Bernard Jacob
email: bernard.jacob@ifsttar.fr

Sio-Song Ieng
email: sio-song.ientg@ifsttar.fr

Franziska Schmidt
email: franziska.schmidt@ifsttar.fr

Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment

Bridge weigh-in-motion uses an instrumented bridge as a scale to weigh vehicles.

Several types of bridges may be used, if being sensitive to wheel or axle loads. Here some strains of steel orthotropic deck bridges are measured by extensometers and analyzed by software, to calculate axle loads and gross vehicle weights. Between 2009 and 2011, several large scale tests were done on the Millau viaduct (France), the tallest cable stayed bridge in the world. These tests showed that the system meets the accuracy class C(15)/D+(20) of the European WIM Specifications.

The data obtained can be used for fatigue checks, because it assesses truck sizes and weights of the traffic and the behaviour of the bridge. We show here that bridge lifetimes under current and possible future traffic loads, after an increase of the GVW limit from 40 tons to 44 tons in France, could be reduced by 20%.

Introduction

Concept of bridge weigh-in-motion (B-WIM)

The basics of Bridge Weigh-In-Motion (B-WIM) were first introduced by Moses [START_REF] Moses | Weigh-In-Motion System using instrumented Bridges[END_REF]. Concrete simple supported multi-girder bridges with span length between 10 and 30 m were instrumented by extensometers, which measured the bending strains at mid span under moving heavy vehicles. Axle detectors were installed on the pavement to count the axles, measure the vehicle speed and axle spacing. A simple algorithm determined axle loads and gross vehicle weight by a back calculation using the bending moment influence lines of each girder. The accuracy of gross weight was in the range of 15 to 20%, but the axle loads were inaccurate.

Bridge WIM on orthotropic steel decks

In 1996 the LCPC launched the idea of using steel orthotropic deck instrumentation as a B-WIM option. This type of structure is rather flexible and the longitudinal stiffeners' bending between two cross beams, spaced by 4 to 4.5 m, are sensitive to wheel and axle loads. These stiffeners are generally spaced by 0.6 m, and thus mainly responding to a wheel or twin wheel load. Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ Strain gauges or extensometers are fixed on the bottom of each stiffener under the traffic lanes, and record the strains while the vehicle crosses the short span between two cross beams. The principle of "free of axle detector" (FAD) B-WIM, introduced by (Žnidarič et al. 1999) is applied.

Instead of road sensors to detect axles and measure the vehicle speed, some additional strain gauges or extensometers are fixed on a previous short span, 4 to 8 m up-stream the instrumented short span.

They deliver a signal when the first axle of a truck comes, which initiates the data acquisition of the system and allows calculating the vehicle speed and axle spacing.

A global optimization and identification algorithm was developed by [START_REF] Dempsey | Orthotropic Bridge WIM for determining Axle and Gross Vehicle Weights, in Weigh-in-motion of Road Vehicles[END_REF] to calculate these parameters and the axle loads, which is more efficient and robust than Moses' algorithm. A test was carried out on the Autreville bridge (Figure 1), supporting the motorway A31

(Luxembourg-Nancy) over the Moselle river in eastern France (Figure 1), which showed that the prototype B-WIM system was in the accuracy class D+(20) if using a 1-D bridge model, and in the accuracy class C(15) if using a 2-D bridge model [START_REF] Dempsey | Orthotropic Bridge WIM for determining Axle and Gross Vehicle Weights, in Weigh-in-motion of Road Vehicles[END_REF], according to the European WIM Specifications [START_REF] Jacob | Evaluation of dynamic effects of heavy vehicles on bridge fatigue[END_REF].

After the completion of the WAVE project, the Slovenian company Cestel developed a marketed B-WIM system named SiWIM which can be used on several types of bridges. In 2005, the Laboratoire Central des Ponts et Chaussées (LCPC) acquired a SiWIM to test it and assess its performances and reliability on integral concrete slab bridges and orthotropic decks [START_REF] Bouteldja | Test of a B-WIM System on integral and steel orthotropic Deck Bridges in France[END_REF].

Bridge fatigue assessment by WIM data

Bridge load effects, stresses, damage and lifetime in fatigue are assessed either by measurements, using strain gauges, extensometers and other techniques, or by calculation, using traffic load data and bridge models such as influence line or surfaces, if the dynamic interactions are neglected [START_REF] Bailey | Site Specific Traffic Load Models[END_REF][START_REF] Nassif | Dynamic load for girder bridges under normal traffic[END_REF][START_REF] Jacob | Application of weigh-in-motion data to fatigue of road bridges[END_REF][START_REF] Jacob | Evaluation of dynamic effects of heavy vehicles on bridge fatigue[END_REF]. The development and implementation of WIM techniques allowed to collect traffic load data on a large scale and to use them for bridge assessment [START_REF] Jacob | Evaluation of dynamic effects of heavy vehicles on bridge fatigue[END_REF], instead of using simulated data [START_REF] Hwang | Simulation of dynamic load for bridges[END_REF].

In the late 1980's and early 1990's, some extensive works were developed in Europe using traffic data of various EU member states [START_REF] Vrouwenvelder | Traffic Load on Bridges[END_REF][START_REF] Bruls | EVN1991-Part 3: Traffic Loads on Bridges; Calibration of Load Models for Road Bridges[END_REF][START_REF] O'connor | Effects of traffic loads on road bridges -Preliminary studies for the re-assessment of the traffic load model for Eurocode 1 Part 3[END_REF] to design the Eurocode "Traffic loads on bridges" (CEN EN1991-2, 2003). Fatigue calculations were performed to design the fatigue load models [START_REF] Jacob | Calibration of bridge fatigue loads under real traffic conditions[END_REF].

All these models and assessment methods assume that the traffic loads are stationary. But the traffic loads and volume increase with time because of the development of the road freight transport, and the increases of the truck legal weight limits. Thus it is necessary to periodically recalibrate the bridge code load models and to reassess the reliability of existing bridges against the traffic loads. Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ That is one of the goals of the WIM systems installed all around the world on highways and motorways. The methodology and some tools for fatigue assessment are briefly reported here, and an application to forecast the possible consequences of an increase of the truck gross weight limit in France from 40 to 44 tons is presented.

Millau viaduct instrumentation

Millau viaduct

The Millau viaduct is a 2,460 m cable stayed multiple span bridge, completed in 2004 over the Tarn valley in Aveyron, south of France (Figure 1). The deck is a steel box orthotropic deck, 32 m in width and 4.20 m in height, which carries 2 lanes and an emergency lane in each direction. The average daily traffic is app. 12,000 veh. incl. 12 to 15% of trucks (i.e. 1500 trucks/day).

Millau viaduct instrumentation for B-WIM

The WIM data collection the on Millau viaduct is motivated by two main applications: a detailed knowledge of the traffic patterns and traffic loads on the bridge is needed to assess the fatigue damage along the service life, and to check that the guaranteed 120 year lifetime will be safely ensured; Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ the French Department of Transport and the Regional DOT are in charge of overload enforcement on the national road and motorway network to ensure traffic and infrastructure safety and a fair competition between transport modes and transport companies.

Therefore a nation-wide network of WIM systems is now developed to perform continuous checks of truck loads, and to screen the overloads during the control periods [START_REF] Stanczyk | Heavy Traffic Data Collection and Detection of overloaded HGV[END_REF]. Near the viaduct of Millau, a static enforcement area equipped with weighing scales in both directions is installed near the toll gate, 4 km north of the viaduct. A B-WIM system on the bridge could be an efficient tool to screen the overloads in the south-north direction, prior to the static weighing.

In 2009 the LCPC and CEVM agreed to organize a B-WIM test on the viaduct of Millau, jointly with another field test organized by SETRA and Eiffage Group for a French project (Orthoplus) on steel orthotropic deck reinforcement using ultra high performance fibre reinforced concrete (UHPFC), see [START_REF] Pouget | Influence des propriétés élastiques ou viscoélastiques des revètements sur le comportement des ponts à dalle orthotrope[END_REF]. The instrumented section was located in the first span, close to the north end of the viaduct, under the slow lane (#1) in the south-north direction. The trapezoidal stiffeners 2 to 13 were instrumented by extensometers, which covered the lane 1 and part of the lane 2 and the emergency lane, at mid-span between two cross beams (Figure 2). Four more extensometers were installed on the stiffeners 4 to 7, 4 m upstream, as part of the FAD B-WIM system. The measuring location was chosen upstream of the expansion join where the traffic speed is rather constant (the truck speed limit is 80 km/h on the viaduct) in order to avoid dynamic effects which could affect the WIM system. The SiWIM was installed inside the box, well protected against rain and wind. Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________

B-WIM Experimentation

Test plan and organization

During the test, two rented trucks, a rigid 3-axle (C3) and an articulated 5-axle (T2S3, 2-axle tractor and semi-trailer with a tridem axle), were used to calibrate the SiWIM. They made repeated runs, crossing the viaduct at different speeds (60 and 80 km/h) and transverse locations (the right wheel along the emergency lane mark, 0.3 m away and 0.7 m away, i.e. the truck centred in the lane 1).

