Miracle-dz/UniFAR-FTUs huggingface dataset:
Interesting Open Problem Related to Complexity of Computing the Fourier Transform and Group Theory

The Fourier Transform is one of the most important linear transformations used in science and engineering. Cooley and Tukey's Fast Fourier Transform (FFT) from 1964 is a method for computing this transformation in time $O(n\log n)$. From a lower bound perspective, relatively little is known. Ailon shows in 2013 an $\Omega(n\log n)$ bound for computing the normalized Fourier Transform assuming only unitary operations on pairs of coordinates is allowed. The goal of this document is to describe a natural open problem that arises from this work, which is related to group theory, and in particular to representation theory.
Algebraic Calder\'on-Zygmund theory

Calderón-Zygmund theory has been traditionally developed on metric measure spaces satisfying additional regularity properties. In the lack of good metrics, we introduce a new approach for general measure spaces which admit a Markov semigroup satisfying purely algebraic assumptions. We shall construct an abstract form of ‘Markov metric’ governing the Markov process and the naturally associated BMO spaces, which interpolate with the Lp-scale and admit endpoint inequalities for Calderón-Zygmund operators. Motivated by noncommutative harmonic analysis, this approach gives the first form of Calderón-Zygmund theory for arbitrary von Neumann algebras, but is also valid in classical settings like Riemannian manifolds with nonnegative Ricci curvature or doubling/nondoubling spaces. Other less standard commutative scenarios like fractals or abstract probability spaces are also included. Among our applications in the noncommutative setting, we improve recent results for quantum Euclidean spaces and group von Neumann algebras, respectively linked to noncommutative geometry and geometric group theory.
Noncommutative 
AdS2/CFT1
 duality: The case of massive and interacting scalar fields

We continue the study of the nocommutative AdS2/CFT1 correspondence. We extend our previous results obtained for a free massless scalar field to the case of a massive scalar field. Both the free and interacting cases are considered. For both cases it is confirmed that to the leading order in noncommutative corrections the 2- and 3-point correlation functions have the form that is assumed by some (yet unspecified) dual conformal field theory (CFT). We also argue that there does not exist a map which connects the commutative model to its noncommutative counterpart, and therefore the conformal behavior of the noncommutative correlators is a nontrivial result.
Confidence Collapse in a Multi-Household , Self-Reflexive DSGE Model

aLPTMC, UMR CNRS 7600, Sorbonne Université, 75252 Paris Cedex 05, France; bLadhyx, UMR CNRS 7646 & Department of Economics, Ecole Polytechnique, 91128 Palaiseau Cedex, France; cChair of Econophysics and Complex Systems, Ecole polytechnique, 91128 Palaiseau Cedex, France; dCapital Fund Management, 23-25, Rue de l’Université 75007 Paris, France; eAcadémie des Sciences, Quai de Conti, 75006 Paris, France
Statistical Mechanics Approach to Inverse Problems on Networks

Statistical Mechanics has gained a central role in modern Inference and Computer Science. Many optimization and inference problems can be cast in a Statistical Mechanics framework, and various concepts and methods developed in this area of Physics can be very helpful not only in the theoretical analysis, but also constitute valuable tools for solving single instance cases of hard inference and computational tasks. In this work, I address various inverse problems on networks, from models of epidemic spreading to learning in neural networks, and apply a variety of methods which have been developed in the context of Disordered Systems, namely Replica and Cavity methods from the theoretical side, and their algorithmic incarnation, Belief Propagation, to solve hard inverse problems which can be formulated in a Bayesian framework
Quantum metrics on the tensor product of a commutative C*-algebra and an AF C*-algebra

Given a compact metric space X and a unital AF algebra A equipped with a faithful tracial state, we place quantum metrics on the tensor product of C(X) and A given established quantum metrics on C(X) and A from work with Bice and Latremoliere. We prove the inductive limit of C(X) tensor A given by A is a metric limit in the Gromov-Hausdorff propinquity. We show that our quantum metric is compatible with the tensor product by producing a Leibniz rule on elementary tensors and showing the diameter of our quantum metric on the tensor product is bounded above the diameter of the Cartesian product of the quantum metric spaces. We provide continuous families of C(X) tensor A which extends our previous results with Latremoliere on UHF algebras.
Formulas counting spanning trees in line graphs and their extensions

For any connected multigraph $G=(V,E)$ and any $M\subseteq E$, if $M$ induces an acyclic subgraph of $G$ and removing all edges in $M$ yields a subgraph of $G$ whose components are complete graphs, a formula for $\tau_G(M)$ is obtained, where $\tau_G(M)$ is the number of spanning trees in $G$ which contain all edges in $M$. Applying this result, we can easily obtain a formula for the number of spanning trees in the line graph or the middle graph of an arbitrary graph. Applying this result, we also show that for any connected graph $G$ with a clique $U$ which is a cut-set of $G$, the number of spanning trees in $G$ has a factorization which is analogous to a property of the chromatic polynomial of $G$.
Inferring Tracker-Advertiser Relationships in the Online Advertising Ecosystem using Header Bidding

