Ph.d.-projektbeskrivelser

Nidhi

Architectures and Supporting Algorithms for Spectrum and CA for Small Cells and Ultradense Deployments


Project Description & Background:
TeamUp5G is a European Training Network (ETN) in the frame of the Marie Skłodowska-Curie Innovative Training Networks (MSCA ITN) of the European Commission’s Horizon 2020 framework. With the continuous increase of data rates and the number of people using mobile communications, wireless connections are evolving towards 5G. To fulfil the user satisfaction and a plethora of challenging requirements, pivotal to the evolution towards 5G are the ultra-dense networks (UDN) with small-cells (SCs). Because of the technical limitations/challenges observed in the path of providing seamless like; limited available spectrum, the need to coexist within complex environments of multiple heterogeneous technologies and users, the demand of increasing data rates per km etc. the main technical objectives are:

  • Design novel PHY/link/MAC algorithms and protocols to enhance capacity and user satisfaction.
  • Propose new dynamic spectrum management, opportunistic optimisation of radio resources and CR techniques, together with self-organization capabilities, with different levels of collaboration.
  • Devise techniques and methodologies to save energy that make the previously proposed optimisation techniques sustainable and environmental friendly.
  • Develop a proof of concept to demonstrate the feasibility of the proposed innovative techniques and encourage practical deployment, through prototyping and experimental research activities.

Research Objective:
My research objective is to design and evaluate architectures and supporting energy-efficient algorithms for spectrum and carrier aggregation to support energy-efficient communications in the defined reference scenarios and according to the identified usage and system requirements. It will focus on Energy Efficient Spectrum management and harvesting algorithm that would support plug-and-play capabilities that would not add to costs of cell dimensioning and planning. The supporting algorithms should allow for seamless handover between radio (RF) and non-radio (e.g., VLC) technologies, whenever required to offload the unlicensed spectrum.

  • Improved aggregation across a range of spectrum, with particular emphasis on increased densification of frequency and aggregation of opportunities involving UDN.
  • New CA schedulers with reduced implementation complexity that optimise both fairness and service level parameters in a multi-service traffic scenario.

Dimitrios Apostolou

Assessment of a portable RES-based H2 production-storage system towards a zero-emission cycling based transportation

During the last decade the electric vehicle industry has been developed rapidly due to the associated environmental impacts arising from the use of conventional fossil fuel-based internal combustion engines (ICE). If someone take into account that the transportation sector comprises more than 33% of the EU-28 final energy consumption, and in 2015 was responsible for the annual emissions of at least 1182Mt CO2 equivalent (EC, 2017), this turn to sustainable mobility will present several positive effects for the environment including air quality improvement, noise reduction, and fuel independency in the case of renewable sources (RES) utilisation.

One of the most promising technologies for promoting “green” mobility comprises hydrogen based systems via the utilisation of fuel cells (FC). Especially, hydrogen production via water electrolysis supplied from RES results to much lower Life Cycle (LC) emissions and will contribute to an enhanced sustainability of the future transportation sector.

As it is mentioned above, production of H2 via RES consists a very promising method for portable applications. Denmark is a country where RES energy and particularly wind-based electricity is considered essential to the electrical network as it contributes nowadays more than 40% in the national gross electricity generation.  However, wind energy exhibits a stochastic and variable availability, enhancing the mitigation of the RES maximum penetration during the daily and seasonal electricity demand fluctuations. So, it is obvious that even in the case of high wind potential, the produced energy may not be integrated into the electrical network, resulting in a waste of energy and monetary losses for the RES investors. Hence, one may notice that it would be beneficial to combine the potential of hydrogen mobility with the wind energy curtailments in order to deploy a new market including hydrogen powered vehicles and production of hydrogen from the otherwise curtailed power from wind farms.

The main objective of this project focuses on the investigation of a portable hydrogen production and storage unit supplied from the power curtailments of wind farms located in central Denmark in order to produce store and deliver hydrogen to fuel cell based low duty vehicles such as FC bicycles.

More precisely this study will aim at:

  • Investigation of the viability of a small scale portable H2 production/storage device by comparing CAPEX, O&M cost, energy cost, range of the vehicle.
  • Study and analysis of the emerging market regarding the cost benefit of both wind farm and hydrogen portable refuelling infrastructure investors.
  • Design of the pricing mechanism of the real-time emerging market.
  • Investigation of the best scenario in terms of high absorption of wind rejected power and hydrogen demand of FC bicycles in the city of Herning. This investigation will take into account the assumption that the residents of Herning would use for short distances (up to 50km) only FC bicycles, avoiding car and public transportation. In this context, analysis of CO2 emissions avoidance is going to be performed.