Collected data

During this test, 52 trucks from the traffic flow were weighed by the SiWIM and stopped for static weighing, over a period of 4.5 hours. Among them 45 were properly identified on each system with an ID number. 2 of them were not correctly weighed by the SiWIM, one having a tridem axle instead of a tandem, and the other a tandem instead of a tridem. Finally the studied sample size was 43, which correspond to 95.6% of accepted vehicles. The numbers and proportions of each trucks were: four 2axle rigid (9.3%), two 4-axle articulated (4.65%) and 37 5-axle articulated (86%).

Results of B-WIM

Results and assessment of the SiWIM algorithm

According to the COST323 European specifications of WIM [START_REF] Jacob | Evaluation of dynamic effects of heavy vehicles on bridge fatigue[END_REF], the relative errors e r were calculated for each axle load, and gross vehicle weight of the 43 vehicles (Equation 1).

(1)

where According to the test conditions of the COST323 specifications, which are here full reproducibility (R2), i.e. trucks from the traffic flow, and environmental repeatability (EI), i.e. a short test period within the same season, the tolerance intervals for the required confidence levels, [- min , min ], are calculated for each criterion as specified in the COST323 specifications. The associated exact classes of accuracy  c are derived, and both values  min and  c are plotted in (Figure 3). The final accuracy class of any criterion, given in the last column of Table 1, is obtained by rounding up  c to the closest value 5, 7, 10, 15, 20, 25 or 30, which correspond to the standard classes. with a wheelbase of 2 x 1.3 = 2.6 m, on which the total load is applied in the same short span. Thus, the maximum stiffener bending strain is less than for a single axle of the same load, which may explain the rather large negative bias.

W

WIM data and calculation tools for bridge assessment in fatigue

The data obtained through B-WIM experiments can be used twice: first, in order to obtain information about the traffic crossing the bridge (number of trucks, distribution of GVWs, dimensions of trucks ...) and also in order to obtain information about the structural behaviour of the bridge. Indeed, B-WIM makes it possible to assess empirically real influence lines of the bridges (Ieng, S.-S. And al., submitted).

Here, we present a king of study that can be done with these two types of information, measured traffic data and measured influence lines, in the case of application of new regulations in size and dimensions of trucks.

To do that, we use a representative French WIM data and influence lines of typical French bridges. Axle loads and spacing, speed and time of passage in 1/100 s are also recorded for each truck in both lanes. The accuracy of these data are at least in class C( 15), but mostly in class B(10) of the European specifications of WIM [START_REF] Jacob | Evaluation of dynamic effects of heavy vehicles on bridge fatigue[END_REF], i.e. app. 95% of the gross weights are within 10% and of axle loads within 15% of the static values taken as the reference.

WIM data

Influence lines

The effects of traffic on a bridge are usually calculated by applying traffic loads, either measured by WIM systems or simulated by software, on influence lines or surfaces. For local effects sensitive to the wheel transverse location, WIM data shall contain this information and an accurate influence surface, i.e. a two-dimensional calculation, must be used. For most of the global or semi-global and longitudinal effects, such as bending moments at mid-span or on pier, shear forces or pier reactions and for bridges whose transversal behaviour is simple, one or a set of parallel longitudinal influence lines (one per traffic lane) are sufficient, and the traffic data lane by lane are used. That is the case in the study presented here.

The influence lines or surfaces are obtained numerically, through 1-D bridge model or 2-D finite elements calculations, or on site through experimentation (by strain measurement on a bridge under a known truck). In this later case, several parameters are taken into account, such as the stiffness of the pavement surface, sidewalks and safety barriers, which are neglected in the numerical method.

So through the B-WIM algorithm a correct characterisation of the bridge through its real influence Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ surface can be obtained. But here, we will not present the results for this Millau viaduct because of the importance of the transversal position of the vehicles. We will explain the assessment for two simple cases of composite bridges.

The effects considered in this study are, for two bridges:  The bending moment stress at mid-span of a simple supported 40 m span bridge, near Auxerre. This is a composite bridge with two main steel girders and a concrete deck.

 The bending moment stress at mid-spans and on piers of the Libourne 4-span bridge (respectively 48, 60, 60 and 48 meters-long). This is also a 2-steel girder composite bridge.

The influence lines are given in MPa/MN in Figure 5. The dominant effects are in the lower flange at mid-span and in the upper flange on pier. These influence lines are those calculated for a load applied along a steel girder. To obtain the influence surface, they have to be combined with the transverse influence line, given by Courbon's coefficient.

Traffic data adaptation

The WIM data presented in section 5.1 contain two adjacent lanes in the same direction, i.e. one slow lane and one fast (passing) lane. Auxerre bridge supports 3 traffic lanes (each 3.50m in width), including 2 slow lanes (one in each direction) and one fast passing lane. Libourne bridge has 2 slow lanes (one in each direction). Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ Thus, the recorded data are adapted to fit to the bridge operation conditions. The natural data of the slow lane are applied on one slow lane of each bridge, and the data of the fast lane on the fast lane of Auxerre. The slow lanes in the other direction are filled with the slow lane data shifted by 10 minutes, which simulate a traffic correlated (same peak and low hours) but with independent trucks.

CASTOR and POLLUX software

The POLLUX software, developed by the LCPC, is a new and extended version of the former CASTOR software [START_REF] Eymard | Un nouveau logiciel : le programme CASTOR pour le Calcul des Actions et Sollicitations du Trafic dans les Ouvrages Routiers[END_REF]). It uses WIM data and load effect or stress influence lines of any bridge, and calculates the effects of the whole traffic on this bridge.

Different modules of POLLUX perform successive tasks:

 Traffic data cleaner: the traffic data files, provided by WIM systems, are first checked and cleaned if necessary. If some anomalies are detected, the involved vehicles are deleted. For example, vehicles with a length below 1.5 m or over 25 m, or with only one axle or more than 8 axles, are eliminated. If the gap between two successive vehicles is greater than 90 minutes, the system is assumed to have failed and the time period is deleted. All these limits are defined by the user.

 CASTOR, which became a sub-routine of POLLUX, calculates the effects of the traffic loads.

For each effect (set of influence lines for each traffic lane), the time history of the effect is calculated with a constant time step, chosen by the user with respect to the influence line shape.

 The sub-routine "Extrap" calculates the damage and lifetime in fatigue, for a detail submitted to the stress history resulting of the traffic loads applied to a stress influence line, as explained in section 6.1.

Fatigue assessment depending on the weight limit

Fatigue assessment method

This section describes the method used by CASTOR and POLLUX to calculate bridge lifetime in fatigue. The fatigue damage D of a detail is assessed using Miner's rule (Equation 2).

(2) Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ where n i is the number of cycles in the class  i of the stress rain-flow histogram; N i is the number of cycles at failure corresponding to  i in the S-N (Wöhler) two slope curve defined by (Equation 3).

(3) in the Eurocode 1993 Part 1-9 (CEN EN 1993-1-9, 2005), corresponds to cycles, so . The conventional lifetime (in years) of the detail is 1/TD, where T is the length of the time period which corresponds to the rain-flow histogram.

Weight limits in the current French legislation and future plans

In France, and in Europe for international transport, the standard gross vehicle weight limit is 40 tons.

Some countries allow higher weights, such as 44 tons in the UK for 6-axle articulated trucks. In

France, there are a couple of derogations which allow 44 tons for 5-axle articulated trucks if: (i) 40 ft containers are transported in a multi-modal journey, (ii) the freight comes from or goes to a maritime or inland harbor, where it is carried by ship, (iii) some specified agricultural goods are transported during specific seasons. Moreover, log trucks are allowed up to 48 tons on 5 axles and 57 tons on 6 axles by decree.

In 2008, the French parliament voted a law called "Grenelle de l'environnement" to reduce the CO2 emissions and the fossil energy consumption. An article stated that road transport regulation shall be adapted for that. In February 2009, the parliament asked to the government to study the positive and negative impacts of increasing the gross weight limit to 44 tons. The main criteria to consider were road safety, CO2 emission and energy consumption, traffic congestion, and infrastructure (bridges and pavement...) lifetime and maintenance.

Weight limits in the current French legislation and future plans

For bridges, the first task was to compare the effects of a single 44 t truck to those of a 40 t truck.

Because the axle load limit would not be increased, only medium span (15 to 40 m) bridges could be affected, or 10 m continuous span bridge for bending moment on pier. Shorter spans could not support a whole truck at once. Longer spans are not so much sensitive to a single truck. For medium span bridges, the load effects would be increased by less than 10%, which is not too much critical for the extreme loads and load effects on healthy bridges. However, the impact of multiple presences (truck crossing or overtaking) of 44 t trucks, or the effect on the fatigue lifetime was to be investigated more in depth. Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ Therefore, it is necessary to make some assumption on how the whole traffic would change with new regulations and to assess the effects of this whole new traffic, see (O'Brien and al., 2012) for an Irish example. The very simple and crude assumptions done here are: (i) the gross weight of every heavy vehicle lying between 36 and 44 tons would be increased by 10%, the additional weight being uniformly distributed on all axes; (ii) all the other vehicles would have the same load as before (volume limitation or not enough freight to carry).

