Miracle-dz/UniFAR-FTUs huggingface dataset:
Thermal Diffusivity by The Laser Flash Technique

Thermal diffusivity is an important material thermophysical property. The most widely used method for measuring thermal diffusivity is the laser flash technique. In this technique, a sample is placed within a controlled atmosphere furnace and subjected to a finite impulse of radiant energy on its front surface, through the use of a laser. The transport of heat through the sample, as a result of the laser impulse, causes a transient temperature rise on the rear surface of the specimen. This temperature rise is measured by an IR detector placed above the rear sample surface. The net result is a “thermogram” which is a plot of the rear-face temperature versus time. Assuming a proper set-up and careful experimentation, the transfer of heat under these conditions approximates one-dimensional heat flow. Comparing the experimental data with one-dimensional heat flow theoretical predictions, allows an estimation of thermal diffusivity. There are several methods available to determine thermal diffusivity based on experimental and theoretical comparisons. The simplest method is to determine the “half-rise time,” t0.5, which is the time at which the experimentally measured rear-face temperature reaches half of its maximum value. More accurate methods use sophisticated analysis algorithms to model and fit the entire experimental thermogram curve to an ideal theoretical curve by means of a nonlinear least-squares procedure. These approaches can include corrections that account for the fact that the experimental measurements only approximate one-dimensional heat flow conditions. Using the thermogram curve fitting techniques, the measurement of thermal diffusivity of a range of material types including solid thermal insulators and conductors is possible. It is also possible to measure the apparent diffusivity of inhomogeneous samples such as composites and porous materials. Using two- and three-layer analysis methods allows the measurement of thermal diffusivity of liquids. The layer methods can be extended to a determination of the thermal contact resistance of interfaces encountered in coated or bonded materials. Keywords: thermal diffusivity; thermal conductivity; laser flash apparatus; thermophysical properties
A compact 1.9–2.9 GHz tunable bandpass filter with wide stopband range

This paper presents a compact broadband tunable bandpass filter with wide stopband range. The combline topology is adopted, where the varactor-loaded stepped-impedance resonator is used for frequency tuning. A double-stub parallel-line transformer at input/output port is used for generating multiple transmission zeros and matching port and resonator impedances. The measured performances show that the tuning frequency range of 1.9 to 2.9 GHz (51% tuning range) is achieved. The insertion loss is between 2.9 dB and 1.5 dB and the return loss is better than 18.5 dB. The stopband suppression greater than 20 dB is obtained up to 10 GHz. The circuit design, EM simulation and experimental comparison are described.
Experimental Study on Time Series Characteristics of Rock Acoustic Emission in Complete Stress-Strain Process under Uniaxial Compression

Analysis of rock acoustic emission characteristics in complete stress-strain process under uniaxial compression shows that the evolution process of rock deformation and damage can be divided into five stages—compaction, linear elastic deformation, accelerate inelastic deformation, damage and development, plastic flow. Acoustic emission characteristics of rock can well reflect its compressive deformation and damage evolution process. Acoustic emission time series of typical plastic coal is comparatively dispersed and presents group shock type. The acoustic emission frequency events and their energy of coal are bigger around the damage point, but the maximum amplitude and the secondary maximum amplitude have not much difference. The acoustic emission events and their energy of very uniform and dense fragile limestone are mainly concentrated in a very short period of time before its damage and the acoustic emission time series manifests as isolated shock type. For sandstone whose homogeneous degree lies between typical plastic coal and very uniform and dense fragile limestone, its acoustic emission time series manifest as main shock type.
Quantitative Anatomical Evidence for a Dorsoventral and Rostrocaudal Segregation within the Nonhuman Primate Frontal Cortex

