Miracle-dz/UniFAR-FTUs huggingface dataset:
Better Approximation Algorithms for the Graph Diameter

The diameter is a fundamental graph parameter and its computation is necessary in many applications. The fastest known way to compute the diameter exactly is to solve the All-Pairs Shortest Paths (APSP) problem. In the absence of fast algorithms, attempts were made to seek fast algorithms that approximate the diameter. In a seminal result Aingworth, Chekuri, Indyk and Motwani [SODA'96 and SICOMP'99] designed an algorithm that computes in O (n2 + m√n) time an estimate D for the diameter D in directed graphs with nonnegative edge weights, such that [EQUATION], where M is the maximum edge weight in the graph. In recent work, Roditty and Vassilevska W. [STOC 13] gave a Las Vegas algorithm that has the same approximation guarantee but improves the (expected) runtime to O (m√n). Roditty and Vassilevska W. also showed that unless the Strong Exponential Time Hypothesis fails, no O (n2-e) time algorithm for sparse unweighted undirected graphs can achieve an approximation ratio better than 3/2. Thus their algorithm is essentially tight for sparse unweighted graphs. For weighted graphs however, the approximation guarantee can be meaningless, as M can be arbitrarily large. In this paper we exhibit two algorithms that achieve a genuine 3/2-approximation for the diameter, one running in O (m3/2) time, and one running in O (mn2/3). time. Furthermore, our algorithms are deterministic, and thus we present the first deterministic (2 -- e)-approximation algorithm for the diameter that takes subquadratic time in sparse graphs. In addition, we address the question of obtaining an additive c-approximation for the diameter, i.e. an estimate D such that D -- c ≤ D ≤ D. An extremely simple O (mn1-e) time algorithm achieves an additive ne-approximation; no better results are known. We show that for any e > 0, getting an additive ne-approximation algorithm for the diameter running in O (n2-e) time for any δ > 2e would falsify the Strong Exponential Time Hypothesis. Thus the simple algorithm is probably essentially tight for sparse graphs, and moreover, obtaining a subquadratic time additive c-approximation for any constant c is unlikely. Finally, we consider the problem of computing the eccentricities of all vertices in an undirected graph, i.e. the largest distance from each vertex. Roditty and Vassilevska W. [STOC 13] show that in O (m√n) time, one can compute for each v e V in an undirected graph, an estimate e(v) for the eccentricity e (v) such that max{R, 2/3 · e(v)} ≤ e (v) ≤ min {D, 3/2 · e(v)} where R = minv e (v) is the radius of the graph. Here we improve the approximation guarantee by showing that a variant of the same algorithm can achieve estimates e' (v) with 3/5 · e (v) ≤ e' (v) ≤ e (v).
Guest Editorial Introduction to the Special Issue on the 2016 Grand Cooperative Driving Challenge

Cooperative driving is based on wireless communications between vehicles and between vehicles and roadside infrastructure, aiming for increased traffic flow and traffic safety, while decreasing fuel consumption and emissions. To support and accelerate the introduction of cooperative vehicles in everyday traffic, in 2011, nine international teams joined the Grand Cooperative Driving Challenge (GCDC). The challenge was to perform platooning, in which vehicles drive in road trains with short intervehicle distances. The results were reported in a Special Issue of IEEE Transactions on Intelligent Transportation Systems, published in September 2012 [item 1 in the Appendix].
A Distributed Management Scheme for Energy Storage in a Smart Grid With Communication Impairments

With the integration of distributed generations into smart grid, energy storage units (ESUs) are deployed to absorb excessive fluctuation in power flow. Data must be collected from sensors when making ESU charging and discharging decisions. However, existing ESU management schemes have not considered this need of sending data over realistic communication channels with packet errors. This paper proposes a distributed ESU management scheme that can operate reliably over error-prone wireless communication channels. The proposed scheme uses the Markov decision process to make local decision at each ESU, and aims to minimize power loss while keeping the voltage violation probability below an acceptable level. The scheme has been evaluated through extensive simulations. Results confirm that the scheme can operate efficiently over impaired communication channels. Power losses are reduced by up to 50% compared to a naive centralized scheme while maintaining the voltage violation probability below 0.005.
A Direct Matrix Synthesis for In-Line Filters With Transmission Zeros Generated by Frequency-Variant Couplings