With these assumptions, a micro-simulation generated a "modified" traffic file named "44 t" derived from the natural traffic record of the WIM system on the A9 motorway, named "40 t". Both traffics were used with the influence lines introduced in the section 5.2, to obtain the effects and their histograms.

Fatigue damage

To assess the fatigue damage and detail lifetime, the rain-flow histograms are used, with the S-N curves and the Miners' law (section 6.1). Figure 6 Table 2: Auxerre bridge lifetime for A9 traffic, 40 or 44 t gross weight limit.

Similar results are given for Libourne bridge, and more precisely for the weld of the vertical stiffener on the girder lower flange at mid-span of the first span.

These calculations show a decrease of the lifetime by app. 20% with the 44 ton trucks, as with Auxerre bridge.

Conclusions and perspectives

B-WIM system

The B-WIM experimentation on Millau viaduct was the first large scale test of the SiWIM, a marketed B-WIM system developed by Cestel, on a steel orthotropic deck bridge. Ten years after the first tests of a prototype B-WIM system on such type of bridges, carried out on another orthotropic steel deck bridge, the results are very consistent. But some research works were undertaken to develop a 2-D model fully adapted to this type of bridge, in order to improve the SiWIM accuracy.

Bridge assessment in fatigue

Assessment or re-assessment of existing bridges under traffic loads require an accurate knowledge of the load patterns. WIM data are very useful for these applications, either to give an account of the Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. __________________________________________________________________________ current traffic loads or to forecast the potential impact of future loads. This assessment also requires an accurate knowledge of the bridge, in particular its present health condition. This cannot be obtained through calculations like finite elements. But through the B-WIM algorithm, we have access to this real influence line (or influence surface). Adapted assessment can then be performed. The implications of new size and weight regulations for trucks can be assessed.

Figure 1 :

 1 Figure 1: Viaduct of Millau.

Figure 2 :

 2 Figure 2: Millau viaduct. On the left: scheme of the box-girder.On the right: picture of the extensometers that have been glued to the bottom of the longitudinal stiffeners at mid-span of the first span.

Figure 3 :

 3 Figure 3: Classes of accuracy of this B-WIM test at the viaduct of Millau.

  Figure 4: Distribution of GVW of the WIM data used in the study presented here: the blue line is the distribution for the first week of June 2006, the blue one is the distribution for the first two weeks.

Figure 5 :

 5 Figure 5: Influence lines that have been used in this study. On the left: influence line of the bending moment stress at mid-span of a simple supported 40 m span bridge, near Auxerre. On the right: influence line of the bending moment stress at mid-spans and on piers of the Libourne 4-span bridge.

  gives the rain-flow histograms of the bending moment stresses in the lower flange at mid-span for both traffics (40 tons and 44 tons) on Auxerre bridge. An increase of 10% of the peak abscissa (18 to 20 MPa) is visible when the 44 ton trucks are introduced. Reversely, the distribution shows a drop at 18 MPa in this case, because truck gross weights between 36 and 40 tons were increased by 10%, and thus, there are no more trucks in this weight interval.

Figure 6 :

 6 Figure 6: rain-flow histograms of the bending moment stresses in the lower flange at mid-span for both traffics (40 tons and 44 tons) on Auxerre bridge.

Table 1 :

 1 d and W s are the in motion loads measured by the SiWIM and the static loads. Four sub-Bridge weigh-in-motion on steel orthotropic decks and application to bridge assessment, Jacob et al. Accuracy of this B-WIM at the viaduct of Millau.

	populations were considered:
	i.	gross vehicle weight,
	ii.	single axles,
	iii.

axle group (i.e. tandem and tridem), and iv.

axles of a group, and the statistics of the relative errors are given in Table

1

.


Sophie Hooge
email: sophie.hooge@mines-paristech.fr

Laura Le Du
email: laura.le_du@mines-paristech.fr

Stimulating industrial ecosystems with sociotechnical imaginaries: The case of Renault Innovation Community

Keywords: sociotechnical imaginaries, industrial ecosystem, innovation community Stimulating industrial ecosystems with sociotechnical imaginaries: The case of Renault Innovation Community innovation, sociotechnical imaginaries, industrial ecosystem, innovation community

Facing the necessity to increase their innovation capabilities in a more and more holistic context, companies are creating new collaborative organizations aiming to collectively explore potential radical innovation fields. In this paper, we propose to study the nature of these new collectives for innovation through two managerial patterns: objects of collaboration and organizational mechanisms of coordination. Based on longitudinal collaborative research with the French carmaker Renault, the research analyses the case of the Renault Innovation Community, which involved members in original collaboration features to stimulate the industrial ecosystem of mobility and to support the potential emergence of new ecosystems. The main results of the empirical research underlined that: (1) objects of collaboration surpassed the detection of societal expectations to focus on sociotechnical imaginaries stimulation and dissemination; and (2) organizational mechanisms of collaboration exceed open innovation logics to focus on the collective building of favorable emergence conditions for new industrial ecosystems.

Stimulating industrial ecosystems with sociotechnical imaginaries: The case of Renault Innovation Community

Due to shorter and shorter cycles of products renewal, the ability of companies to develop innovative strategies to guide novel and varied developments of technologies and usages of their products becomes crucial to maintain and develop a competitive advantage [START_REF] O'connor | Major Innovation as a Dynamic Capability: A Systems Approach*[END_REF]. To do this, firms must be able to create emulation around various fields of potential innovation that support a conceptual effort both on the development of new technological concepts than tracks of original customers' uses of firm's goods [START_REF] Le Masson | Strategic management of innovation and design[END_REF]. To induce industrial dynamics, this effort must be conducted both inside the company and relying on the cognitive resources of partners, potential stakeholders of future industrial ecosystems that will develop new products or services [START_REF] Adner | Match your innovation strategy to your innovation ecosystem[END_REF][START_REF] Teece | Explicating dynamic capabilities: the nature and microfoundations of (sustainable) enterprise performance[END_REF].

Two managerial logics of collaborative organizations are possible to stimulate innovation in industrial ecosystems. On the one hand, the firm could manage the interactions within the ecosystem as a focal firm (R. [START_REF] Adner | Value creation in innovation ecosystems: how the structure of technological interdependence affects firm performance in new technology generations[END_REF][START_REF] Iansiti | Strategy as ecology[END_REF]) and steers the emulation on some signals that the firm has caught and pre-interpreted. Then, the company select suppliers and business network with undertaking partnerships in order to organize a collective response to the customer requirements that the firm has decided to address [START_REF] Van Lente | Navigating foresight in a sea of expectations: lessons from the sociology of expectations[END_REF]. This first strategy is largely at the heart of open innovation initiatives managed by a leader firm (H. W. [START_REF] Chesbrough | Open innovation: The new imperative for creating and profiting from technology[END_REF]. On the other hand, the firm could look for an emulation focused on the design of collective interests for innovation. In this second strategy, the aim of the collaborative organization becomes to build an area for the design of common purpose for innovation-driven partnerships [START_REF] Segrestin | Partnering to explore: The Renault-Nissan Alliance as a forerunner of new cooperative patterns[END_REF]. Our research addresses the research gap to distinguish these two strategies of ecosystem-based collaborations for innovation. We focus on the second kind of organizational constructions that are in-between more established forms of organizations, looking for more in-depth understanding of their operations -objects of the collaboration and organizational mechanisms of coordinationand their impacts on the innovation management in established firms.

To support such collaboration, the firm has to manage the emulation at the level of the "sociotechnical imaginaries" that could induce new areas for major innovation, by the creation of group integrating a wide network of people with different skills and business approaches in order to organize a collective exploration of new technical objects and emergent uses of goods. Linking the notion with the scholars' sociologic work on expectations, [START_REF] Pickersgill | Connecting neuroscience and law: Anticipatory discourse and the role of sociotechnical imaginaries[END_REF] defines sociotechnical imaginaries as " one means through which anticipatory discourse and practices are structured, and thus as a mechanism through which futures are designed " (2011:28). Indeed, sociotechnical imaginaries differ from expectations because they are created, manipulated and managed directly by individuals.

More precisely, the "sociotechnical imaginaries of a group of designers" has been defined as the shared cognitive framework, including collectively imagined forms of social life and social order -as value representations, institutions and regulations requirements, and symbols -reflected in the design and fulfillment of group-specific scientific and/or technological projects [START_REF] Jasanoff | Containing the atom: Sociotechnical imaginaries and nuclear power in the United States and South Korea[END_REF][START_REF] Strauss | The imaginary[END_REF]. Consequently, in this strategy for ecosystem emulation, the firm must stimulate jointly inventors and creative networks that used to elicit theirs imaginaries and to manipulate an enough abundant variety of images and/or conceptual formulation to describe the potential of new technologies, new products and their uses. Consequently, our research addresses the hypothesis that stimulating sociotechnical imaginaries can be an effective mean to promote the projection of new organizations for disruptive innovations market, i.e. new industrial ecosystems.