The intrinsic white matter connections of the frontal cortex are highly complex, and the organization of these connections is not fully understood. Quantitative graph-theoretical methods, which are not solely reliant on human observation and interpretation, can be powerful tools for describing the organizing network principles of frontal cortex. Here, we examined the network structure of frontal cortical subregions by applying graph-theoretical community detection analyses to a graph of frontal cortex compiled from over 400+ macaque white-matter tracing studies. We find evidence that the lateral frontal cortex can be partitioned into distinct modules roughly organized along the dorsoventral and rostrocaudal axis.
Experimental Comparison of Cluster Ensemble Methods

Cluster ensembles are deemed to be a robust and accurate alternative to single clustering runs. 24 methods for designing cluster ensembles are compared here using 24 data sets, both artificial and real. Adjusted rand index and classification accuracy are used as accuracy criteria with respect to a known partition assumed to be the "true" one. The data sets are randomly chosen to represent medium-size problems arising within a variety of biomedical domains. Ensemble size of 10 was considered. It was found that there is a significant difference among the compared methods (Friedman's two way ANOVA). The best ensembles were based on k-means individual clusterers. Consensus functions interpreting the consensus matrix of the ensemble as data, rather than similarity, were found to be significantly better than the traditional alternatives, including CSPA and HGPA
Hybrid Riemann Solvers for Large Systems of Conservation Laws

In this paper we present a new family of approximate Riemann solvers for the numerical approximation of solutions of hyperbolic conservation laws. They are approximate, also referred to as incomplete, in the sense that the solvers avoid computing the characteristic decomposition of the flux Jacobian. Instead, they require only an estimate of the globally fastest wave speeds in both directions. Thus, this family of solvers is particularly efficient for large systems of conservation laws, i.e. with many different propagation speeds, and when no explicit expression for the eigensystem is available. Even though only fastest wave speeds are needed as input values, the new family of Riemann solvers reproduces all waves with less dissipation than HLL, which has the same prerequisites, requiring only one additional flux evaluation.
HEAT TRANSFER ENHANCEMENT IN A PARABOLIC TROUGH RECEIVER USING WALL DETACHED TWISTED TAPE INSERTS

In this paper, heat transfer and fluid friction performance of a parabolic trough receiver with twisted tape inserts detached from the absorber tube’s wall is numerically studied. The numerical investigations were conducted for twist ratios in the range 0.30 ≤ y ≤ 2.40, width ratios in the range 0.53 ≤ w ≤ 0.91 and Reynolds numbers in the range 10,260 ≤ Re ≤ 320,000. The numerical simulations were performed using a finite volume method with the realisable k-e turbulence model and Syltherm 800 as the heat transfer fluid. The use of twisted tape inserts shows a significant increase in the heat transfer and fluid friction performance of the receiver. The study also reveals significant reduction in absorber tube’s circumferential temperature difference due to the improved heat transfer performance. For the range of parameters considered, the Nusselt number, fluid friction and thermal enhancement factor are 1.01–3.36, 1.32–21.8, and 0.74–1.25 times those in a receiver with a plain absorber tube respectively. The absorber tube’s circumferential temperature difference reduces between 4–76% compared with a plain absorber tube. Correlations for Nusselt number and fluid friction are also reported for the range of parameters considered.Copyright © 2013 by ASME
Distributed spatial division multiple access technique for spectrum sharing systems

Fourth generation (4G) systems will support co-deployment with other wireless networks based on different radio access technologies (RAT). To enable this coexistence and improve spectrum utilization efficiency, many mechanisms will be proposed. In this paper, we propose a distributed spatial division multiple access (SDMA) technique to prevent mutual interference among coexisting peer systems in areas of overlap. The SDMA technique is performed distributively after securing the cooperation of the coexisting base stations. With the implementation of the proposed distributed SDMA technique, the coexisting systems can use the same time-frequency resources to provide wireless services without generating harmful mutual interference. From the simulation results, we demonstrate that the proposed distributed SDMA improves bandwidth efficiency up to three times over the existing method.
Modeling and analyzing power management policies in server farms using Stochastic Petri Nets

