Laverne Floriane
email: floriane.laverne@ensam.eu

Segonds Frédéric

D ' Antonio Gianluca

Le Coq Marc

AM knowledge integration to foster innovation process: a methodological proposal

Keywords: Additive Manufacturing (AM), knowledge, preliminary design, innovation

In a few years, Additive Manufacturing (AM) has become a promising technology and opened up new prospects for the product development. Nevertheless, design methods remain predominantly based on conventional manufacturing processes and AM capabilities need to be better mastered and integrated in the design team. The methodology presented in this article seek to foster the product innovation process by avoiding these weaknesses through a contribution of AM knowledge. This AM knowledge is tailored, i.e. delivered to the right user at the right time and in the right format, in order to be useful and usable during the creative stages of the design process.

1-Introduction

Until 1990's, "manufacturing techniques could be classified in two sets, according to the way the product's shape was generated: forming processes and material removal processes" [1]. The industrial era of Additive Manufacturing (AM) started in 1986 and enabled to make objects "from 3D model data, layer upon layer, as opposed to conventional manufacturing technologies" [2]. Nowadays, seven families of AM processes exist and provide new insights into the product development. Indeed, in AM, tools are not needed, product's functionality can be improved, customized manufacturing and complex shapes with multi materials are possible [3]. Furthermore, AM now allows the achievement of fully functional products. But facing these new possibilities, it is necessary to provide designers a new set of tools and methods taking into account AM specificities.

2-DFAM in the innovation process

-Definition and classification of the DFAM methodologies

In a highly competitive marketplace, the reduction of time to market and the decrease of the production costs are major concerns while the number of product requirements are increasing. Design has become a team work where each stakeholder must bring and share his knowledge and expertise during the preliminary design and also helps to reduce iterations between the product design stage and the downstream stages. This approach, called integrated design, is the purpose of the Design For X (DFX) methodologies which are the "natural response to improve profitability" [4]. They enable the improvement of the "design product as well as design process from a particular perspective which is represented by X" [5]. DFX also revolutionizes the practice of design because all product lifecycle considerations are taken into account through the introduction of comprehensive knowledge, procedures or metrics. Thus, DFAM methodologies are dedicated to the AM paradigm. They are intended to facilitate the consideration of the AM specificities and they provide "an opportunity to rethink [Design For Manufacturing] to take advantage of the unique capabilities of these technologies" [3]. According to Laverne, et al. [6], DFAM methodologies can be classified according to the systemic level they are focusing for a product: component level and assembly level. Component-based DFAM (C-DFAM) are dedicated to an AM suitable and AM optimized component design from a given product architecture. Assembly-based DFAM (A-DFAM) are intended to the improvement of a product architecture through the decrease of the components number or to design new product architecture using databases.

-Limits of current DFAM methods in an innovative context

There are, in the literature, various kinds and types of innovation: product or process innovations and organizational innovations designed to amend the company's structure and business processes. This article questions how a new technology (i.e. AM) can enable product innovation. Indeed, according to Nelson [START_REF] Nelson | Contribution à l'analyse prospective des usages dans les projets d'innovation[END_REF], innovation does not always comply with a request of a clearly identified market, but may be intended to the enhancement of technological know-how: this is techno-push. Currently, AM leads to such concerns.

As Perrin [START_REF] Perrin | Concevoir l'innovation industrielle: méthodologie de conception de l'innovation[END_REF] declares, there is "no innovation without design stages": design is the backbone of an innovation process. To succeed in it, early design stages, starting from the research of concepts to the delivery of a preliminary layout [START_REF] Segonds | PLM and early stages collaboration in interactive design, a case study in the glass industry[END_REF], are crucial. Indeed, during these stages, creativity plays a major role "in the production of novel and useful ideas by an individual or a small group of individual working together" [START_REF] Amabile | A model of creativity and innovation in organizations[END_REF]. In the current C-DFAM and A-DFAM methodologies, the integration of AM Knowledge (AMK) is not used for challenging the specifications obtained during the preliminary studies or for defining new ideas or concepts. Thus deliverables in these methodologies are mostly redesigned products; that also means an incremental innovation at the assembly level. These methodologies are not adequate to produce "creative outputs" [START_REF] Howard | Describing the creative design process by the integration of engineering design and cognitive psychology literature[END_REF] i.e outputs satisfying two essential criteria for the development of radical innovation : originality and appropriateness. Therefore the methodology presented in this article, is intended to fill this gap through an intake of AM knowledge, suitable to the early design process.

3-Presentation of the methodology

-Methodological objectives

We showed in the previous section that the major limit of the current DFAM to develop innovative products is the difficulty for designers to break free of their architectural knowledge. An appropriate methodological response can be based on the improvement of the Design With X (DWX) methods. Indeed, DWX objective is "to inspire designers and supports them in creating products [because DWX focuses] on innovations so the product design solutions have always an innovative character" [START_REF] Langeveld | Design with X is new in product design education[END_REF]. As opposed to the DFX approaches, a DWX method is not intended to focus the design on a specific purpose but to widen the space solution with special attention to an innovative aspect X and its characteristics. In an innovative process, DWX can also assist early design activities and is carried out before a DFX method in order to enhance design creativity (Figure 1).

Figure 1 DWX and DFX in the innovation process

Since AM opportunities and restrictions are poorly known whereas those related to traditional processes are mastered by designers, we can see the interest of a DWX methodology enriched with AM paradigm. We call it Design With AM (DWAM). It aims to increase the creative potential by introducing a suitable AM knowledge in order to enable the undermining of the architectural knowledge and the development of original and appropriate concepts (also called working structures). Thus, when innovative concepts are created, the use of DFAM methodologies become possible.

-Importance of AM knowledge for creativity.

Among Popadiuk and Choo [START_REF] Popadiuk | Innovation and knowledge creation: How are these concepts related?[END_REF] one of the difference between incremental and radical innovation is the resource and skill requirement: for radical innovation, "additional expertise from outside might be required". Moreover, in their C-K theory, Hatchuel and Weil [START_REF] Hatchuel | A new approach of innovative Design: an introduction to CK theory[END_REF] highlight the importance of a reasoning focused, on the one hand on the knowledge space ("K" space) and, on the other hand, on the concepts space ("C" space) to succeed in an innovative design. The methodology presented in this article is specifically focused on the transition from K to C, called disjunction. It aims to improve the generation of alternative by extending the C space "with elements coming from the space K". These elements are AM knowledge. The relationship between creativity and knowledge has been formalized by several researchers [START_REF] Christiaans | Creativity in design engineering and the role of knowledge: Modelling the expert[END_REF]; nevertheless, there is no data available to specify how AM knowledge, which is the innovative aspect of the methodology, should be introduced to designers. In a previous study [6], the creative potential of design groups with expert or guided AMK was compared with an inexperienced group in the AM field. We showed that a huge intake of AMK was not suitable to develop innovative and manufacturable working structures. It is more appropriate to split this knowledge to make it more understandable and immediately usable. This requires to identify the appropriate AMK (i.e. founding the "what") designers need for each of their design activities. This tailored AMK is depending from three parameters: who, when, how.

-Who is the target i.e. the stakeholder (industrial designer, ergonomist or engineer) or the pluridisciplinary group who will use the AMK -When corresponds to the most adequate moment to introduce the AMK. -How is the best form that embodies and transmits the AMK.

-Initial model of the methodology

To succeed in the objectives presented in section 3.1, the first model of our methodology is adapted from stage based with iterative activities models of the design process where we highlight some key elements that identify a temporality in the design progression. These elements are the product representations created during a design stage and called Intermediate Representation (IR). For a design stage, divergent activities (called ideation) are dedicated to IR generation and convergent activities (called selection) provide a ranking of these IR following specific criteria.

As triggers for the supply of AMK, we select IR related to three major stages of the early design: the search of ideas, the concepts development and the arrangement of the architecture. These IR are the possible function, the ideas sheets, the drawing of concepts and the preliminary layout (Figure 2).

Figure 2 Key IR and activities of the methodology

In order to define the tailored KAM needed for each stage of our methodology, we conducted several experimentations whose protocol and results are detailed in section 4.

4-Formalization of the "just need" knowledge

4.1 -Experimentation 1

Protocol

This experiment is dedicated to the identification of the tailored AMK i.e. the useful knowledge to enhance the design creativity.

It is based on an analysis of the cognitive and informational process followed by designers working on the early stages of innovative industrial projects.

The study was carried out in two phases. First, participants have to describe their current design practices; especially what kind ok knowledge about traditional processes is retrieved and applied during. Then they have to fulfill a questionnaire dealing with the relationship between the product-level characteristics of innovative products [START_REF] Saunders | The characteristics of innovative, mechanical products[END_REF] and their possible ways of improvement thanks to AM. The interview focuses on the following topics:

-Listing of the IR usually created and illustration in the selected project, -Description of the design activities, design considerations and design stages followed to produce IR or to take decision, -Presentation of the inspirational and informational sources, -Description of the AM role in the daily work At the end of the interview, the participant is asked to fulfill the survey.

Results

The interviews were used to map design process within the framework of innovative projects. The analysis of these maps shows that there is a shift, for a given design activity, between the use of knowledge dealing with traditional processes and the AMK (if held by the designer): either it is not used or it is later. But for a specific activity, it is conceivable that the availability of an AMK is necessarily performed in conjunction with the first instantiation of this same content referring to traditional knowledge. Although designers say they are aware of the AM working principle and particularly of its usefulness for concepts prototyping, 86% of them (Figure 3) answer in the survey that a better knowledge would bring them new opportunities for product innovation during the ideation stages.

Figure 3 Evaluation of the usefulness of AMK in early design stages

Moreover, when they are more precisely questioned on the product-level characteristics that could be affected by this AMK, we notice that the possible ways of innovation highlighted in the literature are poorly known (Figure 4). This also gives us indications on the AMK contents we need to give to the designer to improve its exploration of innovative concepts.