Although the interest of such approach seems obvious for industrials, the implementation of such emulation remains unclear. The process of identification and selection of concepts, which drive the exploration, has few management tools and methods to manage this collective activity. Similarly, the resource that may constitute the collective activity dedicated to anticipation -business intelligence, technological forecasting, prospective -is to clarify: could they generate collective exploration of new concepts? What types of deliverables can they provide to emerging industrial ecosystems? And how to manage this collaboration? This paper fits into this knowledge gap and proposes to investigate through a case study the experience of an industrial group which, in its practices, is ahead of societal trends by creating and stimulating new sociotechnical imaginaries within an cross-industrial ecosystem.

Inside the company, willingness to be proactive about the imaginary constitution of uses and technologies, examines the role of R&D departments. If companies want to act on societal changes, the object is no longer to be able to learn about which will make potentially tomorrow's markets, as absorptive capacity field suggests [START_REF] Cohen | Absorptive capacity: a new perspective on learning and innovation[END_REF]), but to stimulate industrial ecosystem where, economic actors collectively generate innovative and coherent proposals, able to support the generation of new markets. According to this assumption, what organizational devices can enable and support these collective actions? How R&D departments can become players involved in these efforts?

The paper focuses on two research issues on the nature of collective exploration that will be at In this paper, we propose to study the nature of new collectives for innovation through these two specific managerial patterns: objects of collaboration and organizational mechanisms of coordination. The research relies on an original material from a collaborative longitudinal study with the Renault Innovation Community, the innovation-based think tank of the French car manufacturer, that gather representatives from various industrial sectors, institutions and disciplines. In a first section, we discuss former proposals of scholars on the management of the two managerial patterns for collective exploration of new markets creation. In the second section, we present how we conduct the case study and analyzed the data from the collaborative research partnership. Then, we develop the case study analysis (section 3) detailing the results and managerial implications, then we discuss the impacts of the collaborative organization on the ecosystem and innovation management (section 4) and finally, section 5 concludes the paper and propose further research.

Theoretical framework on collective exploration for new markets creation: objects of collaboration and organizational mechanisms

1.1/ Objects of collaboration for ecosystem emulation: from expectations detection to stimulation of sociotechnical imaginaries

In line with work on foresight approach, building of corporate strategy is traditionally based on the identification and modeling of societal, environmental and technological trends proposed by the strategic unit of foresight (e.g. [START_REF] Godet | The art of scenarios and strategic planning: tools and pitfalls[END_REF]). Based on a management approach of anticipating changes in customer and market, contemporary studies on societal expectations are now the subject of a theoretical modeling nurtured in the international scientific literature (e.g. [START_REF] Gordon | Frontiers of futures research: what's next?[END_REF][START_REF] Van Lente | Navigating foresight in a sea of expectations: lessons from the sociology of expectations[END_REF])), which is beyond the scope of foresight. Anticipatory vision developed by this literature structures collective action and collective organizations around this objective of common response to exogenous expectation. Two main approaches have been developed: the first, sociological, relies on the assumption of a collective cohesion made possible by the superposition of anticipatory visions of several companies (van Lente, 2012); while the second, more rationalist, is part of a decision-making paradigm where the object is to reduce uncertainties about the possible variations of the commercial future of a company by developing the most accurate modeling of potential alternatives related to each project and associated investments (R. [START_REF] Adner | What is not a real option: Considering boundaries for the application of real options to business strategy[END_REF][START_REF] Fredberg | Real options for innovation management[END_REF].

The effectiveness of both approaches -by societal expectations or by expected profitable investments -turns out to be limited by the knowledge on existing markets, and thus the management of the renewal of former products or of the reaction to competitive fallbacks. It appears inadequate when it comes out of the conventional ways of developing new products since it enhances the fixation effects within collectives due to previous technical choices of designers [START_REF] Kaplan | Thinking about technology: Applying a cognitive lens to technical change[END_REF][START_REF] Thrane | Innovative path dependence: Making sense of product and service innovation in path dependent innovation processes[END_REF]. Indeed, if we go into details of tools for foresight or uncertain investments, the most used method -the scenarios method -is based on the meta-descriptive modeling of exogenous characters of the company (cost of raw materials, laws, etc.) and the study of contrasting developments of these characters to describe the possible states of a market at a distant term [START_REF] Coates | Scenario planning[END_REF][START_REF] Schnaars | How to develop and use scenarios[END_REF]. To do it, foresigthers and economists use specific objects to collaborate: they build scenario on confirmed societal trends and signals (as for example, household composition, purchasing power of targeted customers, availability of resources, etc.). These specific objects of collaboration have a status strongly distanced to functional or technical description of the products developed by the firm, that allows a high degree of generalization but decreases the ability of designers to embed it in their works. Thus, scenarios turn out to be powerful management tools to guide the search of concept and investigations of knowledge but appear insufficient to support a social imaginaries conjunction with technical imagination.

Moreover, the scenario technique involves the development of a proactive and naturalizing strategy relying on the stability of the dominant design model [START_REF] Abernathy | Patterns of innovation in technology[END_REF].

For example, prospective scenarios disseminated in the automotive industry highlight the strengths and weaknesses of existing design resources in case of changes in multiple exogenous factors: oil prices, legislation, geo-political context, the purchasing power of households, etc. They are therefore useful in helping the company to pre-position itself against a set of variations considered as probable [START_REF] Lichtenthaler | Technology intelligence processes in leading European and North American multinationals[END_REF] but with a strong assumption: it supposes the technical, functional and commercial stability of product and automotive industrial ecosystem. This approach is consequently heavily defensive and seems ill suited to markets where competition concerns the very identity of objects and specific characteristics of differentiation. Indeed, it does not support the firm to develop proactive strategy that generates new spaces of value. Focusing in designing a new industrial ecosystem for innovation [START_REF] Adner | Match your innovation strategy to your innovation ecosystem[END_REF][START_REF] Iansiti | Strategy as ecology[END_REF][START_REF] Moore | Business ecosystems and the view from the firm[END_REF] and thus creating new markets, the organization of a repeated and sustained innovation process arises the issue of adapted objects for strong interactions between actors. These objects of collaboration aim generating new societal expectations or new imaginative concepts [START_REF] Le Masson | Platforms for the design of platforms: collaborating in the unknown[END_REF], and thus amplify the stimulating nature of some concepts at the level of the company itself, but also for all an emerging industrial ecosystem. Consequently, these objects have to support conjunctions of social imaginaries with technical imagination.

Nevertheless, objects of collaboration relying on joint changes of social imaginaries and technical imagination are under investigated, mostly because imaginaries used to be seen as largely shared and stable across a society, slowly renewed through scientific progress [START_REF] Durand | The implication of the imaginary and societies[END_REF]. Nevertheless, [START_REF] Jasanoff | Containing the atom: Sociotechnical imaginaries and nuclear power in the United States and South Korea[END_REF], who defined sociotechnical imaginaries as "collectively imagined forms of social life and social order reflected in the design and fulfillment of nation-specific scientific and/or technological projects" (2009: 120), have underlined that some non-scientific actors -institutional actors in their researchcould play an important role in interaction with scientists and technologists on the societal dissemination and evolutions of sociotechnical imaginaries. Even if sociotechnical imaginaries had been investigated in a few industrial context (e.g. [START_REF] Brayton | Mediated, Worlds Calculated The Sociotechnical Imaginary of 'Precision Warfare'and Case Study Analysis[END_REF][START_REF] Felt | Keeping Technologies Out: Sociotechnical imaginaries and the formation of a national technopolitical identity[END_REF][START_REF] Jasanoff | Containing the atom: Sociotechnical imaginaries and nuclear power in the United States and South Korea[END_REF][START_REF] Pickersgill | Connecting neuroscience and law: Anticipatory discourse and the role of sociotechnical imaginaries[END_REF]), a lack of knowledge remains on the interaction between social group and industrial communities, that could efficiently drive this scientific progress through a coordinate R&D effort. Despite philosophers have highlighted the impacts of imaginaries on science and collective coordination -as Gaston Bachelard have underlined that imagination may limit or challenge the individual capacity in the building of scientific models [START_REF] Chimisso | Gaston Bachelard: Critic of science and the imagination[END_REF], or as Cornelius Castoriadis have claimed that social groups are at the origin and in charge of the evolution of their imaginaries [START_REF] Castoriadis | The Imaginary Institution of Society[END_REF]) -, their impact as effective drivers for the emergence of new industrial ecosystems is still an open issue for innovation management.