Dafni-Despoina Avgoustaki

Growth perspectives of small scale hydroponic systems in cities: The sustainable energy-based business approach

The continuing increase of the human population, the competition for land, water, energy supply security and overexploitation of natural resources has led to many changes in the agriculture domain. Urbanizations and industrialization as long as global warming and deterioration of the environment and the natural resources are bound to minimize the available arable land for cultivations and its productivity. It is clear that by developing and growing innovative and optimizing materials and by the utilization of the energy resources a better exploitation of soil area for plant growth can be provided. Under these circumstances, providing sufficient yield while meeting the consumers’ needs in terms of quality for the entire population using conventional agricultural production methods will become even more demanding.

Coupling of indoor hydroponic systems and relative technologies and mass deployment may lead potentially to significant benefits for the environment and the economy. Indoor hydroponic farming requires significant amounts of energy (heating demand of the plants and lighting) operating 24/7. By controlling the energy requirements of the system, while at the same time optimizing the plants’ growth, has great potentials leading to the integrated energy-food nexus. When electricity prices are high, indoor farming demand could be lowered and electricity prices are low, indoor farming electricity and heating requirements can be sufficiently met. A mass deployment of such systems, can even help make the grid more efficient by providing the utility Demand Response (DR), so when power is needed elsewhere on the grid, hydroponics can reduce the amount of energy they're using, allowing the utility not to switch on expensive and “dirty” peak power plants.

Through this project it is aimed to be researched the reaction of specific plant species in the energy demand and consumptions. The plants need specific conditions of temperature, humidity, water, solar radiation and fertilizers in order to develop and grow. The inertia point, is the optimum and appropriate conditions of development which are ceased suddenly for the plants.

More specifically this project will aim at: 

  • Analysis and evaluation of the main advantages and drawbacks of the existing hydroponic market regarding the participation of individuals via the DR programs of small consumers in those markets
  • Installation and setup of the lab scale experimental unit. Tests and initial linkage with the electricity markets aiming at maximizing the renewable energy sources integration. Wind power curtailment and hydroponic deployment scenarios.
  • Research the inertia point of the plants and how long the plant will be able to keep growing in the best conditions and with a stable rhythm and when this pace will start descending
  • Optimization of conditions and plants growth inertia.
  • Design of a mobile app and distance control optimization

Joy Dalmacio Billanes

Human activity (e.g. heavy use of fossil fuel in buildings) is considered the main driver of climate change. Buildings (residential, commercial, or industrial) are significant energy consumers which share about 40% of the total global energy consumption. In this regard, various organizations explore the potential of renewable energy to reduce carbon footprints while maintaining reliable energy systems. However, the main concern in the future is not about producing more renewable energy but reducing energy consumption.

And as the global economy and consumers’ demands change rapidly, embracing innovative approaches to reduce energy consumption and improve energy efficiency are desired. Adoption to smart energy technologies can help reduce energy consumption and improve energy efficiency. However, the socio-economic and environmental benefits of smart energy technologies are not fully realized. Studies show low awareness and engagement to smart energy technologies due to several factors. For instance, older adults have very low engagement to smart technologies due to lack for technical skills and confidence of using smart technologies. In addition, demographics (e.g. age, education, and occupation), and lack of knowledge about the benefits of smart energy technologies affect users’ willingness to adopt smart energy technologies.

Certainly, financial incentives contribute significantly to changing social behavior. However, a sustainable growth requires knowledgeable consumers who can just simply engage with the smart energy technologies without even receiving financial rewards.

Changing social behavior by empowering energy consumers through education and information ensures the adoption of smart technologies. This could be done through strong collaboration among stakeholders (e.g. government, community and end-users). Sustainable business model encourages the involvement of multiple stakeholders that creates social, environmental and economic value.

Thus, this research aims at examining the potentials of sustainable business model in enhancing awareness and engagement to smart energy technology to improve energy efficiency.