Abstract Online advertising relies on trackers and data brokers to show targeted ads to users. To improve targeting, different entities in the intricately interwoven online advertising and tracking ecosystems are incentivized to share information with each other through client-side or server-side mechanisms. Inferring data sharing between entities, especially when it happens at the server-side, is an important and challenging research problem. In this paper, we introduce Kashf: a novel method to infer data sharing relationships between advertisers and trackers by studying how an advertiser’s bidding behavior changes as we manipulate the presence of trackers. We operationalize this insight by training an interpretable machine learning model that uses the presence of trackers as features to predict the bidding behavior of an advertiser. By analyzing the machine learning model, we can infer relationships between advertisers and trackers irrespective of whether data sharing occurs at the client-side or the server-side. We are able to identify several server-side data sharing relationships that are validated externally but are not detected by client-side cookie syncing.
On the geometry of polytopes generated by heavy-tailed random vectors

We study the geometry of centrally symmetric random polytopes, generated by [Formula: see text] independent copies of a random vector [Formula: see text] taking values in [Formula: see text]. We show that under minimal assumptions on [Formula: see text], for [Formula: see text] and with high probability, the polytope contains a deterministic set that is naturally associated with the random vector — namely, the polar of a certain floating body. This solves the long-standing question on whether such a random polytope contains a canonical body. Moreover, by identifying the floating bodies associated with various random vectors, we recover the estimates that were obtained previously, and thanks to the minimal assumptions on [Formula: see text], we derive estimates in cases that were out of reach, involving random polytopes generated by heavy-tailed random vectors (e.g., when [Formula: see text] is [Formula: see text]-stable or when [Formula: see text] has an unconditional structure). Finally, the structural results are used for the study of a fundamental question in compressive sensing — noise blind sparse recovery.
Direct Kinematic Problem Based on RBFNN of Parallel Manipulator

The kinematic model of paraller manipulators presents an inherent complexity due to their closed-loop structure and kinematic constraints and, correspondingly, the algorithm for the solution to relavant direct kinematic problems is complex. An algorithm of RBFNN for kinematic problems is thus presented in a nearest neighbor-clustering way to solve simply the positions and orientations of Stewart platform with needed precision, of which the process of solution is simple with good result provided. Comparing with the Newton-Raphson algorithm, the errors of neural network are appproximatively invariable without the effects of initial values and rated number of cycles on them. The results show that this approach can be used for the in-line control of parallel manipulators.
Interactive intent-based illustration: a visual language for three-dimensional worlds

The objective of this work is to devise a scheme for effective visual communication. A visual presentation can be designed to solve communicative intent; that is, both convey what we want to communicate as well as elicit, from our audience, a desired action or interpretation. In this thesis we define a visual language and a methodology for its use to both design and generate automatically 3D graphics that fulfill a specified communicative intent. The visual language we have defined is used to capture the full cycle of communication: Given specific communicative goals, the system begins to create an illustration by choosing sets of visual effects that, in turn, specify the parameters that define a computer-generated picture. The system then examines the picture to determine if each effect is achieved, and thus evaluates how well each communicative goal is achieved. Our visual language represents an illustration on three levels: what is being conveyed, what visual effects are used, how these visual effects are achieved. Thus, we separate design or the set of visual effects selected to satisfy communicative goals, from style, or how each visual effect is accomplished. Computer graphics need not be static; we have exploited the dynamism of the system to support four different types of interactivity: user-navigation, changing goals, changing worlds, and self-evaluation. During all phases of interaction, the illustration remains bound to the (possible changing) communicative intent, modifying the illustration to achieve violated goals. We have implemented IBIS as proof-of-concept for our ideas. IBIS generates illustrations that explain the use, maintenance and repair of objects. IBIS generates fully shaded 3D graphics that are displayed on a high resolution display for a multimedia explanation system and IBIS also generates overlaid 3D bi-level illustrations that are projected on a see-through head-mounted display that appear over the user's view of the world for an augmented reality system.
Usage of Kernel K-Means and DBSCAN cluster algorıthms in health studies:An application

