Miracle-dz/UniFAR-FTUs huggingface dataset:
On The Hardness of Approximate and Exact (Bichromatic) Maximum Inner Product

In this paper we study the (Bichromatic) Maximum Inner Product Problem (Max-IP), in which we are given sets $A$ and $B$ of vectors, and the goal is to find $a \in A$ and $b \in B$ maximizing inner product $a \cdot b$. Max-IP is very basic and serves as the base problem in the recent breakthrough of [Abboud et al., FOCS 2017] on hardness of approximation for polynomial-time problems. It is also used (implicitly) in the argument for hardness of exact $\ell_2$-Furthest Pair (and other important problems in computational geometry) in poly-log-log dimensions in [Williams, SODA 2018]. We have three main results regarding this problem. First, we study the best multiplicative approximation ratio for Boolean Max-IP in sub-quadratic time. We show that, for Max-IP with two sets of $n$ vectors from $\{0,1\}^{d}$, there is an $n^{2 - \Omega(1)}$ time $\left( d/\log n \right)^{\Omega(1)}$-multiplicative-approximating algorithm, and we show this is conditionally optimal, as such a $\left(d/\log n\right)^{o(1)}$-approximating algorithm would refute SETH. Second, we achieve a similar characterization for the best additive approximation error to Boolean Max-IP. We show that, for Max-IP with two sets of $n$ vectors from $\{0,1\}^{d}$, there is an $n^{2 - \Omega(1)}$ time $\Omega(d)$-additive-approximating algorithm, and this is conditionally optimal, as such an $o(d)$-approximating algorithm would refute SETH [Rubinstein, STOC 2018]. Last, we revisit the hardness of solving Max-IP exactly for vectors with integer entries. We show that, under SETH, for Max-IP with sets of $n$ vectors from $\mathbb{Z}^{d}$ for some $d = 2^{O(\log^{*} n)}$, every exact algorithm requires $n^{2 - o(1)}$ time. With the reduction from [Williams, SODA 2018], it follows that $\ell_2$-Furthest Pair and Bichromatic $\ell_2$-Closest Pair in $2^{O(\log^{*} n)}$ dimensions require $n^{2 - o(1)}$ time.
A capacitor voltage balancing method for cascaded H-bridge multilevel inverters with application to FACTS

Cascaded H-bridge multilevel inverters have attracted considerable attention in applications such as reactive power compensation, solid-state transformers, and PV systems. The main disadvantage of CHBMLI in these applications is the imbalance of the DC capacitor voltages, especially in high-level inverters. The DC-link voltage unbalance increases the stress on the semiconductor devices and may cause serious damages. To overcome this issue, this paper presents a new DC-link capacitor voltage balancing method for CHBMLI. This method has a very effective and fast voltage balancing capability. Furthermore, the proposed algorithm is independent of the number of modules and voltage distribution; therefore, it could be applied to any CHBMLI regardless of its number of cells and levels without considerable modification. This method reduces computation efforts that makes it suitable for high-cell-number inverters. To verify the performance of the proposed modulation scheme, the proposed method is applied to a four-cell CHBMLI, utilized in STATCOM applications, using simulation studies through the PSCAD/EMTDC® software package. The simulation results show the effectiveness of the method.
Pub Crawling at Scale: Tapping Untappd to Explore Social Drinking

There has been a recent surge of research looking at the reporting of food consumption on social media. The topic of alcohol consumption, however, remains poorly investigated. Social media has the potential to shed light on a topic that, traditionally, is difficult to collect fine-grained information on. One social app stands out in this regard: Untappd is an app that allows users to 'check-in' their consumption of beers. It operates in a similar fashion to other location-based applications, but is specifically tailored to the collection of information on beer consumption. In this paper, we explore beer consumption through the lens of social media. We crawled Untappd in real time over a period of 112 days, across 40 cities in the United States and Europe. Using this data, we shed light on the drinking habits of over 369k users. We focus on per-user and per-city characterisation, highlighting key behavioural trends.
Microscopy capabilities of the Microscopy, Electrochemistry, and Conductivity Analyzer

The Phoenix microscopy station, designed for the study of Martian dust and soil,consists of a sample delivery system, an optical microscope, and an atomic force microscope. The combination of microscopies facilitates the study of features from the millimeter to nanometer scale. Light-emitting diode illumination allows for full color optical imaging of the samples as well as imaging of ultraviolet-induced visible fluorescence. The atomic force microscope uses an array of silicon tips and can operate in both static and dynamic mode.
Accuracy Analysis of a Dam Model from Drone Surveys

