381023 research outputs found
Sort by
Analyzing latent outcomes via ranks
No full textIn this dissertation, we focus on developing techniques for data including a latent outcome variable. Latent variables are variables that are not directly observed, but rather theoretically postulated or empirically inferred from observed variables (i.e. indicators or proxies). Although Structural Equation Modeling (SEM) is a well-known technique, we believe that valuable alternative or complementary techniques can be explored since rank-based methods remained largely unnoticed in the SEM literature despite their attractive properties.
Therefore, we introduce and develop rank-based techniques for continuous latent outcome variables in this dissertation. First, we focus on a technique to compare two independent groups. We start from an existing and well-established rank-based method, i.e. the Wilcoxon—Mann—Whitney (WMW) test. We consider the performance of an adaptation of this WMW test in terms of hypothesis testing, the estimation of the probabilistic index and the construction of a confidence interval.
Next, we extend our scope and construct a regression framework. By doing so, the inclusion of different observable predictors is possible, both continuous and categorical. After the theoretical justification of this technique, we discuss the results of a simulation study that reveals good finite sample properties.
All methods are recurrently demonstrated throughout this dissertation on case studies
Salt crystallization in lime-based mortars: multi-scale mechanisms and long-term performance
No full textZoutkristallisatie is een van de meest destructieve aantastingsmechanismen in poreuze bouwmaterialen, maar de prestaties van kalkmortels onder dergelijke belasting zijn nog onvoldoende onderzocht. Dit proefschrift onderzoekt het microstructurele gedrag en de duurzaamheid van kalkmortels blootgesteld aan natriumchloride en natriumsulfaat, met nadruk op variaties in samenstelling door additieven en gerecyclede materialen.
Met behulp van complementaire analytische methoden toonde het onderzoek aan dat gedeeltelijke vervanging van kalk door cement de sterkte verhoogt, maar de porositeit en het ademend vermogen vermindert, wat leidt tot een grotere gevoeligheid voor zoutschade. Verschillende evaluatiemethoden werden vergeleken om hun geschiktheid voor het bestuderen van kalkmortels te beoordelen. Een aangepast RILEM-protocol bleek de schadepatronen in kalkmortels realistischer te reproduceren.
Gemengde functionele additieven op basis van fosfonaat en polyacrylaat verbeterden de sterkte en carbonatatie en veranderden de dynamiek van de zoutkristallisatie, waardoor de schade bij hogere doseringen werd verminderd. Gerecycleerde granulaten, zinkoxide en additieven op basis van bacteriën leverden gemengde resultaten op, wat de afwegingen tussen mechanische sterkte, duurzaamheid en milieuvriendelijkheid onderstreept.
Over het geheel genomen draagt dit werk bij aan een beter begrip van de mechanismen van zoutschade in kalkmortels en ondersteunt het de ontwikkeling van geoptimaliseerde, compatibele en milieuvriendelijke formuleringen voor zowel monumentenzorg als moderne bouw.Salt crystallization is one of the most destructive degradation mechanisms in porous building materials, but the performance of lime mortars under such loads has not yet been sufficiently investigated. This dissertation examines the microstructural behavior and durability of lime mortars exposed to sodium chloride and sodium sulfate, focusing on compositional variations due to additives and recycled materials.
Using complementary analytical methods, the research demonstrated that partially replacing lime with cement increases strength but reduces porosity and breathability, leading to greater susceptibility to salt damage. Various evaluation methods were compared to assess their suitability for studying lime mortars. A modified RILEM protocol proved to reproduce the damage patterns in lime mortars more realistically.
Mixed functional additives based on phosphonate and polyacrylate improved strength and carbonation and altered the dynamics of salt crystallization, reducing damage at higher dosages. Recycled aggregates, zinc oxide, and bacterial additives yielded mixed results, highlighting the trade-offs between mechanical strength, durability, and environmental friendliness.
