Miracle-dz/UniFAR-FTUs huggingface dataset:
Ergodic capacity and SER performance analysis of amplify-and-forward cognitive relay networks with partial relay selection

This paper investigates the performance of amplify-and-forward (AF) cognitive relay networks with partial relay selection (PRS) in a spectrum-sharing context. The PRS schemes can be divided into two different types: source-relay PRS and relay-destination PRS, which are respectively called SR-PRS and RD-PRS for short. Different from most of the existing studies which only consider interference power constraint on secondary source and relay nodes, transmit power constraint on secondary relay nodes is further considered in our work. In this condition, we derive the lower bound on symbol error rate and the upper bound on ergodic capacity of the two schemes aforementioned over Rayleigh fading channels, which has never been studied before. According to the analyses, the power constraints and the number of secondary relay nodes are the main factors affecting the system performance. Furthermore, the performances of the two schemes are compared by simulations and the correctness of the analytical results are verified by Monte Carlo simulations.
Variation of dislocation morphology with strain in Ge_xSi_1−x epilayers on (100)Si

A change in microstructure, including dislocation Burgers vector, length, and behavior, has been observed to occur when the epilayer mismatch is varied in Ge_ x Si_1− x layers grown on (100) Si. At low mismatches (<1.5%), there is an orthogonal array of very long 60° misfit dislocations. At higher mismatches (>2.3%) there is an orthogonal array of short edge dislocations. At intermediate mismatches (1.5 to 2.3%) there is a mixture of 60° and edge dislocations. The nature of the microstructure has a pronounced effect on the density of threading dislocations in the epilayer, which increase by a factor of ∼60× through a relatively small range of mismatch (1.7 to 2.1%, corresponding to x ranging from 0.4 to 0.5). These morphologies are discussed in the light of recent work on the sources of misfit dislocations. While mechanisms for the introduction and propagation of dislocations at low mismatch have recently been observed and explained, the high misfit case is clearly very different; i.e., surface nucleation seems to be likely in the latter case as opposed to operation of an internal source in the former. A mechanism for edge dislocation formation is proposed.
Virulence Properties and Serotypes of Shiga Toxin-Producing Escherichia coli from Healthy Australian Slaughter-Age Sheep

ABSTRACT A group of 1,623 ovine fecal samples recovered from 65 geographically distinct mutton sheep and prime lamb properties across New South Wales, Australia, were screened for the presence of Shiga toxin-producing Escherichia coli (STEC) virulence factors (stx1, stx2,eaeA, and ehxA). A subset was cultured for STEC isolates containing associated virulence factors (eaeAand/or ehxA), which were isolated from 17 of 20 (85%) and 19 of 20 (95%) tested prime lamb and mutton sheep properties, respectively. STEC isolates containing stx1,stx2, and ehxA were most commonly isolated (19 of 40 flocks; 47.5%), and this profile was observed for 10 different serotypes. Among 90 STEC isolates studied, the most common serotypes were O91:H− (22 isolates [24.4%]), O5:H− (16 isolates [17.8%]), O128:H2 (11 isolates [12.2%]), O123:H− (8 isolates [8.9%]), and O85:H49 (5 isolates [5.6%]). Two isolates (2.2%) were typed as O157:H−. A total of 78 of 90 STEC isolates (86.7%) expressed Shiga toxin in Vero cell culture and 75 of 84ehxA-positive isolates (89.3%) expressed enterohemolysin on washed sheep blood agar. eaeA was observed in 11 of 90 (12.2%) ovine STEC isolates, including serotypes O5:H−, O84:H−, O85:H49, O123:H− O136:H40, and O157:H−. Although only 2 of 90 isolates were typed as O157:H−, the predominant serotypes recovered during this study have been recovered from human patients with clinical disease, albeit rarely.
Hybrid orthosis system with a variable hip coupling mechanism

Existing reciprocating gait orthoses, to help restore gait to individuals with paraplegia, have a fixed 1:1 hip flexion/extension coupling ratios (FECR), limiting stride length and gait speed. The purpose of this study was to develop a hip reciprocating mechanism for the hybrid orthosis system that is capable of variable hip FECR. The design of the new variable hip reciprocating mechanism incorporates a hydraulic system which utilizes solenoid valves to control coupling between cylinders linked to each hip joint of the orthosis. A specific set of valves are pulsed to achieve continual variable hip coupling. It was shown that piston velocity was inversely proportional to pulse width and also dependent on pulsing frequency. Internal losses in the hydraulic hip reciprocating mechanism occur primarily in the cylinders. Feedback control will be achieved with a dual layer gait event detector consisting of a fuzzy inference system and a set of supervisory rules
Dynamic positioning of beacon vehicles for cooperative underwater navigation