Figure 4 Perceived utility of AMK for different categories of innovation

At last, 57% of the participants (Figure 3) feel that the contribution of knowledge dealing with AM restriction will not help them. It put forward an idealized view of AM in which the AM has no impact on converging activities. It is therefore necessary to bring AMK also during these phases in order to assess IR according to criteria such as certification, development time of the solution… 4.2 -Experimentation 2

Protocol

The purpose of this experiment is to identify the adequate knowledge forms usable in the methodology and more particularly those which are not suitable for conveying the knowledge.

The study was conducted with different business profile of designers (engineers, industrial designers and ergonomist). Each participant had to evaluate a transcription of knowledge predominantly based on: a text, a video, a picture, an artifact. The appreciation of each format was marked on a 5 levels Likert scale (1 = dislike and 5 = appreciate)

Results

Among the proposed forms, only three of them have an average score higher than 4 (Figure 5), which means they are appreciated by users. Using only text to bring a knowledge is not adequate.

Figure 5 Appreciation of knowledge forms

Secondly, a knowledge transferred with an artifact is admittedly appreciated but is poorly compatible with a need to regularly and quickly update the knowledge contents because of the current developments in the AM field. It is also a necessity to set up a AMK form, compatible with the data management enabled by a PLM environment.

-Experimentation 3

Protocol

This last experiment focuses on the couple knowledge contenttiming. It was performed with 18 design students in research master. These students are formed in the design and innovation processes and have basic knowledge in AM. The V0 model methodology is presented and explained to each participant beforehand. Next, different typologies of AMK are introduced and detailed. Then each participant have to place among the 3 stages of the model where this knowledge could be useful and usable for their design activities.

Results

The graph below (Figure 6) shows the first, the average and the last occurrence for each typology of knowledge.

Figure 6 Preferred time for the introduction of different AMK

We notice the misuse of several AMK in the design process. Indeed, the study shows that all typologies of AMK are required during the concepts development and its sorting. Creativity tools such as TRIZ or brainstorming encourage the research of ideas in various fields, without restriction. Therefore it may be necessary to provide knowledge (e.g. on AM application areas) in order to avoid missing out some ideas or eliminating others just because they seem unrealistic. AMK dealing with of the complexity for free seems required during the development of concepts, i.e. the combination of ideas (functions and working principles) into a solution. Finally, it is surprising that knowledge on the characteristics of AM machines are perceived as useful for selecting concepts while dimensions or mechanical behavior have not been specified. It is therefore necessary to indicate designers to integrate this knowledge does not at this stage but later

5-Proposition of an enriched with AM knowledge model (final model)

The model, resulting from the compilation of the experimental studies, defines five specific contributions of AM knowledge, during the early design (Figure 7). Three of them are intended to improve the ideation stages (AMK 2, AMK 3 and AMK 5) and the two others to improve the selection stages (AMK 1 and AMK 4). At this point of our study we cannot distinguish content dedicated to a particular expert skill, we also propose a "universal" model which must be refined with other experiments.

A demonstration tool was created jointly with the development of the V1 model. Based on results from experiment 2, AMK contents are mainly presented using pictures, but some short comments are also added to facilitate the understanding. The methodology have to be tested both in its content but also in its usefulness in the innovation process.

The assessment of the contents will be achieved with user test in a context of industrial innovation projects. It aims to improve the AMK contents but more specifically the three associated parameters who, what, and when. Thereby, a robust V2 model will be obtain. The validation of its usefulness for the creation of innovative architecture will be performed through a comparative analysis of two workshop carried out on the same project. The first one will have to work with the methodology (V2 model and tool), the other will be free to use its own approach. The comparison will be based on qualitative (expert evaluation) and quantitative results (number of ideas, number of components or functions …)

7-References

Figure 7 Final model with AM knowledge 6 -

 76 Figure 7 Final model with AM knowledge

  . Kruth, "Material Incress Manufacturing by Rapid Prototyping Techniques," CIRP Annals -Manufacturing Technology, vol. 40, pp. 603-614, 1991. [2] ASTM, "F2792-12a : Standard terminology for Additive Manufacturing Technologies," ed, 2012. [3] I. Gibson, D. R. Rosen, and B. Stucker, Additive Manufacturing Technologies 2nd Edition. New York: Springer US, 2015. [4] D. P. Fitzgerald, J. W. Herrmann, and L. C. Schmidt, "A Conceptual Design Tool for Resolving Conflicts Between Product Functionality and Environmental Impact," ASME Journal of Mechanical Design, vol. 132, pp. 091006-091006, 2010. [5] T. Tomiyama, P. Gu, Y. Jin, D. Lutters, C. Kind, and F. Kimura, "Design methodologies: Industrial and educational applications," CIRP Annals -Manufacturing Technology, vol. 58, pp. 543-565, 2009. [6] F. Laverne, F. Segonds, N. Anwer, and M. Le Coq, "Assembly-based methods to support product innovation in Design for Additive Manufacturing:


Hajer Maraoui
email: hajer.maraoui@fst.utm.tn

Kais Haddar
email: kais.haddar@yahoo.fr

Laurent Romary
email: laurent.romary@inria.fr

Segmentation tool for hadith corpus to generate TEI encoding

Keywords: Hadith corpus, hadith structure, segmentation tool, TEI encoding

A segmentation tool for a hadith corpus is necessary to prepare the TEI hadith encoding process. In this context, we aim to develop a tool allowing the segmentation of hadith text from Sahih al-Bukhari corpus. To achieve this objective, we start by identifying different hadith structures. Then, we elaborate an automatic processing tool for hadith segmentation. This tool will be integrated in a prototype allowing the TEI encoding process. The experimentation and the evaluation of this tool is based on Sahih al-Bukhari corpus. The obtained results were encouraging despite some flaws related to exceptional cases of hadith structure.

Introduction

A segmentation phase is necessary to analyse and standardize corpora especially for hadith corpora. In fact, the automatization of the segmentation of large hadith corpora guarantee the treatment optimization in term of time and results precision. Moreover, it facilitates the processing and the manipulation for some tools that analyze and standardize each part of the text in hadith corpus. However, this phase imposes some problems especially with the structure of large hadith corpora, which characterised with text particularity and variant features. Furthermore, these corpora are originally in Arabic language, which impose some difficulties that related with language specificities.

In this context, to segment a large corpus of hadith, such as Sahih al-Bukhari, we must first start with a deep study on hadith corpora specificities and identify the features of hadith text. Then, we must classify the separator terms that recognise the different units in hadith corpus and develop the necessary resources to realise the segmentation process. After that, we need to develop a tool for the segmentation of hadith corpus.

In the present paper, we begin with a state of art on hadith in Sahih al-Bukhari corpus. Then, we illustrate the features of hadith text. After that, we present our segmentation tool for hadith text from sahih al-Bukhari. Then, we continue with by an evaluation step. We cloture our paper with a conclusion and some perspective.

Stat of art on hadith in Sahih al-Bukhari corpus

Sahih al-Bukhari (or البخاري صحيح in Arabic) is one of the six major hadith collections of Sunni Islam. The Arabic word sahih )صحيح( translates as authentic or correct. The prophetic traditions (or hadiths), were collected by the Muslim scholar Muhammad al-Bukhari, after being transmitted orally for generations [START_REF] Zaho | العربي الفكر ,دار Riyadh[END_REF]. Al-Bukhari went to Mecca when he was 16 years old and learned hadith there. He traveled around other Islamic countries to collect hadiths. He had collected 600,000 hadiths of which he only considered 7,275 ones as authentic in his well-known work, Sahih al-Bukhari. He finished his work around 846/232 AH [START_REF] Brown | Hadith: Muhammad's Legacy in the Medieval and Modern World[END_REF]. The book is considered as one of the two most authentic and trusted collections of hadith along with Sahih Muslim. Sahih al-Bukhari covers almost all aspects of life in providing proper guidance of Islam such as the method of performing prayers and other actions of worship directly from the Prophet Muhammad. In Islamic terminology, the term hadith refers to reports of statements or actions of the Prophet Muhammad, or of his implicit approval or criticism of something said or done in his presence. Classical hadith specialist Ibn Hajar al-Asqalani says that the intended meaning of hadith in religious tradition is something attributed to Muhammad but that is not found in the Quran. The two major aspects of a hadith are the Matn which is the actual narration, and Sanad or Isnad which is the chronological list of narrators. Each Isnad reporter mentions the person from whom he heard the hadith all the way to the prime reporter of the Matn itself. The Isnad was an authentication of the hadith to verify that it is actually come from the Prophet Muhammad. The Isnad means literally 'support', so it is the support in determining the hadith authenticity or weakness (more details in [START_REF] Zaho | العربي الفكر ,دار Riyadh[END_REF] and [START_REF] Al-Ansari | الحديث علوم في [END_REF]).

Research in the Isnad is very important in the science of hadith. To define the hadith authentication, the traditional methods consist of following clear steps in the judgment on the Isnad. Currently, software tools allow hadith judging like electronic hadith encyclopedias and some websites. Moreover, information retrieval and search engines that related to semantic web can be used to serve in deciding the authenticity of hadith.

Many projects worked on hadith corpus. Indeed, these projects focused on several branches of researches such as hadith ontology, linguistic analyzing, Hadith segmentation, classification and the mining of information.

In [START_REF] Boella | The SALAH Project: Segmentation and Linguistic Analysis of hadῑṯ Arabic Texts[END_REF], the researchers proposed a model named SALAH for the unsupervised segmentation and the linguistic analysis of the hadith texts. The model automatically segments each text unit in Isnad and Matn. After that, a personalized augmented version of the AraMorph morphological analyzer (RAM) examines and annotates lexically and morphologically the text content. The system generates as final output a graph with relations among transmitters and a lemmatized text corpus in XML format.