Overall, this work contributes to a better understanding of the mechanisms of salt damage in lime mortars and supports the development of optimized, compatible, and environmentally friendly formulations for both historic preservation and modern construction
Assessment tools for vitamin A status in children 36-59 months and their associations with infection and inflammation markers and aflatoxin exposure : results from a pilot study in Burkina Faso
No full textOptimisation of reverse osmosis processes through hybrid modelling and model predictive control
No full textProspecting a pathogen : pathogen, host and environmental dynamics driving the emerging Batrachochytrium salamandrivorans epidemic
No full textEmerging infectious diseases are a major force contributing to global biodiversity declines. Amphibians are emblematic of this pattern- the last 50 years have seen global declines and extinctions in hundreds of species, making this group the most threatened Class within the animal Kingdom. One of the most recently described emerging infectious diseases contributing to these declines is Batrachochytrium salamandrivorans (Bsal), a chytrid fungus that has been associated with mass mortality events in a growing number of European amphibian populations over the last 10 years. Since its description in 2013, various studies have described key Bsal characteristics such as its lifecycle, suitable conditions for growth and potential species susceptibility. However, these studies focused on the type strain, isolated from the index outbreak site. The aim of this thesis was to characterize variation within the European Bsal epidemic – with a specific focus on pathogen variation, but also considering key elements of host variation that may influence epidemiological outcomes
Phenomenology, impact and underlying mechanisms of perceived injustice in the context of pain in children
No full text(De)constructing humanitarian representations of forcibly displaced people : a mixed-methods and multidimensional research project on the public communication strategies of international refugee organizations
No full textAlthough forced migration has always occurred throughout history, it has increased significantly recently. The largest increase took place between 2012 and 2015 and was largely driven by conflicts in Syria, Iraq, Yemen, and Central African and East African countries (the Office of the United Nations High Commissioner for Refugees [UNHCR], 2021). Worldwide, forcibly displaced people are, however, nowadays confronted with hostility, xenophobia and the increasing popularity of extreme right-wing political parties (Frelick, 2007; Freedman, 2015). Furthermore, in recent decades, several states have tightened their asylum policies and/or become more reluctant to cooperate with refugee organizations (Johnson, 2011; Freedman, 2015). Since 2015, the theme of forced migration has been ubiquitous in (often polarized, overlapping and interacting) public, media and political debates (Hellman & Lerkkanen, 2019).
Within such contexts, UNHCR, which is mandated to lead and coordinate refugee protection worldwide (Jones, 2013), and other international nongovernmental organizations (INGOs) play key roles as providers of assistance and/or protection to forcibly displaced people (Betts et al., 2012). However, through public communication, they also try to inform, raise awareness and set news media, public, political and donor agendas. Therefore, they provide diverse communication content to news media and increasingly communicate directly with citizens via social media and websites (Atkin & Rice, 2013). Hence, these organizations can significantly influence how the general public perceives forcibly displaced people and related displacement crises (Chouliaraki, 2012a) and consequently can have broader policy and societal consequences. Nevertheless, few studies have examined how they attempt to influence public, media and political agendas, and even less studies have analysed the underlying reasons behind the use of their discursive strategies. While most research has analysed the news-making activities of humanitarian organizations, and broader changing journalism-NGO relationships in evolving news and humanitarian ecologies (e.g., Ongenaert & Joye, 2016; Powers, 2018; Van Leuven & Joye, 2014), fewer studies specifically investigated refugee organizations. Second, most research centres on agenda-setting (e.g., McCombs & Valenzuela, 2021) and, to lesser extents, stakeholders’ efforts to influence about which subjects news media, citizens or other stakeholders should think (cf. first-level agenda-building) (Kim & Kiousis, 2012). However, to our knowledge, only a few studies, have thoroughly explored refugee organizations’ second-level agenda-building strategies which attempt to influence how stakeholders perceive certain subjects (Kim & Kiousis, 2012). Further, they mainly textually focus on one organization, media genre, year, and/or crisis, lacking essential explanatory comparative, production, and/or societal perspectives.
Therefore, adopting a mixed-methods research design, this research project analysed refugee organizations’ public communication strategies from multiple perspectives. More specifically, we examined various relevant international refugee organizations’ public communication strategies regarding the recent Syrian and Central African crises. Hence, the central research objective of this project is to investigate the conceptual, textual, production and societal dimensions and their interactions involved in international refugee organizations’ public communication strategies. This overarching objective is operationalized through three more specific, interrelated sub-objectives, corresponding to three components and adopting a source-to-end product perspective.