This paper investigates the accuracy of models obtained by drone surveys. To this end, this work analyzes how the placement of ground control points (GCPs) used to georeference the dense point cloud of a dam affects the resulting three-dimensional (3D) model. Images of a double arch masonry dam upstream face are acquired from drone survey and used to build the 3D model of the dam for vulnerability analysis purposes. However, there still remained the issue of understanding the real impact of a correct GCPs location choice to properly georeference the images and thus, the model. To this end, a high number of GCPs configurations were investigated, building a series of dense point clouds. The accuracy of these resulting dense clouds was estimated comparing the coordinates of check points extracted from the model and their true coordinates measured via traditional topography. The paper aims at providing information about the optimal choice of GCPs placement not only for dams but also for all surveys of high-rise structures. The knowledge a priori of the effect of the GCPs number and location on the model accuracy can increase survey reliability and accuracy and speed up the survey set-up operations.
Performance analysis of IEEE 802.11 Rate Selection for Industrial Networks

IEEE 802.11 wireless LANs introduced the Multi-Rate Support as an effective tool for performance tuning. This feature is implemented by means of specific Rate Adaptation (RA) algorithms, that in general have been designed with the goal of throughput maximization, targeting at general purpose communication networks. Unfortunately, industrial real-time communication systems are characterized by very different performance requirements, and hence dedicated, more tailored, RA algorithms have to be devised. The proposed algorithm called Rate Selection for Industrial Networks (RSIN) is a significant step in this direction, being designed from its beginning as an optimization problem, in which the knowledge of the signal-to-noise-ratio is exploited to cope with the industrial traffic requirements. A preliminary assessment has indicated that the performance figures of RSIN are promising. In this paper, we aim at providing a complete characterization of such algorithm, assessing the impact of possible uncertainties in the estimation of the channel status and evaluating the scalability of the proposed strategy from one link to a network. The outcomes of these analyses revealed that RSIN is able to enhance timeliness and reliability of a wireless network in a robust and scalable way, making it suitable for adoption in industrial contexts.
A comparative study of the chondrogenic potential between synthetic and natural scaffolds in an in vivo bioreactor

Abstract The clinical demand for cartilage tissue engineering is potentially large for reconstruction defects resulting from congenital deformities or degenerative disease due to limited donor sites for autologous tissue and donor site morbidities. Cartilage tissue engineering has been successfully applied to the medical field: a scaffold pre-cultured with chondrocytes was used prior to implantation in an animal model. We have developed a surgical approach in which tissues are engineered by implantation with a vascular pedicle as an in vivo bioreactor in bone and adipose tissue engineering. Collagen type II, chitosan, poly(lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) were four commonly applied scaffolds in cartilage tissue engineering. To expand the application of the same animal model in cartilage tissue engineering, these four scaffolds were selected and compared for their ability to generate cartilage with chondrocytes in the same model with an in vivo bioreactor. Gene expression and immunohistochemistry staining methods were used to evaluate the chondrogenesis and osteogenesis of specimens. The result showed that the PLGA and PCL scaffolds exhibited better chondrogenesis than chitosan and type II collagen in the in vivo bioreactor. Among these four scaffolds, the PCL scaffold presented the most significant result of chondrogenesis embedded around the vascular pedicle in the long-term culture incubation phase.
Risk Factors for Poststroke Depression

Objective: Depression after stroke or poststroke depression (PSD) has a negative impact on the rehabilitation process and the associated rehabilitation outcome. Consequently, defining risk factors for development of PSD is important. The relationship between stroke and depression is described extensively in the available literature, but the results are inconsistent. The aim of this systematic review is to outline conflicting evidence on risk factors for PSD. Methods: PubMed, Medline, and Web of Knowledge were searched using the keywords “stroke,” “depression,” and “risk factor” for articles published between January 01, 1995, and September 30, 2012. Additional articles were identified and obtained from a hand search in related articles and reference lists. Results: A total of 66 article abstracts were identified by the search strategy and 24 articles were eligible for inclusion based on predefined quality criteria. The methodology varies greatly between the various studies, which is probably responsible for major differences in risk factors for PSD reported in the literature. The most frequently cited risk factors for PSD in the literature are sex (female), history of depression, stroke severity, functional impairments or level of handicap, level of independence, and family and social support. Conclusions: Many risk factors are investigated over the last 2 decades and large controversy exists concerning risk factors for development of PSD. These contradictions may largely be reduced to major differences in clinical data, study population, and methodology, which underline the need for more synchronized studies.
Alignment and Opening of Giant Lecithin Vesicles by Electric Fields

