domain: nlin spi sde

text:
value. Hence, the technique of the suggested method is close to those procedures which are applied in the homogenization theory. The flow equations averaged over r represent the main interest of this paper. Owing to the particularity of the method used, the solutions obtained do not need to provide an exact detailed flow pattern, but they are expected to exhibit adequate homogenized behavior.

A. Asymptotic solution

Let us introduce the regular asymptotical expansion of with respect to the small parameter  as below:

The definite form of the velocity and pressure gradient field will be where the details on the solutions and the solutions to are provided in Appendix A. For the special case of regular pipe we obtain

When there is no fluid exchange with the porous host rock through the walls, u* = v* = 0, we obtain the flow in a regular pipe: the parabolic profile for the longitudinal velocity, Fig. 4, the zero radial velocity, and the constant pressure gradient along the pipe. The fluid flow through the walls, u* = v* = 1, creates a non-zero radial velocity and deviates the streamlines from.

being parallel to the walls as shown in Figs. 5 and 6. At higher Reynolds, Fig. 6, a reverse flow forms in the pipe close to the wall boundaries.

For the channel with impermeable wavy walls in low Reynolds, the streamlines follow the wall geometry due to viscous effects as it is shown in Fig. 7(a). We assumed the case of the channel's sinusoidal corrugation as with a being a dimensionless parameter equal to the ratio of the corrugation amplitude to the mean radius and = 0.01,  = 0.01 0.75 = 0.0316 and a = 0.3. The flow is from left to right, the upper half-domain is presented.

B. Two-scale form of the solution

In order to average the fluctuations caused by the wavy walls, we can use the fact that the scale of the oscillations is small with respect to the long length of the channel. Due to the large difference between the two scales, the behavior at two scales may be assumed to be independent from one another. The small-scale ("fast") variable y = x/" is considered to be independent from the slow variable x. Then we introduce the extended functions

The spatial derivative is defined as

The detailed two-scale results for the velocity and pressure field are given in Appendix B. For the impermeable walls, secondary flows are not visible up to some certain Reynolds number, as it is seen in Fig. 7(a). With the fluid flow through the walls secondary flows form even in low Reynolds number, Fig. 7(a). In Fig. 8, a relatively high Reynolds number, Re = 5, is chosen in order to ensure the formation of secondary flow. As it is seen in Fig. 8(a), secondary flows form even where there is no fluid flow through the walls. In Figs. 9 and 10, the stream function is plotted using the zeroth, first, and second approximations for permeable and impermeable channel walls and a relatively low Reynolds, Re = 1, and a higher Reynolds, Re = 5. As it can be seen, at lower Reynolds the higher asymptotics for the stream function are less dominant. In higher Reynolds, the most exact correspondence with the true flow pattern is obtained in the second approximation for both cases of permeable and impermeable walls.

It can be seen in Fig. 11 that when there is no fluid flow through the walls, the gradient of pressure along the channel is periodic. In the case of permeable walls, the pressure gradient increases along the channel axis, which results in forming the instability. The rise of instability can be noted through the appearance of the positive pressure drop which determines the reverse flow.

C. Averaged flow model

Let us define the single and double averaging for a two-scale function f (r, y, x)

(17)
Then the averaged velocity and pressure will be Three effective parameters determine the averaged behaviour of the system:

• K ef is the effective permeability [m 2 ], the parameter responsible for the pure viscous dissipation (the friction) which corresponds to Darcy's law. The effective permeability also includes the consequences of irregular boundaries as the local Darcy like term. These effects are assumed as a correction to the effective permeability, here determined in terms of coefficients of  2 / 2 in parameter , the corrugation parameter. In Fig. 12 the corrugation parameter is plotted vs. the oscillation amplitude for both permeable walls and impermeable walls. It can be seen that the presence of irregularities in the geometry of the boundaries decreases the effective permeability of the channel significantly, while the presence or absence of fluid flow through the walls has not a significant role on the effective permeability.

•  ef is the inertia parameter having the dimension [m -1 ]. It is responsible for the integral losses of the kinetic energy within a period caused by the radial component of the inflow velocity which is orthogonal to the channel's axis, v*. The radial component of inflow deviates fluid from the axial direction of flow, which reduces the fluid axial velocity. The energy transferred with the inflow plays the role of a decelerator, which means the appearance of a negative acceleration, or the inertia losses of energy.  ef vanishes in the absence of fluid exchange through the walls as shown in Fig. 13.

with the inflow plays the role of a decelerator, which means the appearance of a negative acceleration, or the inertia losses of energy. _ef vanishes in the absence of fluid exchange through the walls as shown in Fig. 13. •  ef is the dimensionless parameter responsible for the visco-inertial cross-effect that represents a supplementary viscous dissipation produced by the deviation of the streamlines due to increase in Reynolds. As the streamline deformation is caused by the inertial forces, this term depends on Re.  ef represents the global and local cross visco-inertial effect. The global effect is zero in the absence of fluid flow through the walls. As it is shown in Fig. 14, this term vanishes for a regular pipe.

In the special case of a regular pipe with permeable walls, one will have F0 =1/2 + v*x and It is seen that for a pipe with permeable walls, the pure inertia effects and cross visco-inertial effects enter the averaged pressure drop. For a regular pipe with no inflow, we reduce to Hagen-Poiseuille equation for pressure drop in pipes, with  = 1. Also in the presence of fluid flow through the walls, the effective permeability increases for a regular pipe, Fig. 15. As a result of <<1, the limit value of the effective permeability reduces to the one for the pipe with impermeable walls.

III. PARALLEL-PLATE WAVY CHANNELS

The same approach presented in Sec. II can be applied to investigate the flow in a slab-shaped parallel-plate wavy channel with permeablewalls immersed in the porous medium, as shown in Fig. 16. The channel's depth perpendicular to the direction of the flow is infinite, so the problem is assumed to be 2D, Fig. Introducing and the asymptotic expansion in terms of powers of , the solution in the two-scale form using the small scale variable y = x/ will be obtained as given in Appendix C.

In Fig. 18, the streamlines and pressure field are plotted for a parallel-plate wavy channel with walls of geometry (x)=0.5(1 + a sin(2x/)) where a is the ratio of the wavy amplitude at half of the mean aperture. In this case, =0.01,  = 0.01 0.75 , a = 0.3, and Re = 12. It is seen that at small Re, the fluid flow through the walls, Fig. 18(b), influences the streamlines in the vicinity of walls, but weakly influences the velocity magnitude.

In Fig. 19, the same plots are presented for a relatively higher Reynolds Re = 55. For higher Reynolds number, the flow through the walls has a significant impact on streamlines and the velocity field in the channel. In the case of permeable walls, the flow in the channel is not periodic anymore.

The pressure gradient along the channel for Re = 12 and Re = 20 is presented in Fig. 20. The pressure drop along the channel is periodic when there is no fluid flow through the channel walls. In the case of permeable walls, the amplitude of oscillations of the pressure gradient increases along the flow direction. At high Reynolds, starting around Re = 20, the pressure gradient becomes locally positive which means the appearance of a local reverse flow. This counter-current flow might result in the appearance of the instability.

We apply twice averaging defined as which gives the averaged longitudinal velocity C1, transversal velocity C2, and pressure gradient along the channel's length C3 in the dimensional form , as the following:

Replacing U 0 by U by using (35), we obtain the averaged momentum balance equation in the form of a cubic law where (39)b (39)c

The effective permeability K ef [m2] depends on the geometry of the channel and weakly depends on the influx through the walls.

The inertial term  ef [m -1 ] is responsible for the integral losses of the kinetic energy caused by the component of the inflow velocity which is orthogonal to the channel's axis, v*.

 ef is the dimensionless parameter responsible for the visco-inertial cross-effect.

Two limit cases help to analyze the behavior of these parameters: the non-corrugated channel and the impermeable walls.

For the case of non-corrugated walls, when  = 1/2, one has Looking into Figs. 13 and 22, it is concluded that the dimensionless inertial coefficient  ef increases for parallelplate channels as the amplitude of the corrugations increase, while it decreases slightly for cylindrical-shape channels. The cross visco-inertial effects in a cylindrical channel decrease the pressure drop along the channel as the amplitude of corrugations increase, Fig. 14. For the slab-shaped channels, the cross visco-inertial coefficient is one order of magnitude smaller than the pure inertial effect and increases the pressure drop along the channel as the corrugation amplitude increases.

FIG. 7 .

 7 FIG. 7. Cylindrical wavy channel: Appearance of secondary flow, Re = 1 (a) without/(b) with inflow through the walls, (x) = 1 + a sin(2x/),  = 0.01.

  17

  FIG. 17. Parallel-plate wavy channel with uniform fluid flow through the walls.

For

  the case of impermeable walls u* = v* = 0, one writes The mass balance along the channel possesses the following integral relation:The dependence of these parameters, taken in dimensionless form, on the dimensionless amplitude of wall oscillations a (the amplitude divided by the channel's aperture H), is shown in Figs. 21-23. It was assumed that  = 0.01,  = 0.01 0.75 . As can be seen in Fig.21, the influence of the fluid flow through the walls on the permeability is not significant, and as is shown in Fig.23, the viscous-inertias parameter is practically independent of the flow through the boundaries of channel. The pure inertia parameter  ef is the most sensible with respect to the fluid flow through the walls and increases when the walls are permeable,Fig. 22. Comparing Figs. 7(a) and 18(a) one can see that flow vorticities form at higher Reynolds in parallel-plate channels.

