Sylvie Blangy

Monique Bernier
email: monique.bernier@ete.inrs.ca

Najat Bhiry

Jean-Pierre Dedieu

Cécile Aenishaenslin

Suzanne Bastian

Laine Chanteloup

Véronique Coxam

Armelle Decaulne

José Gérin-Lajoie

Dedieu Jean-Pierre

Stéphane Gibout

Didier Haillot

Emilie Hébert-Houle

Thora Martina Herrmann

Fabienne Joliet

Annie Lamalice

Esther Lévesque

André Ravel

Daniel Rousse

OHMi-Nunavik: a multi-thematic and cross-cultural research program studying the cumulative effects of climate and socio-economic changes on Inuit communities

Keywords: Inuit culture, global change, participatory action research, sustainable community development, well-being, food and energy independence MOT CLÉS culture Inuit, changement climatique, recherche-action participative, développement communautaire durable, bien-être, indépendance alimentaire

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INTRODUCTION

OHMi-Nunavik: a multi-thematic and cross-cultural research program studying the cumulative effects of climate and socio-economic changes on Inuit communities

Introduction

Adjusting to global climate and socio-environmental changes has become a major issue for Northern communities. The Arctic is one of the most rapidly changing regions on the planet, confronting Inuit communities with many challenges (Larsen and Fondahl 2015). Northern residents are witnessing accelerated warming in this region [START_REF] Pearce | Community research collaboration in the Canadian Arctic[END_REF]). In addition, there is significant pressure to exploit natural resources in these regions, despite calls for sustainable development by local populations [START_REF] Asselin | Plan Nord: les Autochtones laissés en plan[END_REF].

Arctic communities are concerned about their future and wish to better understand the social, environmental and economic changes related to ongoing industrial development and climate change [START_REF] Rodon | De Rankin Inlet à Raglan, le développement minier et les communautés inuit[END_REF]. These concerns include the effects of climate change, mining and non-traditional lifestyles on their health, well-being and quality of life. They also worry about the future of young people and their education, the widening generation gap, the preservation of traditional hunting, fishing and gathering techniques, as well as threats to Inuit culture and language [START_REF] Laugrand | Education and transmission of Inuit knowledge in Canada[END_REF].

Nunavik is an Arctic region comprising the northern third of Quebec, Canada. It has a population of approximately 12,000, mostly Inuit (Nunavimmiut), living in 14 coastal communities. In 2013, an International Observatory of Human-Environment Interactions (OHMI) 1 was established in Nunavik in collaboration with the Kativik Regional Government, the Nunavik Research Centre (Makivik Corporation), the inter-institutional Centre for Northern Studies (CEN) (based in Quebec City) and several French research institutes coordinated by the National Centre of Scientific Research (CNRS) to develop an integrated, holistic research program to assist the Nunavimmiut to address contemporary challenges and better prepare for the future.

The OHMi Nunavik is the 8 th observatory founded under the network 'Laboratoire d'Excellence Dispositif de Recherche Interdisciplinaire sur les Interactions Hommes-Milieux' (LabEX DRIIHM 2 ). OHMs aim at reflection, research guidance and in-depth analysis of spatiotemporal transformations within a given socio-ecosystem [START_REF] Lagadeuc | Les systèmes socioécologiques: vers une approche spatiale et temporelle[END_REF][START_REF] Chenorkian | Étudier les interactions hommesmilieux, pourquoi et comment?[END_REF]. Human beings are at the heart of the studied systems, the research focusing on complex interactions within the systems.

The research priority areas of the OHMi Nunavik are linked to the impact of climate and socioenvironmental changes on Arctic communities: elderyouth knowledge transmission, northern agriculture (greenhouses), preservation of Inuit culture, language and identity, protected areas, mining employment, natural hazards, wildlife vulnerability, food security, landscape transformation, renewable energy, and training and capacity-building. Given the interrelationship between these topics, the OHMi Nunavik chose to study these issues as a system rather than sequentially. The research program was named TUKISIK, which means 'understanding together' 3 in Inuktitut (the Inuit language). This paper has three aims: (i) to introduce the OHMi Nunavik Special Issue, (ii) to present the originality of the OHMi Nunavik methodological approach, which involved multidisciplinary experimental science, citizen science, traditional knowledge, and collaborative research, and (iii) to provide a brief overview of six ongoing projects, the interrelationships between these projects, and how each could contribute to the wellbeing of Nunavik communities. The themes of the six projects are: (1) the relationship of dogs to Inuit health and well-being; (2) strategies to ensure food security;

(3) reducing fossil fuel dependence with renewable energy and energy efficiency; (4) risk assessment of landslides in a national park; (5) Inuit modes of relating to the land; and (6) monitoring water quality of a local river. Finally, the short-term benefits so far generated by the OHMi research projects are discussed.

Ecosystem approach

Location

The research is based in Nunavik, an Arctic region located in the northern third of Quebec, Canada, north of the 55 th parallel. The population of 12,000 is mainly Inuit, living in 14 coastal communities along the eastern Hudson Bay, the Hudson Strait, and Ungava Bay. Figure 1 shows the location of these communities as well as the national parks in the region. OHMi Nunavik currently has projects in four northern villages and two national parks.

OHMi research priorities

The research priorities of OHMi Nunavik were initially identified in 2013 during a one-week field trip of two academics in Kangiqsujuaq and Kuujjuaq, two of the 14 Nunavik communities. Then, the topics were carefully selected by all the academics and Nunavimmiut participants at a 3-day participatory workshop in Québec City and a first call for projects was launched in 2014. The annual calls for projects are widely disseminated in France and Canada. Several French/ Canadian/Inuit interdisciplinary teams have responded, resulting in the funding of 16 annual projects since 2014. The projects are grouped into six main interdisciplinary programs (Figure 1): ECOHEALTH, IMALIRIJIIT, 4 NIQILIRINIQ, 5 NUNA, 6 SEQINEQ, 7 VERSANTS. The themes of these research areas are respectively Dogs-Human Health, Water quality, Food security, Relationship to the land, Energy, and Landslide risks. All these programs are closely interrelated. The OHMi board has made the choice to support a small number of projects (five to seven each year) and strengthen the existing research teams rather than attracting new teams to the program as it takes time to build a trust relationship with the communities. Each year at the annual TUKISIK seminar, participants attempt to strengthen the ties between project teams by exchanging on various issues such as research ethics, communication with communities, outreach, and data management.

OHMi interdisciplinary research teams

The OHMi Nunavik team is multidisciplinary. For example, the community-based water quality survey [START_REF] Gérin-Lajoie | IMALIRIJIIT: a community-based environmental monitoring program in the George River watershed[END_REF]) brings together ecologists, chemists, geographers, and remote sensing specialists. The academics also work in collaboration with an Environment Canada Laboratory, which conducts field sampling and analysis of water samples, as well as with the Nunavik Research Centre, which analyzes contaminants in fish specimens. Veterinarians, epidemiologists and anthropologists are involved in the ECOHEALTH program. Researchers in the different projects also cross-collaborate: for example, the engineers in SEQINEQ (energy) are looking at how to heat greenhouses more efficiently in collaboration with the nutritionists and geographers in NIQILIRINIQ (food security). These teams also work closely together to gain a better understanding of the particularities of greenhouses in a Northern context, in terms of both physical and social aspects [START_REF] Lamalice | Building food security in the Canadian Arcticthrough the development of sustainable community greenhouses and gardening[END_REF].

