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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

The paradox of enrichment in predator-prey systems

Sogoni, Msimelelo January 2020 (has links)
>Magister Scientiae - MSc / In principle, an enrichment of resources in predator-prey systems show prompts destabilisation of a framework, accordingly, falling trophic communication, a phenomenon known to as the \Paradox of Enrichment" [54]. After it was rst genius postured by Rosenzweig [48], various resulting examines, including recently those of Mougi-Nishimura [43] as well as that of Bohannan-Lenski [8], were completed on this problem over numerous decades. Nonetheless, there has been a universal none acceptance of the \paradox" word within an ecological eld due to diverse interpretations [51]. In this dissertation, some theoretical exploratory works are being surveyed in line with giving a concise outline proposed responses to the paradox. Consequently, a quantity of di usion-driven models in mathematical ecology are evaluated and analysed. Accordingly, piloting the way for the spatial structured pattern (we denote it by SSP) formation in nonlinear systems of partial di erential equations [36, 40]. The central point of attention is on enrichment consequences which results toward a paradoxical state. For this purpose, evaluating a number of compartmental models in ecology similar to those of [48] will be of great assistance. Such displays have greater in uence in pattern formations due to diversity in meta-population. Studying the outcomes of initiating an enrichment into [9] of Braverman's model, with a nutrient density (denoted by n) and bacteria compactness (denoted by b) respectively, suits the purpose. The main objective behind being able to transform [9]'s system (2.16) into a new model as a result of enrichment. Accordingly, n has a logistic- type growth with linear di usion, while b poses a Holling Type II and nonlinear di usion r2 nb2 [9, 40]. Five fundamental questions are imposed in order to address and guide the study in accordance with the following sequence: (a) What will be the outcomes of introducing enrichment into [9]'s model? (b) How will such a process in (i) be done in order to change the system (2.16)'s stability state [50]? (c) Whether the paradox does exist in a particular situation or not [51]? Lastly, (d) If an absurdity in (d) does exist, is it reversible [8, 16, 54]? Based on the problem statement above, the investigation will include various matlab simulations. Therefore, being able to give analysis on a local asymptotic stability state when a small perturbation has been introduced [40]. It is for this reason that a bifurcation relevance comes into e ect [58]. There are principal de nitions that are undertaken as the research evolves around them. A study of quantitative response is presented in predator-prey systems in order to establish its stability properties. Due to tradeo s, there is a great likelihood that the growth rate, attack abilities and defense capacities of species have to be examined in line with reviewing parameters which favor stability conditions. Accordingly, an investigation must also re ect chances that leads to extinction or coexistence [7]. Nature is much more complex than scienti c models and laboratories [39]. Therefore, di erent mechanisms have to be integrated in order to establish stability even when a system has been under enrichment [51]. As a result, SSP system is modeled by way of reaction-di usion di erential equations simulated both spatially and temporally. The outcomes of such a system will be best suitable for real-world life situations which control similar behaviors in the future. Comparable models are used in the main compilation phase of dissertation and truly re ected in the literature. The SSP model can be regarded as between (2018-2011), with a stability control study which is of an original.
302

The Resource Efficiency Paradox : A Case Study of the Guerdane Irrigation Project in Morocco

Perera, Kevin January 2020 (has links)
How can we explain the paradoxical outcomes of resource efficiency? As a key pillar of worldwide sustainable development policies, the concept of resource efficiency has become increasingly important to scrutinize. The overreliance on efficiency coupled with the intention of conserving scarce resources can sometimes backfire. Understanding the intermediate process that leads to the negative, paradoxical outcome is imperative for a sustainable future, especially for societies that risks resource degradation. This study takes the explanatory route and aims to problematize the usage of efficient technology in a resource scarce developing country, namely, Morocco. It is argued that the causal mechanism which links the independent variable (drip irrigation technology) to the observed outcome (total increased resource consumption) has to do with production and consumption processes, which is theorized to be spurred by efficiency. These mechanisms have been derived from the theory of Jevons Paradox and juxtaposed with empirical findings from the Guerdane irrigation scheme, a scheme which sought to increase productivity and simultaneously reduce water scarcity. The study makes use of the case-study approach and the process-tracing method. The chosen method provides a means for establishing a timeline of events, alternative explanations, as well as providing grounds for a primary explanation for the observed outcome. The findings point to reduced labour costs and initial water savings as the empirically derived causal mechanisms. These mechanisms, spurred by the implementation of drip irrigation technology, consequently gave rise to the expansion of irrigated land which in turn increased water withdrawals and eventually resulted in a paradoxical, negative outcome where the total consumption of water resources increased. Taken together, these results deepen our understanding of the problematic usage of efficient technology when different types of social processes are not accounted for.
303

