13,413 research outputs found
Erasing-based lossless compression method for streaming floating-point time series
There are a prohibitively large number of floating-point time series data
generated at an unprecedentedly high rate. An efficient, compact and lossless
compression for time series data is of great importance for a wide range of
scenarios. Most existing lossless floating-point compression methods are based
on the XOR operation, but they do not fully exploit the trailing zeros, which
usually results in an unsatisfactory compression ratio. This paper proposes an
Erasing-based Lossless Floating-point compression algorithm, i.e., Elf. The
main idea of Elf is to erase the last few bits (i.e., set them to zero) of
floating-point values, so the XORed values are supposed to contain many
trailing zeros. The challenges of the erasing-based method are three-fold.
First, how to quickly determine the erased bits? Second, how to losslessly
recover the original data from the erased ones? Third, how to compactly encode
the erased data? Through rigorous mathematical analysis, Elf can directly
determine the erased bits and restore the original values without losing any
precision. To further improve the compression ratio, we propose a novel
encoding strategy for the XORed values with many trailing zeros. Furthermore,
observing the values in a time series usually have similar significand counts,
we propose an upgraded version of Elf named Elf+ by optimizing the significand
count encoding strategy, which improves the compression ratio and reduces the
running time further. Both Elf and Elf+ work in a streaming fashion. They take
only O(N) (where N is the length of a time series) in time and O(1) in space,
and achieve a notable compression ratio with a theoretical guarantee. Extensive
experiments using 22 datasets show the powerful performance of Elf and Elf+
compared with 9 advanced competitors for both double-precision and
single-precision floating-point values
Towards A Practical High-Assurance Systems Programming Language
Writing correct and performant low-level systems code is a notoriously demanding job, even for experienced developers. To make the matter worse, formally reasoning about their correctness properties introduces yet another level of complexity to the task. It requires considerable expertise in both systems programming and formal verification. The development can be extremely costly due to the sheer complexity of the systems and the nuances in them, if not assisted with appropriate tools that provide abstraction and automation.
Cogent is designed to alleviate the burden on developers when writing and verifying systems code. It is a high-level functional language with a certifying compiler, which automatically proves the correctness of the compiled code and also provides a purely functional abstraction of the low-level program to the developer. Equational reasoning techniques can then be used to prove functional correctness properties of the program on top of this abstract semantics, which is notably less laborious than directly verifying the C code.
To make Cogent a more approachable and effective tool for developing real-world systems, we further strengthen the framework by extending the core language and its ecosystem. Specifically, we enrich the language to allow users to control the memory representation of algebraic data types, while retaining the automatic proof with a data layout refinement calculus. We repurpose existing tools in a novel way and develop an intuitive foreign function interface, which provides users a seamless experience when using Cogent in conjunction with native C. We augment the Cogent ecosystem with a property-based testing framework, which helps developers better understand the impact formal verification has on their programs and enables a progressive approach to producing high-assurance systems. Finally we explore refinement type systems, which we plan to incorporate into Cogent for more expressiveness and better integration of systems programmers with the verification process
Urbanised forested landscape: Urbanisation, timber extraction and forest care on the ViÈeu Valley, northern Romania
By looking at urbanisation processes from the vantage point of the forest, and the ways in which it both constitutes our living space while having been separated from the bounded space of the urban in modern history, the thesis asks: How can we (re)imagine urbanisation beyond the limits of the urban? How can a feminine line of thinking engage with the forest beyond the capitalist-colonial paradigm and its extractive project? and How can we âthink with careâ (Puig de la Bellacasa 2017) towards the forest as an inhabitant of our common world, instead of perpetuating the image of the forest as a space outside the delimited boundaries of the city? Through a case study research, introducing the ViÈeu Valley in northern Romania as both a site engaged in the circulation of the global timber flow, a part of what Brenner and