Developing collaboration between OHMi researchers has been important for several reasons. One is that researchers want to avoid being intrusive: different groups of scientists may feel like an 'invasion' to small communities (200-2000 inhabitants). Another is to avoid repetitive interviews and visits, which can lead to research fatigue and saturation. A third is to reduce research costs by sharing documents, data and travel logistics. Lastly, the aim is to create synergies in the way results are conveyed to local Inuit partners. For example, the NIQILIRINIQ (food security), SEQINEQ (energy) and ECOHEALTH projects deal with the same communities and closely interact with each other. The ECOHEALTH program served as a source of inspiration to NIQILIRINIQ regarding the 'Ecohealth' approach, which is based on systemic, holistic, cross-disciplinary, participatory research oriented toward local and sustainable solutions with gender and social equality [START_REF] Charron | Ecohealth research in practice innovative applications of an ecosystem approach to health[END_REF]. The SEQINEQ team designed its project collaboratively with NIQILIRINIQ. They shared data and the same Inuit research assistant and intend to develop a web portal to disseminate their results together. SEQINEQ is looking at how to heat greenhouses, thus NIQILIRINIQ serves as a laboratory for that project [START_REF] Lamalice | Building food security in the Canadian Arcticthrough the development of sustainable community greenhouses and gardening[END_REF]). These collaborations are leading to an interdisciplinary synergy that can respond more effectively to the diverse needs of stakeholders, especially with regard to implementing new strategies for food and energy security in Nunavik. Interactions such as these will increase over time as researchers come to know each other and identify their needs for specific expertise. The five communities directly involved in OHMi Nunavik also support this aim of collaborative research.

Participatory action research and community-based environmental monitoring

For the most part, the TUKISIK programs use the methodologies of participatory action research (PAR) and community-based environmental monitoring (CbEM). These approaches have been used for many years in the Canadian Arctic by CEN 8 and ArcticNet 9 researchers [START_REF] Allard | Nunavik and nunatsiavut: from science to policy. An Integrated Regional Impact Study (IRIS) of climate change and modernization[END_REF]. The PAR approach is based on the idea that research should be done 'with' and 'for' rather than 'on' people. It employs a wide range of tools to support evidence-based thinking and processes that link traditional/local knowledge with expert/scientific understanding to create new social knowledge. The PAR approach promotes action learning, meaningful collective work, and community decision-making, empowering participants to define their priorities and to take action (Chevalier and Buckels 2009; 10 Blangy et al. 2010; Blangy 2017). The CbEM approach is a useful way to build bridges between Indigenous and scientific knowledge, to create trust between communities and scientific institutes, to engage community members in the scientific process, and to generate community-oriented data that can be used to make conservation management decisions [START_REF] Lefler | Successful community-based monitoring in Canada: three case studies[END_REF]. In this way, the joint use of PAR and CbEM can lead to community empowerment, especially in terms of the involvement of young people. Nevertheless, there are also challenges associated with PAR and CbEM, such as non-systematic data collection, loss of interest by volunteers, and how data ownership is defined.

In the remote Indigenous communities in Northern Canada, there is growing interest in PAR and CbEM programs. This can be tied to an increase in the following: recognition of the value of Indigenous knowledge, use of participatory methods for community-based research (Berkes and Armitage 2010), community concern regarding the local impacts of environmental change related to anthropogenic activities, interest in building local capacity to monitor changes, and community control over resource management decisions [START_REF] Gordon | Arctic borderlands ecological knowledge co-op community reports 2006-07[END_REF][START_REF] Gearheard | The igliniit project: combining Inuit knowledge and geomatics engineering to develop a new observation tool for hunters[END_REF]). This approach is responsible for the success of the community-based environmental water-quality monitoring program [START_REF] Gérin-Lajoie | IMALIRIJIIT: a community-based environmental monitoring program in the George River watershed[END_REF].

The challenge of community-based monitoring is that it takes months or even years to establish contact with a community, gain its trust, and develop a real partnership. In the initial outreach it is essential to consult representatives from municipal councils, landholding committees, culture committees and youth committees to begin building these relationships. For example, the NUNA (relationship to the land) participation-based program has been particularly well-received as it aims to promote the inhabitants' own perceptions and has focused attention on Tursujuq National Park [START_REF] Chanteloup | The environment of the Nunavimmiut as seen through their own eyes[END_REF]). However, participation and responsibility sharing between researchers and inhabitants has not always been symmetrical. The research strategy was primarily framed by the researchers, although it was discussed with the various research stakeholders. Researchers also encountered translation problems and cultural misunderstandings. For example, words such as 'landscape' and 'national park' lack equivalents in Indigenous languages.

Research questions and benefits by theme

Ecohealth: the relationship of dogs to Inuit health and well-being This project explores the crucial status of dogs within Inuit culture and how they help to improve the wellbeing of Arctic communities. Prior to the settlement of the Inuit in the 1950s, dogs formed a vital part of the community, essential for survival in harsh living conditions [START_REF] Lévesque | Là où le bât blesse: soixante ans de gestion des chiens au Nunavik[END_REF]. Today, interactions with dogs are changing, and they may even represent a threat to human health [START_REF] Messier | Seroprevalence of seven zoonotic infections in Nunavik, Quebec (Canada)[END_REF][START_REF] Jenkins | Tradition and transition: parasitic zoonoses of people and animals in Alaska, Northern Canada, and Greenland[END_REF][START_REF] Aenishaenslin | Characterizing rabies epidemiology in remote inuit communities in Quebec, Canada: a "one health" approach[END_REF][START_REF] Goyette | Seroprevalence of parasitic zoonoses and their relationship with social factors among the Canadian Inuit in Arctic regions[END_REF][START_REF] Schurer | Stabilizing dog populations and improving animal and public health through a participatory approach in indigenous communities[END_REF]. The objective of this project is to understand the impact of dogs on the health and well-being of Kuujjuaq residents (Figure 2) and to mitigate the risks of Inuit-dog-environment interactions to optimize wellness.

Long an integral part of the Inuit's physical, social and cultural environment, dogs today may also pose a health threat to Nunavik residents due to attacks, bites, and the risk of rabies and other diseases, sometimes resulting in death [START_REF] Herbert | Animal-related public health crises in first nation communities[END_REF][START_REF] Jenkins | Tradition and transition: parasitic zoonoses of people and animals in Alaska, Northern Canada, and Greenland[END_REF][START_REF] Aenishaenslin | Characterizing rabies epidemiology in remote inuit communities in Quebec, Canada: a "one health" approach[END_REF]. Dogs in the North are not always tied up and breed freely, leading to a recurring overpopulation that exacerbates these threats. The prevention of issues resulting from human-dog interactions in Nunavik first requires acknowledging Inuit perspectives and the positive impacts of dogs on well-being.

This study is part of a broader initiative carried out by the Université de Montréal (vetnunavik.ca) to set up different animal health services in response to the veterinary public health issues in Nunavik. The problem is complex, with numerous interrelated issues. Stakeholders include public health officials, as well as municipal and regional governments, with individuals playing an important role in a context where two cultures coexist: Inuit and Western. Certain solutions implemented by some are perceived as problematic by others. The trauma following the dog culls by authorities in the 1950s and 60s is still very present in Inuit communities [START_REF] Lévesque | Là où le bât blesse: soixante ans de gestion des chiens au Nunavik[END_REF].

To mitigate risks from dogs while maintaining their positive impacts, an 'Ecohealth' approach was chosen. This is based on systemic, holistic, cross-disciplinary, participatory research, oriented toward local and sustainable solutions with gender and social equality [START_REF] Charron | Ecohealth research in practice innovative applications of an ecosystem approach to health[END_REF]. In addition, a 'two-eyed seeing' framework was adopted, that is, the principle that the contributions of both Indigenous and Western epistemology and knowledge are equally required in order to understand and solve issues [START_REF] Martin | Two-eyed seeing: a framework for understanding indigenous and non-indigenous approaches to indigenous health research[END_REF].

