Miracle-dz/UniFAR-FTUs huggingface dataset:
Metamaterial-Core Probes for Nondestructive Eddy Current Testing

Eddy current testing (ECT) is one of the most important techniques in nondestructive evaluation. A higher probe sensitivity is always pursued in ECT. To improve the probe sensitivity, the near electrical resonance signal enhancement (NERSE) technique was recently proposed. In the NERSE technique, a coaxial cable connecting with the probe coil is introduced to provide a capacitance for the electrical resonance. However, the long coaxial cable is awkward and inconvenient in engineering applications, restraining the usability of such probes. Metamaterials (MTMs) are novel artificial electromagnetic media and have been proved to be effective in manipulating the impedance of a solenoid coil. In other words, in principle, MTMs can be used in the same way as that a coaxial cable in NERSE in ECT. Based on this argument, low-frequency magnetic MTMs are introduced as the probe cores to provide a new approach to achieve the electrical resonance for the NERSE technique. A promising feature of the proposed approach is that the detecting signals and sensitivity are significantly increased due to the extraordinary electromagnetic properties of the MTM. The most salient features of an MTM core over a ferrite core are: 1) effective permeability of the MTM core will vary sharply from a high positive to a high negative values when crossing the resonance frequency, resulting in not only a high magnetic flux density in the tested material but also an extremely large variation of the normalized impedance which is very essential in identifying a crack and 2) electromagnetic properties of an MTM will increase with the increase of frequency, whereas those of a ferrite material usually degrade sharply with the increase of frequency. To demonstrate the advantages of the proposed new probe, comprehensive numerical and experimental studies are conducted, and the results have shown the high performance of the proposed probe. In addition, the proposed MTM-core probe also exhibits a diverse versatility and convenience in engineering applications as compared with the existing NERSE technique.
A Comparative Study of Pretrained Language Models for Automated Essay Scoring with Adversarial Inputs

Automated Essay Scoring (AES) is a task that deals with grading written essays automatically without human intervention. This study compares the performance of three AES models which utilize different text embedding methods, namely Global Vectors for Word Representation (GloVe), Embeddings from Language Models (ELMo), and Bidirectional Encoder Representations from Transformers (BERT). We used two evaluation metrics: Quadratic Weighted Kappa (QWK) and a novel "robustness", which quantifies the models’ ability to detect adversarial essays created by modifying normal essays to cause them to be less coherent. We found that: (1) the BERT-based model achieved the greatest robustness, followed by the GloVe-based and ELMo-based models, respectively, and (2) fine-tuning the embeddings improves QWK but lowers robustness. These findings could be informative on how to choose, and whether to fine-tune, an appropriate model based on how much the AES program places emphasis on proper grading of adversarial essays.
Distribuição da água no solo para o dimensionamento da irrigação por gotejamento

The principal objective of a drip irrigation system design is to choose the appropriate layout and components to obtain adequate distribution of water (and fertilizer) throughout the field. Based on this the contributions which are capable of furmishing the basic elements for the design of drip irrigation were evaluated using the TDR probes. The experiment was divided into two parts. In the first part, the effect of successive irrigations on the wetted volume (horizontal and vertical dimensions) were analyzed under laboratory conditions; and in the second one, the water infiltration and distribution processes were evaluated with respect to formation of the wetted volume in the field. It was concluded that: initial soil water content, applied volume, discharge rate, saturated disk and hydraulic conductivity are important elements and these must be known for an appropriate irrigation design and management.
Neural Knapsack: A Neural Network Based Solver for the Knapsack Problem

This paper introduces a heuristic solver based on neural networks and deep learning for the knapsack problem. The solver is inspired by mechanisms and strategies used by both algorithmic solvers and humans. The neural model of the solver is based on introducing several biases in the architecture. We introduce a stored memory of vectors that holds up items representations and their relationship to the capacity of the knapsack and a module that allows the solver to access all the previous outputs it generated. The solver is trained and tested on synthetic datasets that represent a variety of instance types with different complexities. The solver neural model capabilities to generalize were tested on instances with up to 200 items, the model succeed to obtain near optimal solutions better than the greedy algorithm for instances in which there exists a correlation between items values and weights. The results also show that the capacity of the knapsack has a role in learning useful representations for each item in an instance and for the instance itself. Although the proposed solver may be not superior to other solvers, the results described here are insights for how the connection between combinatorial optimization, machine learning, and cognitive science could serve a great purpose in the operation research field. The goal of this work is not to design a state of the art solver, rather it full-fills some of the holes in the recent line of research that incorporates learning in combinatorial optimization problems.
An Integrated Theory for Chatbot Use in Air Travel: Questionnaire Development and Validation

Airline industry is a major global leader in aviation which has made the world an alluring smaller place with an enormous level of mobility and accessibility. It even provides service to almost every other sector, however, it does not receive significant attention, despite its importance. Moreover, its service quality is an aggregate of different interactions between the customers and airline companies. This drove them to implement new business model to conform to the new competitive atmosphere in the industry whose operation is taking place in a completely globalized environment. Thus, the use of chatbots is one of the avenues to meet this end. However, there is a dearth of standardized and validated instrument that best fit to evaluate the use of chatbots in the airline industry based on the combined set of constructs as identified in the conceptual framework. Thus, this study aims to develop and validate an instrument that will evaluate the adoption of chatbots in a service industry, like the airline industry, as well as its non-adoption. Based on the reliability and internal consistency evaluation, only one item was deleted (PIIT construct) since it has the lowest item-test correlation that caused the reliability coefficient to be less than the suggested value of 0.70. All statements in each of the constructs had positive signs, thus, were not reversely worded. Lastly, all the scale reliability coefficient or the overall alpha values are way higher than the suggested value, which means that the internal consistency is either acceptable or highly acceptable.
Temperature and Intensity Dependence of the Limiting Efficiency of Silicon Solar Cells

The temperature and intensity dependence of the limiting efficiencies of monofacial and bifacial silicon solar cells are calculated from the physical properties of silicon assuming light trapping by Lambertian scattering from rough surfaces. The maximum efficiency of a bifacial cell (28.92%) is lower than the efficiency of a monofacial cell (29.46%) at room temperature and Air Mass 1.5 Global illumination. The effects of electron–electron interactions on the band gap, radiative recombination rate, and optical absorption are included self-consistