Miracle-dz/UniFAR-FTUs huggingface dataset:
Blind Channel Estimation for MIMO-OFDM Systems

By combining multiple-input multiple-output (MIMO) communication with the orthogonal frequency division multiplexing (OFDM) modulation scheme, MIMO-OFDM systems can achieve high data rates over broadband wireless channels. In this paper, to provide a bandwidth-efficient solution for MIMO-OFDM channel estimation, we establish conditions for channel identifiability and present a blind channel estimation technique based on a subspace approach. The proposed method unifies and generalizes the existing subspace-based methods for blind channel estimation in single-input single-output OFDM systems to blind channel estimation for two different MIMO-OFDM systems distinguished according to the number of transmit and receive antennas. In particular, the proposed method obtains accurate channel estimation and fast convergence with insensitivity to overestimates of the true channel order. If virtual carriers (VCs) are available, the proposed method can work with no or insufficient cyclic prefix (CP), thereby potentially increasing channel utilization. Furthermore, it is shown under specific system conditions that the proposed method can be applied to MIMO-OFDM systems without CPs, regardless of the presence of VCs, and obtains an accurate channel estimate with a small number of OFDM symbols. Thus, this method improves the transmission bandwidth efficiency. Simulation results illustrate the mean-square error performance of the proposed method via numerical experiments
Structuring the Transition From Example Study to Problem Solving in Cognitive Skill Acquisition: A Cognitive Load Perspective

Cognitive load research has shown that learning from worked-out examples, in comparison to problem solving, is very effective during the initial stages of cognitive skill acquisition. In later stages, however, solving problems is superior. In this contribution, theoretical analyses of different types of cognitive load and their changes over the stages of skill acquisition are presented. Two basic arguments are put forth: (a) Intrinsic cognitive load gradually decreases so that a gradual increase of problem-solving demands is possible without inducing cognitive overload. (b) In contrast to the earlier stages, different learner activities during the later stages constitute either germane or extraneous load, because different instructional goals are to be achieved. Based on these analyses, we propose a fading procedure in which problem-solving elements are successively integrated into example study until the learners are expected to solve problems on their own. Empirical evidence supporting this fading procedure is provided, and future research is proposed that focuses on how to ensure that the fading procedure is adaptive to the learners' prior knowledge levels.
Spanish Text Simplification: An Exploratory Study

We present an explorative study for the develpment of a Spanish text-simplification system. We use a corpus of Spanish news texts and their simplified versions. We automatically aligned this corpus and annotated a part of it for the editing operations which are necessary in order to transform the original text into a simplified version.
Use of the ePortfolio by Adults in the Tunisian Continuous Education Context

ABSTRACTThis is a case study of using the ePortfolio in a module taught in a Master degree at the High Institute of Continuous Education of a Tunisian university. The first purpose of our initiative is to raise awareness of the concept among the Tunisian teachers because most of our students are teachers. Our second purpose is to support these students throughout their learning. To evaluate the impact of the ePortfolio use, a questionnaire was proposed to the students and its results indicate that they appreciate it. The students were keen to have the ePortfolio extended to the other modules despite the fact that they find it time-consuming. An ideal student’s profile for the continuation of similar initiatives is suggested: it is an adult learner who massively uses the computer in a diversified and a well-targeted manner. This paper addresses also the case study findings concerning teaching adult learners.
Growing neutrino cosmology

In growing neutrino models, the neutrino mass increases in time and stops the dynamical evolution of a dark energy scalar field, thus explaining the 'why now' problem. A new attractive force, mediated by the 'cosmon' scalar field, makes non relativistic neutrino form lumps on the scales of superclusters and beyond. Nonlinear neutrino lumps are predicted to form at redshift z ~ 1 and, if observed, could be an indication for a new attractive force stronger than gravity.
Identification of a subset of murine natural killer cells that mediates rejection of Hh-1d but not Hh-1b bone marrow grafts

NK cells demonstrate many immune functions both in vitro and in vivo, including the lysis of tumor or virus-infected cells and the rejection of bone marrow allografts. However it remains unclear whether or not all NK cells can mediate these various functions or if NK cells exist in functionally distinct subsets. We have developed a new NK-specific mAb, SW5E6, which binds to approximately 50% of murine NK cells. The 5E6 antigen identifies a distinct and stable subset of NK cells and is expressed on about one-half of fresh or rIL-2-activated murine NK cells. Both 5E6+ and 5E6- NK cells are capable of lysing YAC-1 tumor cells in vitro and in vivo. By treating animals with SW5E6, we demonstrate that the 5E6+ subset is necessary for the rejection of H- 2d/Hh-1d but not H-2b/Hh-1b bone marrow cells. Thus NK cells exist as functionally separable subsets in vivo.
A Path Planning Method for Assistant Parallel Car-Parking

