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Performance of machine learning methods in predicting trend in price and trading volume of cryptocurrencies
Get PDFThis study is motivated by the growing interest in cryptocurrency trading and the need for accurate forecasting tools to guide investment decisions. The main aim is to forecast price and trading volume changes of cryptocurrencies by determining their movement directions. Naïve Bayes, support vector machines, logistic regression, regression trees, and the K-nearest neighbors’ algorithm are selected to solve the problem and compared. Performance measures such as accuracy, sensitivity, and specificity are used to assess the models. The study shows that some models are better at predicting volume trends than price trends in cryptocurrencies. Naïve Bayes is good at spotting positive trends, while Logistic Regression is accurate at identifying negative trends. Interestingly, the research reveals that shorter prediction times are more accurate for price forecasts, but intermediate times work better for specificity. These insights help us understand which models work well for different aspects of cryptocurrency forecasting
On the Tautological Ring of Moduli Spaces of Riemann Surfaces.
Get PDFThis thesis gives an overview of known results about the relations on the tautological ring of Moduli spaces. First, we introduce the Moduli Space of Stable Curves as an Orbifold of a etale groupoid, a generalization of complex manifold and orbit space of a group. Then we define the Tautological Ring on it as a subring of the Cohomology Ring. Finally, we present the work of Pandharipande, Pixton and Dvonkine in \cite{3-spin}, they discovered a set of relations on the Tautological Ring that is, up to date, the largest known. This set is obtained by Cohomological Field Theories, a tool to compute and glue cohomology classes in a Tautological way, and a group action on CohFTs. Using Teleman’s characterization of Cohomological Field Theories in a specific case, they manage to deduce an explicit formula for a suitable modification of Witten’s 3-spin CohFT. This turns out to vanish non trivially, providing a set of relations.
Davide Accadi
Life Cycle Assessment of Nature-Based Design Solutions for Buildings and Building Retrofit
Get PDFIn the context of energy efficiency and nature-based design solutions for buildings, this manuscript-based thesis presents a comprehensive Life Cycle Assessment (LCA) framework, applied to practical case studies, that architects, designers, and engineers may consider when conducting the environmental impact assessment of a building or design strategy.
Manuscript #1 presents the LCA framework, relevant software tools, and a methodology to assess the potential carbon offset achievable by integrating tree planting areas around buildings. The net annual carbon sequestration rate of 0.575 kgCO2eq/m2 of tree cover area is considered in this part. Then, two real case study buildings are thoroughly examined and compared: one involving a recently constructed all-electric research laboratory at Concordia University, and the other focusing on a natural gas-heated single-detached house. For the all-electric laboratory, a garden fully covered with representative urban trees could offset around 17% of the life cycle carbon emissions. For the natural gas-heated single-detached house, the offset was around 3% of the total life cycle carbon emission.
Manuscript #2 expands the results from Manuscript #1, specifically focusing on the case study of the research laboratory at Concordia. This part demonstrates how to estimate and report the environmental benefits linked to wood products, biogenic carbon storage, and end-of-life treatment of materials under various scenarios. The results from this part indicate that the set of design solutions adopted on this case study can potentially offset building’s carbon footprint by 37.2% up to 83.9% when included in the LCA estimation, depending on the scenario considered.
After discussing the two manuscripts, an additional chapter explores the application of LCA in the context of building/energy retrofit. This part demonstrates the connection between the local energy profile and the potential carbon offsets achieved through the retrofit process. We analyzed the case study of a Canadian school building to illustrate whether the reduction in GHG emissions from operational energy use savings can counterbalance the environmental impacts associated with manufacturing the new envelope materials and mechanical equipment added during retrofit. The findings underscore the significance of building/energy retrofit in places where the grid-electricity relies on fossil fuel, such as Nova Scotia, but opens a discussion about the extent of the benefits in locations where electricity is currently sourced from renewables. In places like Quebec, if the existent case study building already relied on electricity for space heating, the embodied emissions associated with new components might outweigh the operational emissions savings resulting from the retrofit
La capitalité du diable et de l'Antichrist sur les impies selon Thomas d'Equin