One aspect of the study was a survey conducted with 67 Kuujjuaq dog owners. Of these, 35 (52%) were Inuit: a participation that was higher than expected. This survey comprehensively documented dog demographics, housing, feeding and health [START_REF] Aenishaenslin | Kuujjuaq dog survey-2015[END_REF]. It also provided insight on contacts between dogs and wildlife. With regard to human-dog interactions, Inuit more often than non-Inuit respondents strongly agreed that dogs are important. Inuit also more often reported that they, or a member of their family, had been bitten or scratched by a dog in Nunavik. In case of a dog bite, 70% of respondents would go to the hospital, 21% would kill the dog, and Inuit would less often than non-Inuit consider the risk of rabies. Finally, more Inuit strongly agreed that there were too many dogs in Kuujjuaq, highlighting the dog overpopulation issue.

To report back on the most significant survey results to the residents of Kuujjuaq, three focus groups were held to discuss the content and format in which they should be disseminated. This process led to the production of three posters that were displayed throughout the village and a radio broadcast (also available on Facebook) on the day the annual Ivakkak dogsled race ended in Kuujjuaq in April 2016 (Figure 2). In addition, results from the surveys were combined with direct observations and participative observations to draw a graph illustrating the complexity of the problem (Figure 3). This breaks down the diverse topics raised by Nunavik residents about dog health and well-being, and about human health and well-being as related to dogs, showing the links between those topics. This identification of the issues at stake relating to Inuitdog-environment interactions is the starting point for a joint prioritization of the issues and a selection of optimal mitigating measures in the context of Nunavik. This will be carried out with participatory multicriteria analysis [START_REF] Aenishaenslin | Multi-criteria decision analysis as an innovative approach to managing zoonoses: results from a study on Lyme disease in Canada[END_REF][START_REF] Marsh | Prioritizing investments in public health: a multi-criteria decision analysis[END_REF].

NIQILIRINIQ: strategies to ensure food security and sovereignty

The researchers involved in NIQILIRINIQ (also named Food System or Greenhouse) study how the recent establishment of horticultural production in greenhouses in the Arctic could contribute to improving the quality of life, health and well-being of Nunavik residents. Before colonialism and settlement, the Inuit were self-sufficient in terms of food provision. Today, 80% of the Inuit diet is composed of store-bought food and 62% of Inuit households face food insecurity [START_REF] Huet | The prevalence of food insecurity is high and the diet quality poor in Inuit communities[END_REF]. In less than a century, this has resulted in drastic changes that negatively impacted the health of Northern residents. The OHMi Nunavik team is working on developing alternative food security strategies in collaboration with Northern communities. The first objective is to document the advantages and challenges of the different food systems in Nunavik: the current store-based food supply system, the 'country-food' system, 11 and the more recent local food production system. The second objective is to contribute to the development of alternative food procurement strategies in Kuujjuaq and Kangiqsujuaq by supporting and accompanying the implementation of gardening projects to improve the supply and availability of fresh local food.

In Nunavik, rapid changes in the Arctic environment coupled with lifestyle disruptions due to settler colonialism (e.g., forced sedentarization, evangelization, and integration into the market economy) have greatly affected the ability of residents to meet their dietary needs in a way that responds to cultural sensitivity as well as to a holistic conception of health [START_REF] Counil | Association between trans-fatty acids in erythrocytes and pro-atherogenic lipid profiles among Canadian Inuit of Nunavik: possible influences of sex and age[END_REF][START_REF] Counil | Alimentation et santé publique dans les communautés des inuit du nord du Québec: vers un changement de paradigme?[END_REF]. The increase in consumption of storebought food along with a decline in physical activity have led to the rise of chronic diseases such as obesity and Type 2 diabetes [START_REF] Damman | Indigenous peoples' nutrition transition in a right to food perspective[END_REF][START_REF] Château-Degat | Obesity risks: towards an emerging Inuit pattern[END_REF]. Fresh products such as fruit and vegetables are eaten in low quantities, due to the high cost of shipping and storage, which makes them very expensive, and the long delivery time, which tends to damage them, making their consumption less attractive [START_REF] Avard | Northern greenhouses: an alternative local food provisioning strategy for Nunavik[END_REF].

This research project began in 2015, taking over from an investigation that started in 2009 on Northern agriculture in Kuujjuaq (Avard 2015; [START_REF] Lamalice | Soutenir la sécurité alimentaire dans le Grand Nord: projets communautaires d'agriculture sous serre au Nunavik et Nunavut[END_REF], where two community greenhouses are in operation. The success of Kuujjuaq's greenhouses was of interest to other Nunavik villages facing food insecurity. The current project was coconstructed with local residents around three main themes: (1) Ethnobotany: Which plants are residents particularly interested in and could they be cultivated in a greenhouse? (2) Nutrition and health: What are the nutritional contributions of a community greenhouse in the Arctic? What are the benefits for health and well-being? (3) Technical aspects: What productivity can be expected from a greenhouse? How can gardening techniques be learned and the knowledge shared? How should the greenhouse be designed? What kind of energy system should it use?

Given these multifaceted challenges, a multidisciplinary perspective combining local stakeholders, geographers, ethnobotanists, nutritionists, and energy engineers seemed indispensable. Two field trips were organized to launch this action research project in Kuujjuaq and Kangiqsujuaq. The first phase identified the benefits of a greenhouse project from the viewpoint of the gardeners in Kuujjuaq, and the aspirations of the residents of Kangiqsujuaq, who are planning to develop their own gardening activities. Data was collected using participatory workshops and supplemented by semistructured interviews as well as questionnaires. Nine gardeners from Kuujjuaq's greenhouses volunteered to gather data during the 2016 season.

Benefits of a northern greenhouse project

The main benefit cited by Kuujjuaq gardeners in terms of their participation in the community greenhouse is the general well-being it brings, followed by pride in producing their own food and nutritional benefit of this food. These benefits have an important environmental dimension, with some gardeners explaining that it is a 'more ecological' way to produce and consume food in the North, as shipping food by airplane is highly polluting. Participation in the community greenhouse project represents a learning opportunity for gardeners, as well as for young people.

Comparing the actual benefits perceived by gardeners after the establishment of a greenhouse (as in Kuujjuaq) with the initial motivations of a community before a greenhouse is developed (as in Kangiqsujuaq) gave rise to interesting observations. In Kuujjuaq, the main benefit was related to general well-being, whereas in Kangiqsujuaq the production of good quality food was the most-cited benefit, followed by the cost, as fresh food is currently expensive.

The choice of crops

The two greenhouses in Kuujjuaq are divided into 4 m 2 garden beds which are allotted to gardeners through an annual draw. Leafy green vegetables and radishes represent the main crops as they grow quickly and are therefore the first ready for harvest. Lettuce and arugula also allow several harvests in one season, which is an advantage in the short Arctic summer. In Kangiqsujuaq, where a greenhouse/gardening project is being launched, community members expressed the types of plants they wanted to grow during a workshop in 2016. Interestingly, the first plants considered were local/traditional plants: blueberries (kigutanginnaqutik), cloudberries (arpiqutik) and black crowberries (paurngaqutik). The preferred vegetables were tomatoes, potatoes, carrots and lettuce. These responses indicate the importance people in Kangiqsujuaq give to local plants, which are a key part of the traditional diet as well an integral part of Inuit culture and spirituality. Moreover, recent changes in local climatic conditions are affecting the availability and productivity of wild berries, which further explains the desire to grow these local plants.

The preliminary results show that developing local food production corresponds not only to a need expressed by residents, but has the potential to overcome certain difficulties associated with the transport, freshness, affordability and availability of food, as well as to enhance well-being, health and youth education. The development of community greenhouse projects cannot replace the cultural and spiritual experience of going on the land to gather berries or plants. Nevertheless, the benefits reported by greenhouse gardeners, who most cited well-being as a positive effect, are encouraging. In addition to the social aspects of gardening, the nutritional contributions of the garden plants were also evaluated in term of micronutrients (minerals and vitamins). Further, environmental issues linked to greenhouse gardening were studied, as fertilization of the local soil used in the garden beds, greenhouse energy optimization to increase the length of the growing season, and mitigation of carbon dioxide emissions. Those questions and their results are discussed in [START_REF] Lamalice | Building food security in the Canadian Arcticthrough the development of sustainable community greenhouses and gardening[END_REF]. Although community greenhouses and gardening projects cannot solve the multiple issues linked to food insecurity in the region, they can be considered as one element of a community-based strategy to increase food independence in the North.