First, we examined the conceptual dimension of international refugee organizations’ public communication strategies (component 1). How can the public communication of international refugee organizations be conceptualized? For this purpose, we conducted an extensive literature review.
Second, we studied the textual dimension of international refugee organizations’ public communication strategies (component 2). Which discursive strategies do international refugee organizations mainly use (cf. how, who, what)? Acknowledging current trends and gaps within the literature, this sub-objective can be further divided into three more specific objectives:
1. How are forcibly displaced people mainly (not) represented and discussed in international refugee organizations’ public communication? In other words, which representation and argumentation strategies do the international refugee organizations use?
For this purpose, we conducted two empirical studies. First, acknowledging potential organizational differences, we applied a comparative-synchronic (Carvalho, 2008) critical discourse analysis (CDA) according to Fairclough’s (1992, 1995) CDA model on the international press releases (N=122) of UNHCR and two INGOs, de ‘Danish Refugee Council’ (DRC) and de ‘International Rescue Committee’ regarding the Syrian crisis (2014-2015). Additionally, we conducted semi-structured expert interviews (N=6) with press and regional officers at these organizations to yield additional empirical material about the underlying production and societal contexts. Second, recognizing potential media genre and crisis differences, we applied a comparative-synchronic multimodal critical discourse analysis (MCDA) (Machin & Mayr, 2012), again following Fairclough’s (1992, 1995) CDA model, on UNHCR’s international press releases (N=28), news stories (N=233), and related photos (N=462) and videos (N=50) of the key year 2015.
2. Who is mainly (not) represented and given a voice in international refugee organizations’ public communication?
3. What is mainly (not) represented and discussed in international refugee organizations’ public communication? Which key characteristics (e.g., organizations, crises, media genres, years) and themes do international refugee organizations represent?
To meet these specific objectives and acknowledging organizational, media, crisis and temporal differences, we applied a comparative, longitudinal, intersectional quantitative content analysis (Neuendorf, 2017; Riffe et al., 2019) on the press releases and news stories (N=1244) about the recent Syrian and Central African crises (2015-2018) of UNHCR, and two INGOs, the Norwegian Refugee Council (NRC) and the European Council on Refugees and Exiles (ECRE).
Third, we focused on the production and societal dimensions (component 3). Central to the corresponding component are the production, political, economic and socio-cultural contexts, forces and motivations behind the public communication strategies. How do the underlying production, political, economic and socio-cultural contexts, forces and motivations explain the discursive strategies of international refugee organizations (cf. why)? Likewise, this sub-objective can be further divided into three more specific objectives that correspond with the specific textual objectives:
1. How can we explain how forcibly displaced people are mainly (not) represented and discussed in international refugee organizations’ public communication?
2. How can we explain who is mainly (not) represented and given a voice in international refugee organizations’ public communication?
3. How can we explain what is mainly (not) represented and discussed in international refugee organizations’ public communication?
Therefore, we conducted a three-week office ethnography at NRC’s main press and communication department, semi-structured expert interviews with press and communication officers of NRC (N=10), and a document analysis of the key communication policy documents of NRC. We thereby focused each time on the production and societal contexts of NRC’s public communication regarding the recent Syrian and Central African crises.
