addressing the regulation of incentives for the AV industry. Regulation should ensure safety and monitor the development of this emerging industry, avoiding any market failures. These nations have created rules regarding prototypes that allow testing, licensing and operation of this technology on public roads. These changes, in turn, directly impact manufacturers in the automotive industry, as all actors must work together to implement a "common language" solution.

Moonzur (2012, p. 12) also mentions the likely disappearance of driving schools. "In case the vehicle would be completely autonomous and not require driver intervention, the vehicle that will be in sole command". Morally, the relevant decisions would have been made by the developer of the underlying algorithm. In any case, the automatic system would act, and the consequences cannot be considered accidental because they are determined beforehand. In many cases, different interested parties should cooperate to advance such solutions.

It is important to emphasize that it is not only vehicle manufacturers that are benefitting from advancements in AVs but also the economic system as a whole. The main stakeholders of this advancement are described as telecommunication companies, shared vehicle services, and technology and insurance companies (European Parliament, 2016), and it is expected that they will all have new services and demands as a result of the synergy generated by the QHM. [START_REF] Botelho | Inovações, Pequenas Empresas e Interações com Instituições de Ensino/Pesquisa em Arranjos Produtivos Locais de Setores de Tecnologia Avançada[END_REF] say that this helix concentrates "economic capital" (e.g., entrepreneurship, machines, products, technology, money). Given this concentration, relations with customers and suppliers, with companies competing with research institutes and/or universities, appear to be one of the most important issues [START_REF] Leydesdorff | The triple helix perspective of innovation systems[END_REF].

To ensure strong and sustained public support, the industry will need to engage with the general public and be direct about the limitations and benefits of the technology (BCG, 2015). To accelerate AVs' adoption and, consequently, urban mobility, industry players must collaborate to overcome technology challenges [START_REF] Mosquet | Revolution in the driver's seat: The road to autonomous vehicles[END_REF].

In this sense, actors in the private sector should consider partnerships that go beyond traditional sectorial boundaries (many of which have already begun to blur). Consumers will judge the vehicles by how they are integrated with the services they provide: from in-car entertainment to on-demand rental platforms. Those players in the industry who can unlock new partnerships between technology and service providers will have the best chance of avoiding marginalization [START_REF] Mckerracher | An integrated perspective on the future of mobility[END_REF]. According to the European Automobile Manufacturers Association, the European car industry annually invests € 41.5 billion in R&D, approximately 5% of its total turnover. Although this amount is spent on a variety of research and testing programs, it is undeniable that the development and implementation of AVs represents one of the major interests of car manufacturers [START_REF] Tan | Agent-as-aservice-based geospatial service aggregation in the cloud: A case study of flood response[END_REF].

Although the automotive industry has strong relevance on the national scene, it is worth noting that Brazil is a "technology importer and commodity exporter," and this fact demonstrates certain weaknesses in our OEM industry. According to the KPMG report, Brazil "received the lowest scores on R&D hubs, AV technology company headquarters, patents and investments" (KPMG, 2018, p.33).

The Brazilian industrial scenario is paradoxical: on the one hand, we see growing interest and investment in some companies, e.g., Uber operation has been authorized in large cities in the country since 2016, and Brazil is considered one of the largest Uber markets globally (KPMG,p.33, 2018). On the other hand, we know that there are many problems related to infrastructure and legislation that need to be addressed. The same report notes that Brazil "gets the lowestrating for people's use of technology."

(P3) The Academy can positively impact autonomous vehicles

The convergence between basic and applied research is an opportunity for universities to transfer their knowledge to other spheres. In this regard, the academy plays a central role between the government and industry, especially car manufacturers. It was observed that universities from different countries are now cooperating with large programs involving both public and private actors for the development and application of automated mobility systems.

Technical aspects that permeate AVs were research fields in earlier decades. During the 1990s, the USA Defense Department promoted the development of self-driving vehicles for military purposes by financing projects across academia and automotive companies (U.K. Department for Transport, 2015). Nevertheless, non-technical aspects are still an incipient knowledge field [START_REF] Gandia | AUTONOMOUS VEHICLES: Scientometric and bibliometric studies[END_REF].