The trend forecasting paradox? : An exploratory study of the compatibility of trend forecasting and sustainability

Frohm, Pauline, Tucholke, Kara Xenia January 2020 (has links)
Trend forecasting is perceived to be an essential service for fashion companies to use in order to stay competitive in the fast-paced fashion industry. Yet, in times of climate change, appointing new trends each season is a questioned practice. Since trend forecasting aligns with the inherent obsolescence of fashion’s constant change, forecasting seems to stand in paradox with the imperatives of sustainability. Thus, this thesis aims to explore the role of trend forecasting to understand its compatibility with environmental sustainability. The review of previous research depicts the evolution of the trend forecasting field and displays prominent literature within fashion and sustainability, which together displays an apparent research gap that this study aims to fill. The thesis follows an exploratory design pursuing a multiple case study strategy applied through eight semi-structured interviews with trend forecasters and a content analysis of WGSN online trend forecasts. Findings of this study validate the existence of a trend forecasting paradox while also demonstrating areas of compatibilities. Customized forecasting and long-term approaches were concluded as compatible practices and may be integrated into both long-term and seasonal forecasting. This study also recognizes a need to differ between forecasting sustainability and sustainable forecasting. This thesis is believed contribute to an under-researched area and aid the trend forecasting industry to realize its impact on sustainability, as well as suggesting approaches on how to further incorporate sustainable practices into their work.
304

Chinese Happiness Index and Its Influencing Factors Analysis

Hu, Zimu January 2012 (has links)
In recent decades, economists are gradually showing their interests in the study of happiness. They even put forward some challenges to the traditional theories. In contrast, studies on Chinese happiness problem are not enough in terms of breadth and depth.  This paper used the data provided by China General Social Survey to conduct an empirical analysis. The model author adopted is Ordered Discrete Choice model. In the empirical section, author analyzed the impact of income, macroeconomic variables, etc.  Ultimately, based on the empirical results, author proposed some policy recommendations and further study suggestions.
305

Reaching the Service Recovery Paradox : Using the Anchoring Effect to Reduce Required Monetary Compensation

Björkman, Jesper, Kron, Nathalie January 2022 (has links)
Aim: When service failures occur, companies must use service recovery actions to recover customer satisfaction. The service recovery paradox refers to the paradox which occurs when a customer is more satisfied after successful service recovery, than they would have been if no failure had occurred. The purpose of this thesis is to examine the effectiveness of using the anchoring effect to lower the threshold value for service recovery paradox occurrence in a specific service failure scenario in the hotel industry. I.e., using the anchoring effect, this thesis aims to reduce monetary compensation required for the service recovery paradox to occur in the specific scenario. Method: 225 respondents were given a survey based on a scenario of a service failure in the hotel industry. The method used was a between-subject experimental design survey, manipulating anchor size, with 5 conditions; SEK 200, SEK 450, SEK 700, SEK 950, and no anchor, to see if the different conditions affected requested compensation whilst customer satisfaction remained constant. Gender and age of the participants was also measured to see if the requested compensation rates depended on these variables. Results: Results showed that it was possible to reduce monetary compensationrequired to reach the SRP by using anchoring values. The control group, which was given the scenario without any anchors, rendered a higher requested compensation than all groups which were given anchors. Furthermore, results showed that the mean compensation required to reach the SRP for the scenario decreased as the anchor values decreased, which indicates that the lower the anchor is set the lower the claim for requested monetary compensation becomes. Finally, the results indicated that age was a relevant variable whilst gender was not a relevant variable regarding compensation requirements. Contribution: Reaching the SRP can sometimes be expensive, especially when it comes to major service failures such as double-booked hotel rooms as is analysed in this thesis. The main contribution of this thesis is to provide an instrument for managers with which they might reach the SRP at lower costs. The results from this research can be directly implemented by managers in similar situations in the hotel industry and may also be used as a foundation for reaching the SRP in other industries as well as other scenarios. Suggestions for future research: As this survey only analyses Swedish participants, results may not be directly applicable to hotels in other cultures. Future research should, thus, focus on examining whether results vary depending on geographic and cultural factors. Other aspects that should be further investigated are what causes the differences in answers between different age groups and if gender displays any differences in other cultures, as it does not seem relevant with Swedish participants. Furthermore, the same surveys, with adjustments, could be used to conduct similar research on other scenarios and in other industries. Finally, researching whether anchoring levels below the lowest anchor used in this thesis, SEK 200, could further lower the required compensation would provide a more complete framework for this research.
306