Autonomous Underwater Vehicles (AUVs) are used for an ever increasing range of applications due to the maturing of the technology. Due to the absence of the GPS signal underwater, the correct estimation of its position is a challenge for submerged vehicles. One promising strategy to mitigate this problem is to use a group of AUVs where one or more assume the role of a beacon vehicle which has a very accurate position estimate due to an expensive navigation suite or frequent surfacings. These beacon vehicles broadcast their position and the remaining survey vehicles can use this position information and intra-vehicle ranges to update their position estimate. The effectiveness of this approach strongly depends on the geometry between the beacon vehicles and the survey vehicles. The trajectories of the beacon vehicles should thus be planned with the goal to minimize the position uncertainty of the survey vehicles. We propose a distributed algorithm which dynamically computes the locally optimal position for a beacon vehicle using only information obtained from broadcast communication of the survey vehicles. It does not need prior information about the survey vehicles' trajectory and can be used for any group size of beacon and survey vehicles.
Detecting and Localizing Identity-Based Attacks in Wireless and Sensor Networks

Wireless networks are vulnerable to identity-based attacks, including spoofing and Sybil attacks, which allows for many other forms of attacks on the networks. Although the identity of a node can be verified through cryptographic authentication, authentication is not always possible, because it requires key management and additional infrastructural overhead. In this paper, we propose a method for detecting both spoofing and Sybil attacks by using the same set of techniques. We first propose a generalized attack-detection model that utilizes the spatial correlation of received signal strength (RSS) inherited from wireless nodes. We further provide a theoretical analysis of our approach. We then derive the test statistics for detection of identity-based attacks by using the K-means algorithm. Our attack detector is robust when handling the situations of attackers that use different transmission power levels to attack the detection scheme. We further describe how we integrated our attack detector into a real-time indoor localization system, which can also localize the positions of the attackers. We show that the positions of the attackers can be localized using either area- or point-based localization algorithms with the same relative errors as in the normal case. We further evaluated our methods through experimentation in two real office buildings using both an IEEE 802.11 (WiFi) network and an IEEE 802.15. 4 (ZigBee) network. Our results show that it is possible to detect wireless identity-based attacks with both a high detection rate and a low false-positive rate, thereby providing strong evidence of the effectiveness of the attack detector utilizing the spatial correlation of RSS and the attack localizer.
Aligned Multiwalled Carbon Nanotube Membranes

An array of aligned carbon nanotubes (CNTs) was incorporated across a polymer film to form a well-ordered nanoporous membrane structure. This membrane structure was confirmed by electron microscopy, anisotropic electrical conductivity, gas flow, and ionic transport studies. The measured nitrogen permeance was consistent with the flux calculated by Knudsen diffusion through nanometer-scale tubes of the observed microstructure. Data on Ru(NH3)63+ transport across the membrane in aqueous solution also indicated transport through aligned CNT cores of the observed microstructure. The lengths of the nanotubes within the polymer film were reduced by selective electrochemical oxidation, allowing for tunable pore lengths. Oxidative trimming processes resulted in carboxylate end groups that were readily functionalized at the entrance to each CNT inner core. Membranes with CNT tips that were functionalized with biotin showed a reduction in Ru(NH3)63+ flux by a factor of 15 when bound with streptavidin, thereby demonstrating the ability to gate molecular transport through CNT cores for potential applications in chemical separations and sensing.
Concept-aware ensemble system for pedestrian detection

For pedestrian detection in ADAS, using multiple classifiers generally performs better than using a single classifier in terms of accuracy since the classifiers can be made to complement one another. On the other hand, such a pedestrian detector needs to be tuned dynamically to the variation of real-world environment such as different poses of pedestrians and variable background. Thus the system is requested to incrementally accept new information while retaining the old one. This paper presents an environment-adaptive ensemble system that performs incremental learning for pedestrian detection. It combines a pedestrian detector comprised of multiple classifiers with a front-end concept recognizer that selectively turns on and off the member classifiers adaptively according to the recognized concept of the input image. It adopts an incremental learning algorithm to add a new classifier, which is trained with a newly added batch of dataset, to the existing ensemble. With the intervention of the front-end concept recognizer, the system can retain good accuracy for old environments while not losing the focus on current environment.
Technologies for Multilayered Scaffolds Suitable for Interface Tissue Engineering