In this sense, Cavaza et al. (2017) identified five knowledge categories that could contribute to the dissemination of AVs: policy issues (law); ethics, moral issues, liability; transport planning; consumer behavior and business models. It should be highlighted that even with the academy's efforts in projects that stimulate synergy among the spheres, there is still a gap that affects all the interested parties as proposed by the QHM.

As for the academic area, Brazil does not have an impressive percentage of publications according to information extracted from the Web of Science database. Regarding the field of AVs, the country ranks 17 th in publications worldwide. Although it ranks first in Latin America, the discrepancy in numbers of publications is huge (95 publications for Brazil versus 1796 for the first-place country); Brazil is responsible for just 1.41% of all publications in the world [START_REF] Gandia | AUTONOMOUS VEHICLES: Scientometric and bibliometric studies[END_REF].

If we consider the business and management fields, the results are even worse. According to a previous investigation in the 3 main international databases, of the 644 papers found (244 from Scopus, 56 from WoS and 344 from SD), there was no single paper originally from Brazil [START_REF] Cavazza | Management and Business of Autonomous Vehicles: A Systematic Integrative Bibliographic Review[END_REF].

It is important to highlight that this lack of academic knowledge in our country regarding this object of study [START_REF] Gandia | AUTONOMOUS VEHICLES: Scientometric and bibliometric studies[END_REF][START_REF] Cavazza | Management and Business of Autonomous Vehicles: A Systematic Integrative Bibliographic Review[END_REF] has a direct impact on AVs' development, as academia is a valuable actor as a provider and manager of information and knowledge for other helices.

(P4) Society can positively impact autonomous vehicles

In an era where innovation is blooming, in which social innovation and ecological innovation imply behavioral changes at both individual and social levels, the challenges of health, poverty and climate change, and especially the future of cities, must be addressed. The regional governance system and companies should be open to new groups in society that are capable of promoting a culture of challenge.

This new era also includes perceptions of consumption that are different in each country; for instance, in emerging economies (e.g., Brazil), the ownership of a car is perceived as conveying status, independence and power. In this sense, it is also worth understanding consumers' needs [START_REF] Attias | The Autonomous Car, a Disruptive Business Model?[END_REF].

While consumers expect automakers to produce reliable, high-quality and safe vehicles, they also believe that technology companies must bring in their expertise. Apple and Google are top-of-mind possibilities. Consumers in India, in the United States, and China are more likely to see a technology company as an ideal coordinator of the entire chain. One reason may be the importance and visibility of the technology industry in these economies [START_REF] Mosquet | Revolution in the driver's seat: The road to autonomous vehicles[END_REF].

A survey conducted by the Boston Consulting Group and the World Economic Forum with 5500 consumers in 10 countries (North America, Europe, Middle East and Asia) highlighted the fact that users who adhere most to the AVs are more numerous in emerging countries such as India (85 %) and the United Arab Emirates (70 %) than in France (60%) and Germany (44 %) or Japan (36 %). Another point to note in this survey is that traditional manufacturers are by far those that consumers consider the most reliable (between 50 and 58% of reliability), and they think about other technology players such as Apple and Google as bringing "relevant, but complementary expertise" [START_REF] Mosquet | Revolution in the driver's seat: The road to autonomous vehicles[END_REF]WEF 2015).

On the other hand, social pressure can be an obstacle. Generally, audiences who are very keen on new technologies may change their minds quickly. If, for example, a horrible accident involving an AV occurs in the early stages (market introduction), regulators could face pressure to take a strong position against such vehicles. To ensure strong and sustained public support, the industry will need to engage with the general public and be direct about the limitations and benefits of this technology [START_REF] Lang | Revolution Versus Regulation The Make-or-break Questions About Autonomous Vehicles[END_REF].