SEQINEQ: reducing fossil fuel dependence with renewable energy and energy efficiency

Nunavik's electricity production is currently based on diesel-powered generators (Hydro-Québec 2013a, 2013b). Heating and domestic hot water are mainly fueled by oil. In 2009, each household in the region consumed an average of 3200 liters of heating oil, for an annual total of 28 million liters [START_REF] Cherniak | Report on the state of alternative energy in the Arctic[END_REF]. This dependence on fossil fuels causes a number of problems, ranging from the emission of greenhouse gases and pollutants to increased vulnerability to price changes and supply problems. Furthermore, due to population growth and industrial development, Nunavik's energy consumption is projected to increase by 23% every ten years (Hydro-Qu ébec 2013b). To meet this rising demand for energy while reducing dependence on petroleum products, several solutions have been considered (e.g., hybrid wind/diesel systems, micro-hydropower plant) but

have not yet been implemented for technical and/or economic reasons [START_REF] Cherniak | Report on the state of alternative energy in the Arctic[END_REF]. The SEQINEQ project is investigating a strategy known as 'negaWatt' well-known to French energy engineers aiming at first implementing energy reduction actions, then energy efficiency measures, before finally implementing renewable energy solutions [START_REF] Négawatt | The negaWatt energy scenario, association négaWatt[END_REF].

Energy reduction is best explained by the motto 'The best way to save energy is to avoid consuming it!' This type of measure is only possible if there is a genuine desire for energy reduction in a local community. It can be promoted through awareness-raising actions that accept and encourage the participation of all stakeholders. In Nunavik these types of actions have been carried out by the Kativik Municipal Housing Bureau, which is in charge of 2700 dwellings and has integrated energy issues in its 'Nanuk' workshops targeting primary school children [START_REF] Pivallianiq | Forging a pact for better living with Nunavik's communities[END_REF].

Energy efficiency involves minimizing the energy consumption of a given service. In Nunavik, the main sources of energy consumption are lighting, electronics and household appliances (electricity); and heating and domestic hot water (fuel). Given the region's cold weather, heating undoubtedly makes up the largest proportion of energy consumption. To reduce it, the energy efficiency of buildings must be improved, for example by improving the quality of insulation and ventilation systems. Programs are in progress to investigate the best way to do this. Of these, a new housing prototype was built in Quaqtaq in 2015 as part of the 'Living in Northern Quebec' research project (established in 2015 to address the Northern Indigenous habitat in all its complexity). Architects and engineers came up with a design based on the principles of the 'passive house', obtaining high efficiency through position relative to the sun, better insulation, triple-pane windows, and a tightly sealed thermal envelope [START_REF] Arsenault | Energy-efficient housing prototype in Quaqtaq, Nunavik[END_REF].

Regarding renewable energy solutions, the SEQINEQ team first focused on the suitability of photovoltaic technologies. These systems, which are reliable and easy to maintain, have been used for 7 years in a pilot project in Iqaluit (Nunavut) and have shown higher performance levels than initially expected [START_REF] Cherniak | Report on the state of alternative energy in the Arctic[END_REF]. The team is currently working on a similar economic study of a solar thermal technology that converts photons to heat with higher efficiency than photovoltaic solutions (60-70% electricity conversion with photons compared to 10-15% with photovoltaics).

Case study: Kuujjuaq cooperative greenhouse A case study was developed in collaboration with the NIQILIRINIQ (Greenhouse) team to investigate technical solutions for energy-efficient greenhouses [START_REF] Lamalice | Building food security in the Canadian Arcticthrough the development of sustainable community greenhouses and gardening[END_REF]). To launch this, interviews were conducted with local stakeholders involved in the community greenhouse projects in Kuujjuaq and Kangiqsujuaq in the summer of 2016. These discussions highlighted many technical challenges in terms of water, soil and energy supply. In parallel, the Kuujjuaq greenhouse was equipped with probes to record temperature and relative humidity and pyranometers to measure solar radiation inside and outside the greenhouse. Three main findings resulted from data analysis [START_REF] Lamalice | Building food security in the Canadian Arcticthrough the development of sustainable community greenhouses and gardening[END_REF]

):

(1) There is a large contrast between day and night temperatures (Figure 4): during the growing season, this difference is an average 25 °C, which is damaging to plant growth. (2) Solar energy technology has high potential in Kuujjuaq: from July 2016 to June 2017, recorded solar radiation was 1156 kWh/m 2 (in the same period it was 1235 kWh/m 2 in Toulouse in the south of France). ( 3) The temperature within the horizontal axis of the greenhouse is homogeneous; the vertical gradient is low except when the ventilation is turned on.

These results suggest implementing a thermal storage system in the greenhouse. The objective would be to avoid the loss of excess heat to the atmosphere by storing it during the day so it can be used during the night (Figure 5). As there is a large amount of available solar energy, the storage system could be coupled with a thermal solar system to increase the growing period which is 3.5 months currently.

Versants: risk assessment of landslides in a national park

This study focuses on the threat posed by mass earth movement events in the area of Clearwater Lake (Wiyâshâkimî in the Cree language) located about 115 km east of Hudson Bay (56°20ʹN; 76°17ʹW) in Tursujuq National Park (Figure 1). Clearwater Lake includes two neighboring craters with distinctive inner rings of islands. One of the largest islands with the most prominent hills is Lepage Island (Figure 6(a)). Those hills, which formed around 6000 yr BP (following deglaciation), are exposed to harsh climatic conditions. Despite the fact that elevation ranges between only 50 and 160 m, the cumulative effects of periglacial processes and gravity significantly affect the recurrent geodynamics on these slopes [START_REF] Bégin | Analyse dendrochronologique d'un glissement de terrain de la région du Lac à l'Eau Claire (Québec nordique)[END_REF][START_REF] Marion | The holocene development of a debris slope in Subarctic Québec, Canada[END_REF]. As Tursujuk National Park includes multifunctional spaces where both environmental protection and use by local cultures need to be taken into account, the park authorities wanted to know if there are risks of gravity-related earth movements for park visitors. The objectives of this study were thus to identify the range of slope processes that are currently active (including rockslides, screes and debris flows), estimate their degree of activity, and document the risk for park visitors. Aerial and satellite images were analyzed to determine the most dynamic sectors. During the summers of 2015 and 2016, landforms created by different gravity processes were identified, measured and analyzed using geomorphological approaches, both on the ground and from a helicopter. The northern face of Lepage Island shows a wide range of gravity processes (Figure 6(b)), with both recent/active and inherited landforms (Figure 6(c)). This indicates that slope geodynamics may have been active during the entire post-deglaciation period (i.e., the last 6000 years). Active slope processes primarily include screes and debris flows, which are prominently visible. Snow avalanches have less evident outlines as they create few landforms in the area, but some have been locally observed.

Slope morphometry was characterized in detail along three distinct slopes of scree talus using field-based methods, including geomorphological, granulometric and plant distribution surveys. The details of this slope morphometry study are presented in [START_REF] Decaulne | Geomorphic evidence of slope dynamics on the Canadian shield throughout the Holocenea study from Lac à l'Eau-Claire, western Nunavik[END_REF]. Results showed that the accumulation of talus exhibits a complex signature of several slope processes. Some of these processes are still active, leaving fresh deposits, attesting that risk is present. More accurate dating helped to reconstruct the post-deglaciation chronology of gravity processes [START_REF] Bhiry | Development of a small peatland linked to slope dynamics at Wiyashakimi Lake (Nunavik)[END_REF]. The findings were presented to local relevant authorities in short reports highlighting the precise locations of potentially dangerous processes.

