40 research outputs found
A Dynamic Context-Aware and Role-Capability Based Access Control Mechanism for Internet of Things
No full textThe Internet of Things (IoT) presents distinct challenges for access control due to its dynamic, heterogeneous, and evolving nature, which existing mechanisms often struggle to address. To overcome these challenges, this paper proposes a novel context-aware role-capability based access control (CRCBAC) system which ef-fectively handles key issues such as dynamic adaptation, capability delegation, con-text awareness, scalability, and security. At its core, CRCBAC utilizes a structured role capability tree (RCT) to ensure secure capability propagation and manage-ment across roles, resolving conflicts through a priority system. Additionally, we design a set of protocols leveraging RCT-operations to securely evaluate access requests, as well as to create, transfer, and revoke capabilities. These protocols are validated through formal analysis using BAN logic and Scyther-based attack simulation, demonstrating CRCBAC’s robustness in ensuring both confidentiality and integrity. Experimental evaluation confirms CRCBAC’s superior scalability and efficiency, achieving up to 75% lower response times and 4.6 times higher through-put compared to state-of-the-art approaches. The capability delegation mechanism consistently maintains response times below 3 ms, even as user capabilities scale, while also reducing energy consumption by 87.5% compared to state-of-the-art approach, making CRCBAC particularly well-suited for energy-constrained IoT environments
Impacts of medical and wellness tourism centers on the communities around them: case studies in Delhi and Kerala
No full textOver the past decade or so the movement of patients and wellness seekers across borders, over long distances, has increased and India has been the destination of choice for many. This is private sector led growth, but the government has provided support in terms of subsidies and its promotion. With the alignment of governmental support and other enabling circumstances, many new centers-both corporate hospitals and Ayurvedic wellness centers-have opened in India. The case studies for this research were centers in Delhi, for medical tourism, and Kerala, for wellness tourism. This study involved assessing the impacts of these centers on the local communities around them, in terms of medical, economic, and infrastructural consequences. Another question was whether these centers formed enclaves, of varying degrees, where the impacts were focused, or were there significant benefits for these communities from the centers being there. The flow of benefits to the locals, in terms of access to healthcare and other economic and infrastructural impacts was limited, more so around the wellness tourism centers. Many, living close to these centers, could not afford the facilities because of the expense involved. All the medical tourism centers in the study were built on land given at concessional rates, with the promise that the hospitals would reserve a certain percentage of their outpatient and inpatient capacities for people below poverty level. Most of these hospitals have failed to follow that. In terms of other benefits, some local businesses and the accommodation sector have benefitted from these centers being located in their neighborhoods.Ph. D.Includes bibliographical referencesIncludes vitaby Purba Rudr
Firm as a Nonmarket Actor in Regulatory and Governance Setups:Perspectives on Risk and Capabilities in the Changing Mining Industry
No full textThe author has not given permission for Aaltodoc -publishing.In this thesis, I deal with nonmarket risk referring to those issues which are anything that do not fall under the purview of market economics - demand, supply, and pricing. In particular, I tackle social, environmental, and political issues. My take on things is from the perspective of mining firms and how by managing their nonmarket environment well, they can build capabilities that are hard to replicate and can generate competitive advantage for firms in the long run. Further narrowing down the scope of investigation lead me to two setups – regulatory and governance environments of the firm. This was done so as to sharpen the investigation on nonmarket risk and bring in the systemic notion. Nonetheless, although the thesis focusses on the nonmarket environment, it considers market driven parameters as part of the contextual setting primarily because market forces are the reasons why firms are in business in the first place. Against this backdrop, the overarching research question is "How do mining firms tackle - regulate and govern - nonmarket risk?" And in relation to this, I launch an investigation, both from the perspective of a firm's internal risk capabilities as well as from the standpoint of its activities in the external stakeholder environment.Essay 1 throws light on the evolving efforts at risk management, both from an academic literature standpoint as well as from an industry guidelines perspective and finds the gap that extreme event risks are not well accounted for and that existing market-based risk techniques have to be broadened and expanded to solve nonmarket risk problems. Extreme events are of special value to understand gaps in risk science because they push the limits of fundamental research.