Clearly, societal acceptance is very crucial to AVs' adoption, especially considering that stakeholders must address the interests and concerns of consumers and policy makers. Overcoming this challenge requires strong collaboration among the parties involved, especially industry and government, to address concerns adequately (e.g., by establishing stringent safety standards) and to transparently provide economic alternatives to those who are adversely affected [START_REF] Lang | Revolution Versus Regulation The Make-or-break Questions About Autonomous Vehicles[END_REF].

Contrary to the government helix, the societal one emerges as the strongest link in the Brazilian context. First, it is important to note that the Brazilian auto market stands out on the world stage and can be considered the gateway to Latin America (ICCT, 2015;SEBRAE, 2015). Another important factor is the Brazilian consumer profile:

Brazilians are the keenest of all 20 countries on AV technology, mobile phone penetration is more than 100% of the population and Brazilians are known for being early adopters of new technologies. Despite this, the country gets the lowest rating for people's use of technology (KPMG, 2018, p.33) When analyzing the profile and the behavior of the Brazilian consumer, we can observe great acceptance potential for AVs in our country. Such characteristics, which are linked to the size and potential of the Brazilian market, have attracted attention from researchers and industries worldwide and serve as a counterpoint to the shortcomings presented by other helices.

(P5) Environment can positively impact autonomous vehicles

One could argue that concepts such as "sustainability", "sustainable development" or "social ecology" are already, per se, interdisciplinary and transdisciplinary, as they are now fundamental to the conception of products and to academic research. Research questions and problem-solving in relation to ecology, the environment, environmental changes and environmental protection increasingly depend on interdisciplinary and transdisciplinary network configurations of different knowledge and innovation modes. Cross-linking human rights, human development and the environment already bridges analytically into sustainable development, clearly including features of social ecology (Carayannis & Campbell, 2010).

In this context, AVs can reduce fuel consumption and pollution; moreover, this emerging technology promises several potential benefits, such as reducing collisions and deaths, reducing traffic congestion, improving mobility for people incapable of driving and mitigating environmental impacts. Sustainability is a crucial desideratum for engineers and policy makers considering vehicle design, public versus private transportation, and infrastructure manufacturing [START_REF] Mladenovic | Engineering social justice into traffic control for self-driving vehicles?[END_REF].

There is an expectation that AVs can reduce fuel use and pollution (because they will be electric) by strictly following hypermiling strategies. They may position themselves closely behind other cars because AVs have a faster reaction response and do not need to have the same safety margin as humans [START_REF] Spieser | Toward a systematic approach to the design and evaluation of automated mobility-on-demand systems: A case study in Singapore[END_REF]). In the future, the progressive replacement of fleets of combustion vehicles by electric vehicles will also be positive in this regard.

In a study carried out by [START_REF] Fagnant | The travel and environmental implications of shared autonomous vehicles, using agent-based model scenarios[END_REF], the authors found that a single shared AV has the potential to replace approximately 11 private vehicles. In addition, reductions in energy consumption and emissions of air pollutants can be expected when the AV system begins to be used by 5% of the population.

Sustainability is also an important element in the pursuit of social justice: institutions that ensure fair relations between people and reduce harm to future generations are unquestionably important. For these reasons, sustainability is a crucial point for engineers and policy makers who consider vehicle design, public transport vs. private transport, and infrastructure manufacturing [START_REF] Mladenovic | Engineering social justice into traffic control for self-driving vehicles?[END_REF].

Perhaps this is the helix with fewer inputs to discuss in the national scenario. The Brazilian population in July 2016comprised 206,081,432 inhabitants (IBGE, 2016), and it is possible to calculate an average of 4 inhabitants per car (automobile). This is a relevant environmental impact, especially considering the impressive number of people using private transportation. A study from the Institute of Applied Economics Research (IPEA, 2011) showed that 65% of the population of Brazilian capitals uses public transportation to commute, and this number drops to 36% in non-capital cities. Only 2.85% of capital populations commute by foot, while in other cities, this percentage rises to 16.63%. On average, in all Brazilian cities, 23% of the population uses a car as a means of transportation.