NUNA: Inuit modes of relating to the land NUNA explores concepts of contemporary native territoriality in comparison with the Western idea of wilderness, especially as related to the representation of the Far North [START_REF] Joliet | À l'envers du Grand Blanc, le sens inuit du paysage publié dans Projets de paysage[END_REF]. Living between western and traditional local ways of life, the Nunavummiut have regularly expressed their attachment to traditions and the land [START_REF] Collignon | Knowing places: the inuinnait, landscapes and environment, circumpolar research series[END_REF][START_REF] Aporta | Shifting perspective on shifting ice: documenting and representing Inuit use of the sea ice[END_REF]. Continuing the research carried out by [START_REF] Joliet | À l'envers du Grand Blanc, le sens inuit du paysage publié dans Projets de paysage[END_REF] on the Inuit's relationship to the land, 12 the team focused on the contemporary territoriality of Inuit and Cree, within the context of the creation and opening of the Tursujuq National Park (Figure 1).

The research aimed at understanding and characterizing the way Nunavimmiut and Cree relate to places around and within the perimeter of the Tursujuq National Park. It is carried out in partnership with the park authorities and in close collaboration with the communities of Umiujaq, Kuujjuarapik and Whapmagoostui (Figure 1). Research on the social acceptability of the national park has been designed and conducted using a participatory approach, integrating local communities throughout the whole research process and enabling participants to become research actors [START_REF] Joliet | La participation photographique des Inuit dans le développement touristique du parc national Tursujuq (Nunavik)[END_REF][START_REF] Joliet | À l'envers du Grand Blanc, le sens inuit du paysage publié dans Projets de paysage[END_REF]). An analysis of photographs and videos produced by community members allowed the research team to characterize various modes of landscape sensitivity and identify four main elements of contemporary Inuit territoriality [START_REF] Joliet | Les redresseurs d'imaginaire[END_REF]:

(1) In Indigenous cultures, nature is 'socialized'. It does not correspond to the Western conception of wild, unspoiled nature for an individual to contemplate or surpass. Many of the photographs showed scenes of daily life in which Indigenous people bond with the environment, whereas villages were never photographed.

(2) The photographs revealed a marked taste for monumental landscapes (e.g., waterfalls), a mirror of the permanence of Indigenous presence on the land. Some photographs showed ephemeral phenomena (e.g., sunsets, rainbows, cloudbanks, snow or ice), expressing the adaptability of the Inuit people to changing environmental conditions. (3) Nature is seen as a healing place to face hard times.

The strength of a mountain or the stillness of a lake bring peace and strength. This function of the land is as important as its provisioning function (through hunting, fishing and gathering). (4) The changing world (climate change, globalization) is perceived as a contemporary challenge that Indigenous people have to face. [START_REF] Chanteloup | The environment of the Nunavimmiut as seen through their own eyes[END_REF] report the views, feelings and day-to-day experience of the Nunavik (Quebec, Canada) environment by the Inuit people from different generations, looking at the multiple dimensions of their surroundings. It focuses on understanding and characterizing contemporary Inuit relationships with the environment, the meaning and the values given to the latter, and how they are evolving. Through Inuit photographs and short films, interviews, and group discussions, they provide an understanding of Inuit-environment interlinkages and bring to life the multiple ties of the Nunavimmiut with the environment.

IMALIRIJIIT: water quality of a local river IMALIRIJIIT, meaning 'those who study water' in Inuktitut, is a community-based water quality survey which is described in detail in [START_REF] Gérin-Lajoie | IMALIRIJIIT: a community-based environmental monitoring program in the George River watershed[END_REF]. This project involved science land camps, capacity-building workshops, and scientific data collection with the participation of youth, elders, local experts, and researchers. It was co-initiated by the Inuit community of Kangiqsualujjuaq and university researchers. This community is located at the mouth of the George River (58.69°N, 65.94°W) in Nunavik (Figure 1). Community members indicated they wanted their own independent long-term survey of water quality of the river in order to generate baseline data. They also showed interest in a youth-training component for local capacity-building. The community was eager to participate in this monitoring project due to their concerns about a rare-earth mining project that might soon begin operating in the upper watershed of the George River. The river is crucial for Inuit traditional fishing, hunting and gathering activities. The primary objectives of the study were to:

(5) Include and train Indigenous youth in environment-, food-and energy-based science activities in an outdoor, hands-on, non-academic framework where they can explore issues relevant to their lived experience. ( 6 The first Science Land Camp took place in July 2016, aiming to monitor water quality in the George River. Work at one sampling station included site characterization, in-situ measurements, and collection of water samples for further analysis in a laboratory. Macroinvertebrates were sampled at an additional station in a tributary brook; subsampling and identification were done at the camp. Remote sensing images were used to complement in-situ measurements to estimate three water-quality parameters: turbidity (suspended sediments), chlorophyll and temperature. Coupled with a topographic geodatabase and a runoff station (Quebec Gov.), the ongoing work aims to provide temporal mapping of water quality at the scale of the entire river basin (15 m resolution).

The first objective of the project was achieved by organizing three Science Land Camps (2016, 2017 and 2018). The students rapidly learned how to conduct the experiments, were generally engaged, and remembered the protocols. Interviews and discussions with elders and guides took place several times to encourage intergenerational knowledge transfer and to take into account Inuit knowledge and observations of hydrological changes related to the George River, thus linking scientific and Inuit knowledge. Events and awards such as 'Scientist of the day' were used as tools to boost youth motivation. Camping on the land, doing hands-on activities that mix science with other activities, and sharing between generations and cultures all contributed to a different perception of science for the local participants and a better link between community and researchers.

The second objective was achieved with the establishment of a water-quality monitoring program. Qualitative observations compiled by the students showed clear, transparent water at all stations, which is consistent with the data collected in 2016 highlighting the very high water quality of the site. Dissolved concentrations of 35 metals at all sampling stations were below Canadian regulatory guidelines (CCME, 1999). From visual observations, it was determined that the riverbed is composed of sediments ranging in size from sand to large boulders; aquatic vegetation is very rare and sparse. Consistent with water analyses, the dominant macroinvertebrates identified (Ephemeroptera, Plecoptera and Trichoptera) are good indicators of a pristine environment.

Even if participating in scientific experiments with committed local adults and elders had an important positive impact on the young, as reported by [START_REF] Gérin-Lajoie | IMALIRIJIIT: a community-based environmental monitoring program in the George River watershed[END_REF], it is now clear that youth training is not sufficient, efforts will also need to be put into training adults. This would contribute to create muchneeded jobs such as field research assistants in northern communities and create local interest for involvement in science projects.

Summary

The OHMi Nunavik is a recently established collaborative research network involving local Inuit community members, community organizations and researchers. The ecosystem research approach has the potential to generate many benefits for the communities, contributing to more than just the stated objectives. For example, although the goal of the NIQILIRINIQ (greenhouses) project was a concrete improvement in food security and independence, leading to improved nutrition, the preliminary results show that the establishment of local food production not only corresponds to a need expressed by Northern residents for fresh food, but has the potential to enhance well-being, health and youth education. Collaboration between thematic teams gives rise to an interdisciplinary synergy that allows researchers to better respond to the diverse preoccupations of the stakeholders. The NIQILIRINIQ and SEQINEQ teams are working together to gain a better understanding of the particularities of greenhouses in a Northern context and have designed a case study of technical solutions to make greenhouses more energy efficient. Another key result from the participatory action research (PAR) approach comes from a survey undertaken by the ECOHEALTH team with Kuujjuaq dog's owners. Diverse topics were raised by Nunavik residents about dog health and well-being, and about human health and well-being as they relate to dogs. This analysis is the starting point for a joint prioritization of the issues and the selection of optimal mitigating measures. One of these is raising the awareness of children about how to behave in the presence of dogs. The VERSANTS team noted recent earth movements on hillsides in the Tursujuq National Park that may represent hazards. This information was passed to park authorities and users to warn them about visiting hazardous zones. The team is continuing to study slopes in other regions regularly frequented by tourists and residents of Nunavik. The NUNA team successfully explored ways the Inuit and Cree relate to the land. Photographs and videos produced by local volunteers are displayed at the Visitor Information/Interpretation Center of the Tursujuk National Park in Umiujaq. The IMALIRIJIIT project helped to establish a community-driven long-term water-quality monitoring program. Both local and regional organizations invested significant effort, material and human resources that were essential to the success of the science camps.

