Miracle-dz/UniFAR-FTUs huggingface dataset:
Ergänzung fehlender Daten in Umfragen / Imputation of Missing Data in Surveys

Zusammenfassung Gerade bei Umfragen mit sog. sensitiven Variablen, wie etwa dem Einkommen, ist bekannt, daß z. B. die Bezieher sehr hoher Einkommen eher zur Verweigerung der Beantwortung von Einkommensfragen neigen als andere. Einfaches Vernachlässigen der unvollständigen Datensätze für die statistische Analyse würde jedoch bei systematischen und insbesondere bei den sog. nicht zufälligen, verzerrenden Antwortausfällen zu einer Stichprobe führen, die nicht mehr als repräsentativ für die interessierende Grundgesamtheit betrachtet werden könnte. Verstärkt werden daher Methoden zur Ergänzung der fehlenden Daten, sog. Imputationstechniken, publiziert, in statistischer Standardsoftware zur Verfügung gestellt und in der Praxis eingesetzt. Diese Arbeit gibt zunächst ein Uberblick über gängige ad hoc und neuere modellbasierte Ergänzungstechniken, wobei die meisten dieser Verfahren eine gewisse Zufälligkeit in den Datenausfällen voraussetzen. Mit Hilfe einer Simulationsstudie wird anschließend der Einsatz verschiedener Verfahren zur Ergänzung systematisch fehlender Daten veranschaulicht und diskutiert. An normalverteilten Daten werden die Eigenschaften der üblichen Schätzfunktionen für Mittelwerte, Varianzen und Korrelationen untersucht, wenn verschiedene Ausfallmechanismen den Datenverlust steuern und Werte mit Hilfe unterschiedlicher Verfahren ergänzt werden. Es zeigt sich deutlich, wie wenig verzerrende Ausfälle durch die Ergänzung von Werten „geheilt" werden können. Summary In multivariate datasets missing values due to item nonresponse may occur on any or all variables. Since nonrespondents often differ systematically from respondents deletion of incomplete cases would lead to substantial bias as far as inference is intended to the population of all cases rather than the population of cases with no missing data. Therefore a variety of techniques to fill in missing data with plausible values have been developed and are offered to a broad audience in statistical software packages. An overview of the most common ad hoc and modern modelbased imputation techniques is given herein. Since these techniques rely at least implicitly on the assumption of the so-called ignorability of the missing-data mechanism a simulation study is performed to investigate the power of several imputation techniques especially when the data are missing not at random. Bivariate normal datasets are used to discuss possible biases of common estimates of means, variances and correlations based on the imputed datasets. Following the results of the simulation study the imputation techniques often seem to produce substantially biased estimates, when the missing-data mechanism is nonignorable. At least the modelbased techniques perform somewhat better than the ad hoc ones.
Comparisons and Selections of Features and Classifiers for Short Text Classification

Short text is considerably different from traditional long text documents due to its shortness and conciseness, which somehow hinders the applications of conventional machine learning and data mining algorithms in short text classification. According to traditional artificial intelligence methods, we divide short text classification into three steps, namely preprocessing, feature selection and classifier comparison. In this paper, we have illustrated step-by-step how we approach our goals. Specifically, in feature selection, we compared the performance and robustness of the four methods of one-hot encoding, tf-idf weighting, word2vec and paragraph2vec, and in the classification part, we deliberately chose and compared Naive Bayes, Logistic Regression, Support Vector Machine, K-nearest Neighbor and Decision Tree as our classifiers. Then, we compared and analysed the classifiers horizontally with each other and vertically with feature selections. Regarding the datasets, we crawled more than 400,000 short text files from Shanghai and Shenzhen Stock Exchanges and manually labeled them into two classes, the big and the small. There are eight labels in the big class, and 59 labels in the small class.
SwyftTapp: An NFC based attendance system using fingerprint authentication

Attendance has evolved to become a key requirement in educational institutions worldwide. With empirical evidence showing correlation between students’academic performance and attendance, parents, guardians, lecturers and school administrations make effort to monitor attendance of students to classes and academic events. The conventional method for recording attendance in the Kwame Nkrumah University of Science and Technology (KNUST), is the manual system, where sheets are passed round for students to write their names, student ID numbers and then append their signatures. The current manual system was observed to be both inefficient and time-consuming. In this paper we discuss the use of NFC technology coupled with fingerprint verification technology, designed to work with an API and a web-based application to implement a more effective approach for recording and managing attendance in the university. The Department of Computer Engineering, KNUST was used as the scope of the project. Keywords :Attendance, RFID, NFC, Fingerprint Technology, API, Web-based Management System
A whale optimization algorithm with inertia weight

