Miracle-dz/UniFAR-FTUs huggingface dataset:
Assessment of Composite Delamination Self-Healing Via Micro-Encapsulation

Composite skin/stringer flange debond specimens manufactured from composite prepreg containing interleaf layers with a polymer based healing agent encapsulated in thin walled spheres were tested. As a crack develops and grows in the base polymer, the spheres fracture releasing the healing agent. The agent reacts with catalyst and polymerizes healing the crack. In addition, through-thickness reinforcement, in the form of pultruded carbon z-pins were included near the flange tips to improve the resistance to debonding. Specimens were manufactured with 14 plies in the skin and 10 plies in the stiffener flange. Three-point bend tests were performed to measure the skin/stiffener debonding strength and the recovered strength after healing. The first three tests performed indicated no healing following unloading and reloading. Micrographs showed that delaminations could migrate to the top of the interleaf layer due to the asymmetric loading, and hence, bypass most of the embedded capsules. For two subsequent tests, specimens were clamped in reverse bending before reloading. In one case, healing was observed as evidenced by healing agent that leaked to the specimen edge forming a visible "scar". The residual strength measured upon reloading was 96% of the original strength indicating healing had occurred. Hence, self-healing is possible in fiber reinforced composite material under controlled conditions, i.e., given enough time and contact with pressure on the crack surfaces. The micro-encapsulation technique may prove more robust when capsule sizes can be produced that are small enough to be embedded in the matrix resin without the need for using an interleaf layer. However, in either configuration, the amount of healing that can occur may be limited to the volume of healing agent available relative to the crack volume that must be filled.
Hierarchies in Dictionary Definition Space

A dictionary defines words in terms of other words. Definitions can tell you the meanings of words you don't know, but only if you know the meanings of the defining words. How many words do you need to know (and which ones) in order to be able to learn all the rest from definitions? We reduced dictionaries to their "grounding kernels" (GKs), about 10% of the dictionary, from which all the other words could be defined. The GK words turned out to have psycholinguistic correlates: they were learned at an earlier age and more concrete than the rest of the dictionary. But one can compress still more: the GK turns out to have internal structure, with a strongly connected "kernel core" (KC) and a surrounding layer, from which a hierarchy of definitional distances can be derived, all the way out to the periphery of the full dictionary. These definitional distances, too, are correlated with psycholinguistic variables (age of acquisition, concreteness, imageability, oral and written frequency) and hence perhaps with the ``mental lexicon" in each of our heads.
Scheduling to minimize average completion time: off-line and on-line algorithms

Time-indexed linear programming formulations have recently received a great deal of attention for their practical effectiveness in solving a number of single-machine scheduling problems. We show that these formulations are also an important tool in the design of approximation algorithms with good worst-case performance guarantees. We give simple new rounding techniques to convert an optimal fractional solution into a feasible schedule for which we can prove a constant-factor performance guarantee, thereby giving the first theoretical evidence of the strength of these relaxations. Specifically, we consider the problem of minimizing the total weighted job completion time on a single machine subject to precedence constraints, and give a polynomial-time (4 + {epsilon})-approximation algorithm, for any {epsilon} > 0; the best previously known guarantee for this problem was superlogarithmic. With somewhat larger constants, we also show how to extend this result to the case with release date constraints, and still more generally, to the case with m identical parallel machines. We give two other techniques for problems in which there are release dates, but no precedence constraints: the first is based on other new LP rounding algorithms, whereas the second is a general framework for designing on-line algorithms to minimize the total weightedmore » completion time. « less
Mechanical Properties of Icosahedral Viral Shells. A Molecular Dynamics Study