In conclusion, collaborating with the communities at all steps of the research process helps to increase engagement in the search for solutions to local problems. The co-construction of research questions could be replicated in other communities in order to build durable partnerships and benefits for Nunavik. The ecosystemic approach OHMi's multidisciplinary team aims to promote empowerment within local communities in the face of the major changes taking place in the Arctic.

Notes

Figure 1 .

 1 Figure 1. Location of OHMI research activities in Nunavik (Québec, Canada).

Figure 2 .

 2 Figure 2. Poster presenting the most significant results of the survey of Kuujjuaq residents (Inuit and Western) according to a participatory process.

Figure 3 .

 3 Figure 3. Issues related to dog health (upper half) and human health (lower half) in Nunavik and links between them as documented through direct observation, participatory observation, and a dog-owner survey.

Figure 4 .

 4 Figure 4. Temperature difference between day and night in the Kuujjuaq greenhouse.

Figure 5 .

 5 Figure 5. Representation of the thermal storage function in the greenhouse.

Figure 6 .

 6 Figure 6. Slopes on Lepage Island, inner ring of Clearwater Lake (A), preliminary results on gravity processes recognition (B) and their relative age or degree of activity (C).

Acknowledgments

The authors are very grateful to the numerous Inuit collaborators and to the following Nunavik institutions: Kativik Regional Government, Landholding Corporation of Kangiqsualujjuaq, Makivik Corporation, Nunavik Parks, and Oceans North. They also acknowledge the work of the following collaborators: T. Anaviapik-Soucie, Hamlet of Pond Inlet, Nunavut; M. Annanack, H. Snowball, E. Townley, Northern Village of Kangiqsualujjuaq; T. Napartuk, L. Callaghan, G. Kauki, D. Saunders, E. Emudluk, Northern Village of Kuujjuaq, D. Nulukie, M.-A. Lamontagne, Kuujjuaq Greenhouse; E. Avard, B. Ford, Nunavik Research Center; M. Barrett, É. Rioux-Paquette, Kativik Regional Government; J.-F. Proulx, J. Picard, M. Rochette, Régie régionale de la santé et des services sociaux du Nunavik; D. Bélanger, J. Franssen, P. Leighton, M. Monfette, A. Simon, and J.A. Rowell, Université de Montréal; F. Lévesque, UQAT; J. Saint-Charles UQAM; C. Desbiens, D. Sarrazin, Université Laval; M. Simard, consultant; J.-L. Martin, CEFE/CNRS; X. Py, Université de Perpignan. They also would like to thank Ecoscience's Editor-in-chief for commenting on an earlier draft.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The authors would like to thank the 'Laboratoire d'excellence Dispositif de Recherche Interdisciplinaire sur les Interactions Hommes-Milieux' (LabEX DRIIHM) , and the Observatoire Hommes-Milieux international du Nunavik (OHMi Nunavik) for their financial support through the Agence nationale de recherche (ANR), France.


Jonathan Villain
email: jonathan.villain@imt-lille-douai.fr

Anthony Fleury
email: anthony.fleury@imt-lille-douai.fr

Virginie Deniau
email: virginie.deniau@ifsttar.fr

Christophe Gransart
email: christophe.gransart@ifsttar.fr

Eric Simon
email: eric.simon@univ-lille.fr

Online EM monitoring of 802.11n networks using Self Adaptive Kernel Machine

Keywords: Classification, adaptive approach, identification of attacks, communication monitoring

In this work, we evaluated the performances of an adaptive and online clustering algorithm (Self-Adaptive Kernel Machine -SAKM) adjusted for the automatic and online recognition of attacks on wi-fi communication (802.11n protocol). The results presented here are part of a wider project dealing with wi-fi system monitoring. The radio waves are easy to listen. Due to the quick evolution in the available attacks, the use of learning algorithm cannot cover all configurations. Online clustering constructs evolving models without knowledge of the different cases to discriminate and is therefore well suited to this type of problematic. Based on SVM and kernel methods, the SAKM algorithm uses a fast adaptive learning procedure to take into account variations over time.

I. INTRODUCTION

Whether it is satellite networks through telecommunications satellites, cellular networks, Wi-Fi networks, bluetooth networks or different protocols at lower rates, communications are established through radio waves. But they intrinsically have a great ability to spread in all directions. The main consequence of this "wild propagation" of radio waves is the ease that an unauthorized person to listen to the network, possibly outside the location where the wireless network is supposed to be deployed and confined. The risks of poor protection of a wireless network are various. It is possible to interact with the communications whether to scramble video surveillance, to interrupt calls, to retrieve personal information or to induce themselves into a secure system.

Intrusion Detection Systems (IDS) [START_REF] Rowland | Intrusion detection system[END_REF] can detect an abnormal activity on an analyzed target. Whether it is the Network Intrusion Detection System (NIDS) [START_REF] Sun | Network intrusion detection system[END_REF] which monitors the security state at the network level, the HostBased Intrusion Detection System (HIDS) [START_REF] Vokorokos | Host-based intrusion detection system[END_REF] which monitors the security state at the host level and an hybrid IDS which combines NIDS and HIDS. IDS mainly work on the upper layers of the OSI model and do not protect the wireless communication links. Moreover, the intrusion detection principles used need to be deployed on all terminals.

In [START_REF] Deniau | 11 n communications in the presence of frequency-sweeping interference signals[END_REF], V. Deniau and al. study the effect of jamming signal on IEEE 802.11n communication. In [START_REF] Villain | EM Monitoring and classification of IEMI and protocol-based attacks on IEEE 802.11n communication networks[END_REF], J. villain and al proposed a classification approach to identify jamming signal and deauthentication attacks on the same IEEE 802.11n communication protocol using a monitoring system out of the network. In this study, to extend the detection to unknown attacks, we proposed a streaming classification based on online clustering with kernel [START_REF] Kivinen | Online learning with kernels[END_REF].

In the field of classification, the use of most of the algorithms developed so far requires that the data be completely available in a set of finite cardinality. Some of these algorithms aim to build classes knowing a priori the labels of membership of data classes: We speak of supervised classification. If the labels of the data are not known a priori, the algorithm has the double task of determining the membership of the data to the classes and constructing the partition, generally using a similarity criterion: it is then a non-supervised classification. Depending on the objectives, the desired partition can be determined according to two approaches: The modeling approach aimed at estimating a faithful model of classes (contour or density function) and the separation approach aimed at optimizing decision boundaries separating classes [START_REF] Fukunaga | Introduction to Statistical Pattern Recognition, 2nd edition[END_REF]- [START_REF] Halgamuge | Classification and Clustering for Knowledge Discovery[END_REF]. The first approach represents classes in the form of aggregations of data in closed domains, while the second approach does not exclude their representation in open domains (infinite regions).