Whale Optimization Algorithm (WOA) is a novel nature-inspired meta-heuristic optimization algorithm proposed by Seyedali Mirjalili and Andrew Lewis in 2016, which mimics the social behavior of humpback whales. A new control parameter, inertia weight, is introduced to tune the influence on the current best solution, and an improved whale optimization algorithm(IWOA) is obtained. IWOA is tested with 31 high-dimensional continuous benchmark functions. The numerical results demonstrate that the proposed IWOA is a powerful search algorithm. Optimization results prove that the proposed IWOA not only significantly improves the basic whale optimization algorithm but also performs much better than both the artificial bee colony algorithm(ABC) and the fruit fly optimization algorithm(FOA). Key-Words: whale optimization algorithm;artificial bee colony algorithm;fruit fly optimization algorithm; inertia weight; benchmark functions
'Hey Google, how do I become a more satisfied and frequent user of VUI?' A study in how to improve VUI usability.

Forskning och utveckling har hittills mestadels fokuserats pa den rent tekniska utvecklingen av ’speech recognition’ for anvandningen av produkter med ’Voice user interface’ (VUI). Men det kravs mer for att skapa en bra upplevelse och frekvent anvandande av VUI. Detta examensarbete undersoker hur upplevelsen och vardet av VUI kan forbattrats for anvandaren. Genom intervjuer, observationer och frageformular riktade mot anvandare av VUI-produkter innehallande Google Assistant, Alexa eller Siri, identifierades de tva storsta problemomradena – att VUI inte anpassar volymen pa sina svar efter omgivningens ljudniva, samt bristen pa kunskap om vad VUI kan anvandas till i de olika produkterna. Resultatet fran anvandartester av prototyperna visar att en nuvarande teknisk begransning som volymanpassning kan genom vidareutveckling av tekniken oka anvandarvanligheten avsevart. Testerna visar aven att anvandarupplevelsen okar om anvandaren blir medveten om vad som faktiskt kan goras med VUI, vilket leder till ytterligare forenklingar i vardagen.
Niobian rutile from the McGuire granitic pegmatite, Park County, Colorado: Solid solution, exsolution, and oxidation

Coarse crystals of niobian rutile occur in the hydrothermally altered core-margin zone of the McGuire granitic pegmatite, Park County, Colorado, associated with potassium feldspar, quartz, biotite, ilmenite, and monazite-(Ce). Primary homogeneous niobian rutile, with Fe ≅ Fe and a small excess of (Fe,Mn) over the amount required to compensate the incorporation of (Nb,Ta,W), underwent three stages of exsolution. Primary homogeneous niobian rutile exsolved a fine trellis-like pattern of minor lamellar Nb-bearing pseudorutile I. Most of this phase was broken down to pseudomorphs consisting of microgranular Nb-rich pseudorutile II imbedded in niobian-ferrian “ferropseudobrookite. ” Continued exsolution in niobian rutile and reconstitution of the early exsolution products generated (Fe,Nb)-depleted, microgranular niobian rutile, titanian ferrocolumbite, and minor ilmenite. These three phases did not attain chemical equilibrium but may represent a stable phase assemblage. All these processes seem to have maintained charge balance, suggesting a closed system. Subsequent to the three stages of exsolution, extensive oxidation converted the mineral assemblages to anatase + hematite + titanian-tungstenian ixiolite; primary ilmenite was oxidized into an anatase + hematite intergrowth. In both cases, the hematite component was almost completely leached out, leaving highly porous aggregates of the other phases. The exsolution products in niobian rutile are controlled by the (Fe+Mn+Sc)/(Nb+Ta+W) ratio of the primary phase and by its (Fe+Sc)/ (Fe+Mn) ratio. Dominance of divalent A-cations facilitates exsolution of titanian ferroto manganocolumbite or titanian ixiolite, whereas dominant trivalent cations lead to exsolution of titanian (Fe,Sc)NbO4 phases. Excess (Fe,Mn) over the columbite-type FeNb2 stoichiometry causes exsolution of (Fe,Mn)-rich Nb,Ta-oxide minerals or complementary (Fe,Mn,Ti) phases.
The most heat‐resistant conidia observed to date are formed by distinct strains of Paecilomyces variotii

