Miracle-dz/UniFAR-FTUs huggingface dataset:
SAMPLING TECHNIQUES & DETERMINATION OF SAMPLE SIZE IN APPLIED STATISTICS RESEARCH: AN OVERVIEW

Applied statistics research plays pivotal role in diverse problems of social sciences, agricultural sciences, health sciences, and business research. Many investigations are conducted by survey research. The technique of sampling and determination of sample size have crucial role in survey-based research problems in applied statistics. Specific sampling techniques are used for specific research problems because one technique may not be appropriate for all problems. Similarly, if the sample size is inappropriate it may lead to erroneous conclusions. The present paper gives an overview of some commonly used terms and techniques such as sample, random sampling, stratified random sampling, power of the test, confidence interval that need to be specified for a sample size calculation and some techniques for determination of sample size, and also describes some sampling methods such as purposive random sampling, random sampling, stratified random sampling, systematic random sampling and quota sampling for specific research purposes.
Learning from time series in the presence of noise: unsupervised and semi-supervised approaches

Characteristic for most real-world data mining tasks are the availability of a large number of unlabeled examples and the large rates of noise obliterating the similarity patterns. We study datasets with such characteristics collected across a wealth of domains - web search queries, celestial systems, anthropological artifacts, surveillance footages, etc. Diverse as they are, data from these domains turn out to have intuitive time series representation. As a major theme herein we advocate the belief that the time series representation is versatile enough to allow for accurate learning in the presence of noise, and when there are few or no labeled examples available. This is further achieved without compromising on the efficiency and the scalability of the problems at hand. For certain applications the noisy patterns themselves can be of particular interest - anomalous trajectories, surprising web queries, erroneously recorded light-curves - identifying them, and drawing the domain expert's attention to them, often leads to unexpected discoveries. The early chapters of the thesis introduce the time series discords as a notion of "interesting" outliers in the high dimensional representation space. We develop an effective and highly efficient discord detection algorithm, which used in a parallel fashion can handle hundreds of millions of examples in only a few hours. We then turn our attention to the question of how to decouple the noise from the structured signal within the data. The problem can be especially hard when the time series are embedded within complex, non-convex topological spaces. Local manifold reconstruction techniques, such as Isomap and Locally Linear Embedding, easily fail in the realistic settings of noise. An extension of the Isomap algorithm is thus derived, that remedies the effect of noise and learns more accurately the data embedding subspaces. As a more principled approach, we further develop a dual treatment of the time series manifold reconstruction problem. It computes a global density estimate of the data, which is then regularized locally through the help of multiple factor analyzer models. This results into smoothly reconstructed time series manifolds, unbiased by the effect of the noisy examples. Cast within a semi-supervised framework, our method achieves similar accuracy and several orders of magnitude speed-up over the state of the art transductive learning approaches.
An Energy-Efficient Reconfigurable Mobile Memory Interface for Computing Systems

An Energy-Efficient Reconfigurable Mobile Memory Interface for Computing Systems Majid Jalali Far Doctor of Philosophy in Electrical Engineering West Virginia University Gyungsu Byun, Ph.D., Chair The critical need for higher power efficiency and bandwidth transceiver design has significantly increased as mobile devices, such as smart phones, laptops, tablets, and ultraportable personal digital assistants continue to be constructed using heterogeneous intellectual properties such as central processing units (CPUs), graphics processing units (GPUs), digital signal processors, dynamic random-access memories (DRAMs), sensors, and graphics/image processing units and to have enhanced graphic computing and video processing capabilities. However, the current mobile interface technologies which support CPU to memory communication (e.g. baseband-only signaling) have critical limitations, particularly super-linear energy consumption, limited bandwidth, and non-reconfigurable data access. As a consequence, there is a critical need to improve both energy efficiency and bandwidth for future mobile devices. The primary goal of this study is to design an energy-efficient reconfigurable mobile memory interface for mobile computing systems in order to dramatically enhance the circuit and system bandwidth and power efficiency. The proposed energy efficient mobile memory interface which utilizes an advanced base-band (BB) signaling and a RF-band signaling is capable of simultaneous bi-directional communication and reconfigurable data access. It also increases power efficiency and bandwidth between mobile CPUs and memory subsystems on a singleended shared transmission line. Moreover, due to multiple data communication on a single-ended shared transmission line, the number of transmission lines between mobile CPU and memories is considerably reduced, resulting in significant technological innovations, (e.g. more compact devices and low cost packaging to mobile communication interface) and establishing the principles and feasibility of technologies for future mobile system applications. The operation and performance of the proposed transceiver are analyzed and its circuit implementation is discussed in details. A chip prototype of the transceiver was implemented in a 65nm CMOS process technology. In the measurement, the transceiver exhibits higher aggregate data throughput and better energy efficiency compared to prior works. An Energy-Efficient Reconfigurable Mobile Memory Interface for Computing Systems
Modelling and control of coupled AFM arrays for parallel imaging verified through a macro scale experiment.