Path planning is one of the key technologies in an intelligent car-parking system. This paper presents a path planning method for parallel parking mode. a scheme of a two-arc parking path is proposed, with the start position given but the goal to be yielded. the parking process is formulated as a constrained nonlinear optimization problem, where two objective functions are studied. and we gained the optimized results by MATLAB Optimization Toolbox.
Reading into neuronal oscillations in the visual system: implications for developmental dyslexia

While phonological impairments are common in developmental dyslexia, there has recently been much debate as to whether there is a causal link between the phonological difficulties and the reading problem. An alternative suggestion has been gaining ground that the core deficit in dyslexia is in visual attentional mechanisms. If so, the visual aetiology may be at any of a number of sites along the afferent magnocellular pathway or in the dorsal cortical stream that are all essential for a visuo-spatial attentional feedback to the primary visual cortex. It has been suggested that the same circuits and pathways of top-down attention used for serial visual search are used for reading. Top-down signals from the dorsal parietal areas to primary visual cortex serially highlight cortical locations representing successive letters in a text before they can be recognized and concatenated into a word. We had shown in non-human primates that the mechanism of such a top-down feedback in a visual attention task uses synchronized neuronal oscillations at the lower end of the gamma frequency range. It is no coincidence that reading graphemes in a text also happens at the low gamma frequencies. The basic proposal here is that each cycle of gamma oscillation focuses an attentional spotlight on the primary visual cortical representation of just one or two letters before sequential recognition of letters and their concatenation into word strings. The timing, period, envelope, amplitude, and phase of the synchronized oscillations modulating the incoming signals in the striate cortex would have a profound influence on the accuracy and speed of reading. Thus, the general temporal sampling difficulties in dyslexic subjects may impact reading not necessarily by causing phonological deficits, but by affecting the spatio-temporal parsing of the visual input within the visual system before these signals are used for letter and word recognition.
Modalities and Offshoots of Communication in the Lifeworld: Meaning, Experience, and Interaction

Abstract This chapter elaborates a phenomenological framework for the concept of “communication” by drawing mainly on the notion “lifeworld,” created by Husserl and developed by Habermas. The concept of “lifeworld” is approached as a communication-grounded idea. The chapter is a theoretical essay, grounded mainly on bibliographical research. Main sources are the two volumes of Habermas’ The Theory of Communicative Action (Habermas, 1987), seconded by other works by the German philosopher and some commentators as Stein (2004) e Pizzi (2006). The chapter endeavors to show that the phenomenological notion of “lifeworld” might be key to a critical understanding of main constructivist approaches in communication theory. It could be particularly illuminating where the focus is on a “reality,” which results from intersubjective interactions in everyday life. Most communication theories are media-centered, which means that they regard the “media,” both in its technical and institutional aspects as the main focus of the communication process. This chapter argues that the “lifeworld” is a far broader way to understand communication as a form of social interaction, whether mediated by media technologies or not. The chapter discusses the concept of “lifeworld,” framing its relational and communicative aspects as fundamental to the notion of “reality” as an interactive social creation. It also proposes the understanding of “communication” grounded on this phenomenological notion. Finally, it discusses some problems and limits of this approach, offering an alternative approach to conventional communication theory.
The sound of many hands clapping

n audience expresses appreciation for a good performance by the strength and nature of its applause. The thunder of applause at the start often turns quite suddenly into synchronized clapping, and this synchronization can disappear and reappear several times during the applause. The phenomenon is a delightful expression of social self-organization that provides an example on a human scale of the synchronization processes that occur in numerous natural systems, ranging from flashing Asian fireflies to oscillating chemical reactions 1–3. Here we explain the dynamics of this rhythmic applause. We investigated the mechanism and development of synchronized clapping by making a series of measurements focusing on the collective aspects of the self-organization process as well as on the behaviour of the individuals in the audience. We recorded several theatre and opera performances in Romania and Hungary by using a microphone placed on the ceiling of the hall (Fig. 1a). Typically, after a few seconds of incoherent random clapping, a periodic signal developed (a sign of synchronized clapping), visible in Fig. 1a as pronounced spikes. The transition is also captured by the order parameter (Fig. 1c), which increases as the periodic signal develops, and decreases as it disappears. Although synchronization increases the strength of the signal at the moment of the clapping, it leads to a decrease in the average noise intensity in the room (Fig. 1d). This is surprising, as the driving force for synchronization would be expected to reflect the desire of the audience to express its enthusiasm by increasing the average noise intensity. The origin of this conflict between the average noise and synchronization can be understood by correlating the global signal with the behaviour of an individual in the audience. We demonstrated this by recording the local sound intensity in the vicinity of a group of oblivious individuals (Fig. 1b). In the incoherent phase, the local signal was periodic, with a short period corresponding to the fast clapping of an individual in the audience. However, the clapping period suddenly doubled at the start of the synchronized phase (at about 12 seconds in Fig. 1a,b), and slowly decreased as synchronization was lost (Fig. 1e). The decrease in the average noise intensity is therefore a consequence of the period doubling, because there is less clapping per unit time. An increase in the average noise intensity is possible only by decreasing the clapping period, which can indeed occur (Fig. 1e). However, …
Detection of Genetically Altered Copper Levels in Drosophila Tissues by Synchrotron X-Ray Fluorescence Microscopy