A direct matrix approach is presented for the first time to synthesize high selectivity in-line topology filters where multiple transmission zeros are generated and independently controlled by a set of frequency-variant couplings. As the resultant network only involves resonators cascaded one by one without any auxiliary elements (such as cross-coupled or extracted-pole structures), this paper provides the best synthesis solution in configuration simplicity for narrowband filters. Considering both the couplings and capacitances of a traditional low-pass prototype, a generalized transformation on the admittance matrix is introduced as the basis of the synthesis, which allows more than one cross-coupling to be annihilated in a single step, while generating a frequency-variant coupling simultaneously. It is then shown that the in-line topology as well as some other unique topologies can be determined by applying a specific sequence of the transformations. For the validation, a group of examples with synthesis as well as experimental results are demonstrated.
Tensile Strength of Steel Fiber Reinforced Concrete

Studies have shown that the addition of steel fibers in a concrete matrix improves all the mechanical properties of concrete, especially tensile strength, impact strength, and toughness. The resulting material possesses higher tensile strength, consolidated response and better ductility. Accordingly, this study moves toward deriving an expression that relates split cylinder tensile strength of fiber reinforced concrete to cylindrical compressive concrete strength and fiber reinforcement index, based on data gathered for a wide spectrum of concrete grades, ranging from 20 MPa to 102 MPa. Regression analysis was carried out on gathered data. Eventually a mathematical expression that predicted split cylinder tensile strength of steel fiber reinforced concrete was eventually derived. The predicted values fit well with experimental data.
Influence of snack intake on cardiac autonomic nervous system in patients with type 2 diabetes

Food intake induces significant changes in heart rate (HR) and heart rate variability (HRV) among healthy individuals. It is known that the cardiac autonomic nervous system (CANS) is impaired in patients with type 2 diabetes. The main goal of this pilot study was to investigate whether snack intake can affect CANS in this patient population. For this purpose, ECG was recorded pre- and post-snack intake in 15 volunteers with type 2 diabetes. Mean HR and short-term HRV measures (e.g., SDNN, RMSSD, percentage of power in LF and HF band, and LF/HF) were extracted and compared using the Wilcoxon signed-rank test between pre- and post-snack intake. From pre-to post-snack intake, mean glucose level increased by 24.1 points (p=0.10) while mean heart rate increased by 1.9 beats per minute (p=0.30). Changes in SDNN, RMSSD, power in LF band (%), power in HF band (%), and LF/HF were not existent (p=0.39, 0.80, 0.45, 0.98, 0.36, respectively). As expected, an increase in glucose count was observed shortly after snack intake. No cardiac neural response, however, was observed in our sample of type 2 diabetics.
A Stitch in Time Saves Nine - SPARQL querying of Property Graphs using Gremlin Traversals

Knowledge graphs have become popular over the past years and frequently rely on the Resource Description Framework (RDF) or Property Graphs (PG) as underlying data models. However, the query languages for these two data models -- SPARQL for RDF and Gremlin for property graph traversal -- are lacking interoperability. We present Gremlinator, a novel SPARQL to Gremlin translator. Gremlinator translates SPARQL queries to Gremlin traversals for executing graph pattern matching queries over graph databases. This allows to access and query a wide variety of Graph Data Management Systems (DMS) using the W3C standardized SPARQL query language and avoid the learning curve of a new Graph Query Language. Gremlin is a system-agnostic traversal language covering both OLTP graph database or OLAP graph processors, thus making it a desirable choice for supporting interoperability wrt. querying Graph DMSs. We present a comprehensive empirical evaluation of Gremlinator and demonstrate its validity and applicability by executing SPARQL queries on top of the leading graph stores Neo4J, Sparksee, and Apache TinkerGraph and compare the performance with the RDF stores Virtuoso, 4Store and JenaTDB. Our evaluation demonstrates the substantial performance gain obtained by the Gremlin counterparts of the SPARQL queries, especially for star-shaped and complex queries.
Proximal Protection Devices and Flow Reversal for Embolic Protection