Kristoffer Holm

Adoption of Private Blockchains: A Case of the Wind Industry

The adoption of blockchain (and really new digital technologies in general) into business processes comes with challenges both from a technical side – in terms of what is possible – and from a social point of view – in terms of what is valuable for the organizations adopting new technology. Additionally there are considerations to be had in terms of how these two perspectives overlap (the socio-technical system) and this is really, where the PhD-research takes its place. By following the UnWind-project that is funded by the Danish Industrial Foundation in the period January 2020-June 2022, the PhD-research will have access to empirical findings on a developing blockchain use case. The UnWind-project aims to develop a use case for the wind industry supply chain that will enable enhanced collaboration for the members of the project. The PhD-research supports this process by applying design science research for the development of this use case (artifact), seeking to contribute both to practice (the wind industry) and theory (such as within the general fields of innovation and supply chain management) by contributing to the development of the use case.

The primary research question seeks to answer; what the primary barriers are for private, interorganizational blockchain adoption to overcome. Blockchain technology, that is the focus of the PhD-research (question), is a digital ledger, making use of cryptography (en- and decryption of data) and a distributed nature (i.e. everyone owns and have access to the stored data) to provide new methods for transparency of immutable, append-only information across traditional organizational bounds. The distinction private refers to the type of blockchain that is in focus, i.e. blockchains that has certain restrictions regarding the ability to join, read, write and validate data, while the distinction interorganizational refers to the focus of the research being on blockchains that is adopted by multiple businesses (such as supply chains). The focus on adoption is taken due to the nascent stage of maturity of blockchain in business processes, which is sought to be understood better by understanding the primary barriers perceived and experienced by practioners of business. Primary barriers of blockchain adoption are expected to be tied to aspects such as trust, collaboration, information-sharing, interoperability of organizational systems and business processes etc.

The PhD research is characterized by following an abductive logic, i.e. balancing theoretical and empirical fieldwork for the purpose of systematically combining the two through the development of the UnWind-case. The research will make use of a mixed methods approach, relying mostly on qualitative data from non- and semi-structured interviews with individuals and focus groups as well as observation during the development and testing of the use case all involving parties of the wind industry and blockchain-experts of various backgrounds. Furthermore, quantitative data acquired through one or more (wind) industry surveys will provide the research insights on the perceived pros and cons etc. on blockchain, while literature review of blockchain use cases from other industries will provide secondary, empirical data that can be analyzed for understanding the characteristics of existing blockchain use cases.

Justina Lydekaityte

Digital innovation in cardboard packaging using printed electronics:
smart interactive packaging towards enhanced consumer experience and product functionality

Before advanced technologies such as nanomaterials, Printed Electronics (PE), or Internet of Things (IoT) came to market, packaging served basic principles to contain, protect, preserve, and inform. However, the growing competitiveness, changes in consumer behavior and demand, emerging wireless and digital technologies have led to the improvement of the primary packaging functions and thereby to the emerge of smart packaging. Generally, the smart packaging incorporates advanced technologies to enhance its main functions and thus is divided into active, intelligent, and interactive packaging. Active and intelligent packaging related to food industry aims to prolong products’ shelf life, improve its quality, and inform the user about its current status. Contrary, interactive packaging extends the traditional communication aspects by triggering a conversation between the package and consumer. Recent advances in PE, AR, and IoT allow packaging to embrace the digital transformation and become network-connected. PE uses nanomaterials, as conductive inks, to produce electronics, as NFC tags, which can be printed on packaging, and thereby it highly increases the design freedom for new applications.

However, the potential of such digital innovation is not yet fully explored, whereas the other smart packaging types, active and intelligent packaging is well-researched and already commercialized for food products. While this packaging ensures improved security and preservation of packed goods, brands are still in need to find better ways to connect with their consumers, to build stronger relationships and prolong consumers’ experience with their products. Especially, when packaging becomes an integral part of the product and is able to create strong emotional and memorable states or reactions. Consequently, new forms of packaging can contribute to retailer’s differentiation and connect in-store and at-home experiences with the brands’ digital marketing activities. The digital capabilities of smart interactive packaging to enhance consumers’ interaction are not well-explored. Researchers already approved packaging as a powerful communication tool for product positioning but did not consider the influence of information and communication technology. Furthermore the majority of researches designed applications for the improvement of logistics operations instead of consumer engagement in-store or at home. In response to this apparent lack of research, this project will aim to identify and examine the potential and capabilities of enabling communication technologies of smart interactive cardboard packaging to enhance consumer’s and product’s experiences at the point of purchase and utilization. More specifically this research will aim to:

  • Establish an overview of enabling communication technologies feasible with smart interactive cardboard packaging that contains durable consumer goods.
  • Develop a system architecture model of Internet of Packaging (IoP) based on a combination of IoT, PE, smart sensors, conductive ink and other network-enabled communication technologies.
  • Conduct an experimental research with a presumptive outcome of a functional or semi-functional prototype of smart interactive packaging.
  • Carry out an experimental research to monitor and track changes of the end user behavior towards designed smart interactive packaging in the selected environment.