Tissue-specific manipulation of known copper transport genes in Drosophila tissues results in phenotypes that are presumably due to an alteration in copper levels in the targeted cells. However direct confirmation of this has to date been technically challenging. Measures of cellular copper content such as expression levels of copper-responsive genes or cuproenzyme activity levels, while useful, are indirect. First-generation copper-sensitive fluorophores show promise but currently lack the sensitivity required to detect subtle changes in copper levels. Moreover such techniques do not provide information regarding other relevant biometals such as zinc or iron. Traditional techniques for measuring elemental composition such as inductively coupled plasma mass spectroscopy are not sensitive enough for use with the small tissue amounts available in Drosophila research. Here we present synchrotron x-ray fluorescence microscopy analysis of two different Drosophila tissues, the larval wing imaginal disc, and sectioned adult fly heads and show that this technique can be used to detect changes in tissue copper levels caused by targeted manipulation of known copper homeostasis genes.
Validation of Learning Effort Algorithm for Real-Time Non-Interfering Based Diagnostic Technique

The objective of this research is to validate the algorithm of learning effort which is an indicator of a new real-time and non-interfering based diagnostic technique. IC3 Mentor, the adaptive e-learning platform fulfilling the requirements of intelligent tutor system, was applied to 165 university students. The learning records of the subjects who attended IC3 Mentor were converted into Characteristic Learning Effort CLE curves through the algorithms of learning effort. By evaluating CLE curves and questionnaire survey reports, the findings indicate that the learning effort algorithm is verified to be an effective real-time and non-interfering diagnostic technique. Furthermore, CLE curve is proven to be an effective user-friendly tool for learners and instructors in diagnosing learning progress under adaptive e-learning context. The CLE curve generated by the algorithm of learning effort is a visualized graphic tool which can be applied in the adaptive e-learning platform of education and industry fields.
Neural Network Models of Solar Wind-auroral Electrojet Relations

Artiicial neural networks have been used to model solar wind-auroral electrojet relations at a time resolution (5 min) where substorms are temporally resolved. The network performance depends strongly on the physics encoded into the networks: the set of solar wind parameters and the network's integration time are both important factors. It is found that a network based on a 100-min sequence of interplane-tary parameters n, V , B y , and B z can account for 76% of the variance in the AE index. The linear correlation between model and observation is 0.87. No innuence of B x is found. Individual variables as input give better results than coupling functions, presumably due to a loss of relevant information when combining several solar wind parameters into a single parameter. The Dst index, as predicted from low-time resolution solar wind data or directly measured, is a proxy for the ring current strength. Dst has here been used as an additional input to the AE predicting networks. It is found that this additional information does not signiicantly innuence the AE predictions when the network has access to at least 100 minutes of solar wind parameters n, V , B y , and B z. However, if less high-time resolution solar wind data is available, the additional information improves predictions compared to the case with only solar wind data as input. This points out a possible strategy to make neural networks more tolerant to loss of input data, by combining networks simultaneously working at high and low time resolutions. 1. SUBSTORMS AND AURORAL ELECTROJETS Magnetospheric substorms represent the basic dynamic process in the coupled solar wind-magnetosphere-ionosphere system. It is the reaction to an enhanced energy transfer from the solar wind, mostly following a southward turning of the inter-planetary magnetic eld (IMF). The energy that enters the magnetosphere is either directly dissipated in the polar ionosphere or temporarily stored in the tail region (McPherron 1991). Through mechanisms that are not well understood, the stored energy is suddenly released and dissipated in the polar iono-sphere by means of particle precipitation and electrical currents. The whole substorm sequence of energy loading and unloading develops on a timescale of 1 to 3 hours. An important part of the energy dissipation during substorms is the formation of eld-aligned currents which close through the ionosphere, forming the au-roral electrojets. These currents are continuously monitored by an array of ground based …
Analytical evaluation of turbo multiuser detection algorithms

