Miracle-dz/UniFAR-FTUs huggingface dataset:
Raising teachers’ awareness of technology-enhanced language instruction through teacher education: Insights from Scaffolded dialogues

Abstract Inspired from sociocultural theory, the present research is an interpretive and qualitative study of teachers’ beliefs development through participation in scaffolded dialogues in order to raise their awareness of technology-enhanced language instruction longitudinally. In doing so, 20 teachers, whose informed consent was obtained, were invited to take part in interview sessions three times and join in the sessions of scaffolded dialogues for six months. Classroom observations were also randomly done in order to investigate the relationship between teachers’ theoretical knowledge of technology with their practical understanding of using mobile apps and computer software in the classroom. In addition, the participant teachers’ classroom transcripts were subjected to qualitative investigation through conversation analysis to confirm the findings gathered from observations. Results revealed teachers’ gradual development of their beliefs regarding their “little-to-no awareness of technology” to “relative awareness of technology” and finally toward “raised awareness of technology”. Data gathered from classroom observations highlighted the strong alignment between teachers’ beliefs and actions in using technological devices to create more interaction resulting in the students’ increased self-confidence to take part in doing online tasks. Conversation analysis of teacher-learner interactions verified the findings of classroom observations by concluding that, to a very large extent, teachers’ raised awareness of technology-enhanced instruction was evidenced in the participant teachers’ practice teaching in which they could successfully and consciously apply technological devices in the classroom. As to the implication side, the present study calls for teacher education to familiarize teachers with the most recent theoretical and practical aspects of technology-enhanced instruction by encouraging them to benefit from scaffolded dialogues and share their practice teaching experience for the purpose of quality teaching and learning through technology-mediated classroom.
Revisiting the Privacy Needs of Real-World Applicable Company Benchmarking

Benchmarking the performance of companies is essential to identify improvement potentials in various industries. Due to a competitive environment, this process imposes strong privacy needs, as leaked business secrets can have devastating effects on participating companies. Consequently, related work proposes to protect sensitive input data of companies using secure multi-party computation or homomorphic encryption. However, related work so far does not consider that also the benchmarking algorithm, used in today’s applied real-world scenarios to compute all relevant statistics, itself contains significant intellectual property, and thus needs to be protected. Addressing this issue, we present PCB — a practical design for Privacy-preserving Company Benchmarking that utilizes homomorphic encryption and a privacy proxy — which is specifically tailored for realistic real-world applications in which we protect companies’ sensitive input data and the valuable algorithms used to compute underlying key performance indicators. We evaluate PCB’s performance using synthetic measurements and showcase its applicability alongside an actual company benchmarking performed in the domain of injection molding, covering 48 distinct key performance indicators calculated out of hundreds of different input values. By protecting the privacy of all participants, we enable them to fully profit from the benefits of company benchmarking.
Nonintrusive and Adaptive Monitoring for Locating Voltage Attacks in Virtualized FPGAs

In this work, we present an automated approach for locating power-wasting attackers in shared FPGAs. In this approach, the FPGA shell is responsible for, first, placing the user designs and, second, inserting voltage sensors in a nonintrusive and adaptive manner. We derive a metric for comparing transient voltage fluctuations recorded at different sensor locations and use it to locate the source of the highest disturbance. We implement and test our approach on a Xilinx Virtex-7 FPGA. In all our experiments, we successfully locate the attacker.
Improved privacy-preserving training using fixed-Hessian minimisation