Resolving the Privacy Paradox: Bridging the Behavioral Intention Gap with Risk Communication Theory

Wu, Justin Chun Wah 30 September 2019 (has links)
The advent of the Internet has led to vastly increased levels of data accessibility to both users and would-be attackers. The privacy paradox is an established phenomenon wherein users express concern about resultant security and privacy threats to their data, but nevertheless fail to enact the host of protective measures that have steadily become available. The precise nature of this phenomenon, however, is not a settled matter. Fortunately, risk communication theory, a discipline devoted to understanding the factors involved in risk-oriented decision-making and founded in years of empirical research in public health and disaster awareness domains, presents an opportunity to seek greater insight into this problem. In this dissertation, we explore the application of principles and techniques from risk communication theory to the question of factors in the grassroots adoption of secure communication technologies. First, we apply a fundamental first-step technique in risk communication—mental modeling—toward understanding users' perceptions of the structure, function, and utility of encryption in day-to-day life. Second, we apply principles of risk communication to system design by redesigning the authentication ceremony and its associated messaging in the Signal secure messaging application. Third, we evaluate the applicability of a core decision-making theory—protection motivation theory—toward the problem of secure email adoption, and then use this framework to describe the relative impact of various factors on secure email adoption. Finally, we evaluate perceptions of risk and response with respect to the adoption of secure email features in email scenarios of varying sensitivity levels. Our work identifies positive outcomes with respect to the impact that risk messaging has on feature adoption, and mixed results with respect to comprehension. We highlight obstacles to users' mental interactions with encryption, but offer recommendations for progress in the adoption of encryption. We further demonstrate that protection motivation theory, a core behavioral theory underlying many risk communication approaches, has the ability to explain the factors involved in users' decisions to adopt or not adopt in a way that can at least partially explain the privacy paradox phenomenon. In general, we find that the application of even basic principles and techniques from risk communication theory do indeed produce favorable research outcomes when applied to this domain.
307

Where Service Recovery Meets its Paradox : A search for the level of Service Recovery required for the Service Recovery Paradox to occur in the Hotel Industry

Edström, Andreas, Nylander, Beatrice January 2021 (has links)
Title: Where Service Recovery Meets its Paradox - A search for the level of Service Recovery required for the Service Recovery Paradox to occur in the Hotel Industry  Level: Student thesis, final assignment for Bachelor Degree in Business Administration  Author: Beatrice Nylander & Andreas Edström  Supervisor: Patrik Sörqvist  Date: 2021 – June  Aim: The purpose of this study was to, within the hotel industry, investigate at what level of service recovery the service recovery paradox will come into existence.  Method: Two surveys have been conducted where 190 respondents were introduced to a scenario- based service failure in the hotel industry. Survey 1 collected data about the amount of monetary compensation that customers felt they needed post service failure, in order to subsequently feel a little more satisfied than in the case of an error-free service experience (the point for service recovery paradox). In survey 2, customer satisfaction was then measured at three different levels of compensation after service failure. The three levels were the mean from survey 1, mean -1 SD, and mean +1 SD. This with the aim to, in an independent sample, test whether the point for service recovery paradox in survey 1 causes the paradox to arise in survey 2 or not.  Result & Conclusions: In the event of a specific service failure in the hotel industry, the level of service recovery paradox, through monetary compensation, was found. Survey 1 (N = 40) determined the compensation level to be SEK 1204. The same compensation level was confirmed as a sufficient level to achieve the service recovery paradox in survey 2 (N = 150).  Contribution of the thesis: Service failures are often not completely avoidable, especially not in the hotel industry. This study helps to understand the level of monetary compensation that may be required to achieve the service recovery paradox, in the event of a specific service failure in the hotel industry. The results from this study contribute to guidance in service recovery and give hotel managers knowledge of what monetary compensation level they should apply to restore customer satisfaction and also avoid overcompensation, in case of service failures.  Suggestions for future research: Future researchers should assume that service industries and service failures are all unique. Failure scenarios need to be described in detail in order for results to be applicable by managers. Future research may also examine the anchoring effect in order to avoid overcompensation if possible. SRP researchers who examine the hotel industry in particular may investigate the SRP level of additional customer segments that travel; alone, at work, with friends or with children. Although SRP might occur because of service recovery, repurchase intentions might decrease. A major challenge for future researchers will therefore be to measure how customer satisfaction after service failure and recovery stands long term. Another suggestion is to conduct the study again, but with real service failures and with real compensation.  Keywords: service failure, service recovery, service recovery paradox, service recovery hotel industry, customer satisfaction
308