Once again, if we consider the new technologies, the image is not promising: "Brazil shares the bottom spot with Russia on market share of electric cars which are not generally available, although hybrid cars are starting to be imported" (KPMG, 2018, p.33).

Theoretical framework

The theoretical model of the Quintuple Helix establishes positive relations between urban mobility and the introduction of AVs. Based on the analysis of the general propositions, a theoretical framework was created (Figure 02). It was observed that the helices present synergetic relations, which should act in consonance so that a positive development of AVs is established and, consequently, AVs contribute to urban mobility.

It is noted that the government can exert a direct influence on all helices (from political stimuli to transport plans and laws), and such influence can determine the positive or negative paths along which the devices inherent to the development of AVs and the future of mobility will be established. The academy must act on both the technical and non-technical fronts of this development; it should act like a trigger by identifying the demands of other spheres to point out scenarios that allow orchestrated thought among government, industry, society and the environment.

The social sphere presents cultural, consumer and infrastructure-related specificities, and these factors must be taken into account as the global regulatory aspects of AVs are developed (e.g., automotive technology imports from other countries to Brazil must take into account the cultural aspects of Brazilian consumers). Regarding the environmental sphere, it is important to emphasize the strong interface between AVs and sustainability issues. Several studies point to the gains generated by these vehicles with regard to sustainable development and social ecology. According to [START_REF] Santos | Interação Universidade-Empresa: características identificadas na literatura e a colaboração regional da Universidade de Twente[END_REF] the collaboration academy-industry is increasingly important. In this context, it is important to highlight the role that the industry (including the entire network of stakeholders, OEMs and companies and businesses that will be indirectly impacted) will play in the articulation, deployment and dissemination of AVs. However, in order to achieve the technical and non-technical features of this new technology the industry will need to work together to the academy.

Conclusion

This study has sought to understand the contribution that the QHM can make to the future of urban mobility via the insertion of Autonomous Vehicles. We observed that the QHM contributes favorably to the future of urban mobility, in which AV-related innovation plays a crucial role. It is noteworthy that among projections and scenarios of the future of mobility [START_REF] Lang | Self-Driving Vehicles, Robo-Taxis, and the Urban Mobility Revolution[END_REF][START_REF] Mckerracher | An integrated perspective on the future of mobility[END_REF]PWC, 2016;[START_REF] Mosquet | Revolution in the driver's seat: The road to autonomous vehicles[END_REF][START_REF] Lang | Revolution Versus Regulation The Make-or-break Questions About Autonomous Vehicles[END_REF], AVs are a key factor, even though this innovation is still surrounded by uncertainties.

According to the QHM, the synergy among agents is essential if the impacts of the development of this innovation are to be minimized, and although we observed a need for action by all agents, this was observed in a fragmented way in the documents and studies analyzed. It is understood that the technological development of AVs can be considered at a global level; however, in the case of urban mobility, local specificities should be taken into account, considering social and governmental particularities as determining factors for AV dissemination. This study opens discussions on the topic by demonstrating the importance of establishing AV innovation in a synergistic way. Among the stakeholders responsible for the development of AVs, the academy will be responsible for the search for a suitable model. Second, it is necessary not only to understand AV development as a technological innovation that will bring comfort to society but also to realize that this radical innovation can change the future of urban mobility around the world. Thus, developing this technology without looking at all the helices proposed by the QHM would be like "driving with one eye closed". Governments should be aware of this, but this paper agrees that the academy has an important role to play in stimulating this line of thought; the academy must help the government ensure that this revolution happens with minimum negative impacts.

In the Brazilian context, it was observed that the country needs to improve many aspects of the way it is preparing for the future of urban mobility. Brazilians tend to be early technology adopters, and the country has good mobile networks, but it will need to improve its regulations, local innovation and road quality to take advantage of AVs [START_REF] Kpmg | Autonomous Vehicles Readiness Index: Assessing countries' openness and preparedness for autonomous vehicles[END_REF]. The QHM can corroborate those needed improvements, and the theoretical framework can explain how this dynamic works.