Taking this forward are the other two essays - Essay 2 and 3, where the empirics examine extreme events thereby throwing light on the business continuity of a firm. Essay 2 argues for embeddedness of self-regulation within the regulatory state and firm's subsequent role of subsidiarity wherein the firm follows the broad level mandatory public regulations yet undertakes voluntary standards which are under the light surveillance of the state. I empirically situate the activities of juniors (smaller mining firms who are usually involved in exploration) and established players (big miners), in the regulatory permitting environment of Sweden and Finland. Essay 3 focusses on mining trusts, funds, and foundations (FTF), and capabilities developed by a firm in setting up these FTFs immediately following a disaster and then governing/overseeing their medium-long term administration. Firm involvement in design and influence of risk governance administrations highlights the prominence of nonmarket strategies.
To sum it up, all the three essays look into systemizing nonmarket risk management activities
Inflammation-induced Id2 promotes plasticity in regulatory T cells
No full textTH17 cells originating from regulatory T (Treg) cells upon loss of the Treg-specific transcription factor Foxp3 accumulate in sites of inflammation and aggravate autoimmune diseases. Whether an active mechanism drives the generation of these pathogenic ��ex-Foxp3 TH17�� cells, remains unclear. Here we show that pro-inflammatory cytokines enhance the expression of transcription regulator Id2, which mediates cellular plasticity of Treg into ex-Foxp3 TH17 cells. Expression of Id2 in in vitro differentiated iTreg cells reduces the expression of Foxp3 by sequestration of the transcription activator E2A, leading to the induction of TH17-related cytokines. Treg-specific ectopic expression of Id2 in mice significantly reduces the Treg compartment and causes immune dysregulation. Cellular fate-mapping experiments reveal enhanced Treg plasticity compared to wild-type, resulting in exacerbated experimental autoimmune encephalomyelitis pathogenesis or enhanced anti-tumor immunity. Our findings suggest that controlling Id2 expression may provide a novel approach for effective Treg cell immunotherapies for both autoimmunity and cancer. (C) 2018, The Author(s
Bcl11b prevents catastrophic autoimmunity by controlling multiple aspects of a regulatory T cell gene expression program
No full textFoxp3 and its protein partners establish a regulatory T (Treg) cell transcription profile and promote immunological tolerance. However, molecular features contributing to a Treg-specific gene expression program are still incompletely understood. We find that the transcription factor Bcl11b is a prominent Foxp3 cofactor with multifaceted functions in Treg biology. Optimal genomic recruitment of Foxp3 and Bcl11b is critically interdependent. Genome-wide occupancy studies coupled with gene expression profiling reveal that Bcl11b, in association with Foxp3, is primarily responsible in establishing a Treg-specific gene activation program. Furthermore, Bcl11b restricts misdirected recruitment of Foxp3 to sites, which would otherwise result in an altered Treg transcriptome profile. Consequently, Treg-specific ablation of Bcl11b results in marked breakdown of immune tolerance, leading to aggressive systemic autoimmunity. Our study provides previously underappreciated mechanistic insights into molecular events contributing to basic aspects of Treg function. Furthermore, it establishes a therapeutic target with potential implications in autoimmunity and cancer. Copyright © 2019 The Author
Extractive Explanations for Interpretable Text Ranking
No full textNeural document ranking models perform impressively well due to superior language understanding gained from pre-Training tasks. However, due to their complexity and large number of parameters these (typically transformer-based) models are often non-interpretable in that ranking decisions can not be clearly attributed to specific parts of the input documents.In this article, we propose ranking models that are inherently interpretable by generating explanations as a by-product of the prediction decision. We introduce the Select-And-Rank paradigm for document ranking, where we first output an explanation as a selected subset of sentences in a document. Thereafter, we solely use the explanation or selection to make the prediction, making explanations first-class citizens in the ranking process. Technically, we treat sentence selection as a latent variable trained jointly with the ranker from the final output. To that end, we propose an end-To-end training technique for Select-And-Rank models utilizing reparameterizable subset sampling using the Gumbel-max trick.We conduct extensive experiments to demonstrate that our approach is competitive to state-of-The-Art methods. Our approach is broadly applicable to numerous ranking tasks and furthers the goal of building models that are interpretable by design. Finally, we present real-world applications that benefit from our sentence selection method.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Web Information System
An in-depth analysis of passage-level label transfer for contextual document ranking