With clustering methods variable and individuals which have similar characteristics may be collected in a group. Although clustering methods have many applications, there are limited studies in health researches in our country. While the purpose of this study is to introduce Kernel K-means and DBSCAN clustering algorithms and show how and which cases should be correctly used. At the same time, different clustering algorithms results which can be applied on a real data set were compared. According to the evaluations, the Kappa coefficients were statististically significant and it’s degree are low. In terms of data sets the most convenient and fastest algorithm is Kernel K-Means clustering algorithm. The results obtained by Kernel K-Means gave the most accurate desicions in terms of the distribution of the groups among Framingham risk groups crosstables. As a result, with taking into account the criterion of clinical information it is thought that the examination of clustering of risk factors of the disease, will be played an important role for introduction of accurate disease diagnosis. In addition we believe that when considering data distribution and characteristics of data sets clustering algorithms can be used as a diagnostic tool for the plannings and diagnosis of diseases in the field of health.
A Practical Approach to Enhancement of Accuracy of Similarity Model Using WordNet towards Semantic Service Discovery

Semantic Web service discovery provides high retrieval accuracy. However, it imposes an implicit constraint to service clients that the clients must express their queries with the same domain ontologies as used by the service providers. Fulfilling this criterion is very tedious. Hence, a WordNet (general ontology)-based similarity model is proposed for service discovery, and its accuracy is enhanced to a level comparable to the accuracy of computing similarity using service specific ontologies. This is done by optimizing similarity threshold, which refers to a minimum similarity that is required to decide whether a given pair of services is similar or not. The proposed model is implemented and results are presented. The approach warrants clients to express their queries without specifying any ontology and alleviates the problem of maintaining complex domain ontologies. Moreover, the computation time of WordNet-based model is very low when compared to specific ontology-based model. Chellammal Surianarayanan Bharathidasan University, India Gopinath Ganapathy Bharathidasan University, India Manikandan Sethunarayanan Ramasamy Bharathidasan University Constituent College, India
INFLUENCE OF PROJECT LIFE CYCLE ON INFORMATION AND COMMUNICATION TECHNOLOGY PROJECT PERFORMANCE IN REGULATED SAVINGS AND CREDIT COOPERATIVES

The project is one of the crucial functions in many organizations. Previous studies have revealed several factors that influence project management performance, but this study focused mainly the Project Life Cycle. This central focus of this study was to investigate the influence of project life cycle on ICT projects in regulated Saccos. The specific objectives of the study were to determine the influence of project identification on the performance of ICT projects, to establish the influence of project planning on the performance of ICT projects, to determine the influence of Project execution on performance of ICT projects and to investigate the influence of project closure on the performance of ICT projects. The study was guided by the theory of change, general systems theory, five-phase project model and six phase project model. The study adopted descriptive research design by carrying out a census on all 45 ICT projects in regulated Saccos within Nairobi. The study used primary and secondary data. Pretested questionnaire that contains closed-ended questions were used in collecting primary data. The collected data was edited for consistency and completeness and then coded and entered into SPSS for analysis. Quantitative data was analyzed using descriptive statistics such as frequencies, percentages, mean and standard deviation. Multiple linear regression was used to analyze the relationship between the independent and dependent variables. The descriptive results of the study indicate that there is no statistically significant relationship between project initiation (β=0.048, p<0.05) and project closure (β=0.031, p<0.05) with performance of ICT projects. However, the study found that there is statistically significant relationship between project planning (β=0.095, p<0.05) and project execution (β=0.063, p<0.05) and ICT project performance. The study concludes that the institutions within savings and cooperative societies need to focus on critical activities in all the stages of a project lifecycle. The study suggests that future research need to focus on communication and stakeholder management in ICT projects within the regulated savings and credit cooperatives sector.
Patterns of engineering design collaboration and reasoning activities modelled with Coloured Petri Nets

The increasing complexity of engineering activities emphasises the need to enhance software support for design team collaboration and improve the management of design process dynamics, especially in critical situations. Thus, this paper proposes a new approach in which a set of Coloured Petri Nets (CPNs) enable a practical implementation of design activities ontology by modelling rules and relationships simultaneously with the instantiation of taxonomy elements. The development of the proposed model is based on an in-depth analysis of several long-lasting development projects in a large industrial company and three case studies on designers’ collaboration. To facilitate the implementation of ontology models into industrial practice, this work focuses on the issues of interoperability between design support systems and ontology models. The proposed method has significant potential to provide real-time updating and propagation of design information in teamwork.
Design Guidelines for the Perturb and Observe Technique for Electromagnetic Vibration Energy Harvesters Feeding Bridge Rectifiers

The most widespread architecture of ac/dc converters for resonant electromagnetic vibration energy harvesters (REVEHs) is based on a diode bridge rectifier followed by a dc/dc converter. In order to maximize the power extraction from the harvester, the voltage at the output of the bridge rectifier must be regulated by a maximum power point tracking (MPPT) algorithm. This paper is focused on the optimization of the perturb and observe (P&O) MPPT technique for REVEHs. A complete set of general guidelines leading to the proper choice of the values of the two most important parameters of this MPPT technique is provided and experimentally validated. It is experimentally confirmed that if the P&O MPPT technique is not properly and carefully customized to the particular REVEH application of interest, it may lead to very poor performance of the system.
Efficient Direction-of-Arrival Estimation Method Based on Variable-Step-Size LMS Algorithm