In [START_REF] Dalloul | Partial Fulfillment of the Requirements for the Degree of Master in Information Technology[END_REF], the author constructed an ontology-based Isnad Judgment System (IJS) that automatically generates a suggested judgment of Hadith Isnad. This is based on the standard instructions followed by the Hadith scholars to judge hadith Isnad. A prototype of the approach implemented to provide a proof of concept for the requirements and to verify its accuracy.

Authors of paper [START_REF] Baraka | Building Hadith Ontology to Support the Authenticity of Isnad[END_REF] built a domain specific ontology (Hadith Isnad Ontology) to support the process of authenticating Isnad. They evaluate the ontology through Hadith example and DL-Queries.

In [START_REF] Azmi | iTree -Automating the Construction of the Narration Tree of Hadith[END_REF], the authors reported on a system that automatically generates the transmission chains of a Hadith and graphically display it. They involve parsing and annotating the Hadith text and identifying the narrators' names. They use shallow parsing along with a domain specific grammar to parse the Hadith content.

Arabic hadith features: Sahih al-Bukhari corpus

Sahih al-Bukhari is arranged like books in Islamic jurisprudence (or ِقه ف " " , fiqh). It contains also some additional sections focusing on different topics such as the origins of creation, the exegesis of the Quran and the Holy prophets. Al-Bukhari also expressed his own views of the issues in fiqh by classifying the sections of his book and assigned for each section a significant title which express the fiqh of al-Bukhari. These titles involve all the interpretations and explications of al-Bukhari to clarify the meaning of hadiths which are difficult to understand.

Sahih al-Bukhari corpus is structured into 97 chapters and 3450 sections. The chapters contain 7563 hadith in totality. This number includes repeated hadiths. It confirmed contains 7275 ones, and setting aside the repeated ones, as Nawawi says, it includes 4,000 hadiths, though Ibn Hajar says that on this count, it contains 2,761 hadiths. Moreover, the number of its hadiths is different in different versions of the book; for example, Firabri has cited 300 hadiths more than those cited by Ibrahim b. Ma'qil al-Nasafi, and the latter cited 100 hadiths fewer than those cited by Himad b. Shakir al-Nasawi.

Hadith features

Each hadith in Sahih al-Bukhari is cited in a relative section, titled by the author to express his interpretation of the meaning of hadith, under a chapter combine the sections related with one topic. Moreover, each hadith is quoted with an order number and finish with the references. This structure in accurately respected in Sahih al-Bukhari. As an example, Fig. 1 present hadith number 3209 from chapter 59 "beginning of creation", section 6 "the reference to angels", as it occurs in sahih al-Bukhari. In order to extract hadiths text from Sahih al-Bukhari, it is convenient to keep the relative coordination of each hadith to maintain the structure and authentication support.

Hadith Structure

The typical hadith structure consists of two parts, the transmitter chain (Isnad) and the actual narration (Matn). Since just close sets of words separate both Isnad from Matn and the various transmitters inside Isnad one from another, this explicit organization allows to detect and retrieve information with a relatively small amount of ambiguity.

Despite the regular structure of the majority of hadiths occurred in Sahih al-Bukhari, it still exists others with a different structure. These cases are related with implicit parameters which are referenced or mentioned in implicit way. For example, it common to find a hadith text with only the Matn. But also cited with an expression of the reference where to find the appropriate isnad or came as a continuation of the Matn of a previous hadith. As an Example, Fig. 2 illustrate this case in hadith number 654 from the section 32, chapter 10 "Call to prayers".

م ْ ال ِ ر ْ ِك ذ باب 3209 - ِي ن َ َر ب َخْ أ :َ َال ق ، ٍ ْج ي َ ُر ج ْنُ اب َا ن َ َر ب َخْ أ ،ٌ د َ ل خْ َ م َا ن َ َر ب َخْ أ ، مٍ َ ال َ س ْنُ ب ُ َّد م َ ُح م َا ن َ َّث د َ ح َّ ل َ ص ِ ي ِ َّب الن ِ َن ع ،ُ ْه َن ع ُ َّللاَّ َ ي ضِ َ ر َ ة َ ْر ي َ ُر ه ُو ب َ أ َ َال ق :َ َال ق ، ٍ ِع َاف ن نْ َ ع ، َ َة ب ْ ُق ع ْنُ ب ى َ ُوس م ُو ب َ أ ُ ه َ َع َاب ت َ و ، َ م َّ ل َ س َ و ِ ْه ي َ َل ع ُ هللا ى َ ص ِ ي ِ َّب الن ِ َن ع ،َ ة َ ْر ي َ ُر ه ي ِ ب َ أ نْ َ ع ، ٍ ِع َاف ن نْ َ ع ، َ َة ب ْ ُق ع ْنُ ب ى َ ُوس م ِي ن َ َر ب َخْ أ :َ َال ق ، ٍ ْج ي َ ُر ج ِ ْن اب ِ َن ع ، مٍ َاصِ ع ، َ م َّ ل َ س َ و ِ ْه ي َ َل ع ُ هللا ى َّ ل ِ ْر ب ِ ج َى َاد ن َ ْد ب َ الع ُ َّللاَّ َبَّ ح َ أ َا ذ ِ إ " :َ َال ق اءِ: َ َّم الس ِ ْل ه َ أ ِي ف ُ يل ِ ْر ب ِ ج ِي َاد ُن َي ف ،ُ يل ِ ْر ب ِ ج ُ ُّه ب ُحِ َي ف ،ُ ْه ب ِ ب حْ َ َأ ف ًا َن ال ُ ف بُّ ُحِ ي َ َّللاَّ نَّ ِ إ :َ يل " ِ ض رْ َ األ ِي ف ُ ُول َب الق ُ ه َ ل ُ َع ُوض ي َّ م ُ ث ، اءِ َ َّم الس ُ ْل ه َ أ ُ ُّه ب ُحِ َي ف ،ُ ُّوه ب حِ َ َأ ف ًا َن ال ُ ف بُّ ُحِ ي َ َّللاَّ نَّ ِ إ . ] في طرفاه 6040 , 7435 .[

-Chapter of beginning of creation (…)

6 -Section the reference to angels (…) 3209 -The Prophet (peace and blessing upon him) said, "If Allah loves a person, He calls Gabriel saying, 'Allah loves so and-so; O Gabriel! Love him.' Gabriel would love him and make an announcement amongst the inhabitants of the Heaven. 'Allah loves so-and-so, therefore you should love him also,' and so all the inhabitants of the Heaven would love him, and then he is granted the pleasure of the people on the earth". [Links in 6040, 7435].

10 - كتاب األذان )...( 32 - هر الظ إلى هجير الت فضل باب )...( 537 - « ا َ م ُونَ م َ ْل َع ي وْ َ ل َ و في ا َ م ُونَ م َ ْل َع ي وْ َ ل َ و ، ِ ْه ي َ ل ِ إ وا ُ َق َب ْت َس ال ِ ير ِ ْج َّه الت في ً ْوا ب َ ح وْ َ ل َ و ا َ ُم ه وْ َ ت َ أل ِ ْح ُّب الص َ و ِ ة َ َم ت َ ع ْ ال .» ] أطراف ه 615 ، 721 ، 2689 - تحفة 12570 - 12577 .[
537 -"And if they knew the reward of offering the Zuhr prayer early (in its stated time), they would race for it and they knew the reward for 'Isha' and Fajr prayers in congregation, they would attend them even if they were to crawl". [Links in 615, 721, 2689_ 12570 -12577].

The hadith in this case came to prove the previous one and occurs elsewhere with the reference indicated in the end of the Matn. In other context, other forms of hadith are more abstract and follow an irregular structure. The most of these hadith came to prove the previous hadith.

In Sahih al-Bukhari occurs also other form of hadiths. These traditions contain a complex structure in the part of mentioning the Isnad. Frequently, a hadith can have more than one chain of narrators as Isnad. These chains can occur in the front of the text cited after each other or divided in two sections before and after the Matn. As Example of this composition, Fig. 3 present hadith number 6 from section 1 "How was the revelation on the Prophet", chapter 1 "Revelation". Based on sahih al-Bukhari corpus study, we determinate that to realize a hadith normalization system, we must start with the prime unite of sahih al-Bukhari corpus which is the hadith text. In fact, to reach the corpus normalization, a hadith extraction and segmentation phase is essential to prepare to the succeeding phase for encoding hadith text with TEI. This lead as to investigate the development of an extraction and segmentation tool integrated in our Hadith encoding prototype to split out the hadith text for the next encoding step which is presented in the next section.

Hadith segmentation tool

To implement the segmentation method of hadith text from Sahih al-Bukhari corpus, we developed a tool for this process. This tool is made to prepare the hadith text for the hadith encoding prototype with TEI (more details in [START_REF] Maraoui | Modeling of Al-Hadith Al-Shareef with TEI, ICEMIS Conference[END_REF] and [START_REF] Maraoui | Encoding prototype of Al-Hadith Al-Shareef in TEI[END_REF]). The implementation is based on JAVA language and the API JDOM Library. Fig. 4 presents the general architecture of this program. This tool is developed to extract automatically each hadith text from Sahih al-Bukhari then segment each one to Isnad and Matn which goes as input to the hadith encoding process.