IV. CONCLUSION

The effective model of flow in a channel with permeable wavy walls was investigated through the asymptotic solutions of the steady-state Navier-Stokes equations with non-zero fluid exchange through the boundaries. The solution was obtained for a cylindrical and parallel-plate wavy channel. The fluid flow through the walls increases the Reynolds number along the channel and results in local flow instabilities and forms reverse flow. The local instabilities arise in relatively higher Reynolds numbers in parallel-plate wavy channels than in cylindrical wavy channels. The channel's effective permeability decreases as the amplitude of corrugations increases. It was shown that the linear approximation for proportionality of the average pressure gradient and average velocity cannot explain the effect of fluid flow through the walls and corrugated geometry of the channel. Consequently, the linear approximation cannot express the flow regime in the channel properly. The quadratic correction to pressure drop along the channel is valid only in case of permeable walls. When the channel walls are impermeable the quadratic term vanishes, and the cubic correction to linear pressure drop exists though due to the wavy geometry of the walls. In cylindrical wavy channels, the cubic term decreases the pressure drop along the channel as the corrugation amplitude increases, while in parallel-plate channels the cubic term is less dominant.

APPENDIX A. ASYMPTOTIC SOLUTION IN CYLINDRICAL WAVY CHANNEL

The zeroth order, first order, and second order problems given in Sec. II A may be solved by introducing new variables, Then the zero-order problem of the asymptotic series becomes :

In the second equation, the variables x and  may be separated as

The left-hand side depends on x only; then, this equation is easy to integrate while taking into account the boundary conditions From the last integral relation in Eq. (A1), we obtain

The solution takes the form In a similar way, one can solve the first-order and second-order problem and obtain for

APPENDIX B: TWO-SCALE FORM OF THE SOLUTION IN CYLINDRICAL WAVY CHANNEL

The two-scale form of Eqs. (A4) will be written as

In the cylindrical coordinating system, considering the symmetry with respect to the angular coordinate, the streamlines in terms of radial and longitudinal velocity components, respectively, u, v can be written as where C is an arbitrary constant, representing different streamline sets. It should be noted that the function  oscillates with respect to y and does not depend on x, so one can write d/dx=(1/)d/dy.

APPENDIX C: TWO-SCALE FORM OF THE SOLUTION IN PARALLEL-PLATE WAVY CHANNEL

The two-scale asymptotic solutions for flow in a parallel-plate wavy channel will be derived in the similar way as cylindrical wavy channel given in Appendixes A and B, which rewrite to where C is an arbitrary constant.


Ciara R Wigham
email: ciara.wigham@uca.fr

Müge Satar
email: muge.satar@newcastle.ac.uk

Multimodal (inter)action analysis of task instructions in language teaching via videoconferencing: A case study

Keywords: multimodal (inter)action analysis, task-based language teaching, videoconferencing, instruction-giving practices, print mode, frozen actions

, in this paper we analyse the lower-level actions (modes) that comprise these higher-level actions, specifically focusing on the print mode (task resource sheets, URLs, textchat, and online collaborative writing spaces) wherein certain higher-level actions become frozen. Our findings are unique in depicting the modal complexity of sharing task resources in synchronous online teaching due to semiotic misalignment and semiotic lag that precludes the establishment of a completely shared interactional space. We observe gaze shifts as the sole indicator for learners that the teacher is multitasking between different higher-level actions. Further research is needed to fully understand the interactional features of online language teaching via videoconferencing to inform teacher training policy and practice.

Introduction

Online language learning via videoconferencing is an increasingly important area within the Computer-Assisted Language Learning field. As online language schools grow in number, offering flexible learning and teaching delivery methods, and education institutions including schools and universities turn to videoconferencing in hybrid and distance language learning programmes, the field needs to better understand successful online language teachers' semiotic pedagogical skills [START_REF] Develotte | The use of the webcam for teaching a foreign language in a desktop videoconferencing environment[END_REF]).

An expanding body of research analyses synchronous multimodal pedagogical interactions via videoconferencing and addresses semiotic modes used in online environments for specific purposes, [START_REF] Guichon | Tutorat de langue par visioconférence : comment former aux régulations pédagogiques[END_REF][START_REF] Hampel | The use of videoconferencing to support multimodal interaction in an online language classroom[END_REF][START_REF] Lee | Gesture in speaking tasks beyond the classroom: An exploration of the multimodal negotiation of meaning via Skype videoconferencing on mobile devices[END_REF], discourse types [START_REF] Wang | Negotiation of meaning in desktop videoconferencing-supported distance language learning[END_REF]Guichon, Betrancourt & Prié, 2012), the effects of the webcam on multimodal interactive learning [START_REF] Develotte | The use of the webcam for teaching a foreign language in a desktop videoconferencing environment[END_REF]Codreanu & Combe Celik, 2013;[START_REF] Guichon | A semiotic perspective on webconferencing-supported language teaching[END_REF][START_REF] Cohen | A comparative study of lexical word search in an audioconferencing and a videoconferencing condition[END_REF][START_REF] Kern | Technology as Pharmakon: The Promise and Perils of the Internet for Foreign Language Education[END_REF] and social presence [START_REF] Satar | Multimodal Language Learner Interactions via Desktop Videoconferencing within a Framework of Social Presence: Gaze[END_REF][START_REF] Satar | Meaning-making in Online Language Learner Interactions via Desktop Videoconferencing[END_REF][START_REF] Guichon | The Impact Of The Webcam On An Online L2 Interaction[END_REF]. Whilst most studies investigated pedagogical interactions within a task-based approach, research has not specifically focused on instruction delivery despite this potentially being a key pedagogical competence for task success (Watson Todd, Chaiyasuk, and Tantisawetrat, 2008). Furthermore, published research has focused upon trainee-teachers [START_REF] Cappellini | Analyser des compétences techno-sémio-pédagogiques d'apprentis tuteurs dans différents environnements numériques: résultats d'une étude exploratoire[END_REF][START_REF] Satar | Multimodal instruction-giving practices in webconferencing-supported language teaching[END_REF] with research sites being teacher-training courses led by the researchers. Few studies concern experienced online teachers. This case study examines how experienced online language teachers harness the print mode (resource sheets, URLs, textchat, Google Docs [online document hereafter]) in instructiongiving practices. Adopting multimodal (inter)action analysis [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF][START_REF] Norris | Systematically working with multimodal data: Research methods in multimodal discourse analysis[END_REF] we explore the videoconferencing interface as a site of engagement or "window opened up through practices that make concrete mediated actions possible" (Scollon, 1998in Norris, 2019:120). We then examine the print mode and its role in mediated actions. We then analyse modal configurations and density in the teacher's interactional space, indicating level of attention/awareness for different higher-level actions as the print mode is employed. We address three research questions:

1. How does the site of engagement demonstrate any intersection of different social practices? 2. What is the role of the print mode in achieving the higher-level action of instructiongiving? 3. How does the teacher's modal configuration and density vary when the print mode is utilised?

Theoretical background 2.1 Online teaching competencies

Synchronous online language learning is a semio-pedagogical activity that requires the teacher's use of appropriate socio-affective, pedagogical, semiotic and technological competencies to create and maintain optimal learning conditions to favour language skill development. [START_REF] Guichon | Training future language teachers to develop online tutors' competence through reflective analysis[END_REF] outlines these skills, describing socio-affective regulation as the ability to establish and maintain a relationship with learners. Pedagogical regulation requires expert knowledge of the target language, the ability to design learning scenarios adapted to online learning and propose "clear and concise instructions, providing positive and negative feedback and deploying an array of strategies to facilitate second-language learning" (p.169). Finally, semiotic and technological competencies relate to the online teacher adopting the different communication tools available in the technological environment that are appropriate to the learning scenario and his/her ability to manage the ensuing interactions using the adequate semiotic resources in order to optimize the learning potential and maintain learners' attention [START_REF] Ricci Bitti | Non-verbal communication and cultural differences: Issues for face-to-face communication over the Internet[END_REF]. This latter competency is crucial, as teaching via videoconferencing allows teachers to communicate through an array of modes, including spoken language, print, posture, gesture, head movement, gaze, and proxemics, and, thus, demands that teachers develop critical semiotic awareness [START_REF] Guichon | Une approche sémio-didactique de l'activité de l'enseignant de langue en ligne: réflexions méthodologiques[END_REF][START_REF] Kern | Language, literacy, and technology[END_REF] considered as "a high level of consciousness regarding all the information they are conveying when they interact with their learners" (Guichon & Wigham, 2016:67).

Online teaching and the use of print mode

One affordance of online platforms utilised for teaching synchronously is the availability of textchat. Textchat affords the potential to enhance teaching using the spoken mode with written language and visuals [START_REF] Meskill | Teaching language online[END_REF]. This potential enables the language teacher to capitalise on the multimodality of the teaching medium, for example by offering feedback without interrupting the learners, encouraging learners who are unwilling to participate orally to contribute in writing, checking and confirming vocabulary upon communication breakdown, and to compensate for the absence of a blackboard [START_REF] Hampel | New skills for new classrooms: Training tutors to teach languages online[END_REF], 2012;[START_REF] Wigham | Interactions between text chat and audio modalities for L2 communication and feedback in the synthetic world Second Life[END_REF].

Investigating synchronous language teachers' areas of attention on the screen in an audioconferencing platform using heat maps and gazeplots recorded in an eye-tracking study, Shi, Stickler, and Llyod (2017) The ability to employ the print mode is, thus, crucial for online teachers who should be "comfortable in using computer-mediated communication (CMC) technologies which include text, audio, and video conferencing" (Compton, 2009: 83). This brief overview suggesting online teachers should skillfully utilise the print mode, particularly textchat, in synchronous teaching attests to further need to explore modal configuration and use in interaction.