Multilayered scaffolds that provide tailored space‐specific biological and mechanical functions are promising for interface tissue engineering such as in osteochondral tissue regeneration. In this study, fabrication techniques, including foam replication, gelation, and freeze‐drying techniques, were combined in order to manufacture stratified scaffolds mimicking the layered structure of native osteochondral tissue. 45S5 Bioglass® and alginate were used to fabricate 3D highly porous (composite) scaffolds for the underlying subchondral bone layer. Freeze‐dried alginate‐based scaffolds were produced for the cartilage layer. Finally, both layers were integrated using a novel alginate/45S5 Bioglass® hybrid interface acting as an adhesive, which functions as the cartilage–bone interfacial layer. Novel multilayered scaffolds were optimized to achieve the complex requirements for osteochondral tissue engineering such as the 3D architecture, porous structure, physical, and mechanical properties, which are presented and discussed in the context of the intended application of the novel scaffolds in osteochondral tissue regeneration.
Progress in the Synthesis of Nanocrystalline BaTiO3 Powders for MLCC

Future improvements in the development of highly volume-efficient multilayer ceramic capacitors (MLCC) require manufacturing processes that allow for a reduced dielectric thickness well below 1 μm. Obviously, such thin dielectric layers can only be produced if nanosized dielectric powders are applied and deposited by techniques more advanced than tape casting and screen printing. These processes require high-purity, homogeneous, weakly agglomerated ultrafine powders. Over the past few years, significant progress has been made in the synthesis of nanocrystalline BaTiO3-based powders for use in MLCC. The present review article aims to summarize the present state of the art with respect to some of the technically and industrially most relevant preparation routes, including methods based on solid-state reactions and, more importantly, solution-based approaches.
Backpack: detection of people carrying objects using silhouettes

We described a video-rate surveillance algorithm to detect and track people from a stationary camera, and to determine if they are carrying objects or moving unencumbered. The contribution of the paper is the shape analysis algorithm that both determines if a person is carrying an object and segments the object from the person so that it can be tracked, e.g., during an exchange of objects between two people. As the object is segmented an appearance model of the object is constructed. The method combines periodic motion estimation with static symmetry analysis of the silhouettes of a person in each frame of the sequence. Experimental results demonstrate robustness and real-time performance of the proposed algorithm.
Spark plasma sintering of ceramics: understanding temperature distribution enables more realistic comparison with conventional processing

Abstract Spark plasma sintering (SPS) is a consolidation technique that can combine high heating and cooling rates with a uniaxial applied pressure resulting in short processing time. SPS has been successful in producing ceramics with novel microstructures, which are often reported to have been produced at temperatures lower than would be possible using conventional densification techniques. This has led many authors to infer the presence of additional densification mechanisms intrinsic to the SPS process. The present study considers the relationship between temperature measured in SPS and that experienced by the sample. A simple analytical model enables calculation of the equilibrium temperature distribution in a cylinder of known thermal conductivity and emissivity with constant heat generation per unit volume. Application of this model to the die assembly used in SPS allows estimation of the equilibrium sample temperature. Optimised processing conditions were identified for a fully dense submicrometre grain size alumina, and a SiN–40 vol.-%TiB2 composite. Both materials can only be processed to full density with optimised microstructures in a narrow temperature window. Using the analytical model, the temperature seen by the sample was calculated, and compared with the temperature required using conventional processing techniques. Observed microstructures were consistent with those obtained using conventional processing techniques when processed at the calculated temperatures, suggesting that when SPS is applied to ceramics, additional densification mechanisms intrinsic to the SPS process are not required to explain the observed microstructures. The dynamics of the temperature distribution and problems associated with producing large samples using SPS are also considered.
Extragalactic radio surveys in the pre-Square Kilometre Array era

The era of the Square Kilometre Array is almost upon us, and pathfinder telescopes are already in operation. This brief review summarizes our current knowledge of extragalactic radio sources, accumulated through six decades of continuum surveys at the low-frequency end of the electromagnetic spectrum and the extensive complementary observations at other wavelengths necessary to gain this understanding. The relationships between radio survey data and surveys at other wavelengths are discussed. Some of the outstanding questions are identified and prospects over the next few years are outlined.
Comparative Proteome Analysis Revealing an 11-Protein Signature for Aggressive Triple-Negative Breast Cancer