Schmid (2014) name âplanetary urbanisationâ, where the extractive logging operations beginning in the late XVIIIth century have constructed it as an extractive landscape, and a more than human landscape inhabited by a multitude of beings (animal, plant, and human) the thesis argues towards the importance of forest care and indigenous knowledge in landscape management understood as a trans-generational transmission of knowledge, that is interdependent with the persistence of the landscape as such. Having a trans-scalar approach, the thesis investigates the ways in which the extractive projects of the capitalist-colonial paradigm have and still are shaping forested landscapes across the globe in order to situate the case as part of a planetary forest landscape and the contemporary debates it is engaged in. By engaging with emerging paradigms within the fields of plant communication, forestry, legal scholarship and landscape urbanism that present trees and forests as intelligent beings, and look at urbanisation as a way of inhabiting the landscape in both indigenous and modern cultures, the thesis argues towards viewing forested landscapes as more than human living spaces. Thinking urbanisation through the case of the ViÈeu Valleyâs urbanised forested landscape, the thesis aligns with alternate ways of viewing urbanisation as co-habitation with more than human beings, particularly those emerging from interdisciplinary research in the Amazon river basin (Tavares 2017, Heckenberger 2012) and, in light of emerging discourses on the rights of nature, proposes an expanded concept of planetary citizenship, to include non-human personhood
Beam scanning by liquid-crystal biasing in a modified SIW structure
A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium
CULTURAL HERITAGE AND RISK: LET'S <i>GIVE INTELLIGENCE</i> TO OUR TECHNOLOGIES
In the last decades, the evolution in the sector of technologies applied to cultural heritage has taken on extraordinary accelerations in terms of accuracy and reliability of the measurement and restitution, as well as in the management of acquired data. In particular, the complex of these measurement and documentation actions are of fundamental importance if interfaced with other types of heterogeneous data acquired in different ways. Nevertheless, in face of such a complex framework of know- how, increasingly advanced technologies, dedicated programs and funding, meetings and debates, the establishment of specific Institutional Bodies to manage decision-making plans and their implementation, we continue to witness the frantic chasing of emergencies after the occurrence of catastrophic events. The spectrum of risks is more and more manifesting itself in its breadth: to the evidence of the effects due to Climate Change, those deriving from hydrogeological instability, from the lack of care of the territory and coasts, the devastation of an anthropic nature due to the senseless consumption of soil, and the unsustainable pressure of an uncultured, omnivorous tourism, are added with increasing frequency. This contribution deals in a general way with the theme of technologies for the knowledge of Cultural Heritage. It intends to critically question about the dangers inherent in the "indiscriminate, unconscious and uncritical" use of technologies for the knowledge of Cultural Heritage oriented towards its preservation. The aim is to prompt a discussion within the scientific community dealing with the documentation and conservation of cultural heritage in order to promote an indispensable culture of prevention and planned conservation, in which the intelligent relationship between Man and technology must be rediscovered
Endogenous measures for contextualising large-scale social phenomena: a corpus-based method for mediated public discourse
This work presents an interdisciplinary methodology for developing endogenous measures of group membership through analysis of pervasive linguistic patterns in public discourse. Focusing on political discourse, this work critiques the conventional approach to the study of political participation, which is premised on decontextualised, exogenous measures to characterise groups. Considering the theoretical and empirical weaknesses of decontextualised approaches to large-scale social phenomena, this work suggests that contextualisation using endogenous measures might provide a complementary perspective to mitigate such weaknesses.
This work develops a sociomaterial perspective on political participation in mediated discourse as affiliatory action performed through language. While the affiliatory function of language is often performed consciously (such as statements of identity), this work is concerned with unconscious features (such as patterns in lexis and grammar). This work argues that pervasive patterns in such features that emerge through socialisation are resistant to change and manipulation, and thus might serve as endogenous measures of sociopolitical contexts, and thus of groups.