Summary Fungi colonize habitats by means of spores. These cells are stress‐resistant compared with growing fungal cells. Fungal conidia, asexual spores, formed by cosmopolitan fungal genera like Penicillium, Aspergillus and Peacilomyces are dispersed by air. They are present in places where food products are stored and as a result, they cause food spoilage. Here, we determined the heterogeneity of heat resistance of conidia between and within strains of Paecilomyces variotii, a spoiler of foods such as margarine, fruit juices, canned fruits and non‐carbonized sodas. Out of 108 strains, 31 isolates showed a conidial survival >10% after a 10‐min‐heat treatment at 59°C. Three strains with different conidial heat resistance were selected for further phenotyping. Conidia of DTO 212‐C5 and DTO 032‐I3 showed 0.3% and 2.6% survival in the screening respectively, while survival of DTO 217‐A2 conidia was >10%. The decimal reduction times of these strains at 60°C (D 60 value) were 3.7 ± 0.08, 5.5 ± 0.35 and 22.9 ± 2.00 min respectively. Further in‐depth analysis revealed that the three strains showed differences in morphology, spore size distributions, compatible solute compositions and growth under salt stress. Conidia of DTO 217‐A2 are the most heat‐resistant reported so far. The ecological consequences of this heterogeneity of resistance, including food spoilage, are discussed.
Evaluation of occult hepatitis B infection in tissue donors : a multicenter analysis in Spain

Traditionally, when antibody to the Hepatitis B core antigen (anti-HBc) and antibody to the Hepatitis B surface antigen (anti-HBs) are positive, the donor is considered suitable. However, the literature contains cases with this profile and circulating hepatitis B virus DNA. The aim of the study is to analyze the incidence of occult hepatitis B virus infection (OBI). Retrospective data were evaluated for deceased tissue donors in ten Tissue Establishments (Spain) during 2017. The data included demographic data and the serological markers for hepatitis B that each tissue establishment performed. A total number of 1933 tissue donors were evaluated. A total of 180 donors were excluded: 6 (0.3%) with Hepatitis B surface antigen (HBs positive), and 174 in which DNA testing was not performed. Anti-HBc was positive in 175 donors (10%), in which anti-HBs was negative in 30 (17.1%) and positive in 145 (82.9%). In total, 27 donors with DNA positive (1.5%) were found, of which 3 of 117 donors (1.7%) showed anti-HBc J. Sánchez Ibáñez (&) Cryobiology Unit – Tissue Establishment, Complejo Hospitalario Universitario de A Coruña, A Coruña University Hospital, Avenida As Xubias 84, 15006 A Coruña, Spain e-mail: jacinto.sanchez. ibanez@sergas.es A. Vilarrodona Serrat Tissue Establishment, Banc de Sang i Teixits, Barcelona, Spain e-mail: avilarrodona@bst.cat T. Seoane Pillado Clinical Epidemiology and Biostatistics Research Group, Instituto de Investigacion Biomedica de A Coruña, A Coruña University Hospital, A Coruña, Spain e-mail: maria.teresa. seoane.pillado@udc.es C. Rodriguez Aierbe Tissue Establishment, Centro Vasco de Transfusión y Tejidos Humanos, Galdakao, Spain e-mail: clara.rodriguezairbe@osakidetza.eus R. Villalba Montoro Tissue Establishment, Centro de Transfusión de Tejidos y Células, Córdoba, Spain e-mail: rafael.villalba. sspa@juntadeandalucia.es J. Calvo Benito Tissue Establishment, Balearic Island Blood and Tissue Bank Foundation (FBSTIB), Cell Therapy and Tissue Engineering Group (TERCIT), Balearic Islands Institute of Health Research (IdISBa), Palma de Mallorca, Spain e-mail: jcalvo@fbstib.org M. Pevida Lopez Tissue Establishment, Centro Comunitario de Sangre y Tejidos del Principado de Asturias, Oviedo, Spain e-mail: martapevidalopez@yahoo.es S. Fernández Paneque Tissue Establishment, Centro de Transfusión, Tejidos y Células, Málaga, Spain e-mail: sergio.fernandez. paneque.sspa@juntadeandalucia.es 123 Cell Tissue Bank https://doi.org/10.1007/s10561-019-09784-5(0123456789(). ,-volV) ( 01234567 89(). ,-volV)
In silico clinical trials for anti-aging therapies