Consider the following two situations: A first situation in which all the data to be processed is too large and a second situation in which the learning base is incomplete. In both situations, conventional classification algorithms have limitations. In the first situation, the calculations will become too important or even unrealizable, because of the algorithmic complexity. In this situation, solutions based on selective methods exist and aim to use only the most relevant data to carry out the learning [START_REF] Tong | Active learning: Theory & Applications[END_REF]. The difficulty obviously lies in the implementation of the selection criterion, which risks excluding some important information. In the second situation, the data is acquired online, sequentially. All data are therefore not known a priori, they become available as and when to enrich this database. This is the case in online applications where the objective is to determine the classification model with the data available at each moment, without waiting for the learning base to be completed [START_REF] Jin | Neural Network-Based Decision Support for Incomplete Database Systems. Knowledge Acquisition and Performance Analysis[END_REF], [START_REF] Mouchaweh | Incremental learning in Fuzzy Pattern Matching, Fuzzy Sets and Systems[END_REF]. Support Vector Machine Separators (SVMs) were proposed in the 1990s [START_REF] Vapnik | The Nature of Statistical Learning Theory[END_REF]. The idea of SVM was initially introduced for the search for separation hyperplanes as part of the binary classification. Thereafter, the estimation of a medium distribution is introduced in learning supervised approach by Schölkopf et al. [START_REF] Schölkopf | New Support Vector algorithms[END_REF]. This can be seen as a label-free classification and the developed estimator is called One-class-SVM. The principle beyond the One-class classification is to detect novelties. Novelty detection has many practical applications in real life in different areas. It is critically important for applications involving large data sets acquired from critical systems. Today, many interests are focused on the manipulation of non stationary data. In classification as in various other fields, these data remain very difficult to process because of the evolution of the knowledge model. The dynamic classification expression is thus introduced to qualify the algorithms developed for the automatic classification of these data [START_REF] Lecoeuche | Modelling of Nonstationary Systems based on a Dynamical Decision Space[END_REF].

In the first part of this article, we will explane the experimental configuration used to acquire the data. In a second part, we will recall how the SAKM algorithm works. and propose a modification making more suited for our application where the data are correlated temporally. Finally we will discuss the custom SAKM results for the monitoring application.

II. EXPERIMENTAL CONFIGURATION

In this study, spectra acquisition is performed in an anechoic chamber (see Fig. 1). The communication protocol consid-Fig. 1: Experimentation with a 802.11n communication in the presence of attack ered is the IEEE 802.11n standard, which uses the Orthogonal Frequency-Division Multiplexing (OFDM) modulation scheme. We consider two main attack modes: jamming attacks and deauthentication attacks (which correspond to a protocol attack). The jamming attack is to emit a signal that covers the frequency bands used by the communication system. Different types of jamming signals can be used. The majority of jammers uses an interference signal that sweeps a frequency band [f 1 , f 2 ] over a period of time T . The interference signal that we consider is scanning a frequency band between [2.4; 2.5] GHz in 10 µs. The attack by deauthentication consists of an attack by impersonation. An attacker sends a deauthentication frame to a wireless device, with an address spoofed from the access point. The protocol does not require any encryption for this frame, even when the session has been established with WEP (Wired Equivalent Privacy) or with enhanced encryption protocols. The attacker only needs to know the victim's MAC address, available in clear via the wireless network. The wifi communication was carried out in an anechoic chamber by installing a server, an access point and a client computer. The channel at 2.412 GHz (channel 1) was used. We have included a surveillance antenna near the customer. The monitoring antenna is connected to a spectrum analyzer located outside the chamber. To implement the scramble attacks, another antenna connected to an arbitrary waveform generator has been placed in the chamber to emit the scrambling signal. For deauthentication attacks, the computer that issues the deauthentication signal is placed near the client. The spectrum analyzer is configured as follows: a frequency range of 40 USD, a center frequency of 2, 412 GHz, a resolution bandwidth of 100 kHz. The scan time of the spectrum analyzer was 38, 2 µs. To evaluate the performance of the classification, we implement 6 different configurations. A first configuration corresponds to spectral acquisitions representing only Wi-Fi communications. A second configuration is to degrade the quality of the communication but without any attack. For this, electromagnetic absorbers are placed around the access point to degrade the quality of the signal. A third configuration with a weak interference signal. The rate is still at the maximum level (about 95 Mbps). A fourth configuration uses an interference signal power level that slightly degrades the quality of the communication. The throughput is reduced to about 75 Mbps. A fifth configuration uses an interference signal power level that completely interrupts communication. The last configuration corresponds to the de-authentication attack. The acquired spectra are represented on Figure 2. Due to the data acquisition system over time, the procedure is organized in nine steps (see Fig. 3). We start with a wi-fi communication only (39 spectra) followed by a communication in the presence of absorber (99 spectra). We then switch to Wi-Fi communication (20 spectra) followed by a de-authentication attack phase (99 spectra) and a scrambling phase generating a loss of communication (99 spectra). Next, we return to a wi-fi communication phase (20 spectra) which is followed by a scrambling phase that provides a modification of the communication. Again, we return to a phase with a wi-fi communication only (20 spectra) followed by a scrambling phase that has no effect on the communication (which means that the transfer rate is not reduced by the attack (99 spectra)).

III. ALGORITHM

In online applications, the goal is to gradually incorporate new information to adapt the learning function over time. In order to penalize the learning function of a single-class density support, a loss function is used. SAKM [START_REF] Boubacar | SAKM: Selfadaptive kernel machine A kernel-based algorithm for online clustering[END_REF] is developing as a kernel-based algorithm for grouping non stationary data into a multi-class context. To cope with the difficulties of unsupervised clustering, the SKAM network uses a neural architecture of the feed-forward type. According to a new measure of similarity induced by the kernel, the data are grouped We will first describe the modeling technique of SAKM. Then, we present its kernel similarity criterion defined in the RKHS space. Finally, we will describe a procedure adapted to our problematic.

A. SAKM Classification Model

The SAKM classification model is described using the kernel learning functions. These are non-parametric models capable of modeling complex clusters. In the RKHS space, each of these functions is represented by a hyperplane called a distribution support. The mono-class classifier (One-Class-SVM) has been very successful in estimating the model of a class for which all data are known. However, dynamic classification is a sequential, multi-class and non-supervised problem. SAKM classification model can be described by representing each cluster C m of the dynamic partition π by a distribution medium in the RKHS space. Assuming ψ m the kernel learning function modeling the cluster C m in the space χ, ψ m is defined at each instant t in the following way:

ψ t m (X) = Jm j=1 α t j,m K(X, SV t j,m ) -ρ t m (1)
where SV t j,m and α t j,m are respectively the support vector and its weight in the definition of the learning function ψ t m . The parameter ρ t m is the offset of ψ t m . Following this configuration, each cluster C m is defined by

C m = {X ∈ χ|ψ m (X) ≥ 0} (2)
and the hyperplane is defined as

∆ m : ψ m (X) = 0. (3)

B. Kernel similarity criterion in RKHS

In SVM methods, the learning function is generally used as the measure of similarity between data and clusters. For example, for the single-class SVM classification, it serves as a decision function. SAKM uses another idea proposed in [START_REF] Desobry | An online kernel change detection algorithm[END_REF] which measures in the RKHS space the angle between the new data and the central point of the hyperplane of each cluster. The similarity measure consists in measuring the distance between each new data X t and the closest support vector for each cluster C m in the space RKHS (see Fig. 4). The new data Fig. 4: Similarity measure between a new data and two existing clusters using kernel-induced metric in Hilbert space.

X t is correctly classified in the cluster C m if it is acquired within the contour or in the support vectors set. If not, it is in the set of outliers of C m . So, the closest neighbor of X t is obtained by calculating

ppv = argmin j Φ(X t ) -Φ(SV t j,m ) (4)
The similarity measure S(X t , C m ) = µΦ t,m is defined as

1 - δ (2) Φ(X t ) -Φ(SV t ppv,m ) (5)
where δ = 1 if ψ t m < 0 and else δ = 0. Now that the classification model and the similarity criterion are given, we will go to the explanation of the procedure of learning.