Background Clinical outcome of patients with triple-negative breast cancer (TNBC) is highly variable. This study aims to identify and validate a prognostic protein signature for TNBC patients to reduce unnecessary adjuvant systemic therapy. Methods Frozen primary tumors were collected from 126 lymph node–negative and adjuvant therapy–naive TNBC patients. These samples were used for global proteome profiling in two series: an in-house training (n = 63) and a multicenter test (n = 63) set. Patients who remained free of distant metastasis for a minimum of 5 years after surgery were defined as having good prognosis. Cox regression analysis was performed to develop a prognostic signature, which was independently validated. All statistical tests were two-sided. Results An 11-protein signature was developed in the training set (median follow-up for good-prognosis patients = 117 months) and subsequently validated in the test set (median follow-up for good-prognosis patients = 108 months) showing 89.5% sensitivity (95% confidence interval [CI] = 69.2% to 98.1%), 70.5% specificity (95% CI = 61.7% to 74.2%), 56.7% positive predictive value (95% CI = 43.8% to 62.1%), and 93.9% negative predictive value (95% CI = 82.3% to 98.9%) for poor-prognosis patients. The predicted poor-prognosis patients had higher risk to develop distant metastasis than the predicted good-prognosis patients in univariate (hazard ratio [HR] = 13.15; 95% CI = 3.03 to 57.07; P = .001) and multivariable (HR = 12.45; 95% CI = 2.67 to 58.11; P = .001) analysis. Furthermore, the predicted poor-prognosis group had statistically significantly more breast cancer–specific mortality. Using our signature as guidance, more than 60% of patients would have been exempted from unnecessary adjuvant chemotherapy compared with conventional prognostic guidelines. Conclusions We report the first validated proteomic signature to assess the natural course of clinical TNBC.
Inference on fractal processes using multiresolution approximation

We consider Bayesian inference via Markov chain Monte Carlo for a variety of fractal Gaussian processes on the real line. These models have unknown parameters in the covariance matrix, requiring inversion of a new covariance matrix at each Markov chain Monte Carlo iteration. The processes have no suitable independence properties so this becomes computationally prohibitive. We surmount these difficulties by developing a computational algorithm for likelihood evaluation based on a 'multiresolution approximation' to the original process. The method is computationally very efficient and widely applicable, making likelihood-based inference feasible for large datasets. A simulation study indicates that this approach leads to accurate estimates for underlying parameters in fractal models, including fractional Brownian motion and fractional Gaussian noise, and functional parameters in the recently introduced multifractional Brownian motion. We apply the method to a variety of real datasets and illustrate its application to prediction and to model selection. Copyright 2007, Oxford University Press.
Effects of feed rate and solution conductivity on jet current and fiber diameter in electrospinning of polyacrylonitrile solutions

Abstract Electrospinning of solutions of polyacrylonitrile in dimethylformamide (PAN/DMF) were performed under different voltages at different constant feed rates and the jet electric current was measured. The effects of applied voltage, feed rate and solution conductivity on jet electric current and fiber diameter were investigated. The results showed that the feed rate had no effect on jet current and fiber diameter, whereas by increasing the applied voltage and solution conductivity, both the jet current and fiber diameter were increased.
Curvature-Induced Optical Transitions in Graphene

Optical properties of periodically rippled graphene depending on the direction of hexagonal layer bending were investigated using density functional theory within the random-phase approximation. The corrugation was demonstrated to allow transitions being forbidden in the flat structure, which produce new resonances in the optical spectra of graphene. The most significant distinction between dielectric functions of flat graphene and rippled models was detected in low-energy region for light polarization perpendicular to the layer surface. The structure and positions of resonances were almost independent on the direction of graphene corrugation that can be useful for application of rippled graphene in optics.
High prevalence of seasonal affective disorder among persons with severe visual impairment

Background Light severely affects the occurrence of seasonal affective disorder (SAD). Aims To compare the prevalence of SAD in persons with severe visual impairment and persons with full sight, and in persons with severe visual impairment with or without light perception. Method This cross-sectional study assessed the Global Seasonality Score (GSS) and the prevalence of SAD among 2781 persons with visual impairment and 4099 persons with full sight using the Seasonal Pattern Assessment Questionnaire (SPAQ). Results Respondents with visual impairment had significantly higher GSS and prevalence of SAD compared with full sight controls, P<0.001. Light perception respondents were more vulnerable to seasonal change than both full sight and no light perception respondents. Conclusions The study showed a highly significant association between visual impairment and SPAQ-defined SAD parameters, supporting the hypothesis that decreased retinal light input plays a role in the pathogenesis of SAD.
Multidisciplinary approach in rehabilitating flabby ridge in completely edentulous patient

Hypermobile ridges or flabby edentulous ridges are a common occurrence. The mucostatic or minimally displacive impression technique is one of the treatment options in this scenario. Conventional mucostatic methods like employing a window tray technique, double spacers, multiple relief holes, can be utilized. Even the manual placement and manipulation of a custom tray may distort the tissues. This may violate the principles of mucostatic impression technique. Flabby ridges can be managed surgically by excision, ridge augmentation, injection of sclerosing solutions and also by implant retained prosthesis. Proper recording of these hypermobile tissues and stable occlusal contacts can help to manage flabby tissues to certain extent. This case report is about surgical and prosthodontic approach for management of a maxillary flabby edentulous ridge with the aid of a minimally displacive impression technique.