1.2/ Communities for innovation exploration: from open innovation to the design of new industrial ecosystems

Many studies focused on collaboration for major innovation and contemporary scientific community have developed two main approaches to these partnerships. On the one hand, scholars study the collective action prior to commercial competition that rely on the knowledge about potential customers to develop innovative proposals. When there is collaboration between players, this approach is well known as Open Innovation since the works of H. W. [START_REF] Chesbrough | Open innovation: The new imperative for creating and profiting from technology[END_REF]. On the other hand, researchers underlined new managerial roles of innovation intermediaries, specific to major innovation management [START_REF] Van Lente | Roles of systemic intermediaries in transition processes[END_REF]: whether they are facilitators of the flow of knowledge in these new partnerships, they are called Knowledge brokers [START_REF] Hargadon | Technology brokering and innovation in a product development firm[END_REF][START_REF] Howells | Intermediation and the role of intermediaries in innovation[END_REF]; the Innovation brokers are in charge of linking actors scattered in different organizations [START_REF] Klerkx | Establishment and embedding of innovation brokers at different innovation system levels: Insights from the Dutch agricultural sector[END_REF]; the Gatekeepers translate external information in internal language understandable within the organization [START_REF] Cohen | Absorptive capacity: a new perspective on learning and innovation[END_REF]; and the Innovation capability builders are in charge of the creation of organizational capability for innovation [START_REF] Börjesson | The challenges of innovation capability building: Learning from longitudinal studies of innovation efforts at Renault and Volvo Cars[END_REF]. As instructive as these approaches could be for the management of innovation-based collaborations, they are insufficient to describe collective exploration focused on new markets creation. First of all, these approaches assumed that collectives exist before the beginning of the exploration and players are supposed to have a priori a clear vision of their adjustments in the value chain of the innovation they are targeting, and thus, of their own strategic positioning. This view assumes that the company adopts a predatory logic towards the partnership in which its representatives are responsible for mobilizing the collective exploration as an economic leverage to better contribute to the individual performance of the firm. In this logic, the persistence of the partnership is not pursued or even explicitly rejected (H. [START_REF] Chesbrough | Beyond high tech: early adopters of open innovation in other industries[END_REF]).

However, one can imagine a multi-actors exploration looking for new markets based on a collective that a priori does not exist but whose one or more firms would benefit of its building. Common purpose to collaborate would be to develop a collective knowledge, i.e. with a shared property among all stakeholders [START_REF] Segrestin | Partnering to explore: The Renault-Nissan Alliance as a forerunner of new cooperative patterns[END_REF], that could support the development of new industrial ecosystems. This collaborative approach is more similar to the historical meaning of the concept of community developed by Tönnies [START_REF] Durkheim | Gemeinschaft und Gesellschaft[END_REF] where the value exists in the collective and through the collective, without that members can make a profit in isolation. Indeed, in a group aiming the exploration of the unknown markets, the issue of the division of work will focus more on the process of creating value for the ecosystem [START_REF] Jacobides | Benefiting from innovation: Value creation, value appropriation and the role of industry architectures[END_REF], issues of cohesion within solidarity efforts in partnerships [START_REF] Segrestin | Partnering to explore: The Renault-Nissan Alliance as a forerunner of new cooperative patterns[END_REF], the interdependence of specific assets of each actor and the possible prioritization around a common heart [START_REF] Gawer | Platform dynamics and strategies: from products to services[END_REF]. This approach by the collective-to-design is therefore linked to the management of knowledge as a process of coordination of collectives [START_REF] Alavi | Review: Knowledge management and knowledge management systems: Conceptual foundations and research issues[END_REF][START_REF] Nonaka | The Knowledge Creating[END_REF] and the differences induced by the diversity of the groups' characteristics involved in the innovation communities: community of practice, epistemic and hierarchical communities [START_REF] Cohendet | Routines and incentives: the role of communities in the firm[END_REF][START_REF] Cowan | The explicit economics of knowledge codification and tacitness[END_REF].

Methods and Research settings

This study relies on a longitudinal collaborative research [START_REF] Shani | Handbook of collaborative management research: Sage Publications Thousand Oaks[END_REF] with the French car manufacturer Renault that linked researchers and industrial partners since 2005.

Main method has been intervention research, gathering empirical data collection and action in the firm, with a continuous modeling work [START_REF] Hatchuel | Collaborating for management research: from action research to intervention research in management[END_REF][START_REF] Radaelli | Intervention Research as Management Research in Practice: Learning from a Case in the Fashion Design Industry[END_REF]. The paper is based on the analysis of an industrial case [START_REF] Yin | Case study research: Design and methods[END_REF] of an innovation-based community created by Renault, which brings together stakeholders from contrasting areas of science and industry and whose collaborative organization presents managerial patterns that remain to highlight: the Renault Innovation Community (RI-Community). To understand how a mature firm like Renault initiates and develops original organizations to come through contemporary industrial challenges, a longitudinal case study analysis is a relevant methodology of research as it allows in-depth understanding of practices and a favored access to rich, reliable and comprehensive material.

Research context

Longitudinal analysis of an innovation community initiated by an historical player of the automotive industry is particularly suited to our work, as this sector requires the construction of one or more spaces of renewal of the sociotechnical imaginary about individual mobility. Indeed, we observe that the former stimulation devices of automotive imaginary -car racing, major international exhibitions, specialized presses -have now impoverished and current imaginaries around car mobility crystallize on contemporary difficulties of automobiles, such as energy consumption, pollution and health disorders. Nevertheless, new actors of the mobility that are not historical players of the automotive industry as Autolib, Toowup, ZipCar, etc., multiplied attempts of regeneration of the sociotechnical imaginary of individual mobility. This paradox emphasizes the transition from the historic paradigm based on the ownership of an individual vehicle to a paradigm based on multimodal individual mobility [START_REF] Firnkorn | Selling mobility instead of cars: new business strategies of automakers and the impact on private vehicle holding[END_REF][START_REF] Midler | Project-based learning patterns for dominant design renewal: The case of Electric Vehicle[END_REF], in which manufacturers are struggling to find a competitive place. Given the large and worldwide weakening of the automotive industry the last few years, managers of Renault are betting that historical manufacturers would benefit from an original collaborative approach both in the exploration of new technical imaginary for mobility design and in the stimulation of social imaginary linked to technologies and mobility uses, which would need to investigate other universes of design.

Data collection

The research is a qualitative study that combined theory building [START_REF] Eisenhardt | Building theories from case study research[END_REF][START_REF] Yin | Case study research: Design and methods[END_REF] and the production of actionable knowledge through collaborative research [START_REF] Shani | Handbook of collaborative management research: Sage Publications Thousand Oaks[END_REF]. As both authors are members of the RI-Community, numerous data has been collected during plenary sessions and projects meetings, especially as one of the authors has taken part of the initial building of the community in 2008. Data from intervention research methodology were triangulated [START_REF] Flick | Triangulation in qualitative research[END_REF] with semi-structured interviews, direct observation of RI-Community members' interactions during plenary sessions and RI-Community projects, and from Renault internal documents. Emerging theory and research hypothesis have been deepened through a master degree project dedicated to innovation community investigation between June and December 2012 [START_REF] Tij | Exploring societal values associated with Electric Vehicle: Study of the absorption capacity of the Renault innovation community[END_REF]. All in all, 18 plenary sessions have been investigated (three per year since 2008), one of the author took an active role in a cross-industry project of the RI-Community [START_REF] Gillier | Framing the scope of value in exploratory projects: An expansive value management model[END_REF] and16 interviews dedicated to the study has been led with RI-Community members between June and October 2012 [START_REF] Tij | Exploring societal values associated with Electric Vehicle: Study of the absorption capacity of the Renault innovation community[END_REF]. For the theory building process [START_REF] Eisenhardt | Theory building from cases: opportunities and challenges[END_REF], we mobilized the analytical framework on communities proposed by [START_REF] Cohendet | Routines and incentives: the role of communities in the firm[END_REF] in order to give a detailed characterization of the organizational features built by members of an innovation community, and to structure rigorously the observations.

Context of the case study: introduction of the Renault Innovation Community

The research focuses on the Renault Innovation Community (RI-Community), which is a cross-industries think tank on future patterns of mobility and innovation practices. This community is composed of representatives from highly various industrials sectors (automotive, aeronautics, railway, postal services, but also industries outside mobility markets as cosmetics, sports, energy, chemistry, pharmaceutics, ophthalmic lenses, and others.), consultants, foresighters and academics from management, sociology, and philosophy. It is an original industrial-based community because members, mostly industrial top-managers and intellectuals from academy, are cross-industries and cross-disciplines people. Nevertheless, they share to be involved in the management of radical innovation and in strategic foresight on technological, environmental or societal evolutions. Since the first session in March 2008, the RI-Community grew from 70 members to more than an hundred at the end of 2013, with still around a third of members from Renault. They meet in quarterly plenary sessions of a full day animated by the deputy director of Renault in charge of the RI-Community and two dedicated community managers (one is a Renault employee, the other is independent consultant). These three facilitators of the RI-Community are in charge to plan original presentations and workshops for these sessions but also to animate inter-session workshops and support exchanges between members on the community website.

Case study analysis: the experience of Renault Innovation Community

As previously highlighted, the RI-Community has existed for several years and its membership base grows each year. From a managerial point of view, the collective organization appears as original both on its official topics for ecosystem innovation which are very broad (future patterns of mobility and innovation practices), but also by the large diversity of the individuals and industrial sectors that are involved in the collective.

Nevertheless, its managerial patterns remain to highlight in order to understand the organization as an effective construction to stimulate innovation in industrial ecosystems. We propose here to develop two main patterns that emerged from the case study analysis: 1/ the objects of collaboration between members and more precisely, the gap between the objects expected by the initiators of the community and those really appeared in the collaboration; 2/ the organizational mechanisms of coordination they have developed together.