C. Learning Process

In SAKM, the learning process is described in four main steps. The first step is a creation procedure for inserting new clusters with an appropriate initialization mechanism. The second step is an adaptation procedure based on the technique of stochastic gradient descent in the Hilbert space. In this procedure, a fast and efficient update rule is defined to incorporate new information into evolving clusters. The third step is a merge procedure developed to handle mutual information between similar groups. Finally, the fourth step is a useful elimination procedure to eliminate unrepresentative clusters and then ensures the robustness of online clustering. Thus, when new data is presented, the choice of the learning procedure is summarized by algorithm 24 where γ t = (1 C t m )/N band and 1 ω t m a vector of size N band which take the value 1 if

C N band -1 m = C t
m , 0 otherwise, by using the following criterion:

Ω win = {C t m ∈ Ω t |µφ(X t , C t m ) ≤ t h} (6)
with Ω t = C t 1 , . . . , C t m , . . . , C t M a set of clusters at a time t. This procedure is modified to handle the time correlation into our data and is provided at each new acquisition. Noted N band the size of a sliding window and Γ a threshold.

Θ new = (α t new,new = 1, SV 1 1,1 = X 1 ) and ρ 1 1 = η (7)
where η is the learning ratio. Then, for each new data X t causing the creation of a new class C new , we repeat the creation process and a new model ψ new is initialized

Θ 1 = (α t new,new = 1, SV t 1,new = X t
) and ρ t new = η (8) At the moment of its creation, C new only contains the data X t . This data corresponds to the only support vector SV 1 1,new of C new .

b) Update procedure: the data X t is allocated to a cluster C win . After a normalization of the parameter α win j and once ρ win is determined, the update of ψ win is given by

               α t j,win = (1 -η)α j,win if t -τ < j < t α t new,new = η if ψ t-1 m (X t ) < 0 , α t j,win = α t j,win Jm j=1 α t j,win ρ t win = Jwin j=1 α t-1 j,win K(SV c,win , SV t j,win ), c ∈ [J win ] (9)
where η ∈ [0, 1] the learning ratio and τ represent the maximal number of support vector in the cluster. c) Fusion procedure: is developed to handle ambiguous data. When the number of ambiguous data, ie the data shared by two or more classes, exceeds the ambiguity threshold N Amb in a sliding windows of size N band , these classes will be merged.

d) Elimination procedure: noted T m the time since the last data integration in the cluster m. If the cluster m remains in the same state with a fix number of data N m < N c on a period of time k * N band then the cluster is considered as a local outlier and is Eliminated.

IV. RESULTS

We propose to use an architecture based on a model recognition approach to study the spectra of Wi-Fi communication facing different attack scenarios. Our goal is to improve attack detection by using update templates. The SAKM algorithm is deployed on the data described in section II. The one-class SVM models of the SAKM algorithm use a Gaussian kernel (RBF) [START_REF] Schölkopf | Learning with kernels: support vector machines, regularization, optimization, and beyond[END_REF] with λ = 0.326 the kernel window width estimated by the algorithm sigest [START_REF] Caputo | Appearance-based object recognition using svms: which kernel should i use?[END_REF]. For the η learning rate of the SAKM algorithm, the value was estimated by cross-validation and is set at 0.127. The ν parameter that defines the fraction of support vectors and outliers that are outside the class is set to 0.1 and th which is the acceptance threshold, takes the value 0.8. For the elimination process we put N c = 5 and T = 20. This process is the length of time that a group can hold less than N c communications frames. For the verification procedure, N band = T and Γ = 0.5. By projecting the data on the eigenvectors which correspond to the two highest eigenvalues, we illustrate in Figure 5 the evolution of the clusters after each of the nine acquisition phases. In Figure 5 each color, black, green, purple, brown, blue and red corresponds to spectra affiliated to clusters created by the classification procedure.The color grey corresponds to spectra with no class. In our case, it is important to distinguish protocol attacks, jamming attacks and standard communications. In this sense, SAKM has created 6 clusters. The first cluster represented in blue covers the beginning of the de-authentication attack, the cluster represented in brown is a re-connection of the client after deauthentication attack. The clusters represented in red, green and purple correspond respectively to a jamming attack with loss of communication, a jamming that disrupts communication and a jamming with no effect on the communication. The repartition of communication in the different cluster are presented in Table I. The biggest problem with this classification is that the cluster represented in black contains spectra describing only Wi-Fi communication and Wi-Fi communication in the presence of an absorber in the same cluster. Due to this cluster, the success rate of the detection is 83.33%. This loss in the detection is due to the fact that the jamming signal is too low to be detected and so the two configuration are not significantly different. From these results, we could only note that the SAKM network has a good learning ability and can discriminate well the behavior of electromagnetic waves acquired in anechoic chamber. But the difficulty of this approach is to choose the threshold for which SAKM will merge two clusters. In fact if Γ is too low, when the number of spectra is too important and if the data distribution is defined on R, the number of cluster tend to be 1.

V. CONCLUSION

This study introduces the use of Self-Adaptive Kernel Machine (SAKM) to monitor Wi-Fi communications and detect potential attacks. The SAKM algorithm uses kernel learning functions. These functions are non-parametric models capable of modeling complex classes. These models have given very satisfactory results in spatial data classification problems. From a theoretical point of view, the SAKM classification model is suitable for modeling any distribution class. To monitor Wi-Fi communications, SAKM has a significant advantage: its fast and efficient update rule allows scalable learning, essential for monitoring the Wi-Fi network. The algorithm takes into account the variations in time of new groups by sequentially providing optimal models. Through the application, the SAKM algorithm demonstrates its ability to effectively learn groups and to take into account their evolutions in a non-stationary environment. However, SAKM has difficulty in maintaining homogeneous groups when the amount of data is too large due to is fusion procedure. In the case of temporal data, in order to improve the behavior of SAKM when the volume of data becomes important, we have developed a merge procedure based on the temporal correlation of data acquisition. This procedure is built on the appearance of ambiguous data in a previously defined mobile window width. This work has been driven by the need to use algorithms that can be used on machines with a low computing power. In future work, we plan to check the behavior of our model on data acquired outside the anechoic chamber and verify if our approach is able to discriminate more different EM attacks.

Fig. 2 :Fig. 3 :

 23 Fig. 2: Spectra of IEEE 802.11n communication plus attacks collected by the monitoring antenna

1 7 Determine Ω win 8 ififif 1 :

 781 Require: Online data source X := X t 2 Require: Parameter λ, η, ν, th , k 3 Require: Tresholds τ , A, N c , N band , Γ 4 Initialise: t = 0; f 0 := f t 0 = 0; C 0 := C t 0 = ∅ 5 while Acquisition X t do 6 Evaluate Kernel Similarity Function: µφ t.m Case 1: γ t ≥ Γ and card(Ω win ) = Case 2: γ t ≥ Γ and card(Ω win ) = 0 then 13 Case 3: γ t ≥ Γ and card(Ω win ) k.N band (k ∈ N) Online clustering with SAKM a) Creation procedure: Starting from ψ 0 = 0. At the acquisition of the first data X 1 allowing the creation of a cluster first cluster C 1 , ψ 1 is given by

Fig. 5 :

 5 Fig. 5: Cluster evolution

TABLE I :

 I Contingency table between SAKM cluster and communication configuration

		a	b	c	d	e	f
	black	97 97	0	0	0	2
	blue	0	0	76	0	0	0
	brown	0	0	19	0	0	0
	green	0	0	0	0	96	0
	grey	2	2	4	10	3	0
	purple	0	0	0	89	0	0
	red	0	0	0	0	0	97

ACKNOWLEDGMENT

This work was performed in the framework of the EL-SAT2020 project which is co-financed by the European Union with the European Regional Development Fund, the French state and the Hauts de France Region Council.