The mechanical properties of viral shells are crucial for viral assembly and infection. To study their distribution and heterogeneity on the viral surface, we have carried out atomistic force-probe molecular dynamics simulations of the complete icosahedral shells of Southern Bean Mosaic Virus, a prototypical T=3 virus and Human Rhinovirus 16, in explicit solvent. The simulation systems comprised over 4,500,000 atoms. To facilitate direct comparison with atomic force microscopy measurements, a Lennard-Jones sphere was used as a model of the AFM tip and pushed with different velocities towards the capsid proteins at 19 different positions on the viral surfaces. A detailed picture of the spatial distribution of elastic constants and yielding forces was obtained which can explain corresponding heterogeneities observed in previous AFM experiments. Our simulations reveal three different deformation regimes, a pre-linear regime of outer surface atoms rearrangements, a linear regime of elastic capsid deformation, and a rearrangement regime which describes irreversible structural changes and the transition from elastic to plastic deformation. For both, yielding forces and elastic constants, a logarithmic velocity-dependence was seen over nearly two decades, the explanation of which requires including non-equilibrium effects within the established theory of enforced barrier crossing.
A neural architecture to address Reinforcement Learning problems

In this paper, the Reinforcement Learning problem is formulated equivalently to a Markov Decision Process. We address the solution of such problem using a novel Adaptive Dynamic Programming algorithm which is based on a Multilayer Perceptron Neural Network composed of a parameterized function approximator called Wire-Fitting. Extending such established model, this work makes use of concepts of eligibility to conceive faster learning algorithms. The advantage of the proposed approach is founded on the capability to handle continuous environments and to learn a better policy while following another. Simulation results involving the automatic control of an inverted pendulum are presented to indicate the effectiveness of the proposed algorithm.
Effects of Electromagnetic Stimulation on Gene Expression of Mesenchymal Stem Cells and Repair of Bone Lesions

Objective Most people experience bone damage and bone disorders during their lifetimes. The use of autografts is a suitable way for injury recovery and healing. Mesenchymal stem cells (MSCs) are key players in tissue engineering and regenerative medicine. Their proliferation potential and multipotent differentiation ability enable MSCs to be considered as appropriate cells for therapy and clinical applications. Differentiation of stem cells depends on their microenvironment and biophysical stimulations. The aim of this study is to analyze the effects of an electromagnetic field on osteogenic differentiation of stem cells. Materials and Methods In this experimental animal study, we assessed the effects of the essential parameters of a pulsatile electromagnetic field on osteogenic differentiation. The main purpose was to identify an optimum electromagnetic field for osteogenesis induction. After isolating MSCs from male Wistar rats, passage-3 (P3) cells were exposed to an electromagnetic field that had an intensity of 0.2 millitesla (mT) and frequency of 15 Hz for 10 days. Flow cytometry analysis confirmed the mesenchymal identity of the isolated cells. Pulsatile electromagnetic field-stimulated cells were examined by immunocytochemistry and real-time polymerase chain reaction (PCR). Results Electromagnetic field stimulation alone motivated the expression of osteogenic genes. This stimulation was more effective when combined with osteogenic differentiation medium 6 hours per day for 10 days. For the in vivo study, an incision was made in the cranium of each animal, after which we implanted a collagen scaffold seeded with stimulated cells into the animals. Histological analysis revealed bone formation after 10 weeks of implantation. Conclusion We have shown that the combined use of chemical factors and an electromagnetic field was more effective for inducing osteogenesis. These elements have synergistic effects and are beneficial for bone tissue engineering applications.
Rheological properties of sodium alginate and xanthan pastes on cotton with reactive dye in screen printing