Turbo receivers have gained significant importance in recent years, enabling the effect of the interference-limited propagation channel to be overcome through the iterative exchange of information between the front-end receiver and the channel decoder. Such an iterative process is difficult to describe in a closed form, so the performance evaluation is usually done by means of extensive numerical simulations. We propose an analytical method for the performance evaluation of turbo receivers. The proposed approach, based on the so-called EXIT (extrinsic information transfer) analysis, allows for an accurate prediction of the receiver coded BER for each iteration as a function of the channel state. We show the performance analysis of linear turbo receivers applied to multiuser detection in synchronized CDMA.
Expression of Mutated Mouse Myocilin Induces Open-Angle Glaucoma in Transgenic Mice

We developed a genetic mouse model of open-angle glaucoma by expression of mutated mouse myocilin (Myoc) in transgenic (Tg) mice. The Tyr423His point mutation, corresponding to the severe glaucoma-causing Tyr437His mutation in the human MYOC gene, was introduced into bacterial artificial chromosome DNA encoding the full-length mouse Myoc gene and long flanking regions. Both wild-type (Wt) and Tg animals expressed Myoc in tissues of the irido-corneal angle and the sclera. Expression of mutated Myoc induced the accumulation of Myoc in cell cytoplasm and prevented its secretion into the extracellular space. The levels of ATPase-1 were reduced in the irido-corneal angle of Tg mice compared with Wt animals. Tg mice demonstrated a moderate elevation of intraocular pressure, the loss of ∼20% of the retinal ganglion cells (RGCs) in the peripheral retina, and axonal degeneration in the optic nerve. RGC depletion was associated with the shrinkage of their nuclei and DNA fragmentation in the peripheral retina. Pathological changes observed in the eyes of Tg mice are similar to those observed in glaucoma patients.
IRIT @ TRECVid HLF 2009 - Audio to the Rescue

This notebook paper describes the six runs submitted for the ﬁrst participation of IRIT at TRECVid 2009 High-Level Feature Extraction task. They were submitted in an attempt to start answering two research questions: 1. Can acoustic information be of any help in this (historically) video-only task? 2. Are Support Vector Machines robust enough to deal with noisy and unbalanced datasets? The six submitted runs can be described and compared as follows:
Development of the Crohn's disease digestive damage score, the Lémann score

Crohn's disease (CD) is a chronic progressive destructive disease. Currently available instruments measure disease activity at a specific point in time. An instrument to measure cumulative structural damage to the bowel, which may predict long-term disability, is needed. The aim of this article is to outline the methods to develop an instrument that can measure cumulative bowel damage. The project is being conducted by the International Program to develop New Indexes in Crohn's disease (IPNIC) group. This instrument, called the Crohn's Disease Digestive Damage Score (the Lémann score), should take into account damage location, severity, extent, progression, and reversibility, as measured by diagnostic imaging modalities and the history of surgical resection. It should not be “diagnostic modality driven”: for each lesion and location, a modality appropriate for the anatomic site (for example: computed tomography or magnetic resonance imaging enterography, and colonoscopy) will be used. A total of 24 centers from 15 countries will be involved in a cross-sectional study, which will include up to 240 patients with stratification according to disease location and duration. At least 120 additional patients will be included in the study to validate the score. The Lémann score is expected to be able to portray a patient's disease course on a double-axis graph, with time as the x-axis, bowel damage severity as the y-axis, and the slope of the line connecting data points as a measure of disease progression. This instrument could be used to assess the effect of various medical therapies on the progression of bowel damage. (Inflamm Bowel Dis 2011)
The Interface of Accounting and Gender in Specialist Accounting History Journals in the English Language

This study focuses on the participation of women in the development of the specialist international accounting history literature. Specifically, based on data collected from the three specialist, internationally refereed, accounting history journals in the English language from the time of first publication in each case, the study provides evidence of the involvement of women through publication, through membership of editorial boards and editorial advisory boards and also through holding editor, associate editor and guest editor positions. In doing so, the study builds on the earlier work of Carnegie and Potter (2000) and extends an understanding of publishing patterns in the specialist international accounting history literature.
Building Trust in E-Commerce through Web Interface

The emergence of Internet has revolutionalized the way businesses are conducted. The impact of e-commerce is pervasive, both on companies and society as a whole. It has the potential to impact the pace of economic development and in turn influence the process of human development at the global level. However, the growth in e-commerce is being impaired by the issue of trust in the buyer-seller relationship which is arising due to the virtual nature of e-commerce environment. The online trading environment is constrained by a number of factors including web interface that in turn influences user experience. This article identifies various dimensions of web interface that have the potential to influence trust in e-commerce. The empirical evidence presented in the article is based on a survey of the web interfaces of 65 Indian e-Marketplaces.