Delivering task instructions

The context for this study is task-based language teaching (TBLT) in multimodal synchronous online language teaching. TBLT encourages meaning-focused language use to achieve an outcome, and a task involves, first, some input for learners to process and use in their interactions, and second, instructions explaining the outcome to be achieved through interaction, as well as how to achieve it [START_REF] Ellis | Task-based research and language pedagogy[END_REF]. Drawing on [START_REF] Breen | Contemporary paradigms in syllabus design[END_REF], while teachers can plan task instructions as part of their designed task (instructions-as-workplan), the actual instructions they deliver in interaction with the learners might differ (instructionsas-process). Investigating this perspective in which teachers give instructions verbally during face-to-face lessons, [START_REF] Markee | Giving and following pedagogical instructions in task-based instruction: An ethnomethodological perspective[END_REF] identified six key instruction-giving fragments, including explanation of what resources learners will need during task accomplishment. In [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF], we analysed experienced language teachers' pedagogical instructions to build on [START_REF] Markee | Giving and following pedagogical instructions in task-based instruction: An ethnomethodological perspective[END_REF] fragments. However, given our analytical lens, multimodal (inter)action analysis [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF] which scrutinises mediated higher-and lower-level actions, in our work [START_REF] Markee | Giving and following pedagogical instructions in task-based instruction: An ethnomethodological perspective[END_REF] fragments constitute various higher-level actions the teachers engage in as part of their instruction-giving practices, while the modes they employ in doing so form the lower-level actions. [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF] described that explanation of resources can present challenges in the online teaching context due to lack of shared physical interactional space and artefacts (e.g. task handouts). Rather, teachers need to navigate, for example, sharing URL links to resource websites or shared online collaborative word processors via the text chat, and the distribution of text documents to learners via email or text chat. [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF] reported that the higher-level action labelled managing resources, took about a quarter of the instruction-giving sequence in two of the three teachers' lessons examined, and observed the following sub-categories: sending the resource, allocating the resource, receiving the resource, opening the resource, confirming access to the correct resource, describing the content of the resource, and reading the resource. This paper focuses on this higher-level action of managing resources.

Within the online language teaching literature, two studies to date have addressed instructiongiving practices, both focusing on trainee-teachers. Comparing written instructions in an asynchronous teaching platform with verbal instructions in multimodal synchronous teaching, [START_REF] Cappellini | Analyser des compétences techno-sémio-pédagogiques d'apprentis tuteurs dans différents environnements numériques: résultats d'une étude exploratoire[END_REF] reported that trainee-teachers experienced unexpected challenges concerning managing the digital task resources, such as having to instruct the learners on how to download a document, especially in the synchronous platform. [START_REF] Satar | Multimodal instruction-giving practices in webconferencing-supported language teaching[END_REF] addressed the multimodal resources trainee-teachers employed whilst delivering task instructions, and demonstrated the use of textchat in introducing key vocabulary items in both spoken and written language (dual modality).

Given this background in online language teaching, we now explain the main concepts from multimodal (inter)action analysis that underpin our study.

Multimodal (inter)action analysis

Multimodal (inter)action analysis [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF][START_REF] Norris | Systematically working with multimodal data: Research methods in multimodal discourse analysis[END_REF][START_REF] Norris | Multimodal Theory and Methodology[END_REF] is "a holistic analytical framework that understands the multiple modes in (inter)action as all together building one system of communication" (Norris & Pirini, 2016: 24). Within this framework, all actions are considered interactions between social actors and other social actors, objects, or the environment. It offers a broad socio-cultural perspective which is compatible with detailed micro analysis of interaction, allowing the researcher to address the macro, intermediate and micro analyses as required [START_REF] Norris | Communicating knowledge, getting attention, and negotiating disagreement via video conferencing technology: A multimodal analysis[END_REF]. We now explain multimodal (inter)action analysis' key analytical tools.

Mediated actions

In multimodal (inter)action analysis, the unit of analysis is the mediated action "defined as a social actor acting with/through mediational means" (Norris & Pirini, 2016: 24). Mediated actions are investigated as higher-level and lower-level actions: while lower-level actions are "the smallest interactional meaning unit" (Norris, 2004: 11), higher-level actions are "a chain of lower-level actions, with an opening and a closing" (Norris & Pirini, 2016: 25). For example, a conversation is a higher-level action which constitutes lower-level actions of, for instance, gaze shifts (gaze mode), or utterances (spoken language mode). Higher-level actions can also be embedded in various other levels of higher-actions: a conversation among friends can occur within the higher-level action of walking.

Frozen actions are the third type of actions. They are higher-level actions performed by social actors at an earlier time and that are now entailed in disembodied modes (e.g. printed material, layout of an environment) or material objects [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF]. For instance, [START_REF] Norris | Objects, Frozen Actions, and Identity: A Multimodal (Inter)action Analysis[END_REF] illustrate the higher-level action of raising children as embedded in a selfmade photo calendar present in a web-designer's office and telling of her identity of a working mother.

Site of engagement

A site of engagement is the "'real time window' opened through the intersection of social practices and mediational means that enables a mediated action to occur" (Norris & Jones, 2005: 139) wherein higher-level, lower-level and frozen actions happen. It comprises the social actors and the mediated actions in which the actors are engaged and the frozen actions entailed in material objects within the interactional setting. In our data, the observed frozen actions are entailed in electronic resources in the print mode. [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF] identifies nine communication modes: spoken language, proxemics, posture, gesture, head movement, gaze, layout, music, and print. While layout is a disembodied mode, music and print can be both embodied and disembodied. Norris suggests that print is a visual mode and "refers to written texts, including the language, the medium, the typography, and the content … [and] images in the printed media " (2004: 44). When people comment on the contents of printed media (such as magazines, shopping lists), print is a disembodied mode: the act of writing is frozen as a higher-level action. However, when the mode is employed to express thoughts/feelings (e.g. by writing or manipulating shopping lists or creating images), print becomes an embodied mode1 .

Communication modes and the print mode

Modal configuration, modal density, and attention/awareness continuum

Before presenting our analyses, notions of modal configuration and modal density require explanation. Modal configuration (hierarchical organisation of lower-level actions) allows the analysis of a higher-level action in terms of the (chains of) lower-level actions (e.g. gesture units, utterances, printed materials) that constitute it and their relationships [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF]. In this process "[t]he lower-level actions that are most important to the meaning produced are defined as most important to the construction of the higher-level action" (Norris & Pirini, 2016: 26).

Following the analysis of a higher-level action's modal configuration, its modal density can be mapped out. Modal density can be measured through intensity and complexity. When a mode is absolutely necessary for the completion of a higher-level action, it carries high modal intensity. When the mode is discontinued, if it changes the higher-level action only slightly, then it has medium modal intensity; and when it does not change the higher-level action, it carries low modal intensity [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF]. Communication modes take on particular intensity in specific interactions. For example, when speaking on the phone the spoken mode is strongest. Even though the speaker might gesture or doodle as s/he speaks the gesture and print modes carry less intensity and, if discontinued, do not change the higher-level action of partaking in a phone conversation. However, if another person enters the speaker's physical space and points at a clock and, in turn, the speaker ends the phone call, the gesture mode carries high intensity: when discontinued it leads to a change in higher-level action.

Modal complexity, diversely, "refers to the interplay of numerous communicative modes that make the construction of a higher-level action possible …[when the modes are] intricately intertwined" (Norris, 2004: 87). For example, for the higher-level action of building a piece of flat pack furniture, the print mode in the instruction booklet, the layout mode with regards the positioning of different components on the floor, and a person's posture towards certain components all enable the higher-level action.

Therefore, any given higher-level action can be modally dense either (a) when a mode plays a central role, or (b) when multiple modes are inextricably linked to produce the action.

Modal density is also a measure of social actors' phenomenological attention/awareness [START_REF] Norris | Communicating knowledge, getting attention, and negotiating disagreement via video conferencing technology: A multimodal analysis[END_REF]. Social actors can pay "various levels of attention to simultaneously performed higher-level mediated actions" (Norris, 2019: 247). The modal density of these actions determines their relative position in social actors' attention/awareness continuum: foreground, mid-ground and background. When the higher-level action has high modal intensity, the social actor is more focused upon that action [START_REF] Norris | Communicating knowledge, getting attention, and negotiating disagreement via video conferencing technology: A multimodal analysis[END_REF], which is foregrounded in his/her attention/awareness.

Methods

This paper stems from a larger study investigating experienced online language teachers' instruction-giving practices in English as a Foreign Language lessons via videoconferencing.

In [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF] we identified higher-level actions related to instruction-giving that were employed in the lessons drawing on grounded theory principles [START_REF] Strauss | Basics of qualitative research: techniques and procedures for developing grounded theory[END_REF] and demonstrated how instructions are achieved using multimodal (inter)action analysis [START_REF] Norris | Analyzing multimodal interaction: A methodological framework[END_REF]. Here, we propose a revelatory single-case study (Yin, 2018) of one teacher (Craig) who offered us multiple opportunities to observe and analyse the semio-pedagogical skills of an online language teacher while the print mode is used during an instruction-giving fragment: managing resources. The case study relies on the interaction data from one of the videoconferencing lessons. Although in our larger study we did collect interview data, we are unable to report on it here due to space restrictions.