The fixed-Hessian minimisation method can be used to implement privacy-preserving machine learning training from homomorphic encryption. This is a relatively under-explored part of the literature, with the main prior work being that of Bonte and Vercauteren (BMC Medical Genomics, 2018), who proposed a simplified Hessian method for logistic regression training over the BFV homomorphic encryption scheme. Our main contribution is to revisit the fixed-Hessian approach for logistic regression training over the CKKS homomorphic encryption scheme. We improve on the prior work in several aspects, most notably showing how the native encoding in CKKS can be used to take advantage of SIMD operations. We implement our new fixed-Hessian approach in SEAL and compare it to more commonly-used minimisation methods, based on Gradient Descent and Nesterov’s Accelerated Gradient Descent. We find that the fixed-Hessian approach exhibits fast run time and comparable accuracy to these alternative approaches. Moreover, it can be argued to be more practical in the privacy-preserving training context, as no step size parameter needs to be chosen. As an additional contribution, we describe and implement three distinct training algorithms, based on Gradient Descent, Nesterov’s Accelerated Gradient Descent, and a fixed-Hessian method respectively, to achieve privacy-preserving ridge regression training from homomorphic encryption. To the best of our knowledge, this is the first time homomorphic encryption has been used to implement ridge regression training on encrypted data.
Solving Slitherlink with FPGA and SMT Solver

: “Slitherlink” is one of popular pencil puzzles. The purpose of the puzzle is to make a link according to the digits written in cells. While determining the existence of a solution to a given puzzle is proved to be an NP-complete class of problems, which means it is di ﬃ cult to ﬁnd an e ﬀ ective algorithm to solve the puzzle, solving the puzzle has been studied and there are several previous researches for the puzzle. In this paper, we show two new methods to solve the puzzle. One is with hardware acceleration on an FPGA and the other is based on an SMT solver. We focus on determining inside or outside for each cell instead of making a link and propose a new formulation. With hardware acceleration, it takes 0.1578 seconds on average for solving 10 × 10 puzzles, and with an SMT solver, our solution is faster than previous researches in most cases.
How to Make Private Distributed Cardinality Estimation Practical, and Get Differential Privacy for Free

Secure computation is a promising privacy enhancing technology, but it is often not scalable enough for data intensive applications. On the other hand, the use of sketches has gained popularity in data mining, because sketches often give rise to highly efﬁcient and scalable sub-linear algorithms. It is nat-ural to ask: what if we put secure computation and sketches together? We investigated the question and the ﬁndings are interesting: we can get security, we can get scalability, and somewhat unexpectedly, we can also get differential privacy – for free. Our study started from building a secure computation protocol based on the Flajolet-Martin (FM) sketches, for solving the Private Distributed Cardinality Estimation (PDCE) problem, which is a fundamental problem with applications ranging from crowd tracking to network monitoring. The state of art protocol for PDCE (Fenske et al. CCS’17) is computationally expensive and not scalable enough to cope with big data applications, which prompted us to design a better protocol. Our further analysis revealed that if the cardinality to be estimated is large enough, our protocol can achieve ( ε , δ ) -differential privacy automatically, without requiring any additional manipulation of the output. The result signiﬁes a new approach for achieving differential privacy that departs from the mainstream approach (i.e. adding
Efficient Quantum Public-Key Encryption From Learning With Errors

Our main result is a quantum public-key encryption scheme based on the Extrapolated Dihedral Coset problem (EDCP) which is equivalent, under quantum polynomial-time reductions, to the Learning With Errors (LWE) problem. For limited number of public keys (roughly linear in the security parameter), the proposed scheme is information-theoretically secure. For polynomial number of public keys, breaking the scheme is as hard as solving the LWE problem. The public keys in our scheme are quantum states of size $\tilde{O}(n)$ qubits. The key generation and decryption algorithms require $\tilde{O}(n)$ qubit operations while the encryption algorithm takes $O(1)$ qubit operations.
Light scattering spectra of polarization fluctuations and models of the phase transition in KDP type ferroelectrics

Abstract Recent light scattering studies in KH2PO4 type hydrogen-bonded crystals are reviewed. Dynamical properties of these crystals have been discussed in terms of the coupled tunneling proton-optical phonon model up to date. Light scattering spectra in several GHz and cm−1 regions with various scattering geometries observed in KH2PO4, KD2PO4 and their mixed crystals, however, revealed that all these spectra are well analysed in terms of a coupled polarization relaxation mode-acoustic phonon system. Since most of the spontaneous polarization is due to shifts of K, P and O ions, relaxation motions of H2PO4 dipoles arc concluded to be the origin of these low-frequency spectra. Models of the phase transition mechanism are discussed on the basis of these results and other recent experimental studies including the explanation of large isotope effects in these crystals.
Surface Functionality and Carbon Structures in Lignocellulosic-Derived Biochars Produced by Fast Pyrolysis