Atomic Force Microscopy (AFM) is a mature imaging technology that is utilised in a wide range of applications for the purpose of obtaining high resolution images of sample topography and sample property measurements. Currently, AFM technology is centred around the use of single cantilevers to obtain data for one point on the sample at a time. There is currently a drive to extend AFM technology beyond the capabilities of established measurement techniques, including the ability to measure multiple sample points simultaneously, increase acquisition rate, increase measurement sensitivity to sample variations, and to obtain detailed, localised information about material properties. One possible way to address some of these issues is to use arrays of cantilevers instead of a single beam. Using multiple active sensing cantilevers in close proximity allows for true simultaneous data acquisition across multiple points of interest on a sample, as well as increasing measurement density. The main drawback is that cantilevers in a closely spaced array become mechanically coupled, altering the dynamic response of the system. To ensure reliable functionality, a full understanding of the coupled system dynamics is required, including how response is altered by nonlinear force interactions at each cantilever tip. In this research, a detailed dynamic analysis is conducted for a set of fabricated micro-cantilever AFM arrays fabricated by our collaborators at the Technische Universität Ilmenau (TUI), for the purpose of understanding the system response during Amplitude Modulation operation (AM-AFM). A mathematical model was developed for an array of M beams, each with nearest-neighbour mechanical coupling and individual nonlinear tip-sample force interaction terms. It is shown that this model is able to capture the system eigenmodes, and how the spatial shape of the eigenmodes is altered by tip-sample force interactions. To complement the model, an equivalent macro scale experimental setup was developed to mimic the response of the micro arrays. The macro scale test rig allows for easy and quick parameter variation to gain a better understanding of the micro system response. This approach provided insight into the micro scale dynamics and provided experimental validation of the mathematical model. Using the developed model and macro scale experiment, the observed response of the micro arrays could be linked to the parameter space of the
Perception and production of vowel reduction in second language acquisition

El presente trabajo analiza el grado de adquisicion de la reduccion vocalica lexica por parte de hablantes en un entorno de aprendizaje formal. Se exploran tres lineas de investigacion. Dadas la importantes diferencias entre los contextos de adquisicion naturales y formales que apunta la literatura, se investiga la adecuacion de varios modelos de adquisicion del habla a entornos formales de aprendizaje mediante el analisis de las habilidades de percepcion y produccion de la reduccion vocalica en ingles. Habiendose evidenciado la capacidad de aprendizaje de sonidos no nativos en adultos, se explora el efecto de la administracion de instruccion fonetica explicita en el desarrollo de las habilidades orales en la lengua extranjera. Siendo el vinculo entre la percepcion y produccion del habla un area de investigacion actual, este trabajo estudia esta relacion en el ambito de entrenamiento fonetico-fonologico con el fin de examinar las diferencias entre dos modos de entrenamiento diferentes basados en la practica de habilidades perceptivas y productivas asi como las posibles transferencias de una habilidad a otra.
Combining experimental data and corpus data: Intermediate French-speaking learners and the English present

Abstract This study combines experimental data and corpus data to describe how intermediate French-speaking learners of English perceive and (mis-)use the English present simple and present progressive. A first part of this study reports the results from an interpretation task conducted with first year, French-speaking, English language and literature university students (n = 75). With some exceptions, students were found to show greater acceptance of more prototypical prompts. They also exhibited higher certainty with these prompts. The second part of the study examines productive data from LONGDALE, a new longitudinal database of learner writing and speaking. Using annotated data for first year students, errors involving the present simple and progressive were extracted and classified in light of the interpretation task. Students were found to still make errors involving basic functions of the simple and progressive, as well as other errors that might be amenable to teaching. Finally, pedagogical implications are discussed.
Virtual environments with soundscapes: a study on immersion and effects of spatial abilities