In this study, sodium alginate (SA) and xanthan (XG), selected as two typical pastes, were intensively investigated by steady, transient, and dynamic rheological methods. Compared with SA, in the steady-shear tests it was found that XG showed a prominent shear-thinning feature at low shear rates and low concentrations. In addition, the transient tests suggested that XG had more remarkable hysteresis thixotropy and that the structural viscosity needed more time to return to its original level after shears. What is more, two pastes in the same concentration performed totally different viscoelastic behaviors from the dynamic tests. SA exhibited more viscous behavior and XG more elastic behavior. Furthermore, experimental data have been correlated with different models: flow curves with the Cross and power-law model, mechanical spectra with the Friedrich–Braun model and Generalized Maxwell model. The relationship between dynamic and steady-shear properties (Cox–Merz rule) was satisfactory for SA while undesirable for XG. Through the rheological properties, it may be inferred that those who show weaker elasticity, stronger viscosity, relatively steady viscoelasticity, and the structural viscosity liable to restore the original level after shears may be more appropriate as the pastes to achieve better printing qualities on cotton printing with reactive dye.
Extraction of comparative opinionate sentences from product online reviews

Big volume of product online reviews are generated from time to time, which contain rich information regarding customer requirements. These reviews help designers to make exhaustive analyses of competitors, which is one indispensable step in market-driven product design. How to extract critical opinionate sentences associated with some specific features from product online reviews has been investigated by some researchers. However, few of them examined how to select a small number of representative yet comparative sentences for competitor analysis. In this research, a framework is illustrated to select pairs of opinionate sentences referring to a specific feature from reviews of competitive products. With the help of the techniques on sentiment analysis, opinionate sentences referring to a specific feature are first identified from product online reviews. Then, for the selection of a small number of representative yet comparative opinionate sentences, information representativeness, information comparativeness and information diversity are investigated. Accordingly, an optimization problem is formulated, and three greedy algorithms are proposed to analyze this problem for suboptimal solutions. Finally, with a large amount of real data from Amazon.com, categories of extensive experiments are conducted and the final encouraging results are realized, which prove the effectiveness of the proposed approach.
Virtual 3D camera composition from frame constraints

We have designed a graphical interface that enables 3D visual artists or developers of interactive 3D virtual environments to efficiently define sophisticated camera compositions by creating storyboard frames, indicating how a desired shot should appear. These storyboard frames are then automatically encoded into an extensive set of virtual camera constraints that capture the key visual composition elements of the storyboard frame. Visual composition elements include the size and position of a subject in a camera shot. A recursive heuristic constraint solver then searches the space of a given 3D virtual environment to determine camera parameter values which produce a shot closely matching the one in the given storyboard frame. The search method uses given ranges of allowable parameter values expressed by each constraint to reduce the size of the 7 Degree of Freedom search space of possible camera positions, aim direction vectors, and field of view angles. In contrast, some existing methods of automatically positioning cameras in 3D virtual environments rely on pre-defined camera placements that cannot account for unanticipated configurations and movement of objects or use program-like scripts to define constraint-based camera shots. For example, it is more intuitive to directly manipulate an object's size in the frame rather than editing a constraint script to specify that the object should cover 10% of the frame's area.
Imaging Time After Gd-DTPA Injection Is Critical in Using Delayed Enhancement to Determine Infarct Size Accurately With Magnetic Resonance Imaging

Background—In patients with acute myocardial infarction (MI), delayed enhancement is seen in MRI 5 to 7 minutes after gadolinium–diethylenetriamine pentaacetic acid (Gd-DTPA) injection, and the enhancement occurs in regions that later show recovery of function. However, in a canine model of acute MI, delayed enhancement 20 to 30 minutes after injection only occurs in necrotic regions and not in surrounding, reversibly injured myocardium. The objective of the present study was to determine (1) if the size of the enhanced region varies with time after Gd-DTPA injection and (2) if and when the size of the enhanced region corresponds to the true infarct size. Methods and Results—The left coronary artery was occluded in 15 Lewis rats for 30 minutes (n=9) or 2 hours (n=6); this was followed by reperfusion. MRI scans were performed 48±2 hours after-MI. Midventricular short-axis images were obtained continuously for 40 minutes after Gd-DTPA injection (0.3 mmol/kg). The sizes of enhanced regions at each time were determined by threshold analysis and compared with triphenyltetrazolium chloride–stained sections of the excised rat heart. In all animals, the enhanced region overestimated infarct size (28±5%) immediately after the injection of Gd-DTPA, although it then gradually receded to match the size of the infarct. The time required for enhancement to accurately determine infarct size was significantly different between 2-hour infarcts (16±2 minutes) and 30-minute (26±4 minutes) infarcts (P <0.05). Conclusions—In reperfused acute MI, accurate determination of infarct size by delayed enhancement MRI requires imaging at specific times after Gd-DTPA injection, and this time varies with the duration of occlusion.
Stalking online: on user privacy in social networks