Kristian Løbner

The rise of the digital age has led to increased access to new markets and competition from new organizations. The need to stay ahead of the rapidly developing competition is more essential than ever. Academic focus on innovation leadership throughout the 20th century centered on managing innovation in products and services. The past 20 years, academia and practitioners have acknowledged that innovation in the business model is an essential competitive advantage of the 21st century.

In spite of the increased focus on business model innovation, the organizational and leadership parts of business model innovation (BMI) remain poorly understood. Further, scholars have focused mostly on exciting new and disruptive innovation, new market entrants or how incumbents fail to innovate on their existing business models.  There exist only few insights in how continuous BMI could be lead in incumbent businesses. With the urgency of leading BMI in established businesses, there is a need for further guidance, methods and severe empirical evidence.  

Large businesses have experienced massive transformations (both external and internal) in the last few decades. With the growth of the knowledge economy, the number of project-based businesses has grown considerably as a serious trend. With the trends of 'open innovation', 'sustainability' and 'knowledge-sharing', many businesses are operating many business models depending on the specific project. However, research of BMI in project-based businesses s is scarce.

The existing evidence is primarily based on either ex-post studies of the process of BMI or momentary case studies. There is a severe need for more longitudinal studies to coin why some processes succeed in valuable BMI and why some fail.

Based on three longitudinal studies of how BMI is organized in a large incumbent service business, this study contributes with deep insights on:

  • How the managerial drivers and barriers affects business model innovation.
  • How the needed capabilities for conducting BMI successfully can be developed.
  • How to ensure a continuous progress of BMI.

A main result of this study is a tested framework for leading the organization of BMI in large incumbent service businesses.       

Jørn Bue Madsen

Project title: M&A as management and organisational competencies

Company description:
The project is conducted with Norlys amba as partner and sponsor. Norlys a.m.b.a, headquartered in Silkeborg, is one of Denmark's largest energy companies, providing infrastructure, energy, data and TV packages to private and corporate customers in Denmark. Norlys' shareholders are customers in the company's infrastructure areas. The company has DKK 1.5 million customer relations, 709,000 shareholders, 2,500 employees and subsidiaries in 12 locations in Denmark (2019). Norlys has executed 40 mergers and takeovers the past 10 years, becoming the large entity it is today.

Background:
The number of transactions and value of M&A has been steadily increasing globally over the last 30 years. In 2017, about 52,000 transactions took place globally, corresponding to an aggregated transaction value of app. USD  4,000 bn. (IMAA, 2018). Still, after three decades of research, the success rate has not increased significantly. Depending on choice of literature, the failure rates are still app. 50-80% measured on financial values pre and post merger.

Based on the research in the past, where several disciplines and perspectives related to performance in M&A has been described separately (e.g., cultural phenomena, social processes, strategic management, M&A processes, financial modelling, post merger integration, power hierarchy) and the fact that success in M&A is still very low, there seems to be a basis for further research in the area.

Research objective:
I want to investigate why so many M&A transactions are still failing despite decades of research in the area.

The main question to be answered in this research project is:

What are the explanations for a continued low success rate in M&A?

Subsequent related questions to be answered are:

  1. What are the correlations between organisational and sub-organisational learning (meaning adaptation of existing theories and knowledge and structured continued development and sharing of developed knowledge) and success rates in M&A?
  2. Are there interdependencies between the current existing theories that impact the success rate of M&A, and if so, what is the nature of such linkages?

Expected contribution to research:
Given the vast expenditure of capital and human resources globally every year and previous research showing very little impact on increasing the value creation, despite significant research in the field, succeeding in developing a better understanding of M&A as a theoretical and empirical phenomenon would add significant value to organisations, companies and investors globally.