In general, we found diverse, often mixed results that nuance, extend and sometimes contradict the existing literature on the public communication of refugee organizations and, more generally, humanitarian communication, and frequently interact with and explain each other. For reasons of relevance, focus and space, we discuss below interactions between different dimensions, as evidenced within one or more studies. The literature review indicated that in recent decades the social and scientific relevance of research on strategic and non-profit communication in general and on refugee organizations’ public communication particularly have increased. Nevertheless, these fields remain underdeveloped and are mostly text-focused, while the production and reception dimensions are barely explored. Remarkably, however, little or no research has been conducted from an organizational communication perspective, although this study demonstrates that the subject can be adequately embedded in and examined from the fields of strategic, non-profit and public communication. Specifically, our dissertation highlights the relevance of the holistic Communicative Constitution of Organizations (CCO) perspective. This perspective argues that communication is not just an activity that occurs within or between organizations, but forms the constitutive process of organization (Putnam & Nicotera, 2010). Further, strongly influenced by the understandings of Oliveira (2017), Atkin and Rice (2013), and Macnamara (2016), we define refugee organizations’ public communication as the practice of organized and systematic symbolic social action (diversified communication disseminated through a variety of channels and activities) within the public sphere to reach set goals, co-create the refugee organization, perform civic relations and fulfil its mission by groups of people that pursue the (perceived) common good for forced migration. Finally, our conceptual study argues that future research can benefit by adopting multi-perspective, practice-oriented, multi-methodological, comparative and/or interdisciplinary approaches to which we respond in our empirical studies.
Regarding the ‘how’ and related ‘why’ dimensions, the critical discourse analysis shows that the observed organisations to varying extents dehumanize forcibly displaced people and subordinate them to the ‘Western Self’ and national state interests in their press releases. Acknowledging organizational and media genre differences, these power inequalities can be explained by the use of various discursive strategies, as well as the broader production and social contexts. The findings demonstrate that forcibly displaced people are often portrayed as a homogenous and suffering collective, confirming the dominance of the regime of pity’s traditional ‘negative’ representational strategies (Bettini, 2013; Chouliaraki, 2012a; Johnson, 2011). However, unlike existing fragmented research, this analysis also found evidence of the use of other discursive strategies and explored the production process and the social context. The aforementioned depersonalising humanitarian discourse can be considered to be the product of the specific features of the press releases. The importance of news media attention and commercial reasons are other explanatory factors. In addition, the study found articulations of a simultaneously existing post-humanitarian discourse. The interviews revealed that the humanitarian sector has evolved from a non-economic to a market-oriented sphere within which private choice and self-expression are central. One can relate this post-humanitarian discourse to the regime of irony and consider it as an expression of neoliberalism (Chouliaraki, 2012a). While post-humanitarian discourses respond to the needs for personal development and self-expression, the oft-deployed cross-issue persuasion strategy responds to state interests and reflects political realism (Grieco, 1999). Both strategies are self-directed and reduce forcibly displaced people principally to secondary figures.
Similarly, the comparative-synchronic multimodal critical discourse analysis reveals that UNHCR primarily represents forcibly displaced people in its press releases and, to lesser extents, in its news as generic, anonymized, passive, victimized, deprived, and/or voiceless masses, reproducing humanitarian saviour logics and hierarchies of deservingness. However, stories, photos, and videos frequently combine these representations with portrayals of empowered individual doers, speakers, and/or thinkers. Both representation strategies can be partially explained by news logics such as genre characteristics, news media conventions, and representations, and by respectively political and private sector discourses and agenda-building opportunities, and related organizational goals, as the expert interviews show. Furthermore, we identified several argumentation methods, particularly in textual communication genres. UNHCR mainly attempts to stimulate pity-based solidarity but also voices various neoliberal post-humanitarian (mainly Western) Self-oriented solidarity discourses. Refining cross-issue persuasion, we discovered that UNHCR links protection to states’ (perceived) interests in various issue areas but also in various principles and values, and propose the more appropriate concept of ‘cross-interest persuasion’. Rather than just to other (perceived) important issue areas, refugee organizations link contributions to protection to the interests of states in general. Moreover, the term emphasizes the political realist nature of the pragmatic argumentation strategy. Finally, we consider these discursive strategies as reflections and reproductions of, and responses to dominant migration management paradigms and the increasingly neoliberalized and political realist international refugee regime.