With the extreme popularity of Web and online social networks, a large amount of personal information has been made available over the Internet. On the other hand, advances in information retrieval, data mining and knowledge discovery technologies have enabled users to efficiently satisfy their information needs over the Internet or from large-scale data sets. However, such technologies also help the adversaries such as web stalkers to discover private information about their victims from mass data. In this paper, we study privacy-sensitive information that are accessible from the Web, and how these information could be utilized to discover personal identities. In the proposed scenario, an adversary is assumed to possess a small piece of "seed" information about a targeted user, and conduct extensive and intelligent search to identify the target over both the Web and an information repository collected from the Web. In particular, two types of attackers are modeled, namely tireless attackers and resourceful attackers. We then analyze detailed attacking mechanisms that could be performed by these attackers, and quantify the threats of both types of attacks to general Web users. With extensive experiments and sophisticated analysis, we show that a large portion of users with online presence are highly identifiable, even when only a small piece of (possibly inaccurate) seed information is known to the attackers.
Floating AC-DEP (dielectrophoretic) manipulations of fluorescent nanoparticle at metal nanostructure for plasmonic applications

We propose the fluorescent nanoparticle manipulations at nano-metal structures with floating AC-DEP force for plasmonic applications. The electrode gap was optimized to induce enough DEP force around the nano-structure for manipulation of the nanoparticles. 10um wide gap of electrode was acquired to apply the floating AC-DEP force at various designed metal nano-structure such as nanowire, y-branch and vortex. The all shape of nano-metal structures are formed at the gap of microelectrode and not connected with microelectrode. The gold nano-structures in the gap of microelectrode were fabricated with e-beam lithography and lift-off process. Before the formation of metal nanostructure, micro electrodes for applying the electric field around the metal nano-structures were fabricated with photolithography and lift-off process. Cadmium selenide (CdSe/ZnS) QDs (0.8 nM, emission wavelength of 605 nm) with a 25 nm zinc sulfide capping layer and 100nm polystyrene nano bead (1 nM, emission wavelength of 610nm) were used as fluorescent nanoparticles. We applied the 8 Vpp, 3 MHz sine wave for the positive DEP force, and it resulted in 108 V/m electric field and 1011 V/m electric field gradient around gold nanowire with floating AC. The fluorescent nanoparticle’s attachment at the nanowire is confirmed by the fluorescent optical analysis. The fluorescent nanoparticles are located successfully at designed metal nano-structures for plasmonic applications.
Swelling-activated chloride channels in multidrug-sensitive and - resistant cells