Objects of collaboration in the RI-Community

First of all, the managers in charge of RI-Community targeted specific objects of collaboration when they created the think tank. For Renault's managers and founding members involved at the beginning of the initiative, the aim of the community was the establishment of a collaborative process of exploration of future through an epistemic community on mobility evolutions, in the sense of [START_REF] Cohendet | Organisational innovation, communities of practice and epistemic communities: the case of Linux[END_REF].

This specific goal aimed to increase the scope of Renault Innovation capability and those of firms' partners, through a collaborative approach of open innovation focused on mobility innovation. Renault's manager in charge of the community testified that it was the main goal pursued with the RI-Community but also the most ambitious and known as hard to reach collectively. Indeed, interviews led in 2012, fours years after the creation of the community, underlined the discomfort of members on this issue that they all had identified as crucial, but they also had the feeling to not succeed developing a common object of collaboration.

A second goal targeted was to propose the organizational resources to build an original network on potential disruptive innovations, beyond expected evolutions of mobility (more connected, more sustainable and so on). The aim was to favor the learning on original knowledge and then, its absorption in the diverse partner companies. Initiators of the RI-Community knew scholars' work on absorptive capacity and consequently, they expected to members to involve themselves as gatekeepers [START_REF] Cohen | Absorptive capacity: a new perspective on learning and innovation[END_REF]. Operational project achievement was not targeted even if it could be outputs resulting from partnerships born in the community. To foster members in their gatekeeper role, initiators involved foresighters and consultants specialized in macroeconomics and strategy, in sharing theirs visions of potential societal changes with members. The initial process aimed to support the development of a common vision centered on the analysis of contrasting scenarios of population density, age demographics, and availability of energy and raw materials. Despite this specific investment, members' interviews shown that Renault members were unable to cater for this managerial expectation due to the difficulties of interpretation and translation of the knowledge acquired in the community in their activities. Some of them tried by focusing on the transmission inside their own institution of the knowledge offered by speakers, but they mostly claimed failing to interest people in their firms. Moreover, consultants' presentations were considered as controversial and their insights strongly criticized as superficial, inconsistent or meaningless.

The sharing of best practices among members on radical innovation achievement was the third expected object of collaboration. This goal implicated that, the members from Renault had been chosen for their need or involvement in Renault strategic innovation activities. The sharing on innovation management practices was often mentioned by interviewees as really appreciate by members. This object of collaboration constitutes a best practice today well rooted within the community. Moreover, the RI-Community members recognized the group as a community of practice on major innovation in the sense of [START_REF] Cohendet | Organisational innovation, communities of practice and epistemic communities: the case of Linux[END_REF].

To summarize, managers expected that the RI-Community delivers a collaborative exploration of future by an epistemic community on original mobility evolutions, an absorptive capacity of members as gatekeepers on societal trends to increase the firms' innovation capability, and a community of practice on radical innovation methods and tools.

Only the latter became an object of collaboration in practice, thanks to consistent efforts spanning overs multiple years.

From the longitudinal analysis of plenary sessions and projects led within the community, we could observe objects of collaboration that differ from those expected by managers.

First, it appeared that the members learnt on new mobility paradigm and on potential societal shifts more than on customers' expectations. For example on automotive individual mobility, most presented customer's expectations were about reducing congestion and health disturbance, but members used to focus more the collective discussions on the shift of paradigm that occurs in ownership of cars [START_REF] Midler | Project-based learning patterns for dominant design renewal: The case of Electric Vehicle[END_REF], and the consequences a move of business model could induce on private mobility uses. As members could propose innovative solutions together on the latter point, these debates had twofold results: they increased the sharing of a common understanding of the current mobility paradigm (one driver who is the car owner after a unique purchase) and its potential shifts; and the exploration of potential shifts became a common purpose for the RI-Community [START_REF] Barnard | The Functions of the Executive[END_REF][START_REF] Segrestin | Partnering to explore: The Renault-Nissan Alliance as a forerunner of new cooperative patterns[END_REF].

Moreover, we also observe a better understanding of what could induce potential societal shifts, and how members could organize together the conditions to make them happened. For example, during one of the presentation in a plenary session, a representative of the Belgian chemical company Solvay brought an original and innovative exploration of future mobility with renewable energies through the "Solar impulse" concept. The presentation generated a rich debate of the action that each actor could play individually, collectively or as RI-Community in the achievement of the kind of new paradigm proposed by Solvay's representative. Besides, the 'impulse' concept has been immediately re-used by community members on another topic. This quick re-use of the concept demonstrated an unexpected and fast-acting collective capacity of appropriation and building on conceptual constructs.. Conceptual capability on ill-defined products or services is an unexpected collaborative object of the RI-Community, which members often pointed in interviews. This particular conceptual capability of the collective had been trained through an original method proposed by the RI-Community managers: the 'boxing' of on-going explorative or major innovation projects. The 'boxing sittings' exercise consisted to offer the opportunity to a member to present an idea or a disruptive concept that he or she was currently exploring during a plenary session and be challenged by all members. More the concept exploration is at initial stages of investigation, more the exercise is enriching for each members. The community made this original exercise to try to identify the blurred concept with an unclear outline. For example, one member proposed a starting exploration of the concept of "users collaborative design of local mobility" trough a five minutes presentation of what he thought do with it. The members reacted by characterizing the project with new words, proposing new definitions, challenging it with new questions, enriching the initial concept with new concepts or other notions they had in mind, combining the proposal with other innovations, and at last by criticizing it weaknesses and giving provoking comments to continue to rise the debate. Finally, the concept had been chewed in several directions under-investigated by its owner but valuable for him and served as collaborative support for the members. Thus, when the community involved in 'boxing' a project given by a member, the efficiency of the conceptual description became the object of collaboration. To contribute to the collective enrichment, members had given numerous examples of original products or services but they also illustrated their point of view with rhetoric figures as metaphors or analogies, various references to literature, arts, and myths they associated to the mobility concept: thus, members shared and stimulated sociotechnical imaginaries. The repetition of such 'boxing' practices supported the increase of the RI-Community conceptual capability but also, contributed to the enrichment of the group's sociotechnical imaginary. 'Boxing sittings' were only one of the particular collaborative practices the RI-Community managers developed. Frequent subgroup workshops had supported the opportunity to share and test ideas or disruptive concepts in restrained groups. Innovative methods, intense networking and original forms of feedback to the whole community -as sketches, humoristic theater performance, etc. -led to a radical collective emulation on sociotechnical imaginaries. This is an important result of the RI-Community management as, despite members had reported a fail in the knowledge transmission into the firms, they claimed about a large dissemination of original concepts in the different firms. So the social construction of the imaginaries was spread outside the community into members' firms.

To conclude, the observed objects of the collaboration were a better understanding of new mobility paradigms and its potential shifts, and subsequently a better comprehension of the role that members could play to make it happen; and a collective capability to appropriate and build on new concepts that efficiently supported the sharing of an enriched sociotechnical imaginary.

Organizational mechanisms of coordination of RI-Community

Governance rules of the RI-Community were original for a think tank funded by a single firm.

Voluntarily, Renault rejected to be the "focal firm" of the community [START_REF] Adner | Match your innovation strategy to your innovation ecosystem[END_REF]. Despite the fact the firm funds the logistics of the RI-Community, all members could benefit in the same way of the resources. This 'open resources' were a dedicated virtual platform on a website and two dedicated community managers. How they were the main initiators, Renault's managers used to fund plenary sessions logistic, but other members had hosted RI-Community sub-groups meetings and plenary sessions in their own premises. In the same approach, Renault managers did not want the firm impose its view to the RI-Community: they soon decided to always been less than 30 percent of the participants at plenary sessions. So, other companies have not the feeling that the representatives of Renault have crushed the debates. However, the community managers were playing a strategic role both structural and social in the balance of the community. They allowed the trust relationship between members and spread an open-mind spirit that facilitates the acceptance of original visions. The weight of Renault as initiator was also unquestionable: as all interviewees pointed, they gave to the community to work on mobility paradigm and make possible a "real open innovation" with adapted collaborative patterns, especially supporting non-contractual collaborations. The intense networking that occurred between members reinforced the legitimacy of the community and the choice on governance rules. Interpersonal relationships appeared through the creation of new links between members of several companies but also with the strengthening links in the Renault's hierarchical community. Moreover, the original composition of members, surprisingly heterogeneous, enabled original partnerships on innovative projects between cross-industrial companies, engineering and design schools, consultants, and academics institutions.