In terms of method, the work takes a corpus-based approach to the analysis of data from the Twitter messaging service whereby patterns in usersâ speech are examined statistically in order to trace potential community membership. The method is applied in the US state of Michigan during the second half of 2018â6 November having been the date of midterm (i.e. non-Presidential) elections in the United States. The corpus is assembled from the original posts of 5,889 users, who are nominally geolocalised to 417 municipalities. These users are clustered according to pervasive language features. Comparing the linguistic clusters according to the municipalities they represent finds that there are regular sociodemographic differentials across clusters. This is understood as an indication of social structure, suggesting that endogenous measures derived from pervasive patterns in language may indeed offer a complementary, contextualised perspective on large-scale social phenomena
Grasping nothing: a study of minimal ontologies and the sense of music
If music were to have a proper sense â one in which it is truly given â one might reasonably place this in sound and aurality. I contend, however, that no such sense exists; rather, the sense of music takes place, and it does so with the impossible. To this end, this thesis â which is a work of philosophy and music â advances an ontology of the impossible (i.e., it thinks the being of what, properly speaking, can have no being) and considers its implications for music, articulating how ontological aporias â of the event, of thinking the absolute, and of sovereigntyâs dismemberment â imply senses of music that are anterior to sound. John Cageâs Silent Prayer, a nonwork he never composed, compels a rerethinking of silence on the basis of its contradictory status of existence; Florian Hecker et al.âs Speculative Solution offers a basis for thinking absolute music anew to the precise extent that it is a discourse of meaninglessness; and Manfred Werderâs [yearn] pieces exhibit exemplarily that musicâs sense depends on the possibility of its counterfeiting. Inso-much as these accounts produce musical senses that take the place of sound, they are also understood to be performances of these pieces. Here, then, thought is musicâs organon and its instrument
Deep Transfer Learning Applications in Intrusion Detection Systems: A Comprehensive Review
Globally, the external Internet is increasingly being connected to the
contemporary industrial control system. As a result, there is an immediate need
to protect the network from several threats. The key infrastructure of
industrial activity may be protected from harm by using an intrusion detection
system (IDS), a preventive measure mechanism, to recognize new kinds of
dangerous threats and hostile activities. The most recent artificial
intelligence (AI) techniques used to create IDS in many kinds of industrial
control networks are examined in this study, with a particular emphasis on
IDS-based deep transfer learning (DTL). This latter can be seen as a type of
information fusion that merge, and/or adapt knowledge from multiple domains to
enhance the performance of the target task, particularly when the labeled data
in the target domain is scarce. Publications issued after 2015 were taken into
account. These selected publications were divided into three categories:
DTL-only and IDS-only are involved in the introduction and background, and
DTL-based IDS papers are involved in the core papers of this review.
Researchers will be able to have a better grasp of the current state of DTL
approaches used in IDS in many different types of networks by reading this
review paper. Other useful information, such as the datasets used, the sort of
DTL employed, the pre-trained network, IDS techniques, the evaluation metrics
including accuracy/F-score and false alarm rate (FAR), and the improvement
gained, were also covered. The algorithms, and methods used in several studies,
or illustrate deeply and clearly the principle in any DTL-based IDS subcategory
are presented to the reader
Animating potential for intensities and becoming in writing: challenging discursively constructed structures and writing conventions in academia through the use of storying and other post qualitative inquiries
Written for everyone ever denied the opportunity of fulfilling their academic potential, this is âChloeâs storyâ. Using composite selves, a phrase chosen to indicate multiplicities and movement, to story both the initial event leading to âChloeâsâ immediate withdrawal from a Further Education college and an imaginary second chance to support her whilst at university, this Deleuzo-Guattarian (2015a) âassemblageâ of post qualitative inquiries offers challenge to discursively constructed structures and writing conventions in academia. Adopting a posthuman approach to theorising to shift attention towards affects and intensities always relationally in action in multiple âassemblagesâ, these inquiries aim to decentre individual âlecturerâ and âstudentâ identities. Illuminating movements and moments quivering with potential for change, then, hoping thereby to generate second chances for all, different approaches to writing are exemplified which trouble those academic constraints by fostering inquiry and speculation: moving away from âwhat isâ towards âwhat ifâ.
With the formatting of this thesis itself also always troubling the rigid Deleuzo-Guattarian (2015a) âsegmentary linesâ structuring orthodox academic practice, imbricated in these inquiries are attempts to exemplify Manningâs (2015; 2016) âartfulnessâ through shifts in thinking within and around an emerging PhD thesis. As writing resists organising, the verb thesisising comes into play to describe the processes involved in creating this always-moving thesis. Using âlanding sitesâ (Arakawa and Gins, 2009) as a landscaping device, freely creating emerging âlines of flightâ (Deleuze and Guattari, 2015a) so often denied to students forced to adhere to strict academic conventions, this âmovement-movingâ (Manning, 2014) opens up opportunities for change as in Manningâs (2016) âresearch-creationâ. Arguing for a moving away from writing-representing towards writing-inquiring, towards a writing âthat doesâ (Wyatt and Gale, 2018: 127), and toward writing as immanent doing, it is hoped to animate potential for intensities and becoming in writing, offering opportunities and glimmerings of the not-yet-known
- âŠ