Tor hidden services are anonymous servers of unknown location and ownership who can be accessed through any Tor-enabled web browser. They have gained popularity over the years, but still suer from major usability challenges due to their cryptographicallygenerated non-memorable addresses. In response to this difficulty, in this work we introduce the Onion Name System (OnioNS), a privacy-enhanced distributed DNS that allows users to reference a hidden service by a meaningful globally-unique veriable domain name chosen by the hidden service operator. We introduce a new distributed self-healing public ledger and construct OnioNS as an optional backwards-compatible plugin for Tor on top of existing hidden service infrastructure. We simplify our design and threat model by embedding OnioNS within the Tor network and provide mechanisms for authenticated denial-of-existence with minimal networking costs. Our reference implementation demonstrates that OnioNS successfully addresses the major usability issue that has been with Tor hidden services since their introduction in 2002.

<p>Transition metal dichalcogenides (TMDs) have attracted significant attention in recent years with their immense potential to revolutionize optoelectronics and electrochemical energy applications. However, several challenges have prevented their practical use, including fabrication difficulties, incompatibility with conventional doping techniques, and unwanted environmental effects. This thesis aims to address the issues by introducing novel strategies for transforming TMDs into organic-integrated hybrid structures. Furthermore, this study focuses on gaining a fundamental understanding and a tunability of the unique physical properties of TMDs. Finally, to unlock their full potential, this thesis explores synergetic effects among the hybrid components for the development of advanced optoelectronics and energy devices. </p> <p><br></p> <p>By combining atomically thin TMDs with uniform organic layers, we have developed various two-dimensional (2D) hybrid junctions, including TMD/organic, TMD/TMD/organic, and TMD/organic/TMD. The TMD/organic hybrids are designed for type-II energy band alignments at the heterointerface and exhibit significantly improved (photo)conductivity and uniform photoresponse compared to pristine TMDs. The optoelectronic characteristics vary as a function of the layer number of TMDs, one of the unique features of ultrathin materials. We also find that integrating organic layers can tailor the charge density and polarity of TMD flakes, thus enabling controllable doping without damaging the crystallinity. </p> <p><br></p> <p>The hybrid approach not only modulates the properties of individual TMD layers but also offers an opportunity to study unique phenomena of 2D heterostructures such as interlayer excitons (XIs). XIs are spatially separated bound states of an electron and a hole in TMD/TMD heterolayers. We prepared various TMD/TMD/organic hybrid heterostructures with distinct energy band alignments and demonstrated a selective modulation of XI emission. The photoluminescence from the radiative recombination of XIs can be preserved, quenched, or modulated based on the band alignments. Furthermore, we fabricated organic-layer-inserted heterolayers (TMD/organic/TMD) and investigated the environmental effects on XIs. The organic layers tailor the dielectric screening within XIs and the dipolar interaction among XIs, thus regulating the energy states of XIs.</p> <p> </p> <p>In addition to the rich potential in optoelectronics, the hybrid strategies are advantageous to improve electrochemical energy storage. We constructed hybrid composites from core carbon nanotubes, intermediate metal-organic frameworks (MOFs), and outer TMD layers for supercapacitor electrodes. The 3D hierarchical composites aim to achieve synergetic effects from the components and offer high energy density while maintaining excellent power density and durability. Percolated nanotube networks are highly conductive, MOFs ensure a fast ion diffusivity, and TMD offers a large ion capacity. We engineered the TMD morphologies via topochemical synthesis and determined the optimal structure maximizing faradaic-reactive surface areas for improved ion accumulation and redox energy storage. We found that the hybrid composite of a flower-like TMD structure interwoven with carbon networks exhibits an unprecedentedly high energy density of over 80 Wh/kg, superior to conventional supercapacitors. </p> <p><br></p> <p>In summary, this thesis presents powerful strategies for engineering atomically thin TMDs and critical insights on relevant physics which may not be accessible otherwise. Given the extensive library of organic molecules, the hybrid approach may provide a versatile platform to study 2D materials and open new opportunities. The findings could serve as the foundation for the development of novel optoelectronic and energy storage applications.</p>

Yes / Cementitious composites are generally brittle and develop considerable tension cracks, resulting in corrosion of steel reinforcement and compromising structural durability. With careful selection and treatment, some kinds of bacteria are able to precipitate calcium carbonate and ‘heal’ cracks in cementitious composites through their metabolism, namely bacterial activity. It is envisioned that the bacterial technology-enabled cementitious composites could have great potential for engineering applications such as surface treatment, crack repair and self-healing construction material. This paper presents the state-of-the-art development of bacterial technology-enabled cementitious composites from the following aspects: mechanisms of bacterial induced calcium carbonate precipitation; methods of applying bacteria into cementitious composites; mechanical properties, durability and their influencing factors; various applications; cost effective analysis and prospect. The paper concludes with an outline of some future opportunities and challenges in the application of bacterial technology-enabled cementitious composites in construction. / National Science Foundation of China (51578110) and the Fundamental Research Funds for the Central Universities in China (DUT18GJ203).