1 - الوحي بدء كتاب )...( 1 - ِ َّللاَّ ِ ُول س َ ر ى َ ل ِ إ ِ ى حْ َ و ْ ال ُ ْء َد ب َانَ ك َ ْف َي ك باب )...( 6 - ِ ى ِ ْر ه الزُّ ِ َن ع سُ ُ ُون ي َا ن َ َر ب َخْ أ َ َال ق ِ َّللاَّ ُ ْد َب ع َا ن َ َر ب َخْ أ َ َال ق َانُ ْد َب ع َا ن َ َّث د َ ح َّ د َ ح َ و ح ُ ه َ و َحْ ن ِ ى ِ ْر ه الزُّ ِ َن ع َرٌ ْم ع َ م َ و سُ ُ ُون ي َا ن َ َر ب َخْ أ َ َال ق ِ َّللاَّ ُ ْد َب ع َا ن َ َر ب َخْ أ َ َال ق ٍ َّد م َ ُح م ْنُ ب رُ ْ ش ِ ب َا ن َ ث ِ َّللاَّ ِ ْد َب ع ْنُ ب ِ َّللاَّ ُ ْد َي ُب ع ِى ن َ َر ب َخْ أ َ َال ق ِ َّللاَّ ُ ُول س َ ر َانَ ك َ َال ق ٍ َّاس َب ع ِ ْن اب ِ َن ع َ س َ و ِ ْه ي َ َل ع ُ هللا ى َّ ل َ ص ، َ م َّ ل ُ َاه ق ْ َل ي ينَ حِ َانَ ض َ م َ ر ِى ف ُونُ َك ي ا َ م ُ د َ و جْ َ أ َانَ ك َ و ، ِ َّاس الن َ د َ و جْ َ أ ِ َّللاَّ ُ ُول س َ ر َ َل ف ، آنَ رْ ُ ق ْ ال ُ ُه س ِ َار ُد َي ف َانَ ض َ م َ ر نْ مِ ٍ ة َ ْل ي َ ل ِ ُل ك ِى ف ُ َاه ق ْ َل ي َانَ ك َ و ، ُ يل ِ ْر ب ِ ج ، َ م َّ ل َ س َ و ِ ْه ي َ َل ع ُ هللا ى َّ ل َ ص ْ َي خ ْ ال ِ ب ُ د َ و جْ َ أ نَ مِ ِ ر ِ يح ِ الر ِ ة َ ل َ س ُرْ م ْ ال . ] أطراف ه 1902 ، 3220 ، 3554 ، 4997 - تحفة 5840 - 5 / 1 .[ 1 -Chapter of revelation (…)
1 -Section of how the revelation was for the prophet (…) 6 -Allah's Messenger (peace and blessing upon him) was the most generous of all the people, and he used to reach the peak in generosity in the month of Ramadan when Gabriel met him. Gabriel used to meet him every night of Ramadan to teach him the Qur'an. Allah's Messenger (peace and blessing upon him) was the most generous person, even more generous than the strong uncontrollable wind (in readiness and haste to do charitable deeds). [Links in 1902, 3220, 3554, 4997 _ 5840 -1/5]. In the processing of our hadith encoding prototype, the system need as an input the Isnad and the Matn of each hadith in the used corpus. This input data is the output of the presented tool. To prepare hadith text for the encoding prototype, the system requests the user to choose an external file, with .txt extension which contains the hadith corpus in Arabic language, by selecting the file path. Then, the program reads the corpus and identify each hadith text. To detect hadith text in the corpus, we based on the fact that each hadith starts with a hadith number and a trigger word, as we name it, that express the beginning of the Isnad. We built for this reason a trigger word dictionary in XML format for the words that indicate the hadith beginning. Trigger word dictionary includes also the terms that separate the narrator names and indicates the commencement of the Matn. The trigger word identification allows the manipulation of hadith text. We classify these parts of speech to three classes: Trigger Word Before (TWB), Trigger Word After (TWA) and Trigger Word Between (TWT). Table 1 illustrates the different forms of these terms in the trigger words dictionary.

Trigger Word Dictionary Evaluation and discussion

To evaluate the hadith corpus segmentation tool, we select as input a text file containing Sahih al-Bukhari corpus which include 7563 hadith. Consequently, the tool system creates respectively 7485 hadith text files and save them. Then the system segments each hadith and sends the Isnad and the Matn to the encoding process in the prototype core. Table 2 illustrates the obtained results. Then, the segmentation process separate hadith fragments correctly for 7259 hadith texts. However, we found 304 Hadith that were not segmented properly. These hadith have particular structure which require some rectification to cover these cases. Indeed, we estimate the capacity of this tool manually. Table 3 illustrates the obtained values of precision, recall and F-score.

Table 3. Summary table of the precision, recall and F-score.

According to the value of precision, we conclude that the value of precision is worth 0.96. Also, the recall value is 0.96. These values provide an F-measure equal to 0.96. Consequently, we conclude that the obtained results are encouraging. Besides, the unsupervised tool system does not require a pretreatment or execute modification on the input corpus file. However, we handled some problems. Some of them are related with the particular Hadith forms which need to integrate more specificity.

Conclusion and perspectives

In order to optimize the processing of hadith text, we aimed to developed a segmentation tool for hadith corpus. To achieve that, first, we started with a deep study of Hadith text structure from Sahih al-Bukhari. After that, we designed and created an integrated tool in our TEI encoding prototype for the segmentation of hadith corpus. Then, we tested this tool with a Sahih al-Bukhari corpus which englobe 7563 hadith texts from 94 chapters. As mentioned, the obtained values of measures show that the results obtained from the hadith segmentation tool are encouraging. As perspective, the hadith segmentation tool can be used in others levels of analyses. Furthermore, we want to apply the proposed tool to other types of Hadith corpo-

Hadith corpus

Precision Recall F-score 7563 Hadith 0,96 0,96 0,96 ra such as Sahih Muslim. Also, we want to extend the set of rules to cover the exceptional structures of hadith text.

Fig. 1 .

 1 Fig. 1. Hadith number 3209 from chapter 59, section 6 from sahih al-Bukhari.

Fig. 2 .

 2 Fig. 2. Hadith number 654 from chapter 10, section 32 from sahih al-Bukhari.

Fig. 3 .

 3 Fig. 3. Hadith number 6 from chapter 1, section 1 from sahih al-Bukhari.

Fig. 4 .

 4 Fig. 4. General architecture of the segmentation tool of hadith corpus.

Table 2 .

 2 Sammery table for the hadith extraction and segmenation tool results.

	Evaluated corpus	Extracted hadiths	Correct extraction	Segmented hadiths	Correct segmentation	Incorrect segmentation
	Sahih al-Bukhari
	7563 hadith	7563	7563	7563	7259	304
	97 Chapter

Table 2

 2 shows that sometimes for particular Hadith texts, we can obtain erroneous segmentation. The total number of hadith text in Sahih al-Bukhari is 7563 hadith from 97 different Chapters. The hadith segmentation tool succeeded to extract 7563 Hadith correctly and save them as text files.

َال ق ِ َّللاَّ ُ ْد ب َ "ع (Abdu Allah said). The third-class TWT is for the trigger word that appears between two expressions of narrator names such as َال" ق ه ن َ "أ (That he said). The TWT class include all the terms that relate two sections of trigger word and narrator name. This dictionary allows the prototype, including the integrated programs, to detect the right parts and segment the hadith text. The tool connects to this dictionary and spot the hadith text.

The termination of each hadith is identified by the hadith references numbers and the word " أطر افه " or " تحف ه " (which have as meaning, references and links) or a flexion form of them. This method allows the treatment of Sahih al-Bukhari Arabic corpus with no need to modify the input file or to delete any other data exists in the corpus else then hadith texts. After this step, the program extracts each spotted hadith text and save it in the workspace as text file. As well, the segmentation tool completes the reading and the separation of the Isnad and the Matn from each hadith text. To achieve the hadith segmentation, we start by analyzing Sahih al-Bukhari corpus and identifying the terms that separate the two parts. These terms are included in the trigger word dictionary. Also, the segmentation process of Isnad and Matn is based on trigger word.

Hadith corpus segmentation tool is an integrated program in the hadith encoding prototype which allows the encoding of all the hadiths of Sahih al-Bukhari in one running action. This automatic preparation of hadith text supported the optimization of hadith corpus encoding using prototype. We have evaluated this tool based on Sahih al-Bukhari corpus. The results are presented in the following section.


Mariana Mariño

Philippe Breuil

Mathilde Rieu
email: rieu@emse.fr

Damien Jamon

Jean-Michel Rampnoux

Jean-Paul Viricelle

Florence Garrelie

Simulation of nanosecond IR laser annealing of cerium gadolinium oxide

Keywords: CGO, Infrared laser, Thermal simulation, Single Chamber SOFC

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

Introduction

In Single Chamber Solid Oxide Fuel Cell (SC-SOFC), as the generation of the open circuit voltage (OCV) depends mainly on the electrocatalytic activity and selectivity of the electrodes, and not only on a dense electrolyte as in conventional SOFC, it is possible to operate without a gastight electrolyte [START_REF] Kuhn | Single-Chamber Solid Oxide Fuel Cell Technology -From its Origins to Today's State of the Art[END_REF][START_REF] Suzuki | Performance of a Porous Electrolyte in Single-Chamber SOFCs[END_REF].

It allows to use simple and conventional processing methods to prepare the electrolyte. For example, screen-printing, a simple and low-cost deposition technique can be used to prepare a thin and porous layer, because in such a case a dense electrolyte is not required [START_REF] Suzuki | Performance of a Porous Electrolyte in Single-Chamber SOFCs[END_REF][START_REF] Rembelski | In situ reduction and evaluation of anode supported single chamber solid oxide fuel cells[END_REF][START_REF] Viricelle | Development of Single Chamber Solid Oxide Fuel Cells (SCFC)[END_REF]. However, some authors [START_REF] Suzuki | Performance of a Porous Electrolyte in Single-Chamber SOFCs[END_REF][START_REF] Rembelski | In situ reduction and evaluation of anode supported single chamber solid oxide fuel cells[END_REF][START_REF] Mariño | Laser induced densification of cerium gadolinium oxide:Application to single-chamber solid oxide fuel cells[END_REF] have indicated that the porosity related to the electrolyte may allow the transport of the hydrogen produced locally at the anode to the cathode, which can generate an OCV drop and a decrease of cell performances. To prevent hydrogen transportation, it is thus recommended to have a dense electrolyte or at least a diffusion barrier layer, while at the same time preserving the porosity of the electrodes [START_REF] Suzuki | Performance of a Porous Electrolyte in Single-Chamber SOFCs[END_REF][START_REF] Rembelski | In situ reduction and evaluation of anode supported single chamber solid oxide fuel cells[END_REF][START_REF] Mariño | Laser induced densification of cerium gadolinium oxide:Application to single-chamber solid oxide fuel cells[END_REF].