In addition, this is a theoretical paper; therefore, interviews or surveys have not been conducted. Regarding future research, we suggest practical studies that generate data in order to validate our theoretical framework. We also suggest deeper studies for each helix to determine the importance of each to the QHM. Finally, it is important to highlight that this study represents a starting point for analyses involving AVs and the spheres of the QHM and that it can contribute to advances and future studies on the issues of mobility, eco-innovation, sustainable innovation, smart cities, industry 4.0 and more.

Figure 1 :

 1 Figure 1: Study design.

Figure 2 :

 2 Figure 2: Theoretical framework -the QHM positively assists with advancements in urban mobility as a result of the insertion of AVs into society.


Olivier Langella

Thomas Renne

Thierry Balliau

Marlène Davanture

Sven Brehmer

Michel Zivy

Melisande Blein-Nicolas

Filippo Rusconi

X!TandemPipeline++: Software for Ion Mobility-Enabled Quantitative Proteomics in timsTOF Data Format

niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.


Olivier Langella

Thomas Renne

Thierry Balliau

Marlène Davanture

Sven Brehmer

Michel Zivy

Melisande Blein-Nicolas

Filippo Rusconi

Upgrading X!TandemPipeline and MassChroQ for fast and accurate timsTOF native raw data support for quantitative proteomics

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Olivier Langella*, Thomas Renne, Thierry Balliau, Marlène Davanture, Sven Brehmer, Michel Zivy, Mélisande Blein-Nicolas # and Filippo Rusconi X!TandemPipeline++ performs peptide identifications and area-under-the-curve XIC-based quantifications using the Bruker's native timsTOF raw data format. Using a common HeLa data set, published by Meier et al. (2018, PXD010012), we demonstrate that X!TandemPipeline++ identifies and quantifies significantly more proteins than the MaxQuant and MSFragger competitors, while being also significantly faster.

Please, note that X!TandemPipeline++ will soon be renamed to i2MassChroQ to reflect the identification & inference -mass chromatogram-based quantification capabilities.

Identification and protein inference msruna1 vs msruna4 (r=0.99) Grouping might be performed by processing each sample separately or by creating a consensus protein list starting from multiple combined samples.

Our software supports Mascot-, X!Tandem-generated identi�cation data or any data set in mzIdentML and pepXML formats (from OpenMS, Comet, PeptideProphet). Its Occam's razor-based grouping algorithm can infer protein groups very quickly, in particular by �ltering-out non informative redundancies (Van Den Bossche et al., nature communications, 2021).

Thousands of DDA identi�cation results can be loaded at once as part of the same project.

X!TandemPipeline++ features high throughput and high resolution proteomics and metaproteomics features.

  IDEEV -Institut diversité, écologie et évolution du vivant GQE-Le Moulon, PAPPSO Université Paris-Saclay, INRAE, CNRS, AgroParisTech, F-91190 Gif-sur-Yvette, France Langella et al. 2017) is a free and open source Java software program for proteomics initially designed to filter and group peptide/protein identifications from MS/MS mass spectra. After a complete rewrite in C++17, the new X!TandemPipeline++ program features peptide/protein quantification, in particular with support for native timsTOF raw data.

	X!TandemPipeline (	ABSTRACT
		RESULTS
		median 0.059
		i2MassChroQ
		Main website	User manuals
			HTML	PDF
	# presenting author

* corresponding author

Upgrading X!TandemPipeline and MassChroQ for fast and accurate timsTOF native raw data support for quantitative proteomics olivier.langella@universite-paris-saclay.fr AVAILABILITY i2MassChroQ and its user manual are available as Free Software, licensed under the GNU General Public License (v3 +). The user manual is available in PDF or HTML format. i2MassChroQ is developed on Debian GNU/Linux. Binary packages are built for GNU/Linux and MS Windows.

GIT repository: https://forgemia.inra.fr/pappso/i2masschroq.

  The current version provides real time MS/MS peptide annotation and performs extremely fast ion current extraction and XIC chromatogram visualization.Our native C++-based timsTOF raw data reader was developed from scratch thanks to the technical speci�cations provided by Bruker. Tight optimizations were needed to ensure super-fast access to the Brukerencoded binary data.