Participants and Context

Craig had been teaching English via audio and videoconferencing since 2016. At the time of data collection (May 2018), he had completed 1454 lessons on one specific platform and had received excellent feedback (5 stars out of 5) from almost 200 students. The data for this paper comes from a 60-minute Skype lesson with two female Turkish learners (Eda and Didem) studying English for academic purposes at a foundation year of a Turkish university. All participants gave informed consent.

The lesson was the second in a series of three and was designed around a convergent task [START_REF] Wegerif | Children's Talk and the Development of Reasoning in the Classroom[END_REF]) requiring collaborative work. The task (Appendix 1) comprised two micro-tasks: (1) an information exchange activity in which the learners were given two different gift-packages and required to compare their information in order to make a decision about which to buy for a colleague's leaving present; and (2) a collaborative writing activity in which the learners jointly composed an email to their colleagues about their gift choice. The task was designed by the researchers and two resource sheets (Appendix 1) were provided to the teacher, yet he had flexibility in deciding how to use this task in the lesson and give instructions for it.

Operationalising multimodal (inter)action analysis for this study

The data set used comprises two 60-minute videos of the lesson. The first is a screen-capture recording taken by the teacher himself. The second is the screen-capture recording taken by one researcher who partook in the lesson as a non-participant observer. This gave access to one potential recipients' view of the lesson.

Initially, the verbatim data was transcribed using ELAN [START_REF] Sloetjes | Annotation by category -ELAN and ISO DCR[END_REF]) before using the software to take notes about concepts of interest that emerged over several viewings of the lesson. Following [START_REF] Norris | Systematically working with multimodal data: Research methods in multimodal discourse analysis[END_REF], this open coding allowed us to identify instructiongiving sequences for which we demarcated all sequences considered as higher-level actions (see [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF].

To address RQ1, concerning the site of engagement, a screenshot of the teacher's online environment was taken 29m38s into the interaction. This moment was chosen as the lesson was underway and any initial technical issues had been resolved. It formed part of the instruction-giving sequence for the information exchange activity but was representative of the overall data: all higher-level actions in this social practice are evident.

Regarding our second research question, we chose two data pieces related to the role of print for micro-analysis. Our site of engagement was thus narrowed to part of the instruction-giving sequence for the information exchange activity and an instruction sequence regarding the second micro-task. The teacher's and researcher's screen-recording videos were aligned imported side-by-side into the ELAN workspace. Both researchers watched this video data together in ELAN, discussing their observations and taking notes. Multimodal transcriptions of the micro actions that participants performed in the modes of gesture, proxemics, gaze, posture and head movement2 allowed us to analyse the (inter)actions in detail and embed aspects of analysis. The analytical tools and units of analysis used to conduct the micro analyses related to RQ2 are mediated actions: lower-, higher-, and frozen actions [START_REF] Norris | Systematically working with multimodal data: Research methods in multimodal discourse analysis[END_REF].

Multimodal transcription allowed us to analyse modal configuration and density (RQ3). In identifying the hierarchical ordering of lower-level actions, our guiding principle was to discern "what is absolutely necessary to perform this very action and what is not", as well as modal density to determine the place of the higher-level actions within the social actors' attention/awareness (Norris, 2019:246). The analytical tools of modal density, modal configurations and the modal density foreground-background continuum of attention/awareness [START_REF] Norris | Systematically working with multimodal data: Research methods in multimodal discourse analysis[END_REF] were employed.

Analysis 4.1 RQ1: How does the site of engagement demonstrate any intersection of different social practices?

A screenshot (Fig 1, Left) allows us to analyse the different social practices constructed through the higher-level actions at play within the site of engagement (see 2.4.2).

Figure 1. Left: site of engagement; Right: higher-level actions

The site of engagement involves five social actors. Three actors (a volunteer teacher, and two learners) responded to an advert to enlist participants for a research study (conducted by the other two actors: researchers) which comprises one large scale action: partaking in a research project. This is evident in the print mode by the Skype avatar of one of the two principal investigators in the research project [a] and by a software icon in the toolbar for a screenrecording programme to capture the interaction data [b]. Although other social practices regarding data analysis are not visible (e.g. watching the videos, transcribing the mediated actions, writing up findings, etc.), Figure 1, Left helps make sense of our part as researchers in relation to the data set as regards data collection.

The participants are engaged in a second large scale action comprising participating in online language lessons via videoconferencing. This social practice is shown in the sidebar: the videoconferencing call is named 'Online lessons with Craig' [c], and through the presence of the teacher and learners' webcam images [d].

The higher-level actions of completing language-learning tasks and also the higher-level actions of giving instructions for these tasks and of task accomplishment are evident in frozen actions entailed in the resources visible in the textchat window, i.e.in the disembodied print mode. They include task resource/instruction sheets [e] for both sub-tasks and lexical items offered by the teacher to learners as linguistic feedback during the accomplishment of the information exchange [f].

The site of engagement shows an intersection between the social practices of engaging in a research study and partaking in a teaching-learning activity constructed through the higherlevel actions of participating in the second lesson, and particularly completing a convergent task (Fig 1, Right).

RQ2: What is the role of the print mode in achieving the higher-level action of instruction-giving?

We now examine the role of the print mode (textchat) in achieving the higher-level action of instruction-giving, and specifically managing resources, by examining Extract 1 produced during the information-exchange activity (see 3.1). In line 1, Craig begins announcing the next task stage with a gaze shift downwards (#13 ). This is followed by Craig declaring what he will do next in the spoken language mode with emphasis on the word send (#2), with his gaze directed towards the learners, displaying an iconic gesture, and raised eyebrows acting as a beat gesture (for gesture types see [START_REF] Mcneill | Hand and mind: What gestures reveal about thought[END_REF]. As Craig tells the learners that he will send them some information, his gaze shifts towards the web browser, which displays an online newspaper in the current tab (#3).

In line 2, Craig begins to engage with two higher-level actions: sending the resource and allocating the resource to a specific learner. To allocate the resource, he first uses the learners' name, a vocative in the spoken language mode. Yet, Craig's screen no longer portrays the webcam images of both learners. Rather his focal point of attention, illustrated by his downward gaze (#4), is turned to a disembodied electronic resource in the print mode (an online document now displayed on the web browser which includes the task information for student A, Eda).

In line 3, Craig highlights a URL in the resource sheet (#5), which he had generated and pasted into the document in preparation for the lesson. This document entails two frozen actions that are salient in this context, and which are the closest in time, place, and relevance to the current (inter)action: the researchers creating the resource sheet, and the teacher adding a URL to appropriate it for his own teaching practices. These frozen actions reinforce the site of engagement we described in 4.1.

In line 4, Craig uses hesitation markers okay u::hm, and downwards gaze (#7) to signal an upcoming shift to the next instruction-giving fragment, confirming access to the correct resource while still sending the resource, as Craig places his mouse cursor on Didem's webcam image (#6) to activate Skype and access textchat (#7). In line 5, the print mode continues to be embodied while Craig pastes the URL previously copied (line 3) from the resource sheet into the textchat (#8). In lines 5-6, Craig reinforces allocation of the resource to one learner, Eda, by stating that the other learner, Didem, should not look at the URL he has sent. In doing so, his attention/awareness is on the Skype window, his gaze shifts upwards to focus on Didem's webcam image, his gestures become visible in his webcam frame and he raises his eyebrows (#9). This information is repeated (line 6) and Craig's gaze moves to focus on his webcam as he uses the pronoun 'you' to address Didem (#10) before the URL is sent on textchat (#11). In Line 7, we see Didem's reaction: she covers her face with her hand and turns away from her screen (#12), demonstrating the success of this instruction-giving fragment. In lines 8-12, Craig begins the higher-level action of sending the resource for the second learner, Didem. This requires a similar set of lower-level actions by embodying and disembodying the print mode (#13, #14, #16, and #17). Consequently, the simultaneous, multiple higher-level actions become frozen and available throughout the lesson.

An interesting point to note in lines 3-9 is Craig's use of the demonstrative adjectives to refer to the URLs. In lines 3, 5 and 6 (#5, 6, 7, 8, 11), while selecting, copying, and pasting the first URL (embodied print mode), Craig refers to the link with the singular demonstrative adjective this. While embodying the print mode for the second URL, he again uses this (line 8) and adverb here (line 9); both signify closeness to the speaker in time and space. However, once the URL sent, and thus disembodied (line 7, #12), Craig refers to it using the singular demonstrative adjective that indicating distance from Craig in time and space.

Lines 13-15 demonstrate Craig's critical semiotic awareness as he engages with the higherlevel action of confirming access to the resource in the spoken language mode by checking whether learners can see the resources, and announcing his awareness of a potential semiotic lag (line 15). Semiotic lag concerns a time delay or lag between the multimodal communication of one social actor (e.g. a gesture unit, a gaze shift, and electronic document) and its reception by another whereby it no longer forms an aggregate due to delays in online transmission or technical issues (e.g. microphone not working). For instance, one actor may send a textchat message in the print mode whilst simultaneously referring to it in the spoken language mode. However, due to semiotic lag, the receiving actor may receive the written message at a different moment in interaction than its temporal position in the sending actor's interactional space.

In line 14, Craig's confirmation check receives an affirmative response from one learner, before Craig announces verbally a shift into the next higher-level action (here we go then), which concludes the higher-level action of sending the resource.

In Extract 1, Craig achieves the higher-level actions of sending and allocating an electronic resource, and confirming access to and describing the contents of it by actively employing the print mode (textchat) alongside other available modes: gaze, gestures, facial expressions, and spoken language. Gaze shifts appear to be the most salient modal change signalling to learners when Craig is engaged with the technical aspects of sending the resource by embodying the print mode (downward gaze direction in #1-5, 7, 8, 15, 16, 18), and when he is not while directly addressing the learners (upwards gaze direction in #9, 10,17,19,20).