Switchgrass- and pine wood-derived biochars produced by fast pyrolysis were characterized to estimate the degree of thermochemical transformation and to assess their potential use as a soil amendment and to sequester carbon. The feedstocks were pyrolyzed to biochars in an auger reactor at 450, 600, and 800 °C with a residence time of 30 s. Ash contents of switchgrass and pine wood biochars varied from 13 to 22% and from 1.3 to 5.2%, respectively. Nutrients, such as N, P, K, S, Mg, and Ca, in switchgrass biochars ranged from 0.16 to 1.77%. Under combustion conditions, switchgrass chars were decomposed at lower temperatures than pine wood biochars because of the structural differences between the two feedstocks. Principal component analysis of the Fourier transform infrared (FTIR) spectra allowed for the discrimination of all biochars by significant contributions of cellulose-derived functionality at low pyrolysis temperatures, while the same analysis of the Raman spectra presented apparent separation of al.
Chlorophyll a fluorescence as indicator of atmospheric pollutant effects

Chlorophyll a fluorescence is a measurement of the changes in photosystem II (PSII) activity. Damage to PSII will often be the first manifestation of atmospheric pollutant stress in a plant. When atmospheric pollutants are absorbed by a leaf, the induction curve of chlorophyll a fluorescence and its measured parameters show alterations that can be used to determine the PSII damage. Generally, under atmospheric pollutant stress, maximal PSII photochemical efficiency, the PSII-mediated electron flow and the capacity to reduce the quinone pool are decreased. The non-photochemical quenching (NPQ) constitutes an important protective response which could dissipate excitation energy in light-harvesting antenna systems. At the beginning of stress, increase in NPQ correlated with decrease in photosynthetic quantum conversion may be associated with several mechanisms in photoprotective process. On long-time pollutant exposure, the capacity to NPQ formation can be reduced because the protective mechanisms are exhausted. The changes in chlorophyll a fluorescence can be observed in the absence of visual injuries and constitute an important technique for evaluation and diagnosis of negative effects on photosynthesis.
Evolution of N defect states and optical transitions in ordered and disordered GaP1−xNx alloys

We show using an sp3s* tight-binding model that the band anti-crossing (BAC) model describes well the evolution of the lowest N-related conduction states in ordered GaP1−xNx alloys, including the evolution of the Γ character with increasing x. We obtain a good description of the lowest conduction states in disordered GaPN structures by explicitly treating the interaction between the GaP host Γ conduction band minimum and defect states associated with a random distribution of N atoms. We find a very similar value for the total Γ character mixed into the N levels in the ordered and disordered cases, but a wider distribution of states with Γ character in the disordered case. We show that the band gap reduction with increasing composition is dominated by the increasing formation of N cluster states. Overall key features of the band structure can be well described using a modified BAC model which explicitly includes the broad distribution of N levels in disordered GaPN alloys.
Structure, microstructure and physical properties of ZnO based materials in various forms: bulk, thin film and nano

ZnO is a unique material that offers about a dozen different application possibilities. In spite of the fact that the ZnO lattice is amenable to metal ion doping (3d and 4f), the physics of doping in ZnO is not completely understood. This paper presents a review of previous research works on ZnO and also highlights results of our research activities on ZnO. The review pertains to the work on Al and Mg doping for conductivity and band gap tuning in ZnO followed by a report on transition metal (TM) ion doped ZnO. This review also highlights the work on the transport and optical studies of TM ion doped ZnO, nanostructured growth (ZnO polycrystalline and thin films) by different methods and the formation of unique nano- and microstructures obtained by pulsed laser deposition and chemical methods. This is followed by results on ZnO encapsulated Fe3O4 nanoparticles that show promising trends suitable for various applications. We have also reviewed the non-linear characteristic studies of ZnO based heterostructures followed by an analysis on the work carried out on ZnO based phosphors, which include mainly the nanocrystalline ZnO encapsulated SiO2, a new class of phosphor that is suitable for white light emission.
Efficiency-Limiting Processes in Low-Bandgap Polymer:Perylene Diimide Photovoltaic Blends