Nevertheless, all members did not play the same role inside the community. Members classified themselves into four categories they elicited as based on the authority of people's opinion on the others: intellectual people, seniors and top managers, middle managers and consultants, and young people. Still from members' self-assessments, this classification could be crossed with another one they also gave, based on the diversity of involvement of participants in the debates of plenary sessions: organizing members, intellectual people, leading figures and occasional participants. These perceptions induced a kind of hierarchical double-scale between members themselves, resulting from a status -combining an authority of the opinion and the involvement -naturally given to each other between actors inside the community. Different sub-groups emerged inside the community, that converge more in subcommunities of practices according to the authority level of members; and more in epistemic sub-communities if we looked for the involvement criterion. Finally, this dual belonging appeared as an important mechanism of the community cohesion because members identified themselves through different categories according to their feeling of being able to understand and contribute to a sub-group. Practically, members involved themselves in sub-group that shared their language to explore ill-defined topics: in other words, they entered a group because they understood the imaginary references manipulated by these particular members and could contribute to its improvement.

Finally, the Renault Innovation Community also supported the emergence of ephemeral partnerships between members to enable collective design of sub-elements prototypes of a renewed mobility. Inside these partnerships, a few members of the community designed prototypes in dedicated workshops between plenary sessions and then, regularly presented their advancement to all members. Subgroup partners involved the community through uses scenarios of the prototypes, in order that everyone from RI-Community could discuss the emergence conditions of the core concept of the project. For example, one of RI-Community project aimed to learn about "smart-grid intermodal hub", that associates physical and virtual mobility devices to energy low consumption services. The project involved in a subgroup partnership the Parisian public transportation operator RATP, the energy producer and distributor EDF, the research team in innovative design management of MINES ParisTech and Renault. The exploratory team was composed of a representative of each industrial partner, two consultants in energy management, one of the RI-Community managers and a researcher. With the help of graphic designers managed by the consultants, the team developed a virtual prototype of a mobility hub in six months, which have been challenged twice in plenary sessions.

These ephemeral partnerships had several impacts for the community. First, they allowed deepening and testing the value of some concepts the community had nurtured. Second, they simulate new potential industrial ecosystems. And, moreover, they gave concrete outputs of the RI-Community visible to the outside, and especially to the networks of the members, and doing so, they stimulate new potential industrial ecosystems beyond the arena of the RI-Community.

Discussion

Impacts of the organization on ecosystem emulation for innovation

The RI-Community builds an original cross-industry and cross-discipline innovation capability that induces three main effects on industrial ecosystems.

Firstly, the community supported a collective better understanding of the role that members could play, individually, in subgroups, or as Community, in the emergence of sociotechnical shifts. Based on the organizational logics from "open innovation" described by (H. W. [START_REF] Chesbrough | Open innovation: The new imperative for creating and profiting from technology[END_REF], the RI-Community was initiated on the common interest of the members to combine their knowledge, but they mostly differ to classic open innovation because the aim of the collective is not to look for potential innovation but to potential societal shifts. Indeed, as in classic open innovation, members share piecemeal knowledge that each has acquired in order to jointly build a larger and more robust map of knowledge. But, after that, they collectively discuss the different impacts they could operate together to disturb the contemporary societal paradigm of mobility, and what kind of effects their association could have on energy availability, urbanism, worldwide exchanges of people and goods, individual or collective mobility, etc. They adopted rigorous methods to support this exploration: each plenary session of the RI-Community starts with original knowledge sharing, followed by a collective debate and finally a systematical learning on disruptive concepts through thematic workshops.

Secondly, we observed that the organization induces an important emulation of sociotechnical imaginaries between members the community, bringing the interactions at a conceptual level, which disseminate beyond the group. The efficiency of the emulation results from an intensive learning on original knowledge, supported by collective debates on their interpretations. The case study also underlines the need for specific methods of collaboration, as 'boxing sitting' exercise to enrich the debate, and rise to a conceptual level. Then, the variety and the nature of members in the community is the key point to maintain the debate at a conceptual level: as the membership is cross-industrial and cross-disciplinary, members must stay at a conceptual level to be understandable by the others. Intellectuals or academics help a lot to develop the conceptual capability of the group as they are particularly trained to conceptualize and put words on abstract concepts. In this way concepts and sociotechnical imaginaries became the main objects of the collaboration. Indeed, each member takes profit of the others' vision of the same issue: differences and similarities are doubling underlined by cross-discipline argumentations and cross-industrial knowledge sharing. It generates a very emulative learning process when they share their knowledge and forecasts through references from theirs own imaginaries. The collaborative exploration allows gathering the sociotechnical references of each member and to create new one together: the sociotechnical imaginary of the community. Nevertheless, self-classification members operated of subgroups within the community highlights that the people most trained to used imaginaries references and to put into words conceptual notions where the intellectual subgroup. Indeed, the involvement of intellectuals in the debates of plenary sessions strongly supports practitioners in the elicitation of sociotechnical imaginaries. But, it also induces formulation of industrials' imaginaries when they tried to enrich their contributions or oppose them. If interviews underlined that the exercise is felt as perilous because practitioners usually had a poorer rhetoric, they also claimed that those who tried gained a better capability to disseminate in their firms the concepts mobilized in the RI-Community. However, for all members, the community supports an individual better understanding of potential sources of radical innovation. In return, it helps each actor to understand its own fixation effects on what the future "must" be: they could put into word their sociotechnical imaginary, and linked to this, the one of its industry. Doing that, members become able to describe their own fixation effects in creative situations [START_REF] Smith | The Creative Cognition Approach[END_REF], those of their firm and the core rigidities in term of the corporate values of it firm (Leonard-Barton, 1992) and could better disseminate his learning when he comes back inside the firm.

Finally, the initiative became an incubator for cross-industry partnerships that supports new industrial ecosystems emergence. The collective is made possible by the shared recognition of all these members of a situation of "shared uncertainty" and an ecosystem impact leading to "complex and changing coordination" of industrial and institutional actors [START_REF] Aggeri | Managing Creation and Learning of New Expertise in Automobile Development Projects[END_REF]. Even if the most of underlying concepts are macroscopic sociotechnical imaginaries, it seemed that the workgroups were fruitful for all members to discuss contemporary challenges they need to overcome in shorter terms. When some similar issue emerged between a few members and if they could do it better together, exploratory partnerships also emerged. The study of long-term solutions in the community generated so many exchanges that the members learnt on the potential benefits of working together. As members meet regularly, trust develops between actors and negotiations start in merge of plenary sessions. The RI-Community has already led to several partnerships and joint ventures between members.

Implications for collaborative management of innovation

The case study highlights that objects of the collaboration when looking for new markets creation are different than expected by an open innovation approach and they are quite uncommon: concepts and associated sociotechnical imaginaries. The research shows that collective capabilities for innovation could be developed through an active emulation at this level, but it needs specific governance rules and management tools. In this case, the organizational construction becomes an incubator of new industrial ecosystem.

First of all, these three fields proposed tools and methods based on existing markets and in a stable environment. Beyond to anticipate the unknown from the known basis, due to original objects of collaboration, the paper highlights that the community adopts a new position. This new positioning reveals another point of the distinction from classic collaboration based on business intelligence, technological forecasting and prospective. Indeed, the collective is no more focused on the potential evolutions of existing markets in stable industrial environment. At the opposite, the behavior of this RI-Community is rather based on a proactive attitude that used societal, environmental and technological trends as cognitive resources and no more as constraints, whose they are obliged to answer. This specific point of view raises the community capability for innovation to an ability of cross industrial and cross discipline action that supports the creation of an original industrial ecosystem and offers new visions of potential roles the companies could take in them.

Finally, to make it possible, tools and methods are necessarily different than those exposed in existing literature and need for a specific effort from innovation management practitioners and researchers. Through this case study, we contribute to a first understanding of new practices: we identify and qualify an original phenomenon of a cross industrial and cross discipline innovation-driven community, according two patterns, the objects of collaboration and organizational mechanisms of coordination. To increase our understanding, additional indepth studies are needed to validate key reproducible elements and demonstrate their managerial implications.

Conclusion and further research

Strongly contingents to an industrial ecosystem, objects of the future modeling aiming to detect expectations do not support the emergence of a cross-industrial project, and conversely, scenarios support a partitioning of actors, averse to the constitution of new ecosystems, and thus to new emerging markets. However, think of disruptive innovation in partnership requires a prior effort within the firm in order to express and make understandable concepts outside the organization [START_REF] Felk | DESIGNING PATENT PORTFOLIO FOR DISRUPTIVE INNOVATION-A NEW METHODOLOGY BASED ON CK THEORY[END_REF] and a conceptual absorption capacity, i.e. a capacity to meaning some concepts out of traditional design paths usually followed by the firm and stimulating business environment for their exploration [START_REF] Le Masson | Revisiting absorptive capacity from a design perspective[END_REF]. The case study presented here underlined that people could be trained and supported to become more efficient to conceptualize and give imaginaries references, thus opening the research issue of what could be a 'gatekeeper of sociotechnical imaginaries' for companies?

In this context, the activity of collective exploration of the future is no longer to "see" before other economic competitors or to build an immediate strategy but more to prepare new commercial spaces and propose objectives, enough generic to support the establishment of new rich imaginaries, both among potential users than designers. In the case of the Renault Innovation Community, we observed that the sociotechnical imaginary support an effective pre-positioning of knowledge of potential businesses in new ecosystems. Thus, surprising objects of coordination are observed, as concept demonstrators embodying proposals of shifts in societal trends. Voluntarily positioned in opposite of the conventional approach to reach detected expectations, these objects support involvement mechanisms between actors no longer based on knowledge exchanges for uncertainties reduction (traditional convergence objective on the known), but focused on the exchange of exploration tracks (original objective of partnering in the unknown). Beyond the work presented here, the communication modes mobilized by such actors are studied in an emerging literature [START_REF] Eris | Asking generative design questions: a fundamental cognitive mechanism in design thinking[END_REF][START_REF] Eris | Effective inquiry for innovative engineering design[END_REF].