Michael Engkær Engsig Madsen

Servitization is an organizational transformation embracing the entire organization (T. S. Baines et al., 2009), from taking a product- to a service-centric approach, originating in the firms ´installed base´ (S. A. Brax & Visintin, 2017). Findings of the service paradox (Neely, 2008), the contradictory findings of servitization outcome by Eggert et al., (2011, 2015), and the numerous case studies of failed transformations (Sawhney et al., 2004), all points at the existence of the practical problem within servitization, namely the failed attempts to obtain profitable. The cost of such failure is the lost opportunities for competitive advantage, customer loyalty (Cusumano et al., 2014), inimitable solutions, and steady revenue streams (de Brentani, 1995) due to the retraction of servitization. Thus in time, include the consequences of commoditization, competitive pressure, and hence loss of market shares (Bustinza et al., 2018; Oliva & Kallenberg, 2003). For this reason, the practical problem is highly relevant to investigate from a managerial perspective.

Previous literature has emphasized that, the lack of profitability are influenced by the intensified investments (Visnjic Kastalli & Van Looy, 2013), the volume of service ratio (Nezami et al., 2016), as well as the capabilities within the organization (Eggert et al., 2011, 2015) and execution of building the right organizational capabilities and culture (Neely et al., 2011; Tenucci & Supino, 2019). While academics seems to agree on the curvilinear relation of profitability throughout the transformation presented by Nezami et al., (2016), a greater focus into how to optimize the position on the curve through the second stage of the deliberately servitization transformation, is insufficient. Furthermore, additional calls have been made for further investigations into the multi-dimensional perspective of the operationalization of servitization. However, although some dimensions have been identified within the field of servitization (Capabilities, organisational orientation, etc.) (Adrodegari et al., 2018; Coreynen et al., 2017), academia lacks insight into which dimensions occur in the field, and how these impacts the profitability of servitization. For this reason, the research problem is the ignorance of academia on how the servitization dimensions impact the profitability of manufacturing firms, in their deliberate operationalization of it.

The aim of this PhD project is to study the multi-dimensional operationalization of servitization among SMEs, in order to find out what impact the dimensions have on the servitization success, and thus help the readers understand how to increase the likelihood for a successful and profitable transformation. This investigation is following three main objectives:

  1. The investigation seeks to identify servitization dimensions within the existing literature, to enable a profound investigation of their impact on the servitization success. This identification seeks to consolidate existing literature in order to guide future research within these dimensions, as well as impose an understanding of the complex concept for the managers.
  2. This investigation seeks to illuminate the consequential impact of the compound dimensions on the servitization success. This to identify new insight of how to increase the likelihood for a successful transformation, as well as the identification of why some might fail their servitization.
  3. This investigation seeks further to establish a new method for assessing the success of servitization, which embrace more than profitability. This, due to the increased complexity of servitization, needs a comprehensive assesment tool, which highlight both direct and indirect factors.

Fabien Rezac

Investigating Data-Driven Business Models & Ecosystems in the Context of Privacy 

Recently, due to the exponential technological development, the humanity found itself standing on the verge of the Fourth Industrial Revolution. The biological, physical and digital worlds are gradually fusing and people have never been so close to technology before. The numbers are staggering and barely imaginable. In fact, each of us is now a walking data generator. The data-driven technologies have significantly impacted the way of how business is conducted and companies started to innovate their business models through digitalization. The importance of leveraging data for the commercial purpose is so far-reaching, that some even call it data capitalism. Companies now co-specialize through creating bonds that promote collaboration without excluding competition and form business ecosystems that gradually take over the world. Without exaggeration, literally every aspect of the business landscape has radically shifted and besides the undoubtable ubiquitous benefits, the exponential data-driven progress encompasses number of substantial concerns, with privacy being one of the most critical. The power of digital became so promising that organizations started to abuse the customers’ personal data, capitalize on them and use them without their permission or awareness – on a massive scale.

The notorious scandals of data-mining tech behemoths have drawn attention to the colossal imbalance of profit and privacy. Despite the regulatory mechanisms being employed, it is apparent that the digital business models of many precedent-setting companies practically stand upon the premise of exploiting personal data and mitigation through external intervention can be ineffective or even counterproductive for innovation. Moreover, the newly redefined status quo of competition dominated by technology platforms only emphasizes the infamous trade-off between customers’ security, convenience and privacy, a fundamental human right recognized in the UN Declaration of Human Rights. According to Tim Berners-Lee himself, the current form of internet basically suffers from two key myths – “advertising is the only possible business model for online companies” and that “it is too late to change the way platforms operate”. Since it is time to stop applying intrusive techniques and find a safer way to develop business, an extensive ecosystem of decentralized open-source disruptors tackles the incompatibility of the current Web environment with technological solutions centred around human-centric principles of privacy. Nonetheless, technology by itself has no single objective value - the privacy-by-default commercial alternatives need to embrace sustainable business models and secure their roles in competitive ecosystems in order to ensure viability of the technology that has a chance to disrupt the unsustainable state of affairs per se.