	Peptide quanti�cation is handled	Quantitative analysis	timsTOF data native support
	by calculating extracted ion
	current chromatograms from
	precursor ion MS data
	(MassChroQ module).
	Protein quanti�cation is performed
	by the MCQR module that
	computes protein intensities by
	�ltering and aggregating peptide
	intensities and carrying over
	cluster analysis, ANOVA, and		Full processing of a 2 hour PASEF run can be performed
	comparisons between treatments.		in less than 10 s for 1 peptide, less than 30 m for 100
			000 peptides+isotopes XICs, peak detection and area
			under the curve computation.
	TimsTOF PASEF quantification reproducibility	Quantification accuracy
		While quantifying more proteins than
		competitors (1 ion or more), X!
		TandemPipeline still shows excellent correlations between replicates and very low median CV (4 Hela technical replicates, PXD10012)	Plot of the 6428 proteins quanti�ed (2 ions or more) and compared to ground truth ratio (2:1 for Yeast, 1:1 for Human, 1:4 for Ecoli, PXD01477)


Louanes Hamzioui
email: louanes.hamzioui@univ-msila.dz

Fares Kahoul

Abdrazek Guemache

Michel Aillerie

Ahmed Boutarfaia

Fe 1/2 Nb 1/2 ]O 3 -0.9Pb[Zr x Ti (1-x) ]O 30 Ceramics

Keywords: MPB, Piezoelectricity, Ceramics, Dielectric properties, X-ray methods]

niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

9Pb[ZrxTi(1-x)]O30 Ceramics

Introduction

Lead zirconate titanate (PZT) ceramics with general chemical formula Pb(Zr x Ti (1-x) )O 3 have been extensively studied because of their favourable characteristics. [1][2][3][4] Especially, the solid solution composition located near the rhombohedral (antiferroelectric PbZrO 3 )-tetragonal (ferroelectric PbTiO 3 ) morphotropic phase boundary (MPB, 0.5), depending on Zr/Ti ratio, possesses eminent piezoelectric characteristics. [5][6][7][8][9][10] Lead based ferroelectrics have been in great demand because of their outstanding dielectric and piezoelectric properties which make them suitable for applications like multilayer capacitors, microelectro mechanical systems (MEMS) and integrated devices such as ferroelectric memories, infrared sensors, micro actuators, etc. Among these materials, Pb(Zr x Ti 1-x )O 3 system and its modified solid solutions are among the most promising materials for piezoelectric applications. [11][12][13][14] Classically, the electrical properties of PZT ceramics are modulated by the addition of a small quantity of cations (typically 0.5-2 mol%). Modification of PZT at Pb 2+ and Zr 4+ /Ti 4+ sites with sufficient substitutions of single or multiple cations helps to improve its physical and electrical properties. Two main types of dopants exist: [15][16][17] (i) 'Donor' dopants, such as La 3+ , Nb 5+ , Ce 3+ and Ta 5+ , which produce 'soft' PZT, resulting in the following changes in PZT characteristics: higher dielectric constant and losses (at room temperature), much lower Q m mechanical efficiency factor, higher d 31 /d 33 load coefficient and simple mechanical stress depolarization; lead vacancies compensate for the excess of positive charge in soft PZT. (ii) 'Acceptor' dopants, such as K + , Na + , Sc 3+ and Fe 3+ , which produce 'hard' PZT, inducing the following changes in PZT characteristics: lower d 33, lower dielectric constant and losses (at room temperature), much higher mechanical Q m and difficult mechanical stress depolarization; the loss of a positive charge in hard PZT is offset by vacancies in oxygen. It is anticipated that the dynamic doping of two or more elements combines the properties of donor doped and/or acceptor doped PZT, which could exhibit better stability or improved piezoelectric and dielectric properties than those of the single element doped by PZT. [18][19][20][21][22] The objective of the present work is to study the effect of Zr/Ti ratio on structural, piezoelectric and dielectric properties of 0.1Pb[Fe 1/2 Nb 1/2 ]O 3 -0.9 Pb[Zr x Ti (1-x) ]O 3 with x = 0.49-0.55. In this paper, an effort has been made to determine the MPB phase contents with variations in the Zr/Ti ratio.