We now examine use of another communication technology (online document / print mode) to create content during instructions for the second micro-task (Appendix 1), illustrating how the higher-level actions are created and become frozen within the document.

Extract 2 begins with Craig summarising the decision made by the learners to choose the cheaper package in the first micro-task. Craig types the price of this package in textchat, and similar to Extract 1, his embodiment of the print mode is signalled to the learners via downward gaze shifts (#1 and #2). Summarising previous task stage becomes a frozen action in the textchat as key information for the next stage. Craig then proceeds to verbally communicate the instructions (line 2), contextualising the task for the learners, stating the task outcome (an email), giving key task information and informing them how they will be working (together), before initiating the higher-level action of sending the resource fragment (line 3). In line 3, Craig's gaze moves towards the web browser icon in the task bar at the bottom of his screen (#3), and once the pre-prepared online document is visible (#4), he proceeds to embody the resource in the print mode. In line 4, Craig opens the menu in the resource to share the online document (#5), selects and copies the URL (#6), pastes it in textchat (#7), sends the URL (#8), and as it becomes visible to the learners (#9), the URL and the online document becomes disembodied again. During this time, his utterances show his critical semiotic awareness regarding semiotic misalignment. We define semiotic misalignment as a difference in the semiotic meaningmaking resources available to the social actors involved in the interaction that distorts the shared interactional space. It can be due to two factors. Firstly, a difference in how each social actor views the interactional space where both/all actors are present and, potentially, differences in the semiotic resources available to them, due to variations in hardware and software specifications and screen layout (e.g. the appearance and affordances of Skype on an Android phone as opposed to a Mac laptop or when Skype is open full screen as opposed to a minimised window). Secondly, semiotic misalignment can occur when a social actor uses or has access to a semiotic resource in his online or physical personal interaction space that cannot be seen by the other participant(s). For example, a participant may use or have access to a dictionary app/website on his/her screen or to paper notes that are not available to other participants. To bring these resources into the interaction the social actor can verbalise/describe the resource or share it visually (e.g. by screensharing or bringing the resource within the webcam frame).

In line 4, Craig announces here we go but shows there is some semiotic misalignment between the semiotic resources to which the teacher and learners have access for the task. Indeed, he states I've got the e::r thing here already to go, demonstrating he is accessing a previously prepared disembodied resource to which learners do not have access in their interactional spaces. Similarly, in line 5, his choice of the future tense (all you've gotta do is click on it and you'll see the page) shows his awareness of the fact that due to semiotic lag (see supra), the learners do not yet have access to the URL. In line 6, as the URL becomes visible in the shared textchat space, Craig's gaze moves from the textchat towards the learners' webcam images. This gaze shift allows him to check that the link has appeared in the textchat: the learners now have the possibility to embody the link and access the online collaborative writing space. The resource in the print mode, thus, becomes an integral part of the pedagogical interaction, as it is embodied and disembodied for the different participants. The next higher-level action of describing the content of the resource (line 6) allows the learners to check that, by clicking on the URL thus embodying it, they have accessed the correct resource and ensures coordinated action. summarise the previous task stage before stating the task outcome (write an email) and giving key task information. Throughout his utterance, he types these instructions into the online document. In doing so, he creates a record of the instructions to which learners can refer during the task, thereby creating frozen actions in which his instruction-giving sequence is entailed. As Craig completes this action (#15), there is joint attention on the written instructions by the learner, Didem, and Craig: the learner's cursor is now placed at the beginning of the text Craig just wrote.

Having presented a turn-by-turn micro-analysis of Extracts 1 and 2, we now analyse Craig's modal configuration and density in selected representative lines from these extracts to illustrate simultaneous management of multiple higher-level actions with reference to the print mode.

RQ3: How does the teacher's modal configuration and density vary when the print mode is utilised?

Variation in Craig's modal configurations and density of his interactional space indicates his level of attention/awareness for various higher-level actions as he utilises the print mode. In this section, we examine how Craig simultaneously engages in multiple higher-level actions related to instruction-giving and evidenced in the actions performed in Extract 1, line 1; Extract 1, lines 3-5; and Extract 2, line 10. Firstly, in Extract 1, line 1, the higher-level action of announcing next task stage is foregrounded in Craig's attention/awareness. This is mainly achieved through the spoken language mode, which is absolutely necessary to perform this action and, thus, has high modal intensity. Therefore, spoken language appears to have the highest hierarchical prominence to perform this instruction-giving fragment. Secondly, Craig's modal configuration varies throughout this spoken utterance. We observe highest modal density, achieved through modal complexity, in #2 as Craig produces the key word send for this instruction-giving fragment, accompanied by the modal aggregate which comprises word stress in spoken language, iconic gesture, upwards gaze shift towards the screen (learners), posture shift towards the screen, and raised eyebrows; all of which carry medium modal intensity as they would impact the higher-level action were they discontinued. Finally, Craig's other lower-level actions, object handling (moving the cursor over the browser icon) and attempt to access the print mode (the electronic resource) carry low modal intensity for the higher-level action of announcing next task stage: they are not visible to learners via the webcam (due to semiotic misalignment) and would not change the higher-level action if discontinued.

However, Craig uses three lower-level actions (gaze, object handling, print) in line 1 to perform another simultaneous higher-level action in the background of his attention/awareness: preparing for the next instruction-giving fragment, i.e. sending the resource. This is achieved using different modal aggregates throughout #1-3. While #1 shows Craig's gaze and object handling, #2 involves object handling and print mode. #3, however, demonstrates the highest modal complexity for this higher-level action achieved through the modal aggregate gaze (towards the browser), object handling (cursor over the browser), print (webpage), and spoken language (information) as the higher-level action sending the resource moves to the foreground of his attention/awareness.

During Extract 1, lines 3-5, Craig embodies the print mode as he selects, copies and pastes a URL for the learners to access the resource, thus performing the higher-level action of sending the resource (see 4.2). For this action, although only signalled to the learners through gaze shifts, object handling and the print mode gain high modal density because the action cannot be achieved without these modes. On the other hand, spoken language (line 4) has low modal intensity as it functions as a filler, and would not change the action of sending the resource. In lines 3 and 4, the higher-level action sending the resource is thus foregrounded in Craig's attention/awareness.

Spoken language in lines 3 and 5, however, carries high modal intensity for two other higherlevel actions. Whilst Craig sends the resource, he performs the actions of allocating the resource and confirming access to the correct resource; both which cannot be accomplished without spoken language. In line 3, his modal configuration involves object handling (moving the mouse / using the keyboard to select and copy the URL), embodied print mode (the electronic resource), and downward gaze. This modal aggregate, produced alongside spoken language, has low modal density to achieve the action of allocating the resource. In line 5, however, the modal aggregate that accompanies the spoken language has medium modal density: its removal might impact the higher-level action of confirming access to the correct resource. #8 shows Craig's downward gaze and embodied print mode as he pastes the URL into textchat; the referent of the word this in the spoken language mode. Likewise, Craig's upward gaze direction towards the learner, Didem, his gesture, and his raised eyebrows (facial expression, #9) reinforce the negative imperative in the spoken language (don't look).

Finally, we examine Craig's modal configuration in Extract 2, line 10, as he embodies the print mode by typing his instructions on the shared online document while simultaneously verbalising them. During this sequence, Craig performs three higher-level actions: summarising previous task stage, stating task outcome, and communicating key task information. Two modes carry high modal intensity here: print and spoken language. Once Craig types the instructions, the print mode becomes disembodied and continues to entail these three higher-level actions during task completion as frozen actions. Thus, by its temporal virtue of being available for a sustained period, the print mode carries high modal intensity in performing the higher-level actions in line 10. Spoken language also has high modal intensity because although it is a think-aloud sequence that ensures bimodal production of the typed instructions (indicated by Craig's verbalisation of his spelling mistakes: for Anne e::r that wasn't Anne fo:r Anne); it involves repetitions, and vocabulary explanations (i.e. contribute), discontinuation of which would significantly change the action. Consequently, modal density achieved through high modal intensity of both the print mode and spoken language foregrounds these higher level-actions in all participants' attention/awareness and becomes a joint focal point of attention.

Findings and discussion

To investigate an experienced online teacher's instruction-giving practices, multimodal (inter)action analysis was employed to firstly examine the site of engagement (RQ1). Our analysis demonstrated the intersection of two large-scale social practices constructed through the mediated actions within the data set: partaking in a learning-teaching activity and engaging in a research study, i.e. how the data set acted as the mediational means and cultural tool within the social practice of conducting the research study. From an epistemological viewpoint, the notion of site of engagement appears to be a useful construct that could help the sociocultural researcher identify, acknowledge, reflect upon and render explicit the theoretical lens s/he applies to the study and may contribute to documenting how research practices into online and face-to-face classrooms are fundamentally different forms of knowledge generation (cf. [START_REF] Stickler | Qualitative Research In Online Language Learning -What Can It Do[END_REF].