Solid oxide electrolytes based on cerium gadolinium oxide (CGO) materials are considered to be the most promising candidate materials for use in single-chamber solid oxide fuel cells, because they offer considerably high ionic conductivity at intermediate operating temperatures (450-700•C) [START_REF] Morales | Intermediate temperature single-chamber methane fed SOFC based on Gd doped ceria electrolyte and La0.5Sr0.5CoO3-δ as cathode[END_REF][START_REF] Chourashiya | Synthesis and characterization of electrolytegrade 10%Gd-doped ceria thin film/ceramic substrate structures for solid oxide fuel cells[END_REF].

Nevertheless, the achievement of dense materials requires sintering temperatures above 1400•C [START_REF] Kleinlogel | Sintering and properties of nanosized ceria solid solutions[END_REF][START_REF] Van Herle | Low temperature fabrication of (Y, Gd, Sm)-doped ceria electrolyte[END_REF][START_REF] Ma | Ce0.8Gd0.2O2-δ ceramics derived from commercial submicron-sized CeO2 and Gd2O3 powders for use as electrolytes in solid oxide fuel cells[END_REF]. Densification of the electrolyte by conventional heat treatment is obviously possible, but this also leads to an undesired densification of the support material (most often anode). To solve this difficulty, Mariño et al [START_REF] Mariño | Laser induced densification of cerium gadolinium oxide:Application to single-chamber solid oxide fuel cells[END_REF] proposed to selectively densify the electrolyte in anode supported SC-SOFC by a laser treatment, using either a pulsed nanosecond ultraviolet (UV) laser or an infrared (IR) laser.

Laser annealing is a technique that allows localized modifications to the materials without affecting the entire structure [START_REF] Ma | Ce0.8Gd0.2O2-δ ceramics derived from commercial submicron-sized CeO2 and Gd2O3 powders for use as electrolytes in solid oxide fuel cells[END_REF][START_REF] Sandu | Densification and crystallization of SnO2:Sb sol-gel films using excimer laser annealing[END_REF]. This technique has been employed successfully to treat ceramic materials with an increasing interest in their densification [START_REF] Tsagarakis | Nanocrystalline barium titanate films on flexible plastic substrates via pulsed laser annealing[END_REF][START_REF] Chen | Modeling and experimental analysis in excimer-laser crystallization of a-Si films[END_REF][START_REF] Palani | Crystallization and ablation in annealing of amorphous-Si thin film on glass and crystalline-Si substrates irradiated by third harmonics of Nd3+:YAG laser[END_REF][START_REF] Theodorakos | Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications[END_REF][START_REF] Bäuerle | Laser Processing and Chemistry[END_REF][START_REF] Brygo | Etude de l'interaction laser -matière appliquée à la décontamination de peintures[END_REF][START_REF] Samant | Laser machining of structural ceramics-A review[END_REF] and it has been demonstrated that pulsed laser irradiation offers an attractive alternative to conventional thermal annealing for oxides densification [START_REF] Sandu | Densification and crystallization of SnO2:Sb sol-gel films using excimer laser annealing[END_REF][START_REF] Tsagarakis | Nanocrystalline barium titanate films on flexible plastic substrates via pulsed laser annealing[END_REF].

The changes induced on the surface of a material treated by a laser strongly depend on the amount of energy absorbed by the material. To obtain the desired results, it is important to figure out the surface temperature and its distribution within the material. However, the in situ measure of the temperature remains still difficult during a laser treatment with a pulsed laser [START_REF] Chen | Modeling and experimental analysis in excimer-laser crystallization of a-Si films[END_REF][START_REF] Palani | Crystallization and ablation in annealing of amorphous-Si thin film on glass and crystalline-Si substrates irradiated by third harmonics of Nd3+:YAG laser[END_REF]. For a better understanding and control of the laser annealing process , this work proposes a numerical simulation of laser-mater interaction based on previous experiments made by Mariño et al concerning local densification of CGO electrolyte in SOFC [START_REF] Mariño | Laser induced densification of cerium gadolinium oxide:Application to single-chamber solid oxide fuel cells[END_REF]. Here, we will only focus on results obtained with a pulsed IR laser. Furthermore, a measurement of the optical properties of CGO material as a function of temperature is presented, necessary to implement realistic simulation of material properties.

Thermal modelling

The temperature distribution in a material, induced by the absorption of a laser irradiation can be described by the heat equation which depends on the optical and thermal parameters of the medium [START_REF] Theodorakos | Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications[END_REF]. If the thermal diffusivity length (defined hereafter) is negligible with respect to the laser beam diameter [START_REF] Palani | Crystallization and ablation in annealing of amorphous-Si thin film on glass and crystalline-Si substrates irradiated by third harmonics of Nd3+:YAG laser[END_REF][START_REF] Bäuerle | Laser Processing and Chemistry[END_REF], a one dimensional model can be used and the heat equation can be expressed by the equation [START_REF] Kuhn | Single-Chamber Solid Oxide Fuel Cell Technology -From its Origins to Today's State of the Art[END_REF]. The heat radial diffusion is then neglected. In this case, the differential equation

The left part of the equation represents the temporal and spatial distribution of the temperature. The temporal distribution of the temperature is determined by the density of the material ρ(T) and the heat capacity Cp(T), while the spatial evolution depends on the thermal conductivity κ(T) and also determines the heat diffusion in the material [START_REF] Theodorakos | Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications[END_REF][START_REF] Bäuerle | Laser Processing and Chemistry[END_REF][START_REF] Brygo | Etude de l'interaction laser -matière appliquée à la décontamination de peintures[END_REF]. Values used in this work for cerium gadolinium oxide (CGO) are presented in table 1.

The right part of equation (1), Q(x,t), corresponds to the laser energy absorbed by the material. It depends on the optical properties of the material like the absorption coefficient (𝛼) and the reflectivity (R), the laser fluence (F) and the time dependence of the laser pulse q(t) [START_REF] Theodorakos | Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications[END_REF][START_REF] Samant | Laser machining of structural ceramics-A review[END_REF]. If the absorption coefficient 𝛼 is constant (and then not dependent on the temperature), the integrated form of the Beer-Lambert law may be used as in equation [START_REF] Suzuki | Performance of a Porous Electrolyte in Single-Chamber SOFCs[END_REF].

𝑄(𝑥

, 𝑡) = F(1 -𝑅)𝑞(𝑡)𝛼exp (-αx) [W m -3 ] (2)
Thermal simulations based on previous equations were carried out using an IR pulsed laser on a CGO surface. The induced temperature profile after laser pulse irradiation was calculated using COMSOL Multiphysics software, which uses a finite element method. This software has a database of equations to model different phenomena. In this case, the heat transfer in solids module was used.

We remind here that the thermal diffusivity length 𝑙 𝜏 is defined qualitatively by equation [START_REF] Rembelski | In situ reduction and evaluation of anode supported single chamber solid oxide fuel cells[END_REF].

𝑙 𝜏 = 2√𝐷𝜏 (3)
 is the laser pulse duration. D is the thermal diffusivity of the material which depends on the thermal conductivity κ, the heat capacity Cp and the density of the material ρ, reported in equation ( 4).

𝐷 = 𝜅 𝜌𝐶 𝑝 (4)
Table 1. Physical properties of CGO used for simulations

Properties Values [Reference] Cps [J.kg -1. K -1 ] 350 [19] 𝜅 [W.m -1 .K -1 ] 2.52 [19] D [m 2 .s -1 ] 1.0 x 10 -6 [19] ρ [kg.m -3 ] 7220 (provider)
The program solves the macroscopic thermal equation ( 1) at each node of the grid and generates the temperature profile inside the volume of the structure.

Several steps and conditions were determined to carry out this simulation:

a. The geometry of the 1D model is simple (Fig. 1) as we consider only 1D diffusion in CGO electrolyte. The thickness of the CGO layer is around 20 μm in depth and it is assumed that the heat diffusion is limited in the electrolyte layer and no thermal effect reach the anode.

b. The time profile of the laser pulse q(t) ( 5) is described by a normalized Gaussian function [START_REF] Theodorakos | Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications[END_REF] depending on laser characteristics.

𝑞(𝑡) = 1 √2𝜋 * 𝑡 𝑠 𝑒𝑥𝑝 (- (𝑡-𝑡 𝑜 ) 2 2𝑡 𝑠 2 ) (5)
where 𝑡 𝑠 = 𝜏 2√2𝑙𝑛2 and 𝑡 𝑜 = 3 * 𝑡 𝑠 .  is the laser pulse duration, this parameter being specific to the used laser. c. Meshing: This procedure is a very important step for the reliability of the simulation results.

The meshing functionality allows the geometric model to be discretized into small units of simple shapes, called mesh elements. After several simulation tests with different meshing sizes, we have checked that the maximum meshing size that we can use has to be lower than the optical adsorption depth, which is defined as the reverse of the adsorption coefficient .

In such conditions, meshing size has minor effects on simulation results. d. Heat source is defined by equation ( 2), thereby it is necessary to determine optical properties of CGO (α and R).

e. Limit conditions have to be defined. The initial temperature of the sample is the ambient temperature, set at 20 ° C. The lower edge (bulk of material) is considered as adiabatic according to equation [START_REF] Morales | Intermediate temperature single-chamber methane fed SOFC based on Gd doped ceria electrolyte and La0.5Sr0.5CoO3-δ as cathode[END_REF] where n is the normal vector at the surface.