Experimental

The specimens were manufactured by using a conventional mixed oxide process. The study was carried out on the system 0.1Pb[Fe 1/2 Nb 1/2 ]O 3 -0.9Pb[Zr x Ti (1-x) ]O 3 (hereafter named as PFN-PZT) with varying x (49%x55%) and a step of x = 2%. The starting materials, viz. Pb 3 O 4 (99.9%; M/s Aldrich chemicals, USA), TiO 2 (98.9%; M/s Travancore Titanium Products), ZrO 2 (99.9%; M/s Aldrich Chemicals, USA), Nb 2 O 5 (99.6%; Biochem) and Fe 2 O 3 (98%; Acros), were mixed in acetone medium by using a magnetic stirrer for 2 h. The obtained paste was dried at 80 o C in a drying oven for 2 h, and then crushed in a glass mortar for 6 h. After crushing, the obtained powder was compacted in the form of pastilles with a pressure of 300 kg/cm 2 . Then, a preliminary calcination at 800 o C was carried out for 2 h with a heating rate of 2 o C/min. The calcined mixture was crushed for a second time for 4 h, and pressed into discs of 10 mm diameter and ~1 mm thickness at 200 MPa. The samples were then sintered at 1180 o C for 2 h in a covered alumina crucible. To prevent the evaporation of PbO from the pellets, a powder of PbZrTiO 3 was used as the embedding powder.

For phase characterization, powder X-ray diffraction (XRD) measurements were carried out using a Rigaku X-ray diffractometer with CuK radiation. XRD patterns were recorded at a scan rate of 2 o /min for 2 varying from 30 o to 60 o . Bulk densities of the sintered ceramics were determined by the Archimedes method.

The sintered PFN-PZT specimens were polished and electroded with silver paste and poled. The piezoelectric constant (d 31 ) and electromechanical planar coupling factor (k p ) were calculated by using resonance-antiresonance technique using another impendence analyzer (SI1260 Impedance/Gain-Phase Analyzer; Solartron, UK):

k p = [2.51(f a -f r )/f r )] 1/2
, where f r and f a are the resonance and antiresonance frequencies, respectively. 23 Zr/Ti ratio dependent dielectric constant ( r ) and tangent loss (tan) were obtained at 1 kHz using an inductance capacitance resistance meter (LCR meter 800 series).

Results and Discussion

Densities of the samples containing different amounts of Zr/Ti ratio were measured, and the results are shown in Fig. 1. As seen, the densities of the ceramics were in the range of 7.52-7.67 g.cm -3 (94-97% theoretical density) and dependent on Zr/Ti ratio. With increasing Zr/Ti ratio, the density of the samples was increased, achieved the highest value (7.67 g.cm -3 ) at the ratio of 51/49, and then decreased. This may be explained from the microstructures of the ceramic samples.

Figure 2 shows the SEM images of PFN-PZT ceramics sintered at 1180 o C with different Zr/Ti ratios. The figure shows that the microstructures are dense and uniform. When the amount of Zr/Ti ratio increased, the ceramic samples became more dense, and at Zr/Ti = 51/49, a thick and uniform microstructure with a minimal porosity was observed (Fig. 2a); the ceramic sample was almost fully dense for the Zr/Ti ratio of 51/49. The grain size was distributed widely up to 3 m for Zr/Ti ratios of 51/49 and 53/47. For Zr/Ti ratio of 55/45 porosity was increased. Overall, it was noted that grain growth was encouraged as the Zr/Ti ratio was increased. The quality of the material increased with increasing density and with increasing sintering temperature. 24 XRD patterns of PFN-PZT ceramics sintered at 1180 o C with varying Zr/Ti ratios (51/49, 53/47 and 55/45) are shown in Fig. 3. The presence of sharp and well-defined peaks indicates the presence of a pure perovskite phase with a good degree of crystallinity and no secondary phase formation. Tetragonal and rhombohedral phases were identified by analysis of (002) and (200) peaks in the 2 range of 43 o -47 o . 25,26 The splitting of (002) and (200) peaks indicates ferroelectric tetragonal phase, while the single (200) peak indicates ferroelectric rhombohedral phase. Triplet peak indicates that the samples consist of a mixture of tetragonal and rhombohedral phases. It can be observed from the XRD pattern that mixtures of tetragonal and rhombohedral phases were formed at Zr/Ti = 51/49 and (Figs. 3a and3b), and rhombohedral phase was identified when Zr/Ti was increased to 55/45 (Fig. 3c).