The charge generation and recombination processes following photoexcitation of a low-bandgap polymer:perylene diimide photovoltaic blend are investigated by transient absorption pump–probe spectroscopy covering a dynamic range from femto- to microseconds to get insight into the efficiency-limiting photophysical processes. The photoinduced electron transfer from the polymer to the perylene acceptor takes up to several tens of picoseconds, and its efficiency is only half of that in a polymer:fullerene blend. This reduces the short-circuit current. Time-delayed collection field experiments reveal that the subsequent charge separation is strongly field-dependent, limiting the fill factor and lowering the short-circuit current in polymer:PDI devices. Upon excitation of the acceptor in the low-bandgap polymer blend, the PDI exciton undergoes charge transfer on a time scale of several tens of picoseconds. However, a significant fraction of the charges generated at the interface are quickly lost because of fast g.
Effects of the Flipped Classroom Model on Student Performance for Advanced Placement High School Chemistry Students

This mixed-methods study investigated the effects of the flipped classroom on academic performance of high school advanced placement chemistry students. Student perceptions about the approach were also studied. The control group consisted of students from the 2011–2012 academic year, in which traditional teaching methods were used. The treatment group consisted of students from the 2012–2013 academic year, in which the flipped classroom approach was used. Identical assessments were administered and analyzed through both descriptive statistics and independent t tests. A statistically significant difference was found on all assessments with the flipped class students performing higher on average. In addition, most students had a favorable perception about the flipped classroom noting the ability to pause, rewind, and review lectures, as well as increased individualized learning and increased teacher availability. This contribution is part of a special issue on teaching introductory chemistry in the context .
Experimental determination of the dielectric virial coefficients of atomic gases as a function of temperature

The second dielectric virial coefficient of atomic gases has been measured precisely as a function of temperature in the range 77 to 407 K. The experimental values are compared with the ab initio calculations and the collision‐induced polarized scattered spectra (CIS). Except for helium, the Be values derived from ab initio calculations and CIS parameters do not agree with the experimental values.
Structure of a grafted polymer brush: a molecular dynamics simulation

Etude d'un polymere constitue de 10 a 150 monomeres dont une extremite est statistiquement attachee a une surface repulsive, le systeme etant dans les conditions d'un bon solvant et en utilisant 3 valeurs de couverture de la surface. Comparaison avec les calculs a champ autocoherent de Milner
Protein Recovery from Sweet Potato Starch Wastewater by Foam Separation

In this study, an inclined foam separation column was designed to effectively recover protein from sweet potato starch wastewater. The effects of the influent protein concentration, pH, air flow rate, influent volume, foaming time, and inclined column angle on foam separation performance were assessed. The optimum foam separation conditions consisted of influent protein concentration 4.51 mg/mL, pH 4, air flow rate 0.15 mL/min, influent volume 500 mL, foaming time 100 min, and inclined column angle 30°. In these conditions, protein recovery percentage and enrichment ratios were 84.1% and 1.3, respectively. The biochemical oxygen demand (BOD5) and chemical oxygen demand (CODCr) of the residual solution (620 and 950 mg/mL, respectively) were lower than those of the original (influent) solution.
Diffuse Scattering of X-rays by Ice