Abstract AC electric fields ware applied to suspensions of giant lecithin vesicles observed under a phase contrast microscope. Elongated vesicles were found to align parallel to the field. In sufficiently strong fields the vesicles opened at both ends and became cylinders which in some cases were immutable under further increase of the field. The cylinder parameters can be used to calculate the edge energy of the cylinder wall. For the single bilayer we obtain 2-10-6 erg cm-1.
Computing matched-epipolar projections

A new method is given for image rectification, the process of resampling pairs of stereo images taken from widely differing viewpoints in order to produce a pair of matched epipolar projections. These are projections in which the epipolar lines run parallel with the x-axis and disparities between the images are in the x-direction only. The method is based on an examination of the essential matrix of Longuet-Higgins (1981), which describes the epipolar geometry of the image pair. The approach taken is consistent with that advocated by O. Faugeras (1992) of avoiding camera calibration. A matrix called the epipolar transformation matrix is defined. It is used to determine a pair of 2-D projective transforms to be applied to the two images in order to match the epipolar lines. The advantages include the simplicity of the 2-D projective transformation, which allows very fast resampling, as well as subsequent simplification in identifying matched points and in scene reconstruction. <<ETX>>
Marine spawning sites of perch Perca fluviatilis revealed by oviduct-inserted acoustic transmitters

In the 1970s, a flood-protection system dramatically changed a large part of the coastal environment of Koge Bugt, a bay in the western Baltic Sea, from open coast to a brackish lagoon habitat. An anadromous stock of European perch Perca fluviatilis seems to have benefitted from this change, but details about their spawning behavior remain unknown. We used oviduct- inserted acoustic transmitters to reveal the pre-spawning behavior and spawning sites of this pop- ulation. Thirteen female perch were caught in the lower stream basin of St. Vejle A, and were tagged with acoustic transmitters inserted through the oviduct. The fish were tracked from March 2 to May 24, 2012 with both passive and active telemetry systems. The pre-spawning behavior involved short trips between the stream and adjacent lagoons. Twelve of the 13 transmit- ters (92%) were expulsed during spawning, providing for the first time a strong proof of concept of oviduct-inserted acoustic transmitters in brackish and marine fish spawning studies. The trans- mitter expulsions were validated using an egg map, which was based on visual observations of perch egg-strands, and 11 of the 12 expulsed transmitters (92%) were located in areas with eggs. Many fish spawned in the brackish water with salinities up to 9.6 PSU. These salinities are higher than those previously observed for European perch spawning in the wild, and call for further investigations of salinity tolerance in perch eggs.
Supporting Open Dataset Publication Decisions Based on Open Source Software Reuse

Publishing and maintaining open data is a costly task for public institutions, that becomes even more challenging in the context of Smart Cities, where large amounts of varied data are generated from different domains. To optimize resources, they should prioritize the publication and maintenance of datasets most likely to generate social and economic impact. However, there is currently a lack of decision-support tools to help public sector data publishers to evaluate datasets on the light of their particular reuse goals. In this paper, we propose to suggest to data publishers the dataset categories with most potential impact, based on the impact of already published datasets of the same category. To measure impact, we propose a set of indicators based on the amount and quality of Open Source Software projects that use datasets. To aggregate indicators according to specific reuse goals, we provide an Analytic-Hierarchy-Process based tool.
Antibiotic use, knowledge and health literacy among the general population in Berlin, Germany and its surrounding rural areas

Objectives Knowledge concerning antibiotic use in the general population is insufficient. The way health literacy is related to antibiotic use aside from knowledge needs further investigation. Our aim was to compare the levels of knowledge of antibiotics and health literacy in individuals who had taken antibiotics in recent years compared with those who not had taken antibiotics. Methods A population-based cross-sectional survey of 2,000 individuals aged 35 and older from Berlin, Germany and its surrounding rural and suburban areas (response rate 59%) with strata urban/rural, sex, age, and education. Computer-assisted personal interviews were conducted by external, trained interviewers during home visits. Knowledge, health literacy, and antibiotic use were assessed using standardized questionnaires. Results In all, 33.3% (666/2,000) of the participants indicated having had an antimicrobial therapy during the previous 12 months. Adjusting for sex, age, educational level and health literacy, individuals with four correct answers regarding antibiotics were 1.70 times and those with three correct answers 1.94 more likely to have had a history of recent antibiotic use than those who did not have any correct answers. Individuals with sufficient health literacy were 0.57 times less likely to have had a recent history of antibiotic use than individuals with insufficient health literacy. Conclusion Patients who have used antibiotics might have more knowledge as a result of their recent involvement with the topic of antibiotic use; health literacy may be a preventive mechanism to use antibiotics more critically. Besides improving the health knowledge of the general population and of vulnerable groups such as patients with low levels of health literacy, intervention strategies should focus on providers as well.
Improving the Hemostatic Property of Common Textile Fibers for Wound Dressings.