Concerning the role of the print mode in achieving the higher-level action of instructiongiving (RQ2), within Extract 1, the print mode was employed in the higher-level actions of sending the resource, allocating the resource, describing the content of the resource, and confirming access to the resource. First, the most salient frozen actions in the print mode (i.e. preparation of the resource sheets by the researchers, and appropriation of the documents by the teacher) reinforced the site of engagement. Second, the disembodied resource sheets created at a previous time by the researchers were embodied by the teacher during the lesson to share the electronic resources with learners. Third, demonstrative adjectives in the spoken language mode conveyed perception in time and space of the URLs as they are embodied and disembodied. Fourth, in the textchat screen, the URLs were represented with preview images of the documents, in which the teachers' higher-level actions in this sequence became frozen and accessible to the participants for task accomplishment. Fifth, the disembodied resources that were made available in textchat also became materials waiting to become embodied again when learners read them.

Further roles were identified within Extract 2. Firstly, the creation of frozen actions related to key task information to which learners could refer to during the activity. These frozen actions were created within the textchat (summarising the decision made during previous activity) and in the online document (giving instructions for this activity) and were available for a sustained period to facilitate task accomplishment. Secondly, the teacher moved back and forth between different resources in the print mode: the online document and the textchat. He embodied the URL in the previously created online document by copying it before sending it to the learners via textchat. Once sent, the link became disembodied for learners to embody it as they opened the resource. As such, in the print mode there was "constant shifting back and forth between embodied and disembodied [actions]" (Norris, 2004: 46). Third, gaze was the most salient signal for learners during the lesson for the teacher's employment of the print mode, to which they do not have access. Finally, Extract 2 illustrated that the participants interact both visually and verbally "while employing, or by employing, the mode of print" and as such "the mode of print [became] an integral part of their interaction" (Norris, 2004: 46). The latter was also elaborated upon in RQ3 (Extract 2, line 10), where we analysed the teacher's modal configuration and density during his bimodal presentation of the instructions which ensured joint attention (cf. Ricci Bitti & Garotti, 2011).

Multimodal (inter)action analysis allowed us to disassemble the modes employed in interaction in Extracts 1 and 2 through exploration of modal configuration and modal density (RQ3), which varied and indicated the relevant position of the higher-level actions within the teacher's attention/awareness as he simultaneously focused on multiple higher-level actions; sending the resource while allocating the resource, and confirming access to the correct resource. The modes or modal aggregates that had high modal density indicated the higherlevel action upon which the teacher focused (i.e. the foregrounded action) at any given moment. Gaze direction and shifts were salient lower-level actions for signalling engagement with the print mode whereas, for the fragment sending the resource, object handling combined with the print mode assumed high prominence. Although emerging CALL research is beginning to utilise multimodal (inter)action analysis as a new method [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF][START_REF] Knight | Multimodal meaning making: Navigational acts in online speaking tasks[END_REF], modal composition of teachers' actions have yet to be revealed in such detail to inform our understanding of online language teachers' multiple foci of attention.

While [START_REF] Cappellini | Analyser des compétences techno-sémio-pédagogiques d'apprentis tuteurs dans différents environnements numériques: résultats d'une étude exploratoire[END_REF] briefly describe trainee-teachers' unexpected challenges in instructing learners to download a document, our turn-by-turn analysis of an experienced online teacher reveals the complexity of using electronic resources in synchronous online language teaching. Teachers need to manage such complexity to organise the semiopedagogical activity [START_REF] Guichon | Training future language teachers to develop online tutors' competence through reflective analysis[END_REF], and plan ahead for the higher-level actions related to instruction-giving to ensure smooth embodiment of the print mode. Teachers also need to develop necessary technological competencies to harness available semiotic resources [START_REF] Hampel | New skills for new classrooms: Training tutors to teach languages online[END_REF]) (e.g. collaborative online documents and textchat), which can be used to deliver instructions bimodally to optimise learning [START_REF] Kozar | Text chat during video/audio conferencing lessons: Scaffolding or getting in the way?[END_REF][START_REF] Ricci Bitti | Non-verbal communication and cultural differences: Issues for face-to-face communication over the Internet[END_REF]. Successful resource management could assist teachers in creating frozen actions which can be referred to during task accomplishment.

Given this perspective, it would be advisable for teachers to:  set up ways of how electronic resources in the print mode (resource sheets, textchat, URLs, online collaborative writing spaces) will be used at the onset of their lessons;  create online versions of the materials prior to the lesson;  use clear and simple file names for the electronic documents;

 compile the materials in a single online folder or repository;  share information around how different materials will be delivered and where they can be found;  check learners' access to the materials before giving the instructions;  guide the learners in the use of the electronic resources and ask them to share their screens where relevant (e.g. in small group of 1-1 sessions);  prepare a list of the URLs of the materials ready to be shared with the learners;  send the resources ahead of time for the learners to study (which is a practice employed by another teacher in our corpus, see [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF]. Having said this, it is important to caution against overly simplistic advice for best practices or pedagogical suggestions given lack of research on the relationship between different instruction-giving practices and outcomes. In such research, the benchmark for success also requires a clear definition, whether this is related to cognitive, social, affective, or task-based outcomes. We elaborate on this further elsewhere [START_REF] Satar | Delivering task instructions in multimodal synchronous online language teaching[END_REF]. Some of these strategies and competences are demonstrated by the case described in this paper in relation to the ways in which the teacher, Craig, uses the task resources, textchat, URLs, and a shared online document. Thus, the case we present could inform training for online teachers to illustrate these semiotic and interactional competencies, but also to raise critical semiotic awareness [START_REF] Guichon | Une approche sémio-didactique de l'activité de l'enseignant de langue en ligne: réflexions méthodologiques[END_REF] pertaining to semiotic misalignment and semiotic lag (as defined in section 4.2) among the lesson participants, which can distort the shared interactional space.

Conclusion

Although synchronous online lessons have become increasingly popular, emerging research with regards language teaching via videoconferencing appears to mainly investigate traineeteachers' practices. Due to the flexibility it offers, teaching via videoconferencing allows for increased access to language learning which could have a socio-economic impact on society. Therefore, it is important to better understand the practices and skills of online language teachers. This study bridged this gap by investigating an experienced online language teacher's use of the print mode when giving task instructions in a videoconferencing environment. The study is novel in that it adopts Norris' multimodal (inter)action analysis (2004,2019): a methodological framework seldom applied within CALL. By exploring how higher-level actions are constructed through lower-level actions, we were able to (1) analyse both macro and micro levels of mediated interaction situating the use of modes within social practices, and (2) reveal semiotic misalignment caused by computer-mediation that precludes the establishment of a completely shared interactional space. The approach required us to extend Norris' (2004) definition of frozen actions being entailed in material objects in the interactional setting to include electronic objects, and her definition of the print mode to encompass electronic print. Therefore, by employing this framework, and appropriating it to our specific context, we tried to respond to the need for "researching online language learning ... from new and innovative approaches, … [which] requires a conscious effort and redirection of research energies to deal with the material differ ences that make online language learning unique" (Stickler & Hampel, 2019: 24).

Our findings are limited to a single-case study with data pieces selected from a semicontrolled corpus. Other case studies from a larger ecological corpus could further knowledge of the challenges of synchronous online environments inherent to instruction-giving, and illustrate teachers' different approaches to overcome these. It would also be useful to track learners' attention/awareness through their screen-recordings while the teacher employs the print mode. This would aid understanding of the interactive, collaborative nature of instructions within a recipient design. Additional data collection methods, such as eyetracking supported by stimulated recall interviews (e.g. [START_REF] Shi | The interplay between attention, experience and skills in online language teaching[END_REF] would also help better understand participants' attention and awareness. Concerning participant numbers, we incorporated two learners to allow for comparisons with previous research [START_REF] Satar | Multimodal instruction-giving practices in webconferencing-supported language teaching[END_REF]), yet individual classes are perhaps more common in online teaching. To overcome this potential limitation, we have collected further data where the same task is conducted with one learner to explore whether the use of the print mode would differ in this context. Yin, R. Y. (2018)

Figure 2 .

 2 Figure 2. Left: Extract 1. lines 1-3; Right: Extract 1. lines 4-7

Figure 3 :

 3 Figure 3: Left: Extract 1. lines 8-12; Right: Extract 1. lines 13-15

Figure 4 .

 4 Figure 4. Left: Extract 2. lines 1-3; Right: Extract 2. lines 4-6

Figure 5 .

 5 Figure 5. Extract 2. Lines 7-10

Figure 6 .

 6 Figure 6. Extract 1. Line 1. Modal configurations.

Figure 7 .

 7 Figure 7. Left: Extract 1. Lines 3-5. Modal configurations; Right: Extract 2. Line 10. Modal configurations.

  . Case study research and applications: Design and methods. 6th ed. Los Angeles: SAGE About the authors Dr Ciara R. Wigham is a lecturer in applied linguistics and TESOL at Université Clermont Auvergne. Her research in the field of Computer-Assisted Language Learning examines the contribution of multimodality to pedagogical interactions, specifically within the context of virtual exchange, Content and Language Integrated Learning, and online teacher training.Dr Müge Satar is a lecturer in applied linguistics and TESOL at Newcastle University, UK. She is interested in technology-enhanced foreign language learning and teacher education, particularly in the concepts of social presence, meaning-making, and translanguaging in multimodal online communication, including online language teaching, virtual exchange, and blended learning.Author #1 ORCiD. Ciara Wigham, http://orcid.org/0000-0001-9704-1906 Author #2 ORCiD. Müge Satar, https://orcid.org/0000-0002-2382-6740

For a discussion about the boundaries between embodied and disembodied print mode, seeNorris (2004: 45- 47).

See Satar & Wigham (2017) for an explanation of our multimodal transcription methods.

#n refers to the image number within the extract transcript being discussed.