-𝑛. (-κ∇𝑇) = 0

On the upper surface (in contact with air), heat is lost by the combined action of natural convection and thermal radiation according to equation [START_REF] Chourashiya | Synthesis and characterization of electrolytegrade 10%Gd-doped ceria thin film/ceramic substrate structures for solid oxide fuel cells[END_REF].

-𝑛. (-κ∇𝑇) = ℎ(𝑇 -𝑇 ∞ ) + 𝜀𝜎(𝑇 4 -𝑇 ∞ 4 ) ( 7
)
where T∞ is the ambient temperature (20°C) , h is the convective exchange coefficient (10

W.m -2 .K -1
), σ the Stefan-Boltzman constant (5.67 x 10 -8 W.m -2 .K -4 ) and ε the emissivity of the material (0.8). These values have been extracted from the literature for cerium dioxide [START_REF] Huang | Highly enhanced infrared spectral emissivity of porous CeO2 coating[END_REF] because no values were found for CGO. We observed from various calculations that convection and thermal radiation do not have a significant influence on the results.

f. Concerning the solver: the time step (dt) of calculation must be imperatively less than the laser pulse duration (τ) for the calculation convergence.

The simulation was first developed for a single laser pulse. Then, simulations presented at the end of this paper consider consecutive laser pulses on CGO surface.

Experimental procedure

Laser annealing of CGO samples

CGO Samples Preparation

Half cells "electrolyte/anode" were prepared to perform laser annealing tests on CGO layers. All the materials used for cells preparation are commercial powders purchased from Fuel Cell Materials. The experimental procedure used to prepare half cells is described in detail elsewhere [START_REF] Rembelski | In situ reduction and evaluation of anode supported single chamber solid oxide fuel cells[END_REF][START_REF] Mariño | Laser induced densification of cerium gadolinium oxide:Application to single-chamber solid oxide fuel cells[END_REF]. made by an UV laser [START_REF] Mariño | Laser induced densification of cerium gadolinium oxide:Application to single-chamber solid oxide fuel cells[END_REF]. Irradiations of the electrolyte surface were performed in air, with series of pulses between 1 and 10 at various fluences. The surface microstructure was analyzed by scanning electron microscopy (FEG-SEM, Jeol JSM 6500 F). .

Optical characterization of CGO samples

Optical measurements were carried out on bulk samples of CGO annealed at 1350 ° C during 3h. The sample preparation was identical to the anode preparation explained in previous part but in this case, only using CGO powder. The surface sample was polished using a polishing cloth and a commercial colloidal solution of 1 μm particle size diamond to obtain a reflective surface.

Surface sample was analyzed by spectroscopic ellipsometry using an ellipsometer (UVISEL) equipped with a heating cell. Optical measurements were taken between 0.6 to 4.8 eV (258 to 2000 nm) with a step of 0.05 eV. To evaluate the evolution of optical properties as a function of temperature, experiments were carried out between 25 to 600 °C with 21 measuring points. The atmosphere in the heating cell was ambient air.

The samples were preheated to remove possible impurities adsorbed by the material. The measurements were made at an angle of incidence of 70° and the spot size illuminated by the light source was 1 mm in diameter.

The optical properties extracted from raw data of the ellipsometric experiments were the refractive index (n) and the extinction coefficient (k). The absorption coefficient was calculated using the equation [START_REF] Kleinlogel | Sintering and properties of nanosized ceria solid solutions[END_REF].

𝛼 = 4𝜋k 𝜆 (8)
where k is extinction coefficient and λ the wavelength.

The reflection coefficient R (9) of the material is deduced from the Fresnel relation

𝑅 = ( 𝑁 -1 𝑁 +1 ) 2 (9)
where N = n + jk is the complex refractive index

Results and discussions

Optical properties of CGO

Figure 2 shows the absorption coefficient (α) regarding to the photon energy and the sample temperature derived from values of n and k obtained by ellipsometry. Blue curves represent colder temperatures starting at 25°C. The highest temperature was around 578°C (black curve). These refractive index values can be compared with those found in the literature [START_REF] Ruiz-Trejo | The optical band gap of Gd-doped CeO2 thin films as function of temperature and composition[END_REF][START_REF] Suzuki | Optical properties of undoped and Gd-doped CeO2 nanocrystalline thin films[END_REF]. The evolution of the measured absorption coefficient is similar to that measured by Ruiz-Trejo [START_REF] Ruiz-Trejo | The optical band gap of Gd-doped CeO2 thin films as function of temperature and composition[END_REF]. For example, a large increase of α begins around 3.5 eV. Moreover, at 4.8 eV, our measured absorption coefficient is around 4.3 x 10 5 cm -1 , which is closed to ≈ 4 x 10 5 cm -1 obtained by Ruiz-Trejo.

A zoom in figure 2 shows that the absorption coefficient (α) in the IR laser region has a low dependence on temperature. For the energy at 1.15 eV (1078 nm) closed to our laser wavelength used for the densification, the mean value of the refractive index is 2.329 ± 0.003 which represents a small variation of about 0.1%, for the entire temperature range. It is therefore considered that the refractive index does not depend on the temperature in the zone of interest (IR laser), and we will use the corresponding value of adsorption coefficient α=5.1 x 10 3 cm -1 . Figure 3 shows the evolution of reflectivity as a function of temperature and photon energy. It is found that the highest reflectivity, around 0.28, is for energies of about 4 eV (309 nm). For the energy of concern in this work (1.16 eV, 1064 nm), the reflectivity is about 0.16. This parameter is also considered to be constant as a function of temperature for the simulation.

The non-dependency of  and R with temperature simplifies the simulation, regarding the equation ( 2). Indeed, it can be considered that the adsorbed IR laser energy do not depend on material temperature. This would not have been the case in the UV domain where  and R have significant variations as a function of temperature. In such a case, expressions of the absorption and reflection coefficients should have been written to express the variation as a function of temperature [START_REF] Theodorakos | Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications[END_REF].

Simulated temperature of laser-annealed CGO samples

As exposed previously, the 1D temperature model is based on the assumption that the thermal diffusivity length 𝑙 𝜏 (eq. 3) is negligible with respect to the laser beam diameter. Considering thermal diffusivity of CGO (D= 10 -6 m 2 .s -1 , table 1) and laser pulse duration ( = 10 -7 s), the calculated value of length 𝑙 𝜏 is 632nm. Regarding the laser beam diameter of 80µm, the hypothesis to apply a 1D simulation is fully acceptable.

Single pulse annealing

Preliminarily, simulations were performed only for a single laser pulse, with a duration of 100 ns. Laserannealing simulations were carried out by varying the laser fluence. We remind that the fluence is defined as the ratio of laser pulse energy over the irradiated area. The investigated range was from 0.4 J.cm -2 up to 3.5 J.cm -2 . Figure 4 represents the evolution of the surface temperature as a function of time for the various fluences. The simulation was evaluated over a time of 40µs, which corresponds to the period between two pulses of the IR laser. As a first result, it can be observed that the surface temperature of the sample increases significantly when the fluence increases. From a fluence close to 2 J.cm -2 , the maximum temperature begins to exceed the melting temperature of the CGO (2600 °C [START_REF] Konings | The Thermodynamic Properties of the f-Elements and their Compounds: Part 2. The Lanthanide and Actinide Oxides[END_REF][START_REF] Kotov | Properties of YSZ and CeGdO nanopowders prepared by target evaporation with a pulse-repetitive CO2-laser[END_REF]) and above 2.5 cm -2 , it can reach vaporization (3500°C [START_REF] Kotov | Properties of YSZ and CeGdO nanopowders prepared by target evaporation with a pulse-repetitive CO2-laser[END_REF]). Therefore, for fluences above 2 J.cm -2 , it should be necessary to consider phase changes in the model.

For all experiments, it is found that the sample does not have time to return to ambient temperature at the end of the simulation period, which is explained by the low thermal conductivity of CGO [START_REF] Brygo | Etude de l'interaction laser -matière appliquée à la décontamination de peintures[END_REF]. If a second pulse is applied, the initial temperature of the sample will be no longer the ambient temperature. Therefore, the surface temperature during the second pulse will be higher. This phenomenon will be simulated in the last part of this paper.

Figure 5 shows the maximum temperature reached by CGO as a function of depth in the electrolyte coating. These temperatures were reached for a time of 2.2 × 10 -7 s, as seen in figure 4.

The figure 5 points out that fusion or even vaporization temperature of CGO material is reached with highest laser fluences and it can concern the first 2 μm of the layer.

In order to confirm this result, SEM observations have been made on samples treated with such high fluences. Figure 6 shows the SEM image of the CGO layer exposed to a fluence of 3.5 J.cm -2 . It reveals that CGO surface appears to have been melted. However, the modifications are not homogeneous, which is probably due to inhomogeneity in the laser beam or in the material, or also to the possible vaporization of some part of the material. Below 2.5 J.cm -2 , no surface modification was observed, in close agreement with simulation result.

Multi pulses annealing

Only single laser pulse annealing was considered in the previous part of the paper. A simulation with consecutive pulses has been developed to be more suitable with experimental developments of laser annealing.

In order to simulate successive pulses during laser annealing, the Gaussian function q(t) defining the temporal profile of the pulse must be repeated periodically over time. As mentioned before, the corresponding time between two successive pulses of the IR laser is 4.10 -5 s.

Figure 7 shows the results obtained with 5 and 10 laser pulses with a fluence of 0.9 J.cm -2 . These results

show the accumulation of heat in the material between each laser pulse. CGO does not return to the initial temperature, so that the maximum surface temperature for successive pulses continuously increases.