No full textPre-trained contextual language models such as BERT, GPT, and XLnet work quite well for document retrieval tasks. Such models are fine-tuned based on the query-document/query-passage level relevance labels to capture the ranking signals. However, the documents are longer than the passages and such document ranking models suffer from the token limitation (512) of BERT. Researchers proposed ranking strategies that either truncate the documents beyond the token limit or chunk the documents into units that can fit into the BERT. In the later case, the relevance labels are either directly transferred from the original query-document pair or learned through some external model. In this paper, we conduct a detailed study of the design decisions about splitting and label transfer on retrieval effectiveness and efficiency. We find that direct transfer of relevance labels from documents to passages introduces label noise that strongly affects retrieval effectiveness for large training datasets. We also find that query processing times are adversely affected by fine-grained splitting schemes. As a remedy, we propose a careful passage level labelling scheme using weak supervision that delivers improved performance (3–14% in terms of nDCG score) over most of the recently proposed models for ad-hoc retrieval while maintaining manageable computational complexity on four diverse document retrieval datasets.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Web Information System
Sensory imbibing, Indian philosophy, and Vedic metal: Implications for music education
No full textThis chapter begins with an exposition of the Indian philosophical tradition and practice of Advaita Vedanta (2000 to 800/600 BCE, the Upanishads), of a contemplation of a Self (ātman) as inner essence of personhood and cosmic universe. Studying exegetical contemplations of corporeality and incorporeality from a distant past raises question about (1) the prospect of applicability in the present, and (2) concepts of sound and music connected with this philosophical tradition. The author explores these issues through a Metal group in Singapore known as Rudra, whose Vedic Metal repertoire is inspired by their commentaries on texts from the Vedanta. Two musical compositions are studied as intersections of Vedic philosophical texts and Rudra’s Metal soundscapes. Coming to terms with sound in Vedanta contexts and Rudra’s soundscapes, the author considers points of coincidence and the implications for the role of Asian philosophy in twenty-first-century music education.</p
Supervised Contrastive Learning Approach for Contextual Ranking
No full textContextual ranking models have delivered impressive performance improvements
over classical models in the document ranking task. However, these highly
over-parameterized models tend to be data-hungry and require large amounts of
data even for fine tuning. This paper proposes a simple yet effective method to
improve ranking performance on smaller datasets using supervised contrastive
learning for the document ranking problem. We perform data augmentation by
creating training data using parts of the relevant documents in the
query-document pairs. We then use a supervised contrastive learning objective
to learn an effective ranking model from the augmented dataset. Our experiments
on subsets of the TREC-DL dataset show that, although data augmentation leads
to an increasing the training data sizes, it does not necessarily improve the
performance using existing pointwise or pairwise training objectives. However,
our proposed supervised contrastive loss objective leads to performance
improvements over the standard non-augmented setting showcasing the utility of
data augmentation using contrastive losses. Finally, we show the real benefit
of using supervised contrastive learning objectives by showing marked
improvements in smaller ranking datasets relating to news (Robust04), finance
(FiQA), and scientific fact checking (SciFact)
Openness and the Politics of Potable Water
No full text Improving access to potable water has become an increasingly urgent concern for developing nations in the current era of globalization. According to standard wisdom, if developing countries undertake certain domestic reforms, such as investing in infrastructure and engineering, then safe and clean drinking water will improve. This analysis uncovers, however, that in addition to such domestic efforts, one of the greatest factors affecting water uncertainty is, in fact, internationally induced: trade. Surprisingly, both scholars and practitioners have neglected the potential impacts of expanding trade on access to potable water. This analysis is the first large- N cross-national study of water that focuses on the interplay of trade and politics—both international and domestic—as the primary driving forces behind improvements in (or constraints to) water access. The author hypothesizes that growing export pressures are constraining drinkable water in poor countries, but a particular domestic condition can mitigate this effect: the existence of lower levels of income inequality. As the socioeconomic actors disadvantaged by openness, particularly in more equal countries, seek reparations for the growing threats to potable water, the adverse affects of trade on water may be averted. Empirical evidence from 77 developing countries and case studies of Vietnam and India provide support for this hypothesis. </jats:p