Resistance to chemotherapeutic agents in neoplastic cells is often mediated by expression of P-glycoprotein, which functions as a drug- efflux pump for a broad range of substrates. We have used a combination of patch clamp and video-imaging techniques to examine the expression and drug-efflux function of P-glycoprotein and to determine the possible correlation with swelling-activated chloride channels in drug- sensitive and -resistant cell lines. Two pairs of cell lines were used in these experiments: (a) control NIH-3T3 cells and a corresponding MDR1-transfectant; and (b) control 8226 myeloma cells and a derivative cell line selected for resistance to chemotherapeutic agents. Control cells lacked detectable P-glycoprotein expression based on Western blotting, immunofluorescence staining with a specific monoclonal antibody, and a functional assay of rhodamine-123 (R123) efflux. Resistant cells expressed P-glycoprotein at high levels and rapidly exported R123. During whole-cell recording using either hyperosmotic pipette solution or hypoosmotic Ringer solution, cell swelling was accompanied by Cl- channel opening in all four cell lines. The rates of induction, biophysical properties and magnitudes of Cl conductance (gCl) were indistinguishable between control and corresponding multidrug-resistant cells: gCl reached 0.96 +/- 0.31 (n = 14) and 0.83 +/- 0.31 nS/pF (mean +/- SD; n = 31) in NIH-3T3 and NIH-3T3/MDR cells, respectively; and 0.31 +/- 0.20 (n = 9) and 0.37 +/- 0.22 nS/pF (n = 7) in 8226 and 8226/Dox40 cells, respectively. gCl exhibited moderate outward rectification in symmetrical Cl- solutions, with a rectification ratio of 1.4 at +/- 50 mV. Cl- channels slowly closed during strong depolarization beyond +60 mV. Using video-imaging techniques with SPQ as a fluorescent probe, we monitored Cl(-)-channel opening in intact drug-sensitive and -resistant cells. gCl, measured either with whole-cell recording or SPQ imaging, was blocked by DIDS (voltage-dependent Kd < 50 microM at +40 mV), NPPB (Kd approximately 30 microM), and tamoxifen (complete and irreversible block approximately 10 microM). None of these blockers inhibited R123 efflux. NPPB accelerated R123 efflux, an effect that was mimicked by CCP, a mitochondrial uncoupler. In contrast, verapamil selectively blocked R123 efflux (Kd = 0.3 to 0.5 microM); 10 microM left gCl unaltered. Induction of gCl was not affected by vincristine or doxorubicin in the pipette solution. Moreover, the rate of R123 efflux did not change during cell swelling. We conclude that P-glycoprotein and swelling- activated chloride channels function independently and are separable by expression and by pharmacological sensitivities.
Evaluation Strategies for Bitmap Indi es with Binning ?

Abstra t. Bitmapindi es are eÆ ient data stru tures for querying read-only data with low attribute ardinalities. To improve the eÆ ien y of the bitmap indi es on attributes with high ardinalities, we present a new strategy to evaluate queries using bitmap indi es. This work is motivated by a number of s ienti(cid:12) data analysis appli ations where most attributes have ardinalities in the millions. On these attributes, binning is a ommon strategy to redu e the size of the bitmap index. In this arti le we analyze how binning a(cid:11)e ts the number of pages a essed during query pro essing, and propose an optimal way of using the bitmap indi es to redu e the number of pages a essed. Compared with two ba-si strategies the new algorithm redu es the query response time by up to a fa tor of two. On a set of (cid:12)ve dimensional queries on real appli a-tion data, the bitmap indi es are on average 10 times faster than the proje tion index.
Combining Learning , Training and Research in Laboratory Course for Design and Test

A conception is described how to combine learning, training and research phases in a laboratory course for educating today’s VLSI and system designers. A method is explained how to use in the introductory teaching and learning phase interactive internet based modules “living pictures”. Further on, the hands-on training phase follows where commercial design tools and low-cost in-labmade test oriented tools are used for solving real engineering tasks with close relationship to not yet solved research problems.
Small Punch Test of Advanced In Situ Synthesized Ti Metal Matrix Composites

Particulate reinforced 10 vol.% (TiB+TiC)/Ti-6Al-4V metal matrix composites (MMCs) were produced by in-situ synthesis using vacuum arc re-melting process, and the mechanical properties of the metal matrix composites were assessed by the small punch testing (SPT). Mechanical properties of the in-situ synthesized Ti MMCs were studied and compared with the Ti base alloy. From the test data, the fracture properties and equivalent fracture strain of the test materials were characterised. The fracture mechanism of the test samples was examined using scanning electron microscopy.