No description available.

Yes / Although IT-enabled dynamic capabilities (ITDCs) add value to firms operating in turbulent and rapidly changing environments, firms face several challenges in developing, deploying, and maintaining the right portfolio of ITDCs. Since ITDCs are not uniformly advantageous, firms need to make strategic decisions in order to accomplish the complex task of achieving optimal ITDC configurations. This conceptual paper draws on the strategic alignment perspective to identify the optimal configuration of ITDCs for a firm based on its business strategy orientation indicated by the Miles and Snow typology. This paper first explicates the theoretically ideal configurations of ITDCs based on the competitive strategy patterns associated with each Miles and Snow archetype and then develops a model for measuring the strategic fit of ITDCs. This paper contributes to the literatures on ITDCs and strategic alignment by identifying optimal ITDC configurations and by conceptualizing the strategic fit of ITDCs respectively.

Yes / With the overnight growth in Working from Home (WFH) owing to the pandemic, organisations and their employees have had to adapt work-related processes and practices quickly with a huge reliance upon technology. Everyday activities such as social interactions with colleagues must therefore be reconsidered. Existing literature emphasises that social interactions, typically conducted in the traditional workplace, are a fundamental feature of social life and shape employees' experience of work. This experience is completely removed for many employees due to the pandemic and, presently, there is a lack of knowledge on how individuals maintain social interactions with colleagues via technology when working from home. Given that a lack of social interaction can lead to social isolation and other negative repercussions, this study aims to contribute to the existing body of literature on remote working by highlighting employees' experiences and practices around social interaction with colleagues. This study takes an interpretivist and qualitative approach utilising the diary-keeping technique to collect data from twenty-nine individuals who had started to work from home on a full-time basis as a result of the pandemic. The study explores how participants conduct social interactions using different technology platforms and how such interactions are embedded in their working lives. The findings highlight the difficulty in maintaining social interactions via technology such as the absence of cues and emotional intelligence, as well as highlighting numerous other factors such as job uncertainty, increased workloads and heavy usage of technology that affect their work lives. The study also highlights that despite the negative experiences relating to working from home, some participants are apprehensive about returning to work in the traditional office place where social interactions may actually be perceived as a distraction. The main contribution of our study is to highlight that a variety of perceptions and feelings of how work has changed via an increased use of digital media while working from home exists and that organisations need to be aware of these differences so that they can be managed in a contextualised manner, thus increasing both the efficiency and effectiveness of working from home.

With the dissemination and widespread use of AI-enabled work tools by IT professionals, the Flow experience, a well-established theory in psychology has crept into the copywriting of such tools. Therefore, this paper aimed to investigate whether AI-enabled work tools influence the Flow experience of IT professionals as they complete work tasks. To gather in-depth data, an interview study was conducted on 12 professionals consisting of UX and/or UI designers and various technical and managerial roles in the IT field. Following Braun and Clarke’s thematic analysis and under an abductive approach, a mix of focused and open codes shaped themes that were then further situated among similar literature. These are presented as theoretical and practical implications. Overall results have indicated that AI-enabled tools mostly do not influence Flow, but that Flow is not entirely absent. Theoretical implications contribute knowledge about the influence of AI-enabled work tools on Flow, some key points discussed include clear goals, exploratory behaviour, broad answers and loops, among others. Practical implications offered design recommendation alongside other published literature, suggesting, for instance, to create effective task context, personalized to workstyle, defining model defaults, and more. Generally, the outcome points to the need for scepticism when faced with unsupported assertions of AI-enabled tools influencing Flow among IT workers, and a need for more published work on the intersection. This is especially prudent given the growing field of AI for the consumer market, where unique opportunities and challenges arise with the usage of AI technologies.