Carotid artery disease leading to stroke is one the primary causes of serious long-term disability in the United States today. Carotid artery stenting (CAS) has proven to be a reasonable alternative to carotid endarterectomy in patients who are felt to be at high risk for endarterectomy. Appropriate indications for CAS include patients with both high physiologic and anatomic risk for the standard therapy of carotid endarterectomy. It is this patient population that has caused the dramatic upsurge in new technologies and techniques to reduce perioperative stroke rates. A good deal of that effort has been focused on embolic protection devices (EPD). The body of literature supporting the use of proximal embolic protection continues to grow. Also, as is the case with other means of embolic protection, the rate of periprocedural cerebrovascular events continues to decline over time as surgeons and interventionalists become more experienced performing CAS with proximal protection and flow reversal. Current data are supportive of the use of proximal protection devices. However, all of the data are from single-arm registry studies. Head-to-head studies comparing proximal protection devices vs distal embolic protection devices are still warranted.
A Lightweight Continuous Authentication Protocol for the Internet of Things

Modern societies are moving toward an information-oriented environment. To gather and utilize information around people’s modern life, tiny devices with all kinds of sensing devices and various sizes of gateways need to be deployed and connected with each other through the Internet or proxy-based wireless sensor networks (WSNs). Within this kind of Internet of Things (IoT) environment, how to authenticate each other between two communicating devices is a fundamental security issue. As a lot of IoT devices are powered by batteries and they need to transmit sensed data periodically, it is necessary for IoT devices to adopt a lightweight authentication protocol to reduce their energy consumption when a device wants to authenticate and transmit data to its targeted peer. In this paper, a lightweight continuous authentication protocol for sensing devices and gateway devices in general IoT environments is introduced. The concept of valid authentication time period is proposed to enhance robustness of authentication between IoT devices. To construct the proposed lightweight continuous authentication protocol, token technique and dynamic features of IoT devices are adopted in order to reach the design goals: the reduction of time consumption for consecutive authentications and energy saving for authenticating devices through by reducing the computation complexity during session establishment of continuous authentication. Security analysis is conducted to evaluate security strength of the proposed protocol. In addition, performance analysis has shown the proposed protocol is a strong competitor among existing protocols for device-to-device authentication in IoT environments.
Mycamoeba gemmipara nov. gen., nov. sp., the First Cultured Member of the Environmental Dermamoebidae Clade LKM74 and its Unusual Life Cycle

Since the first environmental DNA surveys, entire groups of sequences called “environmental clades” did not have any cultured representative. LKM74 is an amoebozoan clade affiliated to Dermamoebidae, whose presence is pervasively reported in soil and freshwater. We obtained an isolate from soil that we assigned to LKM74 by molecular phylogeny, close related to freshwater clones. We described Mycamoeba gemmipara based on observations made with light‐ and transmission electron microscopy. It is an extremely small amoeba with typical lingulate shape. Unlike other Dermamoebidae, it lacked ornamentation on its cell membrane, and condensed chromatin formed characteristic patterns in the nucleus. M. gemmipara displayed a unique life cycle: trophozoites formed walled coccoid stages which grew through successive buddings and developed into branched structures holding cysts. These structures, measuring hundreds of micrometres, are built as the exclusive product of osmotrophic feeding. To demonstrate that M. gemmipara is a genuine soil inhabitant, we screened its presence in an environmental soil DNA diversity survey performed on an experimental setup where pig cadavers were left to decompose in soils to follow changes in eukaryotic communities. Mycamoeba gemmipara was present in all samples, although related reads were uncommon underneath the cadaver.
Thr 175-phosphorylated tau induces pathologic fi bril formation via GSK 3 b-mediated phosphorylation of Thr 231 in vitro