Concerning the textual ‘who’, ‘what’ and connected ‘why’ dimensions, the comparative, longitudinal and intersectional quantitative content analysis shows a mixed picture of what and who are (not) represented, involving interorganizational commonalities and differences. First, regarding ‘what’, the refugee organizations predominantly communicated in 2015 and 2016 about forcibly displaced people involved in the Syrian crisis, because of intertwined organizational, societal and/or financial reasons and mainstream media logics. More specifically, it is far more difficult for international refugee organizations to obtain media attention for the Central African crisis than the Syrian crisis, because of various factors such as the nature, magnitude, implications, mediatization and comprehensibility of the conflicts, and geographic and cultural proximity. As there is more media attention on Syria, international refugee organizations generally obtain also more resources specifically intended for the Syrian crisis, including for press and communication efforts. This leads on its turn to even more attention for this crisis, creating a ‘Vicious Neglected Crisis Circle (VNCC) effect’. Organizational factors generally reinforce this effect, while security and political factors in the case of communication about Syria limit it.
Regarding ‘who’, we observed that primarily forcibly displaced people and refugee organizations obtain voices in het public communication about the investigated forcibly displaced people, refining earlier studies. Additionally, examining several (largely unexplored) sociodemographics, this study finds that individualized forcibly displaced people are represented in significantly unbalanced manners (e.g., mainly along age, geographical location, legal status, current country and continent, nationality, life stance, sexual orientation, family situation, marital status and former and current profession). This can be explained by a myriad of pragmatic, humanitarian, societal, organizational, ethical/personal, practical, security, political and/or narrative reasons. Shaped by production and societal contexts, humanitarian communication reproduces and reflects quantitative mediated hierarchies of suffering, both between (cf. what) and within (who) crises. In general, we can conclude that various pragmatic and contextual factors explain ‘how’, ‘who’ and ‘what’ are represented. Finally, we argue that well-balanced humanitarian communication is essential for societal and strategic reasons (e.g., negative long-term implications of imbalanced humanitarian imagery and sensational public communication, branding opportunities as reliable, accountable ‘authorised knowers’).Hoewel gedwongen migratie doorheen de geschiedenis altijd heeft plaatsgevonden, is het de laatste tijd aanzienlijk toegenomen. De grootste stijging vond plaats tussen 2012 en 2015 en werd grotendeels veroorzaakt door conflicten in Syrië, Irak, Jemen en Centraal-Afrikaanse en Oost-Afrikaanse landen (het Bureau van de Hoge Commissaris voor de Vluchtelingen van de Verenigde Naties [UNHCR], 2021). Wereldwijd worden gedwongen ontheemde mensen tegenwoordig echter geconfronteerd met vijandigheid, xenofobie en de toenemende populariteit van extreemrechtse politieke partijen (Frelick, 2007; Freedman, 2015). Bovendien hebben verschillende staten de afgelopen decennia hun asielbeleid aangescherpt en/of zijn ze terughoudender geworden om samen te werken met vluchtelingenorganisaties (Johnson, 2011; Freedman, 2015). Sinds 2015 is het thema van gedwongen migratie alomtegenwoordig in (vaak gepolariseerde, overlappende en interagerende) publieke, media- en politieke debatten (Hellman & Lerkkanen, 2019).
Binnen dergelijke contexten spelen UNHCR, dat het mandaat heeft om de bescherming van vluchtelingen wereldwijd te leiden en te coördineren (Jones, 2013), en internationale niet-gouvernementele organisaties (ngo’s) een sleutelrol als verleners van bijstand en/of bescherming van gedwongen ontheemde mensen (Betts et al., 2012). Ze proberen via publieke communicatie echter ook te informeren, het bewustzijn te vergroten en nieuwsmedia-, publieke, politieke en donor-agenda’s te bepalen. Daarom bieden ze diverse communicatiecontent aan nieuwsmedia en communiceren ze in toenemende mate rechtstreeks met burgers via sociale media en websites (Atkin & Rice, 2013). Bijgevolg kunnen deze organisaties een aanzienlijke invloed uitoefenen op hoe het brede publiek gedwongen ontheemde mensen en gerelateerde ontheemdingscrisissen