The diffuse scattering of X-rays by single crystals of ice has been found to be of thermal origin. The existing theory is inadequate to explain the observations, and needs extending to include the effects of vibrations of shorter wave-lengths. The main features of the representation in reciprocal space of the diffuse scattering are as follows: (1) There is a strong concentration of scattering power immediately round the reciprocal-lattice points, corresponding to rounded isodiffusion contours. (2) Beyond these regions are weaker bridges, which connect reciprocal-lattice points; they are narrow, quite clearly defined, and their strength varies little along their length; they join together to form plane sheets of scattering power, which are parallel to the c* and to one of the a* axes, and intersect along lines joining rows of reciprocal-lattice points parallel to the c* axis. (3) There is no sheet of scattering power lying along any a* axis, or passing through the origin of the reciprocal lattice, though there are a few bridges, which make only a small angle with the a* axes, which do not fall into this general scheme. (4) The sheets pass through many `forbidden' points, but at some other `real' reciprocal-lattice points they show sharp discontinuities; they are not always centrosymmetrical about the reciprocal-lattice points. (5) The diffuse pattern does not become broader or less clearly defined with increasing angle of reflexion.The amplitudes of vibration of the molecules are of the order of 0.4 A. at −5° C. The strong local disturbances which cause the diffuse streaks could include movements of the hydrogen atoms between neighbouring oxygen atoms.
The determination of the crystal structure of anhydrous theophylline by X-ray powder diffraction with a systematic search algorithm, lattice energy calculations, and C-13 and N-15 solid-state NMR: A question of polymorphism in a given unit cell

When determining crystal structures of organic molecular materials from high-resolution powder diffraction data, the key step is the generation of reliable trial structures fur final refinement. The subject of the study reported here is the pharmaceutical material anhydrous theophylline (3,7-dihydro-1,3-dimethyl- 1H-purine-2,6-dione), which contains both oxygen and nitrogen as possible hydrogen bond acceptor atoms. A systematic search of direct space was employed to assess every possible packing arrangement of the asymmetric unit within the experimentally determined unit cell. Trial structures were ranked in terms of calculated lattice energy and weighted residuals from a comparison of calculated and experimental X-ray diffraction profiles. The systematic search found two packing arrangements with different intermolecular hydrogen-bonding motifs within the same unit cell. In one, denoted NH. N, the amino hydrogen is hydrogen bonded to the aldimine nitrogen, and in the other, denoted (NHO)-O-. , to the carbonyl oxygen neighboring the imidazole ring. These trial structures were "virtually indistinguishable" in terms of calculated lattice energy or X-ray profile fit. Solid-state NMR spectra of a commercial sample not only confirmed immediately that there was only one molecule in the crystallographic asymmetric unit but also produced distinctive C-13 and N-15 chemical shifts. The experimentally determined N-15 chemical shifts showed considerably better agreement with values from ab initio calculations for the trial crystal structure with N--H N hydrogen bonding. In these calculations, representative chains of three hydrogen-bonded molecules were employed as models for the (NHN)-N-. and (NHO)-O-. trial crystal structures. In addition, a more sophisticated analysis of the lattice energy hypersurfaccs. using a distributed multipole based intermolecular potential, indicated that the N-(HN)-N-. trial structure is the more stable. It was noted that the NH N packing motif identified by our studies is observed in a single-crystal determination for theophylline reported independently while our investigations were ongoing. Our study shows how the potential for polymorphism in a "given unit cell'' may be assessed successfully by combining several complementary experimental and theoretical approaches.
Kinetic Model for Moderate Hydrocracking of Heavy Oils

In this work, a kinetic model for hydrocracking of heavy oils is proposed. The model includes five lumps: unconverted resid (538 °C+), vacuum gas oil (VGO; 343−538 °C), distillates (204−343 °C), naphtha (IBP-204 °C), and gases. Kinetic parameters were estimated from the experimental results obtained in a fixed-bed downflow reactor. The proposed lump kinetic model fitted the data for hydrocracking of Maya heavy crude with a Ni/Mo catalyst at 380−420 °C reaction temperature, 0.33−1.5 h-1 liquid hourly space velocity, 5000 scf/bbl, and 70 kg/cm2. Only resid cracked to naphtha at 380 °C, but all heavier fractions produced some naphtha at higher temperature. The predicted product composition is in good agreement with experimental values with an average absolute error of less than 5%.