The simulation results are consistent with microscopic surface observations. With a single laser pulse at 0.9 J.cm -2 , the maximum temperature is close to 1400°C (Figure 4), while with 5 pulses the temperature reaches 2025°C (Figure 7a). These temperatures are lower than the melting temperature and no surface change is observed (Figure 7c). However, with 10 pulses, the maximum temperature reached in the simulation is 2523°C (Figure 7b), a value very close to the melting temperature. Indeed, some surface changes are observed (Figure 7.d) indicating melting of the surface in a consistent way with simulation results.

Conclusions

The objective of this paper was to bring a comprehensive and quantitative simulation of laser matter interaction which can be used for localized thermal annealing of material, like for SOFC electrolyte in

( 1 )

 1 is a model of the temperature. 𝜌(𝑇)𝐶 𝑝 (𝑇) 𝜕𝑇(𝑥,𝑡) 𝜕𝑡 -𝜕 𝜕𝑥 (𝜅(𝑇) 𝜕𝑇(𝑥,𝑡) 𝜕𝑥 ) = 𝑄(𝑥, 𝑡)

Fig. 1 .

 1 Fig. 1. Schematic representation of laser annealing procedure

Fig. 2 .

 2 Fig. 2. Absorption coefficient of CGO at different temperatures as a function of photon energy. (Blue curves represent colder temperatures starting at 25°C and the highest temperature was around 578°C is the black curve. Inset corresponds to IR domain)

Fig. 3 .

 3 Fig. 3. Reflectivity of CGO at different temperatures as a function of photon energy. (Blue curves represent colder temperatures starting at 25°C and the highest temperature was around 578°C is the black curve)

Fig. 4 .

 4 Fig. 4. CGO surface temperature as a function of time with a pulse (100ns) of the IR laser (left: whole simulation duration, 4.10 -5 s, right: zoom on the first microsecond)

Fig. 5 .Fig. 6 .

 56 Fig. 5. Temperature profile at 2.2 x 10 -7 s of CGO layer treated with a single pulse of an IR laser

Fig. 7 .

 7 Fig. 7. CGO samples annealed by the IR laser with a laser fluence of 0.9 J.cm -2 : Thermal simulation results with a) 5 laser pulses, b) 10 laser pulses, and SEM micrographs of CGO surface treated by c) 5 laser pulses, d) 10 laser pulses

  this paper. The numerical resolution of heat equation adapted to thermal and optical properties of the considered material (CGO) allowed the simulation of the temperature profile over time and material depth, depending on the fluence of an IR pulsed laser. Experimental observations by SEM of CGO surface modifications were consistent with the simulation results, regarding maximum temperature leading to the fusion of the considered material. The optical properties of CGO material were reported as a function of temperature. The additional improvement of the present simulation taking into account phase changes (fusion, vaporization) is under way to simulate more accurately real phenomena occurring during laser annealing at high fluences.

Acknowledgements

This work was supported by the LABEX MANUTECH-SISE (ANR-10-LABX-0075) of Université de Lyon, within the program "Investissements d'Avenir" (ANR-11-IDEX-0007) operated by the French National Research Agency (ANR). This work was also performed within the framework of the EQUIPEX MANUTECH-USD (ANR-10-EQPX-36-01) operated by the French National Research Agency (ANR).


Eric Kergosien

Amin Farvardin
email: mohammadamin.farvardin@dauphine.eu

Maguelonne Teisseire

Marie-Noëlle Bessagnet

Joachim Schöpfel
email: joachim.schopfel@univ-lille3.fr

Stéphane Chaudiron

Bernard Jacquemin

Annig Lacayrelle

Mathieu Roche

Christian Sallaberry

Jean Philippe Tonneau

Automatic Identification of Research Fields in Scientific Papers

Keywords: text mining, natural language processing, geographical information retrieval, scientometrics, document analysis

The TERRE-ISTEX project aims to identify scientific research dealing with specific geographical territories areas based on heterogeneous digital content available in scientific papers. The project is divided into three main work packages: (1) identification of the periods and places of empirical studies, and which reflect the publications resulting from the analyzed text samples, (2) identification of the themes which appear in these documents, and (3) development of a web-based geographical information retrieval tool (GIR). The first two actions combine Natural Language Processing patterns with text mining methods. The integration of the spatial, thematic and temporal dimensions in a GIR contributes to a better understanding of what kind of research has been carried out, of its topics and its geographical and historical coverage. Another originality of the TERRE-ISTEX project is the heterogeneous character of the corpus, including PhD theses and scientific articles from the ISTEX digital libraries and the CIRAD research center.

Introduction

Widespread access to digital resources, via academic platforms -for example, the Gallica project (BnF)1 , the ISTEX2 platform, electronic theses and dissertation repositories (TEL), content federation services (Isidore), or electronic publishing platforms (OpenEdition) -offers numerous possibilities for users. The ISTEX initiative was launched to create innovative information retrieval services and provide access to digital resources through different search processes. The increasing adoption of information and communication technologies by researchers in different academic disciplines, especially in the social sciences and humanities, is changing the conditions of knowledge appropriation. Digital humanities have made it possible to develop platforms, providing researchers with large volumes of academic papers and with support services to add value and make use of them (e.g., the TELMA3 application).

The TERRE-ISTEX project was developed in this research context and proposes (1) to identify the covered territories and areas from scientific papers available in digital versions within and outside the ISTEX library, and (2) to evaluate the academic disciplines involved (e.g. history, geography, information sciences, etc.) as well as the evolution of disciplinary and multi-disciplinary research paradigms in selected topics. The results of this project will help scientists working on a given territory (areas at different scales, such as township, region, country, or continent) to retrieve papers on the same territory.

The TERRE-ISTEX Project

The generic approach used in the TERRE-ISTEX project is described in Figure 1. Regardless of any scientific publications corpus, a first step is to standardize textual documents. A second step is to identify, in metadata and contents of documents, the research fields as well as the scientific disciplines involved. The research field is defined as the locations constituting the territory in which the research is conducted on a given date or period of time. In the experimental section, we present a Web application called SISO to help domain experts to analyze and to validate annotated text samples. The indexed and val-idated data are then integrated into a documentary database in order to allow, on the one hand, the analysis of data and, on the other hand, the retrieval of papers on the same field and/or the same period and/or the same discipline or sub-domain using a Web-demonstrator of geographical information search.

The next section describes the corpus used within the framework of our project.

The corpus

Elaborating a corpus is a major prerequisite in the process of analysis and information retrieval. We targeted three sources of scientific papers, namely the ISTEX4 platform, the Agritrop5 open archive (CIRAD6 ), and a sample of PhD theses from the ANRT7 with associated metadata available on the portal theses.fr.

We conducted a case study on the topic of climate change in Senegal and Madagascar. We collected an initial corpus of documents from the ISTEX platform (about 170,000 documents) using queries with the following keywords: "climate change", "changement climatique", "Senegal", "Sénégal", "Madagascar". From the same keywords, we collected 400 theses from the ANRT database. Finally, the documents from Agritrop are related to studies dealing with Madagascar and the Senegal River. The 92,000 references and 25,000 full-text documents include different types of academic papers, i.e., scientific publications (i.e., articles, etc.), grey literature (e.g. reports, etc.), and technical documentation. Each document is associated with metadata, including an abstract.

The metadata formats of the different items depend on the document origin: MODS8 (ISTEX), XML based on the Dublin Core (CIRAD), and RDF (ANRT). The corpus is multilingual: most of the documents are either in French or in English, but there are also documents using both languages (for example, with a summary in French and a summary in English). The corpus is thus composed of multilingual and heterogeneous documents, both in terms of content and format.

An important step to standardize data 2.2.1 The process TERRE-ISTEX

Initially, the process developed by the TERRE-ISTEX project is applied to metadata and abstracts. Because of the data heterogeneity, we chose to standardize metadata using the pivotal MODS (Metadata Object Description Schema) format, recommended on the ISTEX platform. The MODS format has several advantages: (a) it is suitable for describing any type of document and any medium (digital or print); (b) it is richer than the Dublin Core; and (c) it is similar to the models for structuring bibliographic information used in libraries (e.g. MARC format). For these reasons, we apply, in a first step, an algorithm of model transformation to those 92,400 documents of the corpus which do not comply with this format. The second step concerns the annotation in the abstracts of spatial, temporal, and thematic entities. This step is detailed below. As a result, the MODS-TI data model expands the MODS format to describe spatial, temporal, and thematic entities extracted from documents. The MODS-TI model is detailed in the following section. Step 3 implements a new algorithm for transforming the MODS-TI format in order to create indexes so that all data can then be processed in the final stages of analysis and information retrieval.

The TERRE-ISTEX data model

The TERRE-ISTEX data model expands the MODS format to describe spatial, temporal, and thematic information extracted from documents and from corresponding metadata. The choice of MODS was determined by the fact that MODS is the main format on the ISTEX platform and by the advantages described above.

We added three tag sub-trees to a MODS document:

• <spatialAnnotations>,

• <temporalAnnotations>,

• <thematicAnnotations>.

In the following, we give an example of the sub-tree for spatial entities (ES). The tag <spatialAnnotations> contains a set of spatial entities (tag <es>), with the annotated text for each of them. (tag <text>) as well as its spatial footprint obtained by querying the GeoNames resource. The corresponding DTD is shown in Figure 2.