percipieert (Chouliaraki, 2012a) en kunnen dus bredere beleids- en maatschappelijke gevolgen hebben. Desalniettemin hebben maar weinig studies onderzocht hoe ze proberen de nieuwsmedia-, publieke, politieke en donor-agenda’s te beïnvloeden, en nog minder studies hebben de onderliggende redenen achter het gebruik van hun discursieve strategieën geanalyseerd. Hoewel het meeste onderzoek de nieuwsactiviteiten van humanitaire organisaties en bredere veranderende relaties tussen journalistiek en ngo’s in veranderende nieuws- en humanitaire ecologieën heeft geanalyseerd (bv. Ongenaert & Joye, 2016; Powers, 2018; Van Leuven & Joye, 2014), hebben minder studies specifiek vluchtelingenorganisaties onderzocht. Ten tweede, richt het meeste onderzoek zich op ‘agenda-setting’ (bv. McCombs & Valenzuela, 2021) en, in mindere mate, op de inspanningen van stakeholders om te beïnvloeden over welke onderwerpen nieuwsmedia, burgers of andere belanghebbenden zouden moeten denken (cf. het eerste niveau van agenda-building) (Kim & Kiousis, 2012). Naar onze kennis, hebben echter slechts enkele studies grondig onderzoek gedaan naar de agenda-buildingsstrategieën van vluchtelingenorganisaties op het tweede niveau, die proberen te beïnvloeden hoe stakeholders bepaalde onderwerpen waarnemen (Kim & Kiousis, 2012). Verder richten ze zich voornamelijk tekstueel op één organisatie, mediagenre, jaar en/of crisis, en ontbreekt het hen dus aan essentiële verklarende comparatieve, productie- en/of maatschappelijke perspectieven.
Daarom analyseerde dit onderzoeksproject vanuit een ‘mixed-methods’ onderzoeksdesign de publieke communicatiestrategieën van vluchtelingenorganisaties vanuit meerdere perspectieven. Meer specifiek, onderzochten we de publieke communicatiestrategieën van verschillende relevante internationale vluchtelingenorganisaties met betrekking tot de recente Syrische en Centraal-Afrikaanse crisissen. Bijgevolg is de centrale onderzoeksdoelstelling van dit project het onderzoeken van de conceptuele, tekstuele, productie- en maatschappelijke dimensies en hun interacties die betrokken zijn bij de publieke communicatiestrategieën van internationale vluchtelingenorganisaties. Deze overkoepelende doelstelling wordt geoperationaliseerd door middel van drie meer specifieke, onderling samenhangende subdoelstellingen, die overeenkomen met drie componenten en een bron-tot-eind productperspectief hanteren.
Allereerst, onderzochten we de conceptuele dimensie van de publieke communicatiestrategieën van internationale vluchtelingenorganisaties (component 1). Hoe kan de publieke communicatie van internationale vluchtelingenorganisaties worden geconceptualiseerd? Om deze doelstelling te realiseren, hebben we een uitgebreide literatuurstudie uitgevoerd.
Ten tweede, bestudeerden we de tekstuele dimensie van de publieke communicatiestrategieën van internationale vluchtelingenorganisaties (component 2). Welke discursieve strategieën gebruiken internationale vluchtelingenorganisaties vooral (cf. hoe, wie, wat)? De huidige trends en hiaten in de literatuur erkennend, kan deze subdoelstelling verder worden onderverdeeld in drie meer specifieke doelstellingen:
1. Hoe worden gedwongen ontheemde mensen voornamelijk (niet) gerepresenteerd en bediscussieerd in de publieke communicatie van internationale vluchtelingenorganisaties? Met andere woorden, welke representatie- en argumentatiestrategieën gebruiken de internationale vluchtelingenorganisaties?
Om deze doelstelling te verwezenlijken,
Ready to unlock the smartness potential? Engaging customers, employees and organizations with smart products in service systems
No full text[un]Certainty after return : unpacking community expectations, familial geopolitics and [in]formal support for Cameroonian returnees
No full textMigration in Cameroon is often linked to specific expectations towards migrants, particularly with regard to sharing accumulated resources. To understand how differences in post-return experiences are created, this study takes a holistic approach by considering the characteristics of the socio-cultural, economic and political context of Cameroon. This was examined at four levels: (1) the expectations of the local community towards returned migrants (2) Family perspectives towards return (3) tactics in navigating the socio-cultural, economic and political uncertainties after return, and (4) the formal support structures available for returnees. In addition to increasing scientific knowledge, this study leads to clear recommendations for policy and practice