GAJJAR, CHIRAG RAJESH. Improving the Hemostatic Property of Common Textile Fibers for Wound Dressings. (Under the direction of Marian McCord). This project aims to characterize the relationship between fiber properties and the hemostatic behavior of common textile wound dressing materials. The ultimate goal is to improve the hemostatic property of the fibers. Fibers used in this study include cotton, rayon, polypropylene, polyester, nylon and fiberglass. Fiberglass is one of the most hemostatic agents which is believed to be due to its hydrophilicity and highly negative surface charge. Hence, the fibers are characterized using single fiber contact angle and zeta potential measurement in order to find the correlation between these properties and hemostasis, which is measured using a thrombin assay. The fibers are also treated with tetraethyl orthosilicate (TEOS) which imparts a glass-like surface to the fibers. TEOS treatment resulted in the decrease of contact angle and increase in thrombogenicity for all fibers except fiberglass. In order to study the effect of specific functional end-groups on the process of coagulation, fiberglass was functionalized with surface carboxyl (-COOH), amine (-NH2), hydroxyl (OH), methyl (-CH3) and amine (-NH2) functional end-groups. There was no direct correlation between thrombogenicity and hydrophilicity or negativity of the zeta potential of a surface. The observations from this study contradict findings that indicate that a hydrophilic substrate with a highly negative surface charge provides superior hemostatic properties. We propose that a surface with a moderate contact angle, i.e. neither too hydrophilic nor too hydrophobic, and with a specific surface chemistry (with end-groups and surface charge similar to glass) would provide an ideal solution. Improving the Hemostatic Property of Common Textile Fibers for Wound Dressings by Chirag Rajesh Gajjar A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the degree of Master of Science
Generalized Growth of Estuarine, Household and Clinical Isolates of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen of particular concern to immune-compromised people, such as cystic fibrosis patients and burn victims. These bacteria grow in built environments including hospitals and households, and in natural environments such as rivers and estuaries. However, there is conflicting evidence whether recent environments like the human lung and open ocean affect P. aeruginosa growth performance in alternate environments. We hypothesized that bacteria recently isolated from dissimilar habitats should grow differently in media containing artificial versus natural resources. To test this idea, we examined growth of P. aeruginosa isolates from three environments (estuary, household, and clinic) in three media types: minimal-glucose lab medium, and media prepared from sugar maple leaves or big bluestem grass. We used automated spectrophotometry to measure high-resolution growth curves for all isolate by media combinations, and studied two fitness parameters: growth rate and maximum population density. Results showed high variability in growth rate among isolates, both overall and in its dependence on assay media, but this variability was not associated with habitat of isolation. In contrast, total growth (change in absorbance over the experiment) differed overall among habitats of isolation, and there were media-specific differences in mean total growth among habitats of isolation, and in among-habitat variability in the media-specific response. This was driven primarily by greater total growth of estuary isolates when compared with those from other habitats of origin, and greater media-specific variability among household isolates than those from other habitats of origin. Taken together, these results suggest that for growth rate P. aeruginosa bacteria appear to be broad generalists without regard to current or recent habitat, whereas for total growth a signature of recent ecological history can be detected.
Designing a humanoid head for RoboCup challenge

In this paper, we report an initial design of humanoid head platform for RoboCup humanoid challenge. While many research in RoboCup humanoid challenge naturally focus on walking and running behaviors, we focus on perception and high-level behavior issues using an upper-torso humanoid. We have designed an head/neck part of the humanoid with aesthetic design, and various processing for early perception and associated reflex. The goal of this paper is to illustrate issues in designing humanoid head platform for high-level cognition research, and provide some of initial insights obtained during the early stage of implementations. With regards to perception, the emphasis will be placed on how interaction between different perception channel and motor control can complement each other to improve each processing.
Modeling motivations and emotions as a basis for intelligent behavior

We report on an experiment to implement an autonomous creature situated in a two-dimensional world, that shows various learning and problem-solving capabilities, within the Society of Mind framework. This goal is approached from a developmental perspective, where phases in the experiment correspond broadly to cognitive stages in the development of an infant. This paper describes the first stage, the creature being a newborn whose behavior is strongly driven by motivational states—impulses to action based on bodily needs—and basic emotions—peripheral and cognitive responsestriggered by the recognition of a significant event. Physiological parameters are used to model both concepts, which are seen by analogy with control systems. Motivations drive behavior selection and organization based on the notions of arousal and satiation, and the exploitation principle. Emotions exert further control by sending “hormones” that may affect the intensity of the selected behavior, enable it, or prevent it. They also influence the attentional and perception mechanisms.