Server farms are playing an important role in the Internet infrastructure today. However, the increasing power consumption of server farms makes them expensive to operate. Thus, how to reduce the power consumed by server farms has become a important research topic. Power can be thought as a resource of system, just like traditional resources, and we can manage power via improved resource management strategies. In recent studies on power management, the system is attached with multiple states of different power consumption, and by switching among these states, power consumption can be made proportional to the work load. As different job scheduling policies will result in different performance and power consumption, an optimized policy with power as a factor can achieve a better tradeoff between performance and power consumption. In this paper, we summarize some familiar power management policies and propose a novel model using Stochastic Reward Nets(SRN). Based on this model, we analyze the performance and power consumption of different power management policies, and propose a novel cost-aware job scheduling algorithm.
Feature Selection for Genomic and Proteomic Data Mining

The extreme dimensionality (also known as the curse of dimensionality) in genomic data has been traditionally a serious concern inmany applications. This hasmotivated a lot of research in feature representation and selection, both aiming at reducing dimensionality of features to facilitate training and prediction of genomic data. In this chapter,N denotes the number of training data samples,M the original feature dimension, and the full feature is expressed as an M-dimensional vector process
Mechanical properties of silicone composites reinforced with micron- and nano-sized magnetic particles

Silicone composites filled with different-sized nickel particles were prepared. By applying a permanent magnet, both the micron- and nano-sized particles were found to distribute along the magnetic field direction, resulting in chain-like microstructures, which improved the key mechanical properties of the resultant samples effectively, compared to the sam- ples with randomly-distributed particles. The composites were also tested under various magnetic field strengths. The sam- ples with aligned particles showed larger improvements in shear storage modulus than those with random particles.
Fabrication of the nanoimprint template with periodic structures

The holographic lithography - ion beam etching is adopted to fabricate the nanoimprint template with periodic structures. The accurate control of the high aspect ratio of the profile is achieved by the optimization of the holographic lithography and the choice of the appropriate parameters of ion beam etching. There are two major challenging steps of this method: 1) the holographic exposure and development in the fabrication of the photoresist mask and 2) the ion beam etching to transfer the photoresist mask to the fused silica. The experiment indicates that titled rotation of the ion beam etching combined with reactive ion beam etching can achieve the accurate control of the high aspect ratio structure. Two types of nanoimprint template have been fabricated: the period of 250nm and the groove depth of 380nm; the period of 600nm and groove depth of 1400nm, respectively.
Lexical attraction for text compression

[Summary form only given]. The best methods of text compression work by conditioning each symbol's probability on its predecessors. Prior symbols establish a context that governs the probability distribution for the next one, and the actual. The next symbol is encoded with respect to this distribution. However, the best predictors for words in natural language are not necessarily their immediate predecessors. Verbs may depend on nouns, pronouns on names, closing brackets on opening ones, question marks on "wh"-words. To establish a more appropriate dependency structure, the lexical attraction of a pair of words is defined as the likelihood that they will appear (in that order) within a sentence, regardless of how far apart they are. This is estimated by counting the co-occurrences of words in the sentences of a large corpus. Then, for each sentence, an undirected (planar, acydic) graph is found that maximizes the lexical attraction between linked items, effectively reorganizing the text in the form of a low-entropy model. We encode a series of linked sentences and transmit them in the same manner as order-1 word-level PPM. To prime the lexical attraction linker, the whole document is processed to acquire the co-occurrence counts, and again to re-link the sentences. Pairs that occur twice or less are excluded from the statistics, which significantly reduces the size of the model. The encoding stage utilizes an adaptive PPM-style method. Encouraging results have been obtained using this method.
A Pruned Problem Transformation Method for Multi-label Classification

classification has gained significant interest in re- cent years, paralleled by the increasing use of manual multi- labelling, often known as applying"tags"to documents. Well known examples include Flickr 1 , YouTube 2 , CiteULike 3 and Google Bookmarks 4 . This paper focuses on Problem Trans- formation (PT) as an approach to multi-label classification and details these methods as well as their respective advan- tages and disadvantages. A Pruned Problem Transforma- tion method (PPT) is presented, along with several exten- sions, designed to overcome such disadvantages. This new method is empirically compared with existing methods, both in terms of accuracy and training time, and the results are encouraging.
Exponential convergence rate (the spectral convergence) of the fast Padé transform for exact quantification in magnetic resonance spectroscopy