Get PDFLa métaphore paulinienne de l’Église corps mystique du Christ est un sujet clé de la théologie chrétienne. Elle représente l’unité des croyants avec le Christ en utilisant l’image d’un corps humain biologique. La scolastique médiévale a récupéré cette image dans le cadre des traités sur la grâce capitale du Christ. Un des plus notoires nous provient de Thomas d’Aquin (1225?-1274) et se lit, entre autres, dans la Summa theologiae (ST) III, q.8, a.1-8. Les deux derniers articles de cette question sont consacrés au diable et à l’Antichrist comme têtes des méchants (caput malorum). Il s’agit d’un hapax dans l’ensemble du corpus thomasien. Que signifie l’intégration de ces articles sur la « capitalité » du diable et de l’Antichrist dans l’œuvre magistrale de Thomas d’Aquin ? Les études sur la christologie et l’ecclésiologie de Thomas d’Aquin ont négligé cette question. Notre projet de recherche a précisément pour objectif de combler cette lacune. Pour ce faire, nous nous appuyons sur une théologie historique telle que définit par Alister McGrath que nous combinons avec une approche du thomisme vivant décrit par Serge-Thomas Bonino. Notre projet met en branle une double méthodologie. D’abord, une critique externe du texte par une généalogie de l’histoire d’une idée théologique, le corpus diaboli et sa réception dans l’œuvre de Thomas d’Aquin. Ensuite, une critique interne, à la fois chronologique et littéraire, qui fonde l’interprétation de la capitalité du diable et de l’Antichrist à l’aide d’une compréhension de la théologie de gratia capitis de l’Aquinate. Nous soutenons que l’orientation christologico-sotériologique de la Tertia pars permet de saisir l’intégration des articles sur la capitalité du diable et de l’Antichrist sur les impies. La notion d’influentia fournit la clé de lecture de l’ensemble de la ST III, q.8 qui vise à expliquer la transmission de la grâce du Christ à ses membres en vue de leur salut et, par contrariété asymétrique, l’influence du péché par le diable sur les méchants, pleinement reçue par l’Antichrist
Experimental and Computational Investigations on the Adsorption Applications of Covalent Triazine Frameworks
Get PDFAs an emerging subclass of advanced nanoporous materials, covalent triazine frameworks (CTFs) possess distinct properties such as high specific surface area, large pore volume, exceptional thermal/chemical stability, and structural designability. Thus, they have many real-world applications, including, but not limited to, catalysis, energy storage and conversion, adsorption, chemical sensing, and separation. In this doctoral dissertation, three projects related to CTF materials have been performed. Firstly, two electron-rich π-conjugated CTFs with high specific surface area and pore volume were synthesized via the facile and convenient Friedel-Crafts alkylation reaction of cyanuric chloride and trans-stilbene (TS) as well as diphenylacetylene (DPA), containing conjugated C=C double bond and C≡C triple bond functionalities, respectively. The iodine-capturing performance of these two electron-rich CTFs was investigated in a combined experimental-computational approach. Secondly, to design novel functionalized CTFs suitable for heavy metal cations removal from aqueous solutions, a DFT-assisted computational screening approach was employed on various CTFs featuring different electron-rich functionalities with negatively charged atom(s) for efficient adsorption of Cd2+, Pb2+, and Hg2+ cations as three most biohazardous heavy metal species. The metal removal process was also investigated in a combined experimental-computational approach. Thirdly, the gas adsorption and sensing properties of the pristine CTF-1 covalent triazine framework and its platinum atom (Pt)-doped counterpart were investigated computationally for SF6 decomposition products (i.e., H2S, SO2, SOF2, and SO2F2 gases) using the density-functional theory (DFT) method. In this framework, density of states (DOS) analysis examined the adsorption and sensing mechanisms. Computational and experimental results obtained in this dissertation confirmed the promising performance of the CTF materials in efficiently eliminating environmental micropollutants via adsorption
Vagueness, Expressivism, and Stipulation
No full textthe primary objective of this paper is to critically assess expressivism within the framework of the vagueness problem proposed by John MacFarlane. (2016; 2020a; 2020b; 2020c). In general, while it seems that expressivism works within certain contexts, allowing us to provide good explanations for particular instances of vague language use, it falls short of offering a comprehensive solution to the vagueness problem. I will argue that the expressivist response to these cases ultimately boils down to stipulating a cut-off point for vague terms. Furthermore, how expressivists expound on the content of sentences containing vague terms imposes certain logical constraints that expressivism has aimed to avoid. These constraints lead us to the conclusion that expressivism does not provide a better solution when compared to alternative vagueness theories like epistemicism and supervaluationism
Benches Aren’t for Sleeping: On Accessibility and Archiving
Get PDFLaunched in 2005 and rebooted in 2022, the Fred Wah Digital Archive is a digital web project that intends to act as a living archive of the work of Fred Wah, including a new interview with the author. As a consequence of the poet’s interest in the sonic and phonetic aspects of language, the archive is uniquely reliant on audio archival as a means of preservation, and circulation. Highlighted in this recent interview, the relationship between audio and text records within mixed and multimedia preservation is interdependent. Audio records of an author’s performance of their own text are an opportunity to preserve not only a unique instance of a poetic performance, but to also be a reference for a poem’s otherwise ambiguous cadence and sound, similar to music’s relationship with sheet music. However, relative to text archives, audio archives necessitate an increased amount of labour in order to be made accessible. Limiting the most valuable preserved media to only an audience with the time and ability to parse long audio recordings of varying quality for those nuggets of information which they would find valuable is an obstacle not only to research, but to general public engagement with the archive. As such, the financial interests which intersect with this living archive must interrogate the degree to which the expenses of this increased labour are outweighed by its ultimately altruistic returns
A numerical study on the influence of increased instability of quasi-detonation on the critical tube diameter phenomenon
Get PDFAt critical conditions, the effect of instability plays a prominent role in the gaseous detonation transmission from a tube into an unconfined space. This study aims to clarify such an effect by investigating the critical tube diameter of quasi-detonations, i.e., detonations under the influence of minor perturbations along the tube walls. The strategy is to conduct two-dimensional numerical simulations using the reactive Euler equations with a two-step induction-reaction kinetic model. The chemical kinetic parameters were adapted to model the detonation wave in the stoichiometric hydrogen-oxygen mixture at 20 kPa and 300 K. The quasi-detonations are obtained in channels with obstacles (attached to the boundaries) of different sizes to mimic wall roughness, σ , which is defined as the ratio between the obstacle size δ and half of the channel width D1/2 . Below a critical value of σ , the rough wall creates only minor perturbations to the intrinsic cellular detonation. Apart from the velocity deficit, the degree of instability and cellular irregularity increases with roughness, resulting in a broader spectrum in the probability density function of the pressure and induction rate. For σ � 0.24, the intrinsic propagation dynamics are more significantly altered—the cellular structure vanishes locally or small cells re-appear from new re-initiation points. Detonations in these more significantly obstructed channels are not considered quasi-detonations subjected to minor boundary perturbations. The influence of small values of roughness on the critical tube diameter phenomenon is then examined. A shot-to-shot variation in cellular dynamics of quasi-detonations is considered by performing multiple simulations for each value of roughness to assess the probability of successful transmission into an unconfined space. For quasi-detonation diffraction at the sub-critical condition, despite a velocity deficit, increasingly higher instabilities resulting from a rough-walled geometry promote the re-initiation of a detonation in the open area. However, if the roughness increases beyond 0.24, both the velocity deficit and different propagation modes in a significantly obstructed channel lead to a lower probability of successful transmission
Guide to Studying the Visual Arts in Canada
Get PDFGuide to Studying the Visual Arts in Canada is an open source, free e-publication published by the Gail and Stephen A. Jarislowsky Institute for Canadian Art, Concordia University. The objectives of the guide are: to facilitate study and teaching; to encourage pedagogical innovation and research; to improve learning through the sharing of resources and exchange of information; to increase the availability, accessibility, and use of print and online resources; to provide resources beyond the reach of individual universities, libraries, archives, museums, and resource centres; and to stimulate the improvement of online resources and the production of new resources.
The Guide to Studying the Visual Arts in Canada is a snapshot of the field at this moment. It consists of sources available in 2022. We recognize that resources are constantly being produced that collect, organize, and preserve digital information. This means that links to some sources may disappear as new resources are made available. We also realize that over time the profiles of people and descriptions of places will change. We will attempt to update Guide to Studying the Visual Arts in Canada every few years
Mitigating Yo-Yo Attacks on Cloud Using Game-Theoretical Modelling and Learning-Based Approach
Get PDFCloud computing, a transformative paradigm, has ushered in an era of unparalleled convenience and economic efficiency for both service providers and users. Historically, before its widespread adoption, digital services were susceptible to Distributed Denial of Service (DDoS) attacks, which aimed to overwhelm server capacities. The advent of cloud computing has primarily mitigated these threats but, in doing so, has inadvertently introduced new vulnerabilities. In their relentless pursuit of exploitation, attackers have transitioned from targeting server performance to inflicting economic damages. A particularly insidious form of this is the Yo-Yo Attack, an Economic Denial of Sustainability (EDoS) strategy that manipulates the auto-scaling features inherent to cloud systems.
This thesis presents a novel mathematical framework to understand the ongoing tussle between cloud service providers and Yo-Yo Attackers. We conceptualize this conflict as a Repeated Dynamic Bayesian Stackelberg game. This approach is pioneering in capturing the Yo-Yo attacker's nuanced strategies, particularly their adeptness at exploiting the cloud's auto-scaling features. The Learning-Based Attackers’ Type Recognition and Defense Mechanism is central to our game model, which harnesses the power of one-class Support Vector Machine (SVM) to discern the modus operandi of various Yo-Yo attack types.
Our research further introduces an innovative machine-learning algorithm adept at recognizing and countering the unique attack patterns of individual bots. We delve deeper into a proposed defense mechanism, which recognizes different strategies of Yo-Yo attackers aiming to exploit different vulnerabilities of the cloud’s auto-scaling mechanism and thereby confound their efforts. Our empirical experiments underscore the efficacy of our solution. Our approach demonstrates superior reduced compromised services and overall efficiency compared to existing Yo-Yo detection and defense strategies.
In conclusion, as cloud computing continues to dominate the digital landscape, ensuring its security remains paramount. Our research offers a robust solution to a new generation of threats, setting a benchmark for future endeavors in cloud security