In this study we explore how soundscapes can be used as navigational aids in virtual environments and empirically investigate the correlation between immersiveness in virtual environments and spatial abilities when soundscapes are used as landmarks for wayfinding. We attempt to advance knowledge regarding auditory cues contributing to enhanced immersive and navigational experience in virtual environments. Findings are likely to be utilized in effective design for physical environments and wayfinding.
Multi-agent Cooperative Decision Making using Genetic Cascading Fuzzy Systems

Missions consisting of groups of unmanned aerial vehicles (UAVs) require a high degree of coordination for successfully achieving desired goals. From the many types of applications where a group of coordinated agents is potentially able to outperform a single or a number of systems operating independently, the assignment of tasks is an important one. Different authors have addressed multi-agent task assignment problems for UAVs. For instance, [4] presented a robust task assignment algorithm for uncertain environments. The authors of [1] provided a decentralized task consensus algorithm with asynchronous communication. Decisions to communicate are taken by each agent independently based on the outcomes of assignments using different sets of information. In the present paper we envision a cooperative assignment of tasks in which vehicles decide which threats to attack according to collective preferences, in contrast to individual preferences which has been a common approach in the literature [3, 7–10]. The main objective behind this approach is to encourage agents to make decisions that bring greater benefit to the group. Although this objective may not necessarily suit all assignment problems, in some scenarios like the one presented in this paper the collective approach can potentially lead to an improved cooperation among agents. Additionally, the assignments need to be free of conflicts in order to use resources wisely. In the present work, agents are equipped with different types of weapons which need to be used in optimal manner and according to the specific type of threats. All these different factors need to be considered in order to make good and fast decisions. The main tool used in this paper for each local agent to generate these decisions is based on a novel method of Genetic Cascading Fuzzy Systems [6].
The role of entropy in wave propagation

In recent years there has been a growing interest in accurate models of electromagnetic (em) wave propagation in urban areas, mostly due to the growing diffusion of personal wireless communications in densely populated environments. The analytical solution of Maxwell equations with the complicated boundary conditions imposed by the complex geometry of a typical urban area is impossible, and only numerical solutions, tailored to a single specified scenario, are attainable. A different approach consists in developing random models of the area of interest, characterized by a few parameters, hopefully simply measurable. One of such models relies on principles of percolation theory and assumes the urban area to be a regular grid of randomly occupied cells [l]. The propagating field is modelled as an ensemble of optical rays undergoing specular reflections in the environment, see left-hand side Fig 1. A related model of propagation considers point-like obstacles that re-radiate uniformly [a]. In this case the propagating wave is modeled as an ensemble of photons following piecewise linear, random trajectories, as depicted in the right-hand side of Fig. 1. The step lengths are assumed independent, identically distributed random variables, and the direction chosen at each step is assumed to be a uniform random variable. The two models represent two different physical scenarios. In the percolation model the obstacles essentially represent buildings and are assumed large enough that the laws of specular reflection can be applied. The random walk model applies to a smaller scale and can model microcellular environments where the obstacles (trees, vegetation, street signs, pedestrians, cars, building patches etc.) are assumed small compared to the inter-obstacles-hitting distance, and thus re-radiate uniformly. It also applies to a very sparse density of randomly oriented buildings.
The Impact of Electronic Feedback on Second Year English College Students' writing Quality

English, as a foreign language, has become increasingly important to be taught at all school levels in Indonesia. It is indicated from the status of English which remainsthe same until now that English is the first foreign language considered as one of the most substantial elements of education and literacy (Lauder, 2008 as cited by Alwasilah, 2013: 1). The reason to deem English as a paramount foreign language in Indonesia is due to the development of science and technology in the world. Therefore, Indonesia, through its ministry of Education, has seriously responded to the growing needs to foster and strengthen English communication skills of the students (Kemendikbud, 2013).
The Design Of Compact Planar Antennas For Laptop Applications Based On Metamaterial Concepts