This study deals with the most challenging numerical aspect for solving the quantification problem in magnetic resonance spectroscopy (MRS). The primary goal is to investigate whether it could be feasible to carry out a rigorous computation within finite arithmetics to reconstruct exactly all the machine accurate input spectral parameters of every resonance from a synthesized noiseless time signal. We also consider simulated time signals embedded in random Gaussian distributed noise of the level comparable to the weakest resonances in the corresponding spectrum. The present choice for this high-resolution task in MRS is the fast Padé transform (FPT). All the sought spectral parameters (complex frequencies and amplitudes) can unequivocally be reconstructed from a given input time signal by using the FPT. Moreover, the present computations demonstrate that the FPT can achieve the spectral convergence, which represents the exponential convergence rate as a function of the signal length for a fixed bandwidth. Such an extraordinary feature equips the FPT with the exemplary high-resolution capabilities that are, in fact, theoretically unlimited. This is illustrated in the present study by the exact reconstruction (within machine accuracy) of all the spectral parameters from an input time signal comprised of 25 harmonics, i.e. complex damped exponentials, including those for tightly overlapped and nearly degenerate resonances whose chemical shifts differ by an exceedingly small fraction of only 10−11 ppm. Moreover, without exhausting even a quarter of the full signal length, the FPT is shown to retrieve exactly all the input spectral parameters defined with 12 digits of accuracy. Specifically, we demonstrate that when the FPT is close to the convergence region, an unprecedented phase transition occurs, since literally a few additional signal points are sufficient to reach the full 12 digit accuracy with the exponentially fast rate of convergence. This is the critical proof-of-principle for the high-resolution power of the FPT for machine accurate input data. Furthermore, it is proven that the FPT is also a highly reliable method for quantifying noise-corrupted time signals reminiscent of those encoded via MRS in clinical neuro-diagnostics.
Antigen-specific, I-A-restricted suppressor hybridomas with spontaneous cytolytic activity. Functional properties and lack of rearrangement of the T cell receptor beta chain genes

T suppressor (Ts) hybridomas were produced by fusion of the III/4 T cell hybridoma with splenic T cells from CBA mice tolerized with subimmunogenic doses of bovine serum albumin (BSA). Both the Ts hybridoma cells and a suppressor factor (TsF) inhibited in an antigen- specific and I-Ak-restricted fashion the in vitro proliferative response of BSA-immunized lymph node cells. In addition to the suppressive activity, the hybridoma lines displayed spontaneous cytotoxicity against various tumor targets. The isolation of Ts subclones that are suppressive but not cytolytic, as well as the existence of the noncytolytic TsF, indicates that suppression of antigen-specific T cell proliferation is not dependent on cytolytic activity. The Ts hybridomas were I-A restricted, as are many T helper cells. Therefore, a potential similarity with respect to antigen receptor genes was expected. Southern blot analysis with a probe specific for genes encoding the beta chain of the T cell receptor on T helper and T killer cells revealed no rearrangement of the beta genes in the Ts cells. The data imply that neither the antigen receptor on the I-A-restricted Ts cells nor the receptor involved in the cytolytic interaction with tumor targets use the same beta chain constant region as T helper and T killer cells.
QR Cache: Connecting mLearning Practice with Theory