Therapeutic strategies targeting the hallmarks of aging can be broadly grouped into four categories, namely systemic (blood) factors, metabolic manipulation (diet regimens and dietary restriction mimetics), suppression of cellular senescence (senolytics), and cellular reprogramming, which likely have common characteristics and mechanisms of action. In evaluating the potential synergism of combining such strategies, however, we should consider the possibility of constraining trade-off phenotypes such as impairment in wound healing and immune response, tissue dysfunction and tumorigenesis. Moreover, we are rapidly learning that the benefit/risk ratio of aging-targeted interventions largely depends on intra- and inter-individual variations of susceptibility to the healthspan-, resilience-, and/or lifespan-promoting effects of the interventions. Here, we exemplify how computationally-generated proxies of the efficacy of a given lifespan/healthspan-promoting approach can predict the impact of baseline epigenetic heterogeneity on the positive outcomes of ketogenic diet and mTOR inhibition as single or combined anti-aging strategies. We therefore propose that stochastic biomathematical modeling and computational simulation platforms should be developed as in silico strategies to accelerate the performance of clinical trials targeting human aging, and to provide personalized approaches and robust biomarkers of healthy aging at the individual-to-population levels.
Enhanced through Clothing

Since the dawn of the history of humankind, clothes have been an integral part of our culture. In the course of time, clothes have become more advanced both in in used materials and function. In this positioning paper, we present examples and discuss clothes as a platform for augmenting humans and human perception. Due the design opportunities related to them, clothes can offer aesthetic, socially acceptable and usable ways to augmented the wearer both in sensing the surrounding world as well as in expression.
Repairing the surface of InAs-based topological heterostructures

Candidate systems for topologically-protected qubits include two-dimensional electron gases (2DEGs) based on heterostructures exhibiting a strong spin-orbit interaction (SOI) and superconductivity via the proximity effect. For InAs- or InSb-based materials, the need to form shallow quantum wells to create a hard-gapped $p$-wave superconducting state often subjects them to fabrication-induced damage, limiting their mobility. Here we examine scattering mechanisms in processed InAs 2DEG quantum wells and demonstrate a means of increasing their mobility via repairing the semiconductor-dielectric interface. Passivation of charged impurity states with an argon-hydrogen plasma results in a significant increase in the measured mobility and reduction in its variance relative to untreated samples, up to 45300 cm$^2$/(V s) in a 10 nm deep quantum well.
A novel approach to multivariate redundancy and synergy

Consider a situation in which a set of $n$ "source" random variables $X_{1},\dots,X_{n}$ have information about some "target" random variable $Y$. For example, in neuroscience $Y$ might represent the state of an external stimulus and $X_{1},\dots,X_{n}$ the activity of $n$ different brain regions. Recent work in information theory has considered how to decompose the information that the sources $X_{1},\dots,X_{n}$ provide about the target $Y$ into separate terms such as (1) the "redundant information" that is shared among all of sources, (2) the "unique information" that is provided only by a single source, (3) the "synergistic information" that is provided by all sources only when considered jointly, and (4) the "union information" that is provided by at least one source. We propose a novel framework deriving such a decomposition that can be applied to any number of sources. Our measures are motivated in three distinct ways: via a formal analogy to intersection and union operators in set theory, via a decision-theoretic operationalization based on Blackwell's theorem, and via an axiomatic derivation. A key aspect of our approach is that we relax the assumption that measures of redundancy and union information should be related by the inclusion-exclusion principle. We discuss relations to previous proposals as well as possible generalizations.
The Implications of Local Fluctuations in the Galactic Midplane for Dynamical Analysis in the Gaia Era