Acknowledgements

We are grateful to Newcastle University (Faculty of Humanities and Social Sciences Research Fund, 2018 Spring call) and Université Clermont Auvergne (Foreign researchers -short research visit, 2018 call) for funding towards the project titled 'An examination of experienced online language teachers' multimodal instruction-giving practices', as well as to the teacher and learner participants.

Author contributions

Both authors contributed equally to the manuscript.

Ethical statement

Ethical approval was gained from the ethics committee at Newcastle University. All participants gave informed consent prior to their participation in the study. The research project covered the teachers' normal hourly rate for each lesson completed and a £20 ecommerce voucher compensated them for the time spent completing the post-sequence interview. Learners participated on a voluntary basis.

Pseudonyms are used. Images were edited to remove personal identifiers according to participant preferences. An earlier draft of this manuscript was sent to the participating teacher for feedback on our analyses.


Aboutaoufik Anas
email: a.aboutaoufik@gmail.com

Big data in Morocco's transport and logistics sector

Keywords: Big Data, Logistics, Transport, Morocco

Big data is revolutionizing many fields of business, and logistics analytics is one of them, In this article, we aim to establish the level of use of big data in the transport and logistics sector in Morocco, we will define in a first place the concept of big data and its emergence, then we will try to illustrate the positioning of Morocco in this area, we will return after the results of a study conducted among logistics and transport operators in Morocco about the adoption of big data.

I. INTRODUCTION

The world we live in is constantly changing, and one of the fundamental drivers of this change is information. Today, information and communication technology offers us several opportunities and alternatives that shape the way we see and do things. These technologies are made up of all the devices put in place to collect, transmit, exchange, store and process information. They allow faster processing in very short intervals of time, to travel through time and space by transmitting messages almost instantaneously between distant interlocutors (servers), and to memorize a virtually unlimited accumulation of data.

Big Data basically refers to the fact that we can now collect and analyze data in ways that was simply impossible even a few years ago. There are two things that are fueling this Big Data movement: the fact we have more data on anything and our improved ability to store and analyze any data.

Everything we do in our increasingly digitized world leaves a data trail. This means the amount of data available is literally exploding.

Big Data creates a new type of digital divide. Having access and knowledge of Big Data technologies gives companies and people a competitive edge in today's data driven world.

Big data is revolutionizing many fields of business, and logistics analytics is one of them. The complex and dynamic nature of logistics, along with the reliance on many moving parts that can create bottlenecks at any point in the supply chain, make logistics a perfect use case for big data. For example, big data logistics can be used to optimize routing, to streamline factory functions, and to give transparency to the entire supply chain, for the benefit of both logistics and shipping companies alike.

In this article, we aim to establish the level of use of big data in the transport and logistics sector in Morocco, we will define in a first place the concept of big data and its emergence, then we will try to illustrate the positioning of Morocco in this area, we will return after the results of a study conducted among logistics and transport operators in Morocco about the adoption of big data.

The rest of the paper is organized as follows. We will locate and define the emergence of big data, we will detect the main attributes of big data, and then we will elucidate its main challenges, and its use in the transport and logistics industry. We will then reproduce and analyze the results of a study of 116 companies operating in the logistics and transport sector in Morocco in order to define their level of use.

II. THE EMERGENCE OF BIG DATA

A. Definition and birth of Big Data:

The definition of big data is data that contains greater variety, arriving in increasing volumes and with more velocity. This is also known as the three Vs.

Put simply, big data is larger, more complex data sets, especially from new data sources. These data sets are so voluminous that traditional data processing software just can't manage them. But these massive volumes of data can be used to address business problems you wouldn't have been able to tackle before. [START_REF]Oracle : Qu'est-ce que le big data[END_REF] As inconceivable as it may seem today, the Apollo Guidance Computer guided the first spacecraft to the Moon with less than 80 kilobytes of memory. Technology has since developed at a breakneck pace, as has data generation. Global data storage capacity has doubled every three years since the 1980s. When Apollo 11 took off just over 50 years ago, the amount of digital data generated worldwide could have been stored on a standard laptop. Today, International Data Corporation estimates that this figure amounts to 44 zettabytes (44 trillion gigabytes) and will reach 163 zettabytes by 2025. [START_REF] Mark Van Rijmenam | A Short History Of Big Data[END_REF] In fact, the earliest records of using data to track and control businesses date back from 7.000 years ago when accounting was introduced in Mesopotamia in order to record the growth of crops and herds. In 2005 Roger Mougalas from O'Reilly Media coined the term Big Data for the first time, only a year after they created the term Web 2.0. It refers to a large set of data that is almost impossible to manage and process using traditional business intelligence tools. [START_REF] Dumbill | Velocity, Variety: What You Need to Know About Big Data[END_REF]

B. The tree Vs of Big Data: :

Volume:

The volume presents the most immediate challenge to conventional IT structures. It calls for scalable storage, and a distributed approach to querying. Many companies already have large amounts of archived data, perhaps in the form of logs, but not the capacity to process it.

Assuming that the volumes of data are larger than those conventional relational database infrastructures can cope with, processing options break down broadly into a choice between massively parallel processing architecturesdata warehouses or databases. [START_REF] Perry | What is big data? More than volume, velocity and variety[END_REF] People are more connected than ever before, and this interconnection leads to more and more data sources, resulting in an amount of data that is larger than ever before (and constantly growing). The increased volume of data requires ever increasing computing power in order to derive value (meaning) from the data. Traditional computing methods simply don't work on the volume of data accumulating today.

Velocity:

The speed and directions from which data come into the enterprise is increasing due to interconnection and advances in network technology, so it is coming in faster than we can make sense out of it . And the faster the data 1 Oracle : Qu'est-ce que le big data ? : https://www.oracle.com/fr/big-data/definition-big-data.html 2 SAP : Qu'est-ce que le Big Data ?: https://www.sap.com/france/insights/what-is-big-data.html [START_REF] Dumbill | Velocity, Variety: What You Need to Know About Big Data[END_REF] Dr Mark van Rijmenam , A Short History Of Big Data : https://datafloq.com/read/big-data-history/239 come in and more varied the sources, the harder it is to derive value (meaning) from the data. Traditional computing methods don't work on data coming in at today's speeds. [START_REF]Perspectives on Big Data and Big Data Analytics page 5[END_REF] Variety:

Datasets containing only structured data do not necessarily fall under Big Data, regardless of their size. Big Data typically includes structured, unstructured and semi-structured data combinations. Traditional databases and data management solutions lack the flexibility and scope to manage the complex and disparate datasets that compose Big Data. 6 C. Big Data Challenges: [START_REF] Samsung | Le Transport routier dans l'ère du Big Data[END_REF] The understanding of Big Data is very important. In order to determine the best strategy for a company it is essential that the data that you are counting on must be properly analyzed. Also the time span of this analysis is important because some of them need to be performed very frequent in order to determine fast any change in the business environment.

Another aspect is represented by the new technologies that are developed every day. Considering the fact that Big Data is new to the organizations nowadays, it is necessary for these organizations to learn how to use the new developed technologies as soon as they are on the market. This is an important aspect that is going to bring competitive advantage to a business.

The need for IT specialists it is also a challenge for Big Data. According to McKinsey's study on Big Data called Big Data: The next frontier for innovation, there is a need for up to 190,000 more workers with analytical expertise and 1.5 million more data literate managers only in the United States. This statistics are a proof that in order for a company to take the Big Data initiative has to either hire experts or train existing employees on the new field.

Privacy and Security are also important challenges for Big Data. Because Big Data consists in a large amount of complex data, it is very difficult for a company to sort this data on privacy levels and apply the according security. In addition many of the companies nowadays are doing business cross countries and continents and the differences in privacy laws are considerable and have to be taken into consideration when starting the Big Data initiative. In our opinion for an organization to get competitive advantage from the manipulation of Big Data it has to take very good care of all factors when implementing it. One option of developing a Big Data strategy is presented below. In addition, in order to bring full capabilities to Big Data each company has to take into consideration its own typical business characteristics.

II. THE USE OF BIG DATA IN TRANSPORT AND LOGISTICS:

A. Big Data in transport:

Between cost pressure and customer orientation, transportation companies cannot afford to lose sight of customer needs and must continue to provide them with high-quality services. The digital transformation and the utilization of big data technologies provides transportation companies the opportunity to cut costs while strengthening their customer bases by analyzing historic data.

According to Lufthansa industry solutions, Big Data could help transportation companies Optimizing operating procedures and cutting costs, in the way Big data analytics help the transportation sector to predict volumes as precisely as possible. It can also help this companies.

The introduction of big data and smart technologies has resulted in many positive changes for the transportation sector. Operational efficiency and flexibility have increased, fuel consumption has been reduced, and customer experiences have drastically improved. Big data also helps with improving safety in transportation.

Data sensors in fleet vehicles provide real-time information about their performance. They provide accurate data of vehicles' travel speeds, the time spent in transit and how long they are idle for. Sensors also monitor the health of the equipment and the entire engine. This allows for prediction of errors and timely preparations for maintenance.

Providing real-time information such as traffic jams, as well as weather and road conditions, big data helps in maintaining high safety levels. When you add the information about delivery addresses and the locations of fueling stations, you get a system that dramatically increases efficiency.

There are numerous benefits to properly using big data. Forecasting in terms of delivery time, weather and driver characteristics is a huge benefit in itself. The ability to efficiently manage inventory is another time saver and cost saver. Being able to predict capacity availability, in real-time, brings a lot of opportunities for transportation companies.

