3,296 research outputs found
Configuration Management of Distributed Systems over Unreliable and Hostile Networks
Economic incentives of large criminal profits and the threat of legal consequences have pushed criminals to continuously improve their malware, especially command and control channels. This thesis applied concepts from successful malware command and control to explore the survivability and resilience of benign configuration management systems.
This work expands on existing stage models of malware life cycle to contribute a new model for identifying malware concepts applicable to benign configuration management. The Hidden Master architecture is a contribution to master-agent network communication. In the Hidden Master architecture, communication between master and agent is asynchronous and can operate trough intermediate nodes. This protects the master secret key, which gives full control of all computers participating in configuration management. Multiple improvements to idempotent configuration were proposed, including the definition of the minimal base resource dependency model, simplified resource revalidation and the use of imperative general purpose language for defining idempotent configuration.
Following the constructive research approach, the improvements to configuration management were designed into two prototypes. This allowed validation in laboratory testing, in two case studies and in expert interviews. In laboratory testing, the Hidden Master prototype was more resilient than leading configuration management tools in high load and low memory conditions, and against packet loss and corruption. Only the research prototype was adaptable to a network without stable topology due to the asynchronous nature of the Hidden Master architecture.
The main case study used the research prototype in a complex environment to deploy a multi-room, authenticated audiovisual system for a client of an organization deploying the configuration. The case studies indicated that imperative general purpose language can be used for idempotent configuration in real life, for defining new configurations in unexpected situations using the base resources, and abstracting those using standard language features; and that such a system seems easy to learn.
Potential business benefits were identified and evaluated using individual semistructured expert interviews. Respondents agreed that the models and the Hidden Master architecture could reduce costs and risks, improve developer productivity and allow faster time-to-market. Protection of master secret keys and the reduced need for incident response were seen as key drivers for improved security. Low-cost geographic scaling and leveraging file serving capabilities of commodity servers were seen to improve scaling and resiliency. Respondents identified jurisdictional legal limitations to encryption and requirements for cloud operator auditing as factors potentially limiting the full use of some concepts
Proceedings of the 10th International congress on architectural technology (ICAT 2024): architectural technology transformation.
The profession of architectural technology is influential in the transformation of the built environment regionally, nationally, and internationally. The congress provides a platform for industry, educators, researchers, and the next generation of built environment students and professionals to showcase where their influence is transforming the built environment through novel ideas, businesses, leadership, innovation, digital transformation, research and development, and sustainable forward-thinking technological and construction assembly design
Low- and high-resource opinion summarization
Customer reviews play a vital role in the online purchasing decisions we make. The reviews
express user opinions that are useful for setting realistic expectations and uncovering important
details about products. However, some products receive hundreds or even thousands of
reviews, making them time-consuming to read. Moreover, many reviews contain uninformative
content, such as irrelevant personal experiences. Automatic summarization offers an
alternative – short text summaries capturing the essential information expressed in reviews.
Automatically produced summaries can reflect overall or particular opinions and be tailored to
user preferences. Besides being presented on major e-commerce platforms, home assistants
can also vocalize them. This approach can improve user satisfaction by assisting in making
faster and better decisions.
Modern summarization approaches are based on neural networks, often requiring thousands of
annotated samples for training. However, human-written summaries for products are expensive
to produce because annotators need to read many reviews. This has led to annotated data
scarcity where only a few datasets are available. Data scarcity is the central theme of our
works, and we propose a number of approaches to alleviate the problem. The thesis consists
of two parts where we discuss low- and high-resource data settings.
In the first part, we propose self-supervised learning methods applied to customer reviews
and few-shot methods for learning from small annotated datasets. Customer reviews without
summaries are available in large quantities, contain a breadth of in-domain specifics, and
provide a powerful training signal. We show that reviews can be used for learning summarizers
via a self-supervised objective. Further, we address two main challenges associated with
learning from small annotated datasets. First, large models rapidly overfit on small datasets
leading to poor generalization. Second, it is not possible to learn a wide range of in-domain
specifics (e.g., product aspects and usage) from a handful of gold samples. This leads to
subtle semantic mistakes in generated summaries, such as ‘great dead on arrival battery.’ We
address the first challenge by explicitly modeling summary properties (e.g., content coverage
and sentiment alignment). Furthermore, we leverage small modules – adapters – that are
more robust to overfitting. As we show, despite their size, these modules can be used to
store in-domain knowledge to reduce semantic mistakes. Lastly, we propose a simple method
for learning personalized summarizers based on aspects, such as ‘price,’ ‘battery life,’ and
‘resolution.’ This task is harder to learn, and we present a few-shot method for training a
query-based summarizer on small annotated datasets.