Named Entity annotation 2.3.1 Spatial entities

In the TERRE-ISTEX project, the methodology is based on linguistic patterns for the automatic identification of spatial entities (ES) [START_REF] Tahrat | Text2geo: From Textual Data to Geospatial Information[END_REF] Note that ESA and ESR integrated representation significantly reduces the ambiguities related to the identification of the right spatial footprint. Indeed, taking into account spatial indicators (e.g. "river" for "Senegal River") allows us to identify in GeoNames the right spatial footprint. To deal with distinct spatial entities with the same name (e.g. Bayonne in France and Bayonne in the United States), a disambiguation task is proposed in order to analyze the context in the textual documents [START_REF] Kergosien | When Textual Information Becomes Spatial Information Compatible with Satellite Images[END_REF]. In order to identify spatial entities, we apply and extend a Natural Language Process (NLP) adapted to Geographic Information Retrieval (GIR) domain. In this context, some rules (patterns) of [START_REF] Tahrat | Text2geo: From Textual Data to Geospatial Information[END_REF] have been integrated and improved to identify absolute and relative spatial entities in French (e.g. "sud-ouest de l'Arabie Saoudite" (ESR), "dans la région du Mackenzie" (ESR), "golfe de Guinée" (ESA), "lac Eyre" (ESA)). These rules have been translated in English to analyze English corpora (e.g. "Willamette River" (ESA), "Indian Ocean" (ESA), "Wujiang River Basin" (ESA)) of TERRE-ISTEX project. Moreover, we propose new types of rules in order to identify Organization (for example, an "Organization is followed by an action verb"). These different rules developed with GATE1 enable to disambiguate extracted entities and then to improve named entities recognition.

Thematic and temporal entities

In order to enhance the knowledge identified in metadata and to specify the subdomains, we apply modules in text mining to the content of the publications to extract domain vocabularies. First, we use domain semantic resources for lexical annotation. As, in our case, the thematic entities to be annotated are linked to climate change, we rely on the Agrovoc resource [START_REF] Rajbhandari | The AGROVOC Concept Scheme: A Walkthrough[END_REF]. Agrovoc is formalized in XML SKOS. In the indexing phase, we mark for each term the content of an article coming from Agrovoc with the terms "used for" and the generic terms, information that will be exploited in the search engine. In the long term, we aim to propose a generic approach by giving the possibility of easily integrating a new semantic domain resource formalized in XML SKOS. Also, we plan to integrate the BioTex module developed by the TETIS team in Montpellier Lossio-Ventura et al. ( 2016) combining statistical and linguistic approaches to extract terminology from free texts. The statistical information provides a weighting of the extracted applicant terms. However, the frequency of a term is not necessarily an appropriate selection criterion. In this context, BioTex proposes to measure the association between the words composing a term by using a measure called C-value while integrating different weights (TF-IDF, Okapi). The goal of C-value is to improve the extraction of multi-words terms that are particularly suitable for specialist fields.

For the temporal entities, we have integrated the HeidelTime processing chain [START_REF] Strötgen | Multilingual and cross-domain temporal tagging[END_REF] to mark calendar entities (dates and periods). HeidelTime is a free, rule-based, time-sensitive labeling system for temporal expressions, available in several languages. Regarding English, several corpora of documents (i.e., scientific articles, press) have been treated [START_REF] Strötgen | Multilingual and cross-domain temporal tagging[END_REF]. The evaluation of this system shows better results for the extraction and standardization of temporal expressions for English, in the context of the TempEval-2 and TempEval-3 campaigns UzZaman et al. ( 2013) and extended to 11 languages including French [START_REF] Moriceau | French resources for extraction and normalization of temporal expressions with HeidelTime[END_REF]. HeidelTime produces annotations in the ISO-TimeML format, which distinguishes between four categories of temporal expressions: dates, times, durations and frequencies. Since our objective is to know the periods covered in the documents, we are only interested in temporal expressions with a calendar connotation.

Experiments

First experiments

The sociologists and geographers working in the project evaluated the spatial entities extraction process. The French corpus is composed of 4,328 words (71 spatial features and 117 organizations). The evaluations (with classical measures, i.e., precision, recall, and F-measure) have been investigated by comparing the manual extraction done by experts with the web service results. For spatial entities, we obtain a good recall (91%) and an acceptable precision (62%). The F-measure is 0.74. The great majority of Spatial Features (SF) are extracted but there are still some errors. The rules to identify organization are very efficient and give high precision (85%) but the value of recall is lower (67%). The F-measure for organization identification is 0.74. The rules for organization extraction seem well adapted to the domain but they have to be extended in order to improve the recall that remains low.

Moreover, in order to evaluate our approach of annotation of the ESA and ESR on a scientific corpus, we manually annotated 10 scientific articles in French, and 10 in English from the corpus on the 'climate change' topic. Items are randomly selected. The documents averaged 230 words and contained 39 spatial entities (i.e., ESA, ESR). We then annotated these documents with two processes: the CasEN chain, a reference in the field for the marking of named entities [START_REF] Maurel | CasEN: a transducer cascade to recognize French Named Entities[END_REF], and ours.

We obtained good results in terms of precision, recall, and F-measure with our process (see Tables 1 and2). Nevertheless, we have issues with disambiguation of named entities (Organization and spatial entities) in English and we have to improve our process for scientific articles in English.

It is significant that the results coming from the CasEN chain are far better when processing French than English too. Assuming this difference is not directly linked to the test corpus, and besides the above disambiguation issue, we consider English linguistic specificities as an explanation. In particular, links between items of a multiword spatial entity are seldom made explicit, neither by a common morphological feature, nor by a linking preposition. In order to validate these initial results, we are currently working on an evaluation concerning a corpus of 600 scientific articles from the ISTEX platform, 300 written in French and 300 in English. The articles were randomly selected from the 40,000 scientific articles related to the theme of 'climate change'. In this case, on the first 140 documents manually annotated by experts working in the project, we obtain a precision of 78%. The complete evaluation process is in progress. Producing a bigger annotated scientific corpus (with spatial entities, temporal entities and topics) is also an objective for other ISTEX research groups.

To help experts to analyze corpora, and particularly information related to territories, a Web application SISO9 has been developed.

SISO Web Application to index and analyze corpora

The SISO Web application (Figure 3) allows users to upload corpora, to index documents with specific web services in order to mark different kinds of information (spatial features, organizations, temporal features, and themes), to visualize and to correct the results, and to download validated results in XML format. More specifically, it is possible to upload corpora (frame 1), each marked corpus is saved on the server and automatically available in the web application (frame 2). After having downloaded Figure 3: The Web application called SISO documents, users can select the marked features (frame 5), see the results on the selected documents in frame 3. By selecting different categories from frame 5, the related marked information will be kindles in frame 3 and listed by type in frame 4. In case of finding any mistakes, users can unselect marked information (frame 4). Finally experts can export the selected corrected documents as a new corpus by clicking the top right button. The downloaded corpus, in XML MODS format, consists of selected documents with the marked information except those removed by the user.

The administration page allows users to upload, edit, and delete pipelines defined in the GATE format. It is also possible to remove processed corpora, to edit the uploaded pipeline rules and the available lexicons.

In order to provide experts with a web tool to process big data related to their domain, the TERRE-ISTEX approach was improved. The performance of the system, tested on 8,500 documents, are presented below:

• Temporal entity annotation: 8,196 seconds,

• Agrovoc entity annotation: 1,606 seconds,

• Search of concept and linked concept using the offline Agrovoc ontology: 36 seconds,

• Spatial entities annotation (French and English): 4,940 seconds,

• JSON index file generation: 55 seconds.

The global process takes 16,105 seconds for processing all documents, i.e., 1.9 seconds per document. This result is very encouraging.

Conclusion

In this article, we describe a method to deal with scientific literature on climate change from three different corpora of scientific papers. One main issue was the standardizing of data. Therefore, we have developed algorithms and a unified data model. Then, we have defined an automatic process to identify information related to a territory (spatial, temporal, and thematic information) in the documents.

Up to now, the entire corpus is indexed in JSON format. We are currently working on the enrichment of the temporal entity marking chain to integrate the BioTex tool, and on the extension of tagging assessments of marked (spatial, temporal and thematic) entities in voluminous corpus. Recently, we started to index our data with the Lucenebased search engine Elasticsearch1. Elasticsearch will facilitate the test of defined work use-cases. The main goal is to help researchers analyze big data corpora, and especially those who are interested in research related to a territory.

In our future work, we plan to use machine-learning approaches in order to improve the disambiguation process of spatial entities (i.e., ES vs. Organization). More precisely, based on our previous work [START_REF] Tahrat | Text2geo: From Textual Data to Geospatial Information[END_REF], we will propose to integrate the patterns described in section 3.1. as features in the supervised learning model based on the SVM algorithm. Then, we plan to compare our final model to the state-of-theart, and specifically to the ISO-Space model produced to annotate Spatial Information from textual data [START_REF] Pustejovsky | ISO-Space: Annotating Static and Dynamic Spatial Information[END_REF].

Figure 1 :

 1 Figure 1: Generic Approach to Multidimensional Analysis of Scientific Corpus

Figure 2 :

 2 Figure 2: DTD describing the tag <spatialAnnotations>

Table 1 :

 1 Evaluation of spatial entity annotation on 10 articles from the French corpus

		ESA, ESR	ESA, ESR
		(TERRE-ISTEX)	(CasEN)
	Precision	100%	93%
	Recall	90%	77%
	F-Measure	.947	.842
		ESA, ESR	ESA, ESR
		(TERRE-ISTEX)	(CasEN)
	Precision	90%	94%
	Recall	60%	53%
	F-Measure	0.72	0.68

Table 2 :

 2 Evaluation of spatial entity annotation on 10 articles from the English corpus

http://gallica.bnf.fr/

http://www.istex.fr/

http://www.cn-telma.fr/

http://www.istex.fr/category/plateforme/

https://agritrop.cirad.fr/

http://www.cirad.fr

https://anrt.univ-lille3.fr/

http://www.bnf.fr/fr/professionnels/f_mods/s.mods_presentation.html

http://geriico-demo.univ-lille3.fr/siso/

Acknowledgements

This work is funded by ISTEX (https://www.istex.fr/), SONGES project (Occitanie and European Regional Development Funds), and DYNAMITEF project (CNES).