We have previously shown that amyotrophic lateral sclerosis with cognitive impairment can be characterized by pathologic inclusions of microtubule-associated protein tau (tau) phosphorylated at Thr175 (pThr175) in association with GSK3b activation. We have now examined whether pThr175 induces GSK3b activation and whether this leads to pathologic fibril formation through Thr231 phosphorylation. Seventy-two hours after transfection of Neuro2A cells with pseudophosphorylated green fluorescent protein-tagged 2N4R tau (Thr175Asp), phosphorylated kinase glycogen synthase kinase 3 beta (active GSK3b) levels were significantly increased as was pathologic fibril formation and cell death. Treatment with each of 4 GSK3b inhibitors or small hairpin RNA knockdown of GSK3b abolished fibril formation and prevented cell death. Inhibition of Thr231 phosphorylation (Thr231Ala) prevented pathologic tau fibril formation, regardless of Thr175 state, whereas Thr231Asp (pseudophosphorylated at Thr231) developed pathologic tau fibrils. Ser235 mutations did not affect fibril formation, indicating an unprimed mechanism of Thr231 phosphorylation. These findings suggest a mechanism of tau pathology by which pThr175 induces GSK3b phosphorylation of Thr231 leading to fibril formation, indicating a potential therapeutic avenue for amyotrophic lateral sclerosis with cognitive impairment. 2015 Elsevier Inc. All rights reserved.
Presence of Human Enteric Viruses, Protozoa, and Indicators of Pathogens in the Bagmati River, Nepal

Quantification of waterborne pathogens in water sources is essential for alerting the community about health hazards. This study determined the presence of human enteric viruses and protozoa in the Bagmati River, Nepal, and detected fecal indicator bacteria (total coliforms, Escherichia coli, and Enterococcus spp.), human-fecal markers (human Bacteroidales and JC and BK polyomaviruses), and index viruses (tobacco mosaic virus and pepper mild mottle virus). During a one-year period between October 2015 and September 2016, a total of 18 surface water samples were collected periodically from three sites along the river. Using quantitative polymerase chain reaction, all eight types of human enteric viruses tested—including adenoviruses, noroviruses, and enteroviruses, were detected frequently at the midstream and downstream sites, with concentrations of 4.4–8.3 log copies/L. Enteroviruses and saliviruses were the most frequently detected enteric viruses, which were present in 72% (13/18) of the tested samples. Giardia spp. were detected by fluorescence microscopy in 78% (14/18) of the samples, with a lower detection ratio at the upstream site. Cryptosporidium spp. were detected only at the midstream and downstream sites, with a positive ratio of 39% (7/18). The high concentrations of enteric viruses suggest that the midstream and downstream regions are heavily contaminated with human feces and that there are alarming possibilities of waterborne diseases. The concentrations of enteric viruses were significantly higher in the dry season than the wet season (p < 0.05). There was a significant positive correlation between the concentrations of human enteric viruses and the tested indicators for the presence of pathogens (IPP) (p < 0.05), suggesting that these IPP can be used to estimate the presence of enteric viruses in the Bagmati River water.
Automatic coordinate prediction of the exit of ventricular tachycardia from 12-lead electrocardiogram

Automatic localization of the exit site of ventricular tachycardia (VT) can improve the efficiency and efficacy of catheter ablation. Because the exit site of the VT gives rise to its QRS complex on electrocardiogram (ECG), it is possible to build a predictive model to directly localize the exit of a VT from its 12-lead ECG. In previous works, prescribed features such as QRS integrals have been used to build such models. In this paper, we propose a deep network to automatically extract more discriminative features from QRS complex to localize the origin of ventricular activation. To improve the resolution of localization compared to previous works based on a small number of pre-defined segments, we localize the origin of ventricular activation as 3D coordinates. Model training and testing were performed on 12-lead ECG data of 1012 distinct pacing sites, collected from patients during routine pace-mapping procedures. Compared with the use of prescribed QRS-integral as an input feature, the presented deep model achieved an improvement of localization accuracy by approximately 4 millimeters 26%) on average.
Metabolic responses to drought stress in the tissues of drought-tolerant and drought-sensitive wheat genotype seedlings