In the second part, we focus on the high-resource setting and present a large dataset with
summaries collected from various online resources. The dataset has more than 33,000 humanwritten
summaries, where each is linked up to thousands of reviews. This, however, makes it
challenging to apply an ‘expensive’ deep encoder due to memory and computational costs. To
address this problem, we propose selecting small subsets of informative reviews. Only these
subsets are encoded by the deep encoder and subsequently summarized. We show that the
selector and summarizer can be trained end-to-end via amortized inference and policy gradient
methods
On Leveraging Tests to Infer Nullable Annotations
Issues related to the dereferencing of null pointers are a pervasive and widely studied problem, and numerous static analyses have been proposed for this purpose. These are typically based on dataflow analysis, and take advantage of annotations indicating whether a type is nullable or not. The presence of such annotations can significantly improve the accuracy of null checkers. However, most code found in the wild is not annotated, and tools must fall back on default assumptions, leading to both false positives and false negatives. Manually annotating code is a laborious task and requires deep knowledge of how a program interacts with clients and components.
We propose to infer nullable annotations from an analysis of existing test cases. For this purpose, we execute instrumented tests and capture nullable API interactions. Those recorded interactions are then refined (santitised and propagated) in order to improve their precision and recall. We evaluate our approach on seven projects from the spring ecosystems and two google projects which have been extensively manually annotated with thousands of @Nullable annotations. We find that our approach has a high precision, and can find around half of the existing @Nullable annotations. This suggests that the method proposed is useful to mechanise a significant part of the very labour-intensive annotation task
Trusted Provenance with Blockchain - A Blockchain-based Provenance Tracking System for Virtual Aircraft Component Manufacturing
The importance of provenance in the digital age has led to significant interest in utilizing blockchain technology for tamper-proof storage of provenance data. This thesis proposes a blockchain-based provenance tracking system for the certification of aircraft components. The aim is to design and implement a system that can ensure the trustworthy, tamper-resistant storage of provenance documents originating from an aircraft manufacturing process. To achieve this, the thesis presents a systematic literature review, which provides a comprehensive overview of existing works in the field of provenance and blockchain technology. After obtaining strategies to utilize blockchain for the storage of provenance data on the blockchain, a system was designed to meet the requirements of stakeholders in the aviation industry. The thesis utilized a systematic approach to gather requirements by conducting interviews with stakeholders. The system was implemented using a combination of smart contracts and a graphical user interface to provide tamper-resistant, traceable storage of relevant data on a transparent blockchain. An evaluation based on the requirements identified during the requirement engineering process found that the proposed system meets all identified requirements. Overall, this thesis offers insight into a potential application of blockchain technology in the aviation industry and provides a valuable resource for researchers and industry professionals seeking to leverage blockchain technology for provenance tracking and certification purpose
Incremental schema integration for data wrangling via knowledge graphs
Virtual data integration is the current approach to go for data wrangling in data-driven decision-making. In this paper, we focus on automating schema integration, which extracts a homogenised representation of the data source schemata and integrates them into a global schema to enable virtual data integration. Schema integration requires a set of well-known constructs: the data source schemata and wrappers, a global integrated schema and the mappings between them. Based on them, virtual data integration systems enable fast and on-demand data exploration via query rewriting. Unfortunately, the generation of such constructs is currently performed in a largely manual manner, hindering its feasibility in real scenarios. This becomes aggravated when dealing with heterogeneous and evolving data sources. To overcome these issues, we propose a fully-fledged semi-automatic and incremental approach grounded on knowledge graphs to generate the required schema integration constructs in four main steps: bootstrapping, schema matching, schema integration, and generation of system-specific constructs. We also present NextiaDI, a tool implementing our approach. Finally, a comprehensive evaluation is presented to scrutinize our approach.This work was partly supported by the DOGO4ML project, funded by the Spanish Ministerio de Ciencia e Innovación under project PID2020-117191RB-I00, and D3M project, funded by the Spanish Agencia Estatal de Investigación (AEI) under project PDC2021-121195-I00. Javier Flores is supported by contract 2020-DI-027 of the Industrial Doctorate Program of the Government of Catalonia and Consejo Nacional de Ciencia y TecnologÃa (CONACYT, Mexico). Sergi Nadal is partly supported by the Spanish Ministerio de Ciencia e Innovación, as well as the European Union – NextGenerationEU, under project FJC2020-045809-I.Peer ReviewedPostprint (published version
Systemic Circular Economy Solutions for Fiber Reinforced Composites
This open access book provides an overview of the work undertaken within the FiberEUse project, which developed solutions enhancing the profitability of composite recycling and reuse in value-added products, with a cross-sectorial approach. Glass and carbon fiber reinforced polymers, or composites, are increasingly used as structural materials in many manufacturing sectors like transport, constructions and energy due to their better lightweight and corrosion resistance compared to metals. However, composite recycling is still a challenge since no significant added value in the recycling and reprocessing of composites is demonstrated. FiberEUse developed innovative solutions and business models towards sustainable Circular Economy solutions for post-use composite-made products. Three strategies are presented, namely mechanical recycling of short fibers, thermal recycling of long fibers and modular car parts design for sustainable disassembly and remanufacturing. The validation of the FiberEUse approach within eight industrial demonstrators shows the potentials towards new Circular Economy value-chains for composite materials
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