The Design Of Compact Planar Antennas For Laptop Applications Based On Metamaterial Concepts Michael Selvanayagam Master of Applied Science Graduate Department of Electrical Engineering University of Toronto 2010 Two laptop antennas are presented using two different designs based on metamaterials. The first design consists of planar monopole loaded with an electric-LC resonator (ELC). This novel topology allows for the realization of a multi-band antenna by using the ELC to add multiple resonances. This structure is analyzed using full-wave simulations. A circuit model is also developed to gain further understanding. This technique is then used to design a Wi-Fi antenna. The second design uses a modified double-tuned matching network to create a singleband match for a planar monopole antenna. The matching network is implemented using a complementary-split-ring-resonator (CSRR). The design is once again analyzed using full-wave simulations and a circuit model is also developed. This technique is then applied to design a WiMax antenna. Both the Wi-Fi and WiMax antennas are fabricated and show good agreement between the simulated and measured results.
Inequality and the Growth of Bad Jobs

The share of jobs that are low-skill declined by 15% from 1960 to 2005, yet low-wage jobs have made up an increasing share of total job growth over that period. Scholar Matt Vidal discusses how the manufacturing-based, nationally bound economy of the postwar years allowed employers to pay decent wages for low-skill jobs, but in today’s postindustrial, internationalized economy, wage-based competition has returned with a vengeance.
A Combined Technique for Randomisation of a Small Number of Participants with a Variety of Covariates into Treatment and Control Groups in Randomised Controlled Trials

Background: Randomised controlled trials are widely favoured in research design as the most rigorous way of determining the effectiveness of a treatment. For assigning a small number of participants who are identified before the start of the randomisation into treatment and control, the simple randomization technique can lead to imbalance of covariates among the groups. Furthermore while the stratified randomization method can control for the effect of covariates, in smaller clinical trials, the allocation of participants to groups by flip of a coin can result in uneven arms when the number of participants in each stratum in low. Despite the ability of covariate adaptive randomization technique in minimising the difference in covariate between the arms, the techniques comes with an unnecessary increase in the computational process specifically when number of covariates increases, and when all participants are identified prior to the randomisation. The purpose of this study was to propose a method of assigning small number of participants (68) who are identified before the start of randomisation, into treatment and control arms. Methods: The participants were first assigned into strata. For strata with even number of participants, the participants are sequentially pulled out of the strata on a random basis and assigned to arms by flip of a coin until half of the participants are assigned to any of the two arms. Then the remaining participants were assigned to the other arm. When the number of participants in a stratum is odd the first participants was pulled out of the stratum on a random basis and kept separate, then the remaining even number of participants were assigned to arms according to the method for strata that contain even number of participants. The first participants that were pulled out of the strata with odd number of participants were assigned sequentially using covariate adaptive randomisation method. Results: Two arms were created with minimal difference between the two arms and with the sum of absolute difference equal to 12. Conclusions: The method showed to be able to assign small number of participants into balanced arms with minimal computational costs when a number of covariates exist.
Wave height derived by texture analysis of X-band radar sea surface images

The sea state affects the texture of radar sea surface images. Property extraction based on image statistics, an important element of image analysis, is used to distinguish between different, textures. The connection between statistical properties and significant wave height (H/sub m0/) is investigated. The experiences from this analysis are then used for estimating H/sub m0/ from the image statistics. The radar sea surface images used in the analysis are collected with a standard X-band navigation radar from the Gullfaks C (GFC) oil production platform in the North Sea. Reference wave data have been collected with a MIROS Wave Radar Mk II in the same period.
A note on replacing uniform subsampling by random projections in MCMC for linear regression of tall datasets

New Markov chain Monte Carlo (MCMC) methods have been proposed to tackle inference with tall datasets, i.e., when the number n of data items is intractably large. A large class of these new MCMC methods is based on randomly subsampling the dataset at each MCMC iteration. We investigate whether random projections can replace this random subsampling for linear regression of big streaming data. In the latter setting, random projections have indeed become standard for non-Bayesian treatments. We isolate two issues for MCMC to apply to streaming regression: 1) a resampling issue; MCMC should access the same random projections across iterations to avoid keeping the whole dataset in memory and 2) a budget issue; making individual MCMC acceptance decisions should require o(n) random projections. While the resampling issue can be satisfyingly tackled, current techniques in random projections and MCMC for tall data do not solve the budget issue, and may well end up showing it is not possible.