Figure 4 shows the effect of Zr/Ti ratio on the dielectric properties. It can be observed that by increasing the Zr/Ti ratio, dielectric constant ( r ) was increased and dielectric loss (tan) was reduced. r went from 550 to 1150 as the ) ratio was increased from 48/52 to 51/49. It indicates that as Zr/Ti ratio was increased, the charge storing capacity was increased for PFN-PZT.  r (=1150) was maximum for Zr/Ti = 51/49. This maximum dielectric constant can be explained by the presence of several directions of spontaneous polarization related to the existence of two structures, rhombohedral and tetragonal. However, further increase of Zr/Ti ratio above 51/49 led to gradual reduction of  r , most likely due to the change of crystal structure of the materials from MPB to rhombohedral, as shown in Fig. 3. Friction between the domain walls, represented by tan, showed decreasing trend with increasing Zr/Ti ratio; tan was reduced from 0.02 to 0.009 as Zr/Ti ratio was increased from 48/52 to 55/45.

The change in microstructure and Zr/Ti ratio also affects the piezoelectric properties of PFN-PZT ceramics. Figure 5 shows the variation of k p and Q m as a function of Zr/Ti ratio. It is observed from Fig. 5 that as the Zr/Ti ratio increases, value of k p increases initially, reaching a peak of 0.67 at Zr/Ti ratio of 51/49, and then decreases with further increase of Zr/Ti ratio. Q m shows an opposite trend of k p and continues to decrease initially with increasing Zr/Ti ratio, attains a minimum value for Zr/Ti ratio of 51/49, and then increases with further increase of Zr/Ti ratio. This is due to the fact that the phase structure of PFN-PZT ceramics changes from the coexistence of tetragonal and rhombohedral phases to single rhombohedral phase, with the increase of Zr/Ti ratio. Namely, it approaches the morphotropic phase boundary (MPB) when Zr/Ti ratio is 51/49, where the sample obtained a dense and uniform structure. Maximum polarizability resulted into minimum Q m and maximum k p .

Figure 6 shows the piezoelectric properties variation (d 31 and g 31 ) with Zr/Ti ratio. Values of d 31 and g 31 were enhanced with the increase in the ratio of Zr/Ti until 51/49. At this ratio, the optimum value of d 31 (9510 -12 C/N) was obtained. This was due to the decrease in porosity. The presence of pore reduced polarization by unit volume, contributing to decrease in d 31 . 27 As the ratio

  Effect of Zr/Ti Ratio on Piezoelectric and Dielectric Propertiesof 0.1Pb[Fe1/2Nb1/2]O3-0.

Fig. 2 -Fig. 1 -

 21 Fig. 2 -SEM images of the specimens sintered at 1180 o C with Zr/Ti ratio of: (a) 51/49, (b) 53/47 and (c) 55/45

Fig. 3 -Fig. 5 -Fig. 4 -

 354 Fig. 3 -XRD patterns of the specimens sintered at 1180 o C with Zr/Ti ratio of: (a) 51/49, (b) 53/47 and (c) 55/45

Fig. 6 -

 6 Fig. 6 -d 31 and g 31 of PFN-PZT samples sintered at 1180 o C as a function of Zr/Ti ratio 48/52 49/51 51/49 53/47 55/45 Zr/Ti Ratio