Authors suggest differentiating the "generative design questions" that suggest ways of exploration, from the "deep reasoning questions" that seek for clarifications on proposals considered as known. Further research will gain to enroll in the current field providing both empirical data and theoretical modeling of these objects, which are neither physical nor traditional projects.

  the heart of this case study: 1 / what are the objects of exploration? If the actors are no longer working on a specific application, if there are no more functional specifications to guide collective action, on what objects is working the collective? On road map, demonstrators, scenarios of potential applications, usages and businesses? Once determined the nature of these objects, what tools and methods to generate and pass them around players in the ecosystem? How to support a collective action more generative of variety and technical imaginaries, which could carry on a competitive pre-positioning, based on original sociotechnical imaginaries? 2 / what are the organizational mechanisms of coordination of the collectives that appear? Who gather the players? What types of organizations are they adopting? Who will drive the group? What are their interactions with R&D departments, suppliers or users? Do they include partners from outside industry and/or the current market? How do they divide the work among stakeholders?


Evelyne Mounier, Céline Paganelli Cristal-Gresec, Université Stendhal -Grenoble, France

The Representation of Knowledge Contained in Technical Documents: the Example of FAQs (Frequently Asked Questions)

Abstract: This article deals with the representation of knowledge contained in FAQs. Various works showed that it is conceivable to categorise the various information units contained in technical documents according to the type of the information conveyed. Such a model based on various types of information units makes it possible to represent the knowledge contained in technical documents. Besides, this model proposes a method for the automatic recognition of the information units types contained in these documents. This model has been constructed for "traditional" technical documents and it has been validated with expert users of these documents. In this paper, we propose to validate and extend this model to FAQs by an experimental study with a group of users, expert of the technical field described in FAQs.

1-Context

The present study deals with expert users in a technical domain using an information retrieval system because they need information to perform a task. A way of considering the indexing of such documents is to study the requests the users address to these documents and to study the information units, which constitute responses for these users. Various works showed that it is conceivable to categorise the various information units contained in technical documents according to the type of the information conveyed [START_REF] Paganelli | Vers un système de consultation des documents techniques volumineux par des utilisateurs experts: le système Sysrit in IHM et recherche d'information[END_REF].

In the same way, it was shown that the requests of expert users could be categorised according to the type of expected information. Thus, we have shown that when expert users search for information either in order to obtain the description of a task to be executed (these requests belong to PRO type) or in order to obtain a description of an object (they are the requests of the OBJECT type). The OBJECT type is declined in more precise sub-types. (Mounier, 2003) Sub-type DFI relates to the definitions, sub-type DF describes an object by its functions (functional description) and the sub-type DO relates to descriptions of objects with their physical or constituent aspect. Each one of these types presents specific linguistic markers [START_REF] Clavier | Objects and Actions: Two concepts of major interest in information retrieval in full-text databases in Workshop on Applications of Natural Language to Information Systems[END_REF], Mounier 2003), which can be automatically extracted.

2-Validation and extension of the model to FAQs

In this paper, we propose to extend this typology to the FAQs (frequently asked questions), available on the web. Strictly speaking FAQs do not exactly constitute technical documents. There is a conventional structure to FAQs as they are constituted of questions followed by answers but answers and questions are not structured in any particular way, they are not subjected to any rule of form, neither of presentation, nor of structuring. Nevertheless, FAQs seem to be relatively close to the "traditional" technical documents we have studied up to now. First, like the "traditional" technical documents (maintenance handbook, instruction manual...), FAQs are related to a very specialised field. Thus, one will find FAQs about Unix, XML, Latex, electricity and magnetism... Second, FAQs apply to a particular type of identified public: expert or novice users. Finally, FAQs intend to technical information retrieval. Moreover, FAQs seem all the more interesting as they present differences compared to technical documents. First of all, and contrary to traditional documents, FAQs record at the same time the answers and the questions [START_REF] Crowston | The effects of linking on genres of Web documents[END_REF]. Besides, FAQs are built from the information needs the users express. Thus, they can enable us to constitute an important corpus of users' requests.

Then, we know that in traditional technical documents, the answers are information units, which must be extracted automatically from the document, whereas in the FAQs, the answers are built specifically to answer the asked questions. Thus, contrary to technical documents, in FAQs, each answer is autonomous and does not belong to a whole document. This study should make it possible to check if these differences influence the linguistic characteristics of the information units.

3-Methodology

Our work is based on an experimental study. A corpus of FAQs, which apply to expert users, is collected by a search with the Google engine. These FAQs relate to the systems Unix, SQL and Linux. For each system, the first ten results were retained, excluding the FAQ written with an educational aim (for example those dealing with tutorials of programming) and the FAQs that explicitly apply to a novice public. This corpus, made up of 504 answers and 423 questions, has been categorised with the typology previously applied to technical documents. For the experiment, a selection of units (questions and responses) has been submited to the subjects: 25% of PRO, DO and DF types, and 12,5% of DFI and IND types composed our experimental corpus. Questions and answers were separated. In general, each answer is made up of a paragraph but answers of several paragraphs can also be found. In this case, answers are not cut down. Each corpus of questions and answers was submitted to a group of expert subjects of the field described in the FAQ. The subjects were asked to categorise each answer and each question with simple values: PRO (descriptions of tasks) or OBJECT (descriptions of objects), and for the units classified with OBJECT: DO (physical or constituent descriptions), DF (functional descriptions), DFI (definitions). An "unspecified" value (IND) is also proposed to the subjects. The results of this experimentation are analysed in the following way: the frequency of each type and/or sub-type in the questions and in the answers, the proportion of questions and answers unspecified (IND), and the analysis of the units (answers and questions) classified IND.

4-Results

4-1-Distribution of the different types

The table bellow presents the way subjects categorised questions and answers. Questions and answers categorised with PRO type present specific features. In PRO type units, the user is, tacitly or explicitly the agent, verbs are mainly in the infinitive or imperative form, the answers are sometimes made up of lists of numbered actions.

Responses and questions categorised with DF type present the following features: the explicit agent is the system or a component of the system, verbs are at the active voice.

In the questions and answers classified as DO: the explicit agent is the system, verbs are stative verbs.

The requests classified as DFI correspond to questions like "what is X ?", "what does Y mean ?". In these questions, there is no mention of agent and verbs are mainly stative verbs. Finally, questions and responses categorised as IND seems to set problems as they can be understood and interpreted in different ways.

4-2-Agreements and Divergences Analysis

There is more agreements between subjects for questions than for responses. Besides, the agreement rates are higher for questions. The agreement rate between subjects goes from 50 to 100% for 83 % of questions, whereas it goes from 50% to 100% for 59 % of answers.

There are two types of questions that set problems to subjects. Several questions do not directly concern the system. For instance, "do I have to pay fee?". Other questions can be understood and interpreted in different ways. For instance, "my hard disk IDE is very slow." In this case, either the user wants to know how to make his hard disk faster or he wants to know why his disk is so slow. Relating to answers for which there is no agreement, subjects hesitate between all the types for 11%, between DO and DF types for 22%, between DO and DFI types for 22% and between PRO and all the other types for 44%.

The answers for which subjects do not agree are often very long.

They are composed of several information units which belong to different types. In these cases, subjects hesitate between DO, DF and DFI types. Some short answers set problems. Either, they direct the user to a website, or they describe tasks the user cannot do.

When subjects hesitate between PRO type and the others, answers always present the following features: the user is the explicit agent but the answer contains modal verbs (can for instance) associated with negative, or it contains assumption (may be, probably) associated to users actions.

4-3-Discussion

The analysis of several FAQs shows us that it exists different types of FAQs. It seems that some of them are "well writing" FAQs whose structure and organisation are close to traditional technical documentations, whereas other FAQs are closer to questions/answers systems or to discussions whose organisation is similar to verbal exchanges. This experiment shows that the model we propose to categorize information units applies better to questions than to answers. Besides, this model seems to apply to "well writing" FAQs. Nevertheless, subjects met difficulties to make the distinction between the answers of DF, DO and DFI types. There's nothing surprising about that when they are extracted from questions / answers systems, as far as this kind of systems, explicitly aimed at helping users, rarely dissociate the description of a system and the description of its functioning.

5-Future Works

The model we propose, based on the categorisation of the information units contained in FAQs, makes it possible to study a kind of documents available on the Web, to determine the characteristics and the regularities of these documents, and finally to suggest a representation and an automatic recognition of this type of documents. Nevertheless, in order to fit FAQs that are closer to questions/answers systems, this model needs adaptations. Thus, it could be improved by a deeper analysis of the linguistic features of questions/answers systems structure.