Optimal routing and information on weather and traffic congestion makes transportation management a lot easier. Reduction in driver turnover, driver assignment, and using sentiment data analysis simplifies human resources management. The ability to predict future events helps to avoid any unpleasant surprises. [START_REF] Dhl | [END_REF] According to Samsung, tomorrow, the trucks will be full of sensors to bring up vast amounts of information at the company's headquarters. Equipped with steering assistance tools, vehicles will be able to adapt their speed and engine speed to optimize their movements at a lower cost. Drivers will be equipped with communicative watches to monitor their movements and fitness. Self-diagnosis tools will help locate the wear and tear of the truck's organs and schedule technical visits at the right time. This logic will be pushed far beyond the cabin. Beyond the carriers, logistics players will also have to get up to speed by integrating the multiplicity of available modes of transport to optimize their costs. To do this, they will need tools capable of defining, at an M moment, the best "transportation mix" -road, rail, air, sea -for a given commodity. The data is available, remains to organize their sharing and a common exchange format. Companies are already preparing the ground for this major transition. [START_REF] Aujourd | ma : Big Data : Le Maroc dans la course mondiale[END_REF]

B. Big Data in logistics:

Companies are learning to turn large-scale quantities of data into competitive advantage. Their precise forecasting of market demand, radical customization of services, and entirely new business models demonstrate exploitation of their previously untapped data.

As today's best practices touch many vertical markets, it is reasonable to predict that Big Data will also become a disruptive trend in the logistics industry. However, the application of Big Data analytics is not immediately obvious in this sector. The particularities of the logistics business must be thoroughly examined first in order to discover valuable use cases.

A kick-start for discussion of how to apply Big Data is to look at creating and consuming information. In the logistics industry, Big Data analytics can provide competitive advantage because of five distinct properties. These five properties highlight where Big Data can be most effectively applied in the logistics industry:10 Optimization to the core: Optimization of service properties like delivery time, resource utilization, and geographical coverage is an inherent challenge of logistics, large-scale logistics operations require data to run efficiently. The earlier this information is available and the more precise the information is, the better the optimization results will become , advanced predictive techniques and real-time processing promise to provide a new quality in capacity forecast and resource control.

Tangible goods, tangible customers : The delivery of tangible goods requires a direct customer interaction at pickup and delivery , on a global scale, millions of customer touch points a day create an opportunity for market intelligence, product feedback or even demographics, big Data concepts provide versatile analytic means in order to generate valuable insight on consumer sentiment and product quality.

In sync with customer business : Modern logistics solutions seamlessly integrate into production and distribution processes in various industries, the tight level of integration with customer operations let logistics providers feel the heartbeat of individual businesses, vertical markets, or regions, the application of analytic methodology to this comprehensive knowledge reveals supply chain risks and provides resilience against disruptions.

A network of information: The transport and delivery network is a high-resolution data source, apart from using data for optimizing the network itself, network data may provide valuable insight on the global flow of goods, the power and diversity of Big Data analytics moves the level of observation to a microeconomic viewpoint.

Global coverage, local presence :

A fleet of vehicles moving across the country to automatically collect local information along the transport routes, processing this huge stream of data originating from a large delivery fleet creates a valuable zoom display for demographic, environmental, and traffic statistics.

III. THE USE OF BIG DATA IN TRANSPORT AND LOGISTICS:

In a study started in March 2021 with 116 companies operating in the transport and logistics sector in Morocco, we tried to decipher the level of adoption of big data in those companies we choose a multiple choice survey, based on the Likert scale developed by Rensis Likert. The repair of 116 companies studied by type is:  Carrier: 38 answers.  3PL: 51 answers.

 Logistician: 19 answers.

 Customs broker: 8 answers. The first affirmation shared with the audience allowed us to situate the level of use of digital tools in intracompany and inter-company communication. The goal of computerized or digital logistics is to provide the right information, in the right format, in the right place at the right time for the right people in a customer demand approach.



A. The use of digital solutions internally and externally :

The excellence of logistic information in today's agile industrial scenario has become a tactical and strategic concern. Another indicator other than those shown in the diagram below that we can remember when canvassing, is the absence of partial or total disagreement for the logistician and transitory types auditioned, while the type carriers show a disagreement percentage of 13.2% and a total disagreement of 5.3%, while 3PL companies shows only a disagreement of 2%. The second point is to know the strength of companies' ability to react to the excitements due to digitalization: changing processes, using new resources... In the audience studied, the logistician type has the highest percentage of absolute agreement at 42.1%. Neutrality is important because it reaches almost 20% of the total audience of all types, rates vary from 26.3% among logisticians, 25% among customs brokers, and 18.4% among carriers, while the lowest neutrality rate is shown among 3PL firms with 17.6%. The table below traces the choice of response by level of use of technologies on which a big data approach is based dedicated to a logistics environment. The levels of usage shared with the audience were as follows: not started, developing, basic, intermediate, and advanced. For each level of use, we gave a score: The maximum score for each adoption level is as follows: We got this result on the basis of the answers: The score positions big data in a global approach between a level of adoption in development and a basic level of adoption, we can relate that Big Data in the transport and logistics sector in Morocco after the census of 116 companies operating in this sector is basic up to 78.02%

B. Sensitivity of logistics and transport team members to digitalization :

C. Level of use of Big Data :

IV.CONCLUSION

With the rise of Internet and Wi-Fi networks, the banalization of mobile devices, the boom of social networks, the opening to the public of certain "Open Data" databases or the development of major international scientific projects, the phenomenon of "Big Data" is growing. The large volumes of data generated daily represent such an economic, industrial and scientific challenge that countries and companies are increasingly investing in Big Data. Several global surveys have shown that companies that rely on data analytics to develop their strategy increase productivity levels, improve their planning and forecasting processes, and increase knowledge and control of their business. In this article we presented the fundamental concepts of Big Data.

These concepts first include some elements of defining the phenomenon and its challenges. Then we reported the level of use of BIG data in Morocco which turns out to be basic. Remember that in 2021, Morocco sees big for data centers. Indeed, the Mohammed VI Polytechnic University of Benguerir proceeded in February 2021 to the inauguration of its new Data Center housing the most powerful "supercomputing" in Africa (African Supercomputing Center). This is a very important step for the Kingdom in this area that will enable UM6P to put itself at the service of the national digital ecosystem in order to help the digital sovereignty of the Kingdom and to develop new digital services 100% Moroccan. Located in the heart of the green city of Benguerir and spread over an area of 2,000 m2, this Data Center will elevate the capacity of scientific experimentation and thus allow greater control of the massive data collected.11

Figure 1 .

 1 Figure 1. Scale of use of digital solutions internally and externally in pourcentage

Figure 2 .

 2 Figure 2. Scale of sensitivity of logistics and transport team members to digitalization

Figure 3 .

 3 Figure 3. Scale of sensitivity of Big Data

Table - 1

 - Survey result:

	Affirmation	Totally	Agree Neutral Desagree	Totally
		agree				desagree
	In my company, we rely on the use of digital solutions
	to produce, manage and spread data internally and	52	47	9	6	2
	externally.

Table - 2

 - Survey result:

	Affirmation	Totally	Agree Neutral Desagree	Totally
		agree				desagree
	In my company, the members of
	the logistics and transport team
	have a strong sensitivity to	32	42	23	16	3
	digitalization.

Table - 3

 - Survey result:

	Technology	Not started	Developing	Basic	Intermediary	Advanced
	Big Data	40	14	31	19	12

Table 4 -

 4 Level of use scoring

	Level of use	Score
	Not started	0 point
	Developing	1 point
	Basic	2 points
	Intermediate	3 points
	Advanced	4 points

Table 5 -

 5 maximum score per level

	Level of use	Maximum score
	Not started	116 x 0 = 0
	developing	116 x 1 = 116
	Basic	116 x 2 = 232
	Intermediate	116 x 3 = 348
	Advanced	116 x 4 = 464

Table 6 -

 6 scoring results

	Level of use	Score
	Not started	40 x 0= 0
	developing	14 x 1 = 14
	Basic	31 x 2 = 62
	Intermediate	19 x 3 = 57
	Advanced	12 x 4 = 48
	Total score is: 181 points

Edd Dumbill, Volume, Velocity, Variety: What You Need to Know About Big Data : https://www.forbes.com/sites/oreillymedia/2012/01/19/volume-velocity-variety-what-you-need-to-know-aboutbig-data/

IBM developer blog : J. Steven Perry, What is big data? More than volume, velocity and variety : https://developer.ibm.com/technologies/analytics/blogs/what-is-big-data-more-than-volume-velocity-andvariety/

6 SAP : Qu'est-ce que le Big Data ?: https://www.sap.com/france/insights/what-is-big-data.

html[START_REF] Samsung | Le Transport routier dans l'ère du Big Data[END_REF] Database Systems Journal vol. III, no. 4/2012 :Perspectives on Big Data and Big Data Analytics page 5.

Robins consulting : WHY BIG DATA IS SO IMPORTANT TO THE TRANSPORTATION INDUSTRY : https://www.robinsconsulting.com/why-big-data-is-soimportant/#:~:text=Big%20data%20helps%20them%20foresee,provide%20all%20the%20necessary%20data.

[START_REF] Aujourd | ma : Big Data : Le Maroc dans la course mondiale[END_REF] Samsung : Le Transport routier dans l'ère du Big Data. : https://www.samsung.com/fr/business/insights/news/big-data-and-road-transport/

DHL : BIG DATA IN LOGISTICS, A DHL perspective on how to move beyond the hype page 15.

Aujourd'hui.ma : Big Data : Le Maroc dans la course mondiale, Published by Mohamed Badrane, february 22,