Orbital properties of stars, computed from their six-dimensional phase-space measurements and an assumed Galactic potential, are used to understand the structure and evolution of the Galaxy. Stellar actions, computed from orbits, have the attractive quality of being invariant under certain assumptions and are therefore used as quantitative labels of a star’s orbit. We report a subtle but important systematic error that is induced in the actions as a consequence of local midplane variations expected for the Milky Way. This error is difficult to model because it is non-Gaussian and bimodal, with neither mode peaking on the null value. An offset in the vertical position of the Galactic midplane of ∼15 pc for a thin disk-like orbit or ∼120 pc for a thick disk-like orbit induces a 25% systematic error in the vertical action Jz. In Feedback in Realistic Environments simulations of Milky Way-mass galaxies, these variations are on the order of ∼100 pc at the solar circle. From observations of the mean vertical velocity variation of ∼5–10 km s−1 with radius, we estimate that the Milky Way midplane variations are ∼60–170 pc, consistent with three-dimensional dust maps. Action calculations and orbit integrations, which assume the global and local midplanes are identical, are likely to include this induced error, depending on the volume considered. Variation in the local standard of rest or distance to the Galactic center causes similar issues. The variation of the midplane must be taken into account when performing dynamical analysis across the large regions of the disk accessible to Gaia and future missions.
Nambu–Jona-Lasinio model in a sphere

We study the chiral phase transition of the two flavor Nambu-Jona-Lasinio (NJL) model in a sphere with the MIT boundary condition. We find that the MIT boundary condition results in much stronger finite size effects than antiperiodic boundary condition. Our work may be helpful to study the finite size effects in heavy-ion collision in a more realistic way.
Jeffery orbits in shear-thinning fluids

We investigate the dynamics of a prolate spheroid in a shear flow of a shear-thinning Carreau fluid. The motion of a prolate particle is developed analytically for asymptotically weak shear thinning and then integrated numerically. We find that shear-thinning rheology does not lift the degeneracy of Jeffery orbits observed in Newtonian fluids but the instantaneous rate of rotation and trajectories of the orbits are modified. Qualitatively, shear thinning has a similar effect to elongating the particle in a Newtonian fluid. The period of rotation increases as the particle slows down more when aligned with the flow due to a reduction of shear stresses. Unlike Jeffery orbits in Newtonian fluids, in shear-thinning fluids the period of orbits depends on the specific trajectory (or initial orientation of the particle).
Intelligence Stratum for IoT. Architecture Requirements and Functions

The use of Artificial Intelligence (AI) is becoming increasingly pervasive and relevant in many different application areas. Researchers are putting a considerable effort to take full advantage of the power of AI, while trying to overcome the technical challenges that are intrinsically linked to almost any domain area of application, such as the Internet of Things (IoT). One of the biggest problems related to the use of AI in IoT is related to the difficulty of coping with the wide variety of protocols and software technologies used, as well as with the heterogeneity of the hardware resources consuming the AI. The scattered IoT landscape accentuates the limitations on interoperability, especially visible in the deployment of AI, affecting the seamless AI life-cycle management as well. In this paper, it is discussed how to enable AI distribution in IoT by introducing a layered intelligence architecture that aims to face the undertaken challenges taking into account the special requirements of nowadays IoT networks. It describes the main characteristics of the new paradigm architecture, highlighting what are the implications of its adoption from use cases perspective and their requirements. Finally, a set of open technical and research challenges are enumerated to reach the full potential of the intelligence distribution's vision.
On the Riemannian barycentre of a Markov chain

The Riemannian barycentre is one of the most widely used statistical descriptors for probability distributions on Riemannian manifolds. At present, existing algorithms are able to compute the Riemannian barycentre of a probability distribution, only if i.i. d. samples of this distribution are readily available. However, there are many cases where i.i. d. samples are quite difficult to obtain, and have to be replaced with non-independent samples, generated by a Markov chain Monte Carlo method. To overcome this difficulty, the present paper proposes a new Markov chain Monte Carlo algorithm for computing the Riemannian barycentre of a probability distribution on a Hadamard manifold (a simply connected, complete Riemannian manifold with non-positive curvature). This algorithm relies on two original propositions, proved in the paper. The first proposition states that the recursive barycentre of samples generated from a geometrically ergodic Markov chain converges in the mean-square to the Riemannian barycentre of the stationary distribution of this chain. The second proposition provides verifiable conditions which ensure a Metropolis-Hastings Markov chain, with its values in a symmetric Hadamard manifold, is geometrically ergodic. This latter result yields a partial solution, in the context of Riemannian manifolds, to the problem of geometric ergodicity of Metropolis-Hastings chains, which has previously attracted extensive attention when considered in Euclidean space. In addition to these two propositions, the new Markov chain Monte Carlo algorithm, proposed in this paper, is applied to a problem of Bayesian inference, arising from computer vision.