Conventional direction-of-arrival (DOA) estimation methods based on subspace decomposition are computationally complex and difficult to implement in practical applications. Although a fixed-step-size least mean square (FSS-LMS) algorithm for DOA estimation has overcome the complexity problem; however, the manual selection of suitable step size is difficult. In this letter, a variable-step-size LMS algorithm is proposed for DOA estimation. In the proposed method, the step size is updated by using the estimated signal power and the cumulative sum of squared instantaneous error, and the spatial spectrum is obtained by the reciprocal of array pattern, where the peak values indicate the estimated DOAs of signals. The proposed method can choose step size adaptively and provide better performance with low computational complexity. The performance of proposed method is verified by the numerical simulations and compared with some existing methods.
Contractual and Relational Governance as Positioned-Practices in Ongoing Public–Private Partnership Projects

This article introduces a process framework based on the realist social theory for studying governing in ongoing public–private partnerships (PPPs). Contractual and relational practices are defined as activities enacted and re-created by virtue of actors’ dual positions: at both the partnership and the parent organizational levels. In PPPs, complementarities and contradictions between public, rule-bureaucratic logic and private, market-oriented logic define structural demands on actors. Nonpredictive and innovative governing activities emerge from the actors’ reflexive capacity to balance different demands. The framework allows the examination of the complex interplay of relational and contractual practices, illustrated in a PPP Dutch case.
Graphical Analysis Springs Dampers System on the A Freight Cars

In mechanical system where spring and damper are used often create unwanted vibration, due to external forces. Unwanted vibration may cause further noise and other damages such as engine break, etc. To reach system stability, we model of coupling series of freight car and analyze them using root loci and plot waves. From the result we can analyze what is the maximum stability by altering spring and damper constant. It is found when the spring and damper constant increase, the stability will be fast.
Cogging Torque Minimization and Performance of the Sub-Fractional HP BLDC Claw-Pole Motor

Cogging torque reduction measures are hardly applied to low-cost sub-fractional hp brushless direct current (BLDC) motors, because the additional fabrication operations involved typically increase both the manufacturing complexity and cost significantly. By proposing an innovative punching layout, this paper shows how to minimize the high cogging torque of the mass-produced single-phase outer-rotor BLDC claw-pole motor—opposed to conventional cogging torque reduction—with no increase to the manufacturing cost. Systematically, a way is presented in which the selected introduction of auxiliary slots can double the cogging torque fundamental frequency, making stator claw skewing much more effective in reducing the cogging torque; both measures can be included at the stage of punching the steel sheets and subsequent deep-drawing thereof, at no additional cost. A detailed analysis of the effects of the cogging torque reduction measures on the most important motor performance parameters is conducted. The findings show that, with the exception of a three percentage point reduction in the efficiency, the proposed design can reduce the peak-to-peak cogging torque by 70% in both the simulations and experiments. The reduction in the cogging torque translates into a reduction in the output torque ripple of 17%, ensuring smoother operation especially at low speeds.
Design fragments

Frameworks are a valuable way to share designs and implementations on a large scale. Client programmers, however, find it difficult to: understand non-local client-framework interactions, design solutions when they do not own the architectural skeleton, gain confidence that they have engaged with the framework correctly, represent their successful engagement with the framework in a way that can be shared with others, ensure their design intent is expressed in their source code, and connect with external files. A design fragment is a specification of how a client program can use framework resources to accomplish a goal. From the framework, it identifies the minimal set of classes, interfaces, and methods that should be employed. For the client program, it specifies the client-framework interactions that must be implemented. Annotations express design intent; specifically, that it is the intention of the client programs to interact with the framework as specified by the design fragment. The thesis of this dissertation is: We can provide pragmatic help for programmers to use frameworks by providing a form of specification, called a design fragment, to describe how a client program can correctly employ a framework and by providing tools to assure conformance between the client program and the design fragments. We built tools into an IDE to demonstrate how design fragments could alleviate the difficulties experienced by client programmers. We performed two case studies on commercial Java frameworks, using demo client programs from the framework authors, and client programs we found on the internet. This work provides three primary contributions to software engineering. First, it provides a new technique to help programmers use frameworks. Second, it provides a systematic way to increase code quality. Design fragments provide a means to communicate known-good designs to programmers. Third, it provides an empirically-based understanding of how clients use frameworks, which aids researchers in choosing research directions and aids framework authors in delivery of new frameworks.