Productivity of wheat is affected by drought stress; however, the correlation between drought stress and metabolism is still not clear. The aim of this study was to investigate physiological adaptive mechanisms and reveal physiological processes related to drought tolerance. The results indicated that the wheat metabolome is dominated by sugars, organic acids and amino acids; the wheat metabolome plays important roles in enhancing the drought tolerance of shoots. Drought caused system alterations in widespread metabolic networks involving transamination, tricarboxylic acid cycle, glycolysis, glutamate-mediated proline biosynthesis, shikimate-mediated secondary metabolisms and GABA metabolisms.
A Multi-Classification Approach for the Detection and Identification of eHealth Applications

eHealth services category has a diversified set of traffic patterns and demands in terms of QoS assurances. Existing QoS solutions were designed to support only aggregated classes of service and cannot differentiate traffic based on an application's behavioral pattern. In order to improve the performance of eHealth applications for home and mobile users there is a need to develop new traffic identification techniques, which would work at the edge of the network. This paper addresses the above problem by proposing machine learning-based approach for eHealth traffic identification. We investigate different techniques which combine the results from multiple machine learning classifiers and show which combination of techniques is best suited for identifying diverse eHealth traffic. Our approach is validated in a mobile e-health application context and the results prove that multi-classification techniques can be used in practice to provide application-based service differentiation.
Behind the Avatar: The Patterns, Practices, and Functions of Role Playing in MMOs

A two-part quantitative and qualitative study of role players within a virtual game world examined their prevalence, practices, and identity formation. Drawing on unobtrusive behavioral data captured by the game, combined with a large survey and traditional ethnographic methods, the study found that role players both negotiate identity and use their time online as a moratorium for their offline lives. Descriptive results showed that role players are a relatively small, but psychologically burdened subgroup. When examined from the theoretical perspectives of Goffman’s Self-Presentation theory, Huizenga’s Magic Circle, and Turkle’s early work on online identity formation, these players were seen as largely using virtual spaces as creative outlets and for socialization. The worlds also functioned as coping mechanisms for players frequently unable to gain acceptance, social connectivity or social support offline due to their personal situation, psychological profile, or their minority status.
Magnetotactic Bacterium Multi-objective Optimization Algorithm

In this paper, based on Magnetotactic Bacteria Optimization Algorithm(MBOA), magnetotactic bacterium multi-objective optimization algorithm (MBMOA) is proposed for solving multi-objective optimization problems(MOPs). Magnetotactic bacterium optimization algorithm is a novel random research algorithm which simulates the process of magnetotactic bacteria (MTB) producing magnetosomes(MTS) to regulate cell moment and makes the magnetostatic energy reach the minimum . The algorithm MBOA proposed three operators named by MTS producing, MTS amplification and MTS replacement by imitating the development process of magnetosomes, the adjustment process of magnetosomes moment and the replacement process of magnetosome with worse moment. In MBMOA, MBOA is applied to produce the next population, while non-dominated feasible solutions gained by MBOA are conserved in the archive, then the evaluation method of SPEA2 is adopted to update the archive, at the last through benchmark functions test and classic algorithm comparison, the simulation results show that the MBMOA is feasible and effective for solving multi-objective optimization problems.
‘Doing research’ with Gypsy–Travellers in England: reflections on experience and practice

In order to bring the lives of Gypsy-Travellers in line with the sustainable communities' agenda, there is now a duty for local planning authorities in England to assess the accommodation and related needs of Gypsy-Travellers. As such, there has been an increase in research, which aims to ‘find out’ more about these communities. This article explores some of the issues that researchers should consider when carrying out research with Gypsy-Travellers. It focuses specifically on issues around identifying and engaging with members of the Gypsy and Traveller communities, offering some strategies and solutions based on the experiences of the authors and other researchers.