The Social Media Dilemma:Millennials Dealing With Data Tracking in a Mediatized Society

Volman, Hannah January 2021 (has links)
Through its growing popularity, social media platforms have become influential in our society. Data tracking allows social media platforms to continue providing free and personalized services. Scholars and professionals have argued that data tracking can be harmful to individual privacy and can be used to change peoples’ behaviour without them being aware of this. This thesis focusses on how millennials deal with data tracking dilemmas in their social media use. As digital natives, millennials have grown up in a digital society, and therefor are often suggested to have a unique perspective on issues such as data tracking. This study is focused on why millennials use social media platforms, what dilemmas they identify regarding data tracking, how millennials act upon these dilemmas and how millennials reflect on their own behaviour compared to that of other generations. Based on 16 semi-structured interviews and 4 focus groups, this thesis relates the behaviour of Dutch millennials regarding data tracking and social media use to theories such as mediatization, platformization, the privacy paradox and media generations. This thesis finds that besides communication, entertainment and social engagement are also deeply shaped by mediatization and platformization. The participants identified three interrelated aspects of the privacy dilemma: the filter bubble, monetization and power. In acting upon these dilemmas, the behaviour of some participants confirms the notion of the privacy paradox. However, another group of participants indicated that they do not experience the dilemmas as such, and therefore do not act upon them. A last group of participants shared that they have found multiple ways in which to act upon the dilemmas they identify. This study thus concludes that the privacy paradox seems more nuanced than its conceptualization, because the participants find ways to deal with the dilemmas they identify.
309

How is the Psychological Climate Paradox presented in climate change communications? : A Multimodal Critical Discourse Analysis of the Psychological Climate Paradox in the documentary trailers Anthropocene: the human epoch & Kiss the Ground

Frassine Garpenholt, Lydia January 2021 (has links)
Effectively communicating climate change issues to the public have been proven to be a complicated task. Increasing scientific research explaining how humans have caused changes on climate, have led to a decreasing concern, contributing to the Psychological Climate Paradox. The aim of this study is to analyze how the issue of climate change is communicated in the documentary trailers of Anthropocene: The human epoch (Baichwal, Burtynsky & de Pencier, 2018) and Kiss the Ground (Tickell & Tickell, 2020), and whether these contribute to the Psychological Climate Paradox or not. To do so, the presence of three out of five barriers to effective climate communications, which help uphold the Psychological Climate Paradox were taken into consideration. The method of the research consisted of a modified Multimodal Critical Discourse Analysis (MCDA), focusing on the semiotic aspects of denotation and connotation, visual codes, and the linguistic aspect of vocabular choice The study concludes that the three psychological barriers which contribute to climate communication were clearly present in the Anthropocene trailer. However, the Kiss the Ground trailer rather presented the audience with the solutions to the barriers, known as the new Psychological Strategies, which Stoknes (2015) argues contribute to more effective climate change communication.
310

The association between socioeconomic factors, alcohol use and alcohol-related outcomes in South Africa

Govera, Hemish January 2021 (has links)
Philosophiae Doctor - PhD / This thesis researched the relationship between alcohol consumption, socioeconomic characteristics and alcohol-related harms such as subjective health status, chronic health conditions and mental health status in South Africa. The study sought to determine if the alcohol harm paradox (AHP) exists in the country. The AHP is the empirical finding that socioeconomically disadvantaged individuals tend to suffer more alcohol-related harms compared to individuals who are socioeconomically advantaged, despite reporting similar or lower levels of alcohol consumption on average. The research presented the contextual background to alcohol consumption in the country that helped form the current drinking culture, which includes the harmful drinking culture fomented by the apartheid system in the townships and farms of South Africa. The study also reviewed the effectiveness of current alcohol policies and legislation in addressing alcohol-related harms in the South African society. / 2023

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