In online learning, little is known about the impact of mixed reality and its underlying socio-technological factors on social space perceived by learners. The term social space refers to a group's socio-emotional dynamics that structure the social relationships among its members. Drawing upon extant literature on mixed reality, interaction and social presence, this research proposes and validates a theoretical model that elucidates the influence of immersion on users’ social space experiences within digital environments across different mixed realities (i.e., augmented and virtual realities, and video conferencing). Interaction and social presence are identified as two key factors mediating this relationship. To test the proposed model, a survey involving 488 participants in higher education was conducted, and the effects were examined under three conditions: video conferencing, augmented-reality, and virtual-reality. The findings show that 1) an immersion perspective plays a significant role in educational technology, particularly for its role in facilitating social space among learners in higher education; 2) the impact of immersion on social space is entirely mediated by learners’ assessment of interactions and their perception of social presence in digitally facilitated learning environments; and 3) the influences of immersion on learners to experience a prosocial space vary across virtual reality, augmented reality, and video conferencing. VR environments offer the most pronounced sensation of social presence, while AR environments prove to be optimal for interacting in digitally facilitated learning environments. Out of these three conditions, VC environments were perceived the lowest for interaction, sensation of social presence, and the establishment of a communal atmosphere of collaboration in digitally mediated learning environments. These findings make valuable contributions to theory by providing insights into the influence of immersion and variability in mixed reality on learners’ perception of social space experiences. In this respect, this research expands the body of knowledge and research in both the information systems and education fields. Furthermore, this research offers valuable insights for educators to make informed decisions regarding the selection and adoption of augmented and virtual reality technologies, as well as devising digital strategies in higher education. It contributes to our understanding of effective implementation of mixed reality in this context. / Dissertation / Doctor of Philosophy (PhD)

Foram estudados os principais fatores de valor percebido pelo mercado em relação aos produtos e serviços oferecidos pelas empresas fornecedoras de insumos de E-Learning. O estudo desses fatores, relacionados aos respectivos segmentos que compõem essa indústria, permitiu posicionar as principais empresas (uma em cada segmento) que se adequaram melhor a esses fatores de valor percebido. Foi realizada também uma revisão da literatura, para definir o conceito de E-Learning, descrevendo suas diversas aplicações e organizando-as em quatro aspectos: o pedagógico, o tecnológico, o gerencial e o relativo ao negócio dessa atividade. Propôs-se, também, um mapa de valor dessa indústria, tratando de segmentá-lo. O conceito de valor foi estudado, considerando-o dentro da perspectiva da percepção do cliente, ou seja, foram abordados os aspectos relativos aos critérios que constituem o valor percebido. Finalmente, foi aplicada uma pesquisa de campo a um grupo de especialistas da indústria de E-Learning, com o objetivo de classificar os principais fatores de valor percebido pelo mercado, avaliar um fornecedor em cada segmento de atuação e selecionar aquele que atendeu melhor aos critérios de percepção de valor. Os resultados obtidos por meio da análise das respostas dos especialistas apontaram caminhos para a realização de novos estudos sobre o negócio E-Learning, além de estabelecer critérios importantes relativos às principais empresas fornecedoras dessa indústria. / This Masters Degree Dissertation studies the main factors of market perceived value in relation to products and services offered by E-Learning input supplying companies. The study of such factors, related to the segments which comprise this industry, enabled us to identify the main companies one of each segment which best adapted to selected perceived value factors. Initially a literature review was carried out, aiming at defining the concept of E-Learning, describing its different applications and organizing it in four axes of main coordinates: the pedagogical aspect, the technological aspect, the management aspect and the business aspect of the activity. Another aim of such a literature review was understanding the development of this industry, through companies which comprise it, and then propose a value map of such an industry, dividing it into segments with the support of studies on this topic. The third step of this review was a focus on the concept of value. It was therefore adopted a theoretical line which considers value within the clients perception perspective. In other words, the focus was on aspects related to the criteria which comprise the so-called perceived value. Finally, a field research was carried out along with a group of E-Learning experts, with the following aims: ranking the main factors of market perceived values, in order to assess a supplier in each segment; and selecting only one company, in each of the segments, which best fits the perceived value criteria previously obtained. The results obtained by the consolidation and analysis of the experts answers pointed out ways to carry out new studies on the E-Learning business point of view, as well as establish important criteria about the main supplying companies of this industry.

<p>With the rise of the Web, there is more interest among end-users to create different kinds of software that use elements from the Web or allow for networked interaction between users. Currently however, many available tools for this purpose are hard to use or lack a sufficient level of expressiveness. To provide new insights on the construction of tools that allow end-users to create their own Web-enabled software, this thesis explores design issues and consequences of applying the Turtle metaphor from the Logo-programming language to an end-user programming environment for Web-enabled applications. </p><p>In order to explore this, CrawLogo was created - a programmable end-user tool that supports the creation of Web-enabled applications using a Turtle-like control metaphor and language adapted from Logo. As a proof-of-concept, several Web-enabled applications were created using this new tool, including CrawLogo Pong, a somewhat alternative version of Atari’s classic Pong game, and a collaborative browsing environment, in which users can browse the Web together. The resulting CrawLogo environment allows for creating Web-enabled applications that - using more traditional programming languages - would be quite complex and require deep technical programming skills. Further, while utilizing a Turtle-like control metaphor in CrawLogo allows for the creation of some new types of applications and some new ways of interacting with the Web, it also raises new problems such as how to successfully design within the CrawLogo metaphor and how to create a meaningful representation of Turtle- geometry-based navigation on the Web.</p>