Through a series of research articles, Fabien’s PhD project contributes to the state-of-the-art research enquiry by investigating how privacy-centric focus impacts the business model development and innovation of companies, what are the characteristics of their current ecosystems and how can they sustainably enhance privacy while achieving competitiveness.

Eldina Salkanovic

Applying AI-Based Solutions to Avoid Bird Collisions at Wind Parks

The rise in global energy use parallels the ongoing growth and demand of the human population. Due to the rising pressures, which climate change imposes on communities and industries, renewable energy alternatives, such as wind, are sought after to power homes and businesses in a more sustainable manner. Yet, while cleaner air reflects a healthy atmosphere, species diversity and ecological systems are equally important for preserving the balance of natural systems (Windkraft Schonach GmbH 2017). Ornithologists have particularly expressed and published their concerns relating to the threats which wind energy brings to avian species (Windkraft Schonach GmbH 2017). Therefore, species protection issues have arisen since the expansion of wind turbines—particularly, in areas where wind turbines are located in migratory-dense areas with a high population of birds.

Thus, my research aims to address this increasing avian issue. This interdisciplinary undertaking will be accomplished through the lenses of Artificial Intelligence, Ecology, and Multi-Sensor Technologies. The scope of my research is to reduce the quantity of curtailment measures at wind parks with bird-collision avoidance systems already in place; as well as, to save as many birds as possible from an unwelcoming collision with a wind turbine.

Windkraft Schonach GmbH, 2017. Personal Communication.

Cristiano Smaniotto

Towards zero waste consumption: a cultural infrastructure perspective

Global waste still represents one of the most pressing environmental concerns, as it is expected to grow by 70 percent by 2050 (Kaza et al., 2018). Dumping waste in more or less designated areas is connected to issues of water and air contamination, spread of diseases, animals harming, informal economies and infrastructural break-downs (e.g., floods caused by clogged drains) (Kaza et al., 2018). To effectively deal with such issues, we need strategies aimed at preventing waste generation (Bartl, 2014). 

The purpose of this project is to better understand the implications of successful waste prevention for current modes of consumption. To fulfil such purpose, the study rests upon an ethnography of consumption practices of a consumer-led movement that is already radically engaging in waste prevention: the Zero Waste lifestyle movement. The goal of this movement is to minimize the amount of waste ending up in nature, landfills and incinerators by reorganizing their consumption practices (e.g., avoiding disposable items, promoting the re-use of things, encouraging repair activities). Hence, by studying Zero Waste consumers, the project aims at understanding how waste-free lifestyles can be made accessible to a larger share of the population.

Furthermore, the goal of the project is to advance existing sociocultural perspectives on (sustainable) consumption. Drawing upon the marketing research fields of Consumer Culture Theory (see Arnould and Thompson, 2005) and Market System Dynamics (Giesler and Fischer, 2017), the study aims at clarifying the relation between waste and consumption, with a special focus on how infrastructures mediate the generation of waste. While waste has been a central tenet in other social science disciplines, it has not received much attention in marketing (Benton, 2015; de Coverly et al., 2008). Marketing research has simply essentialized waste as the “natural” product of human labour processes, such as consumption. Yet this essentialization fails to explain why until the beginning of last century consumption activities were producing nearly zero waste (Strasser, 1999).  In other words, if we are to prevent the generation of waste, we first need to better understand its relation to consumption.

References

Arnould EJ and Thompson CJ (2005) Consumer culture theory (CCT): Twenty years of research. Journal of Consumer Research 31(4): 868-882.

Bartl A (2014) Moving from recycling to waste prevention: A review of barriers and enables. Waste Manag Res 32(9 Suppl): 3-18.

Benton R, Jr. (2015) Reduce, Reuse, Recycle . . . and Refuse. Journal of Macromarketing 35(1): 111-122.

de Coverly E, McDonagh P, O'Malley L, et al. (2008) Hidden Mountain The Social Avoidance of Waste. Journal of Macromarketing 28(3): 289-303.

Kaza S, Yao L, Bhada-Tata P, et al. (2018) What a Waste 2.0 - A Global Snapshot of Solid Waste Management to 2050. Reportno. Report Number|, Date. Place Published|: Institution|.

Strasser S (1999) Waste and want : a social history of trash. New York: Metropolitan Books.