Qatar presents a unique opportunity to explore potential mLearning applications in a theoretical context. The geographically small country in the Arabian Gulf has nearly ubiquitous mobile and wireless network coverage. The penetration of devices such as smartphones is also incredibly high, including amongst students. And those students have expressed an overwhelming desire to integrate their mobile devices into their learning. With its virtual absence of infrastructural barriers, Qatar offers the potential to focus research on how mobile technologies can fulfill the promise of increasing student engagement by creating novel situated learning experiences. QR Cache was developed to provide an exemplar of mobile reusable learning objects (RLOs). In the pilot phase, RLOs accessed by scanning Quick Response (QR) codes were developed to teach English computer terminology. Feedback was solicited from participating students and instructors to demonstrate the desirability of using such RLOs in combination with learners’ own mobile devices. The study also draws upon Transactional Distance Theory (TDT) (Moore, 1989, 1991) and Koole’s (2009) FRAME model to provide theoretical grounding for both RLO and instructional design decisions. Early results show increased engagement, and reduced transactional distance. They also indicate that the RLOs show a strong convergence of the activity types delineated by the FRAME model. Author
Combinators for impure yet hygienic code generation

Code generation is the leading approach to making high-performance software reusable. Effects are indispensable in code generators, whether to report failures or to insert let-statements and if-guards. Extensive painful experience shows that unrestricted effects interact with generated binders in undesirable ways to produce unexpectedly unbound variables, or worse, unexpectedly bound ones. These subtleties hinder domain experts in using and extending the generator. A pressing problem is thus to express the desired effects while regulating them so that the generated code is correct, or at least correctly scoped, by construction. We present a code-combinator framework that lets us express arbitrary monadic effects, including mutable references and delimited control, that move open code across generated binders. The static types of our generator expressions not only ensure that a well-typed generator produces well-typed and well-scoped code. They also express the lexical scopes of generated binders and prevent mixing up variables with different scopes. For the first time ever we demonstrate statically safe and well-scoped loop exchange and constant factoring from arbitrarily nested loops. Our framework is implemented as a Haskell library that embeds an extensible typed higher-order domain-specific language. It may be regarded as `staged Haskell. ' To become practical, the library relies on higher-order abstract syntax and polymorphism over generated type environments, and is written in the mature language.
Approximating the Number of Network Motifs

Abstract The World Wide Web, the Internet, coupled biological and chemical systems, neural networks, and social interacting species are only a few examples of systems comprising a large number of highly interconnected dynamical units. These networks contain characteristic patterns, network motifs, that occur far more often than in randomized networks with the same degree sequence. Several algorithms have been suggested for counting or detecting the number of occurrences of network motifs as trees and bounded treewidth subgraphs of size O(log n), at most 7 for some motifs. In addition, local motif counting, counting the number of motifs in which a node participates, was recently suggested as a method of classifying nodes in the network. The premise is that the distribution of motifs in which a node participates is an indication of its function in the network. Therefore, local counting of network motifs provides a major challenge. However, no such practical algorithm exists other than local counting of triangles. We present several algorithms with time complexity O(((3e) k · n · |E| · log )/∊2) that approximate for every vertex the number of occurrences of the motif in which the vertex participates, for k-length cycles and k-length cycles with a chord, where k = O(log n), and algorithms with time complexity O((n · |E| · log )/∊2 + |E|2 · log n + |E| · n log n) that approximate for every vertex the number of noninduced occurrences of the motif in which the vertex participates for all motifs of size four. In addition, we show algorithms that approximate the total number of occurrences of these network motifs when no efficient algorithm exists. Some of our algorithms use the “color-coding” technique.
Novel photonically-controlled reflectarray antenna

A novel method for generating a reconfigurable reflectarray based on the creation of photoinduced plasma inside the semiconductor substrate of a reflectarray is presented in this paper. A reflectarray antenna prototype is fabricated and measured to demonstrate the validity of the design methodology. Measurements were carried out to characterize the bandwidth and the gain of the antenna in both the OFF and ON states of an optical flash lamp that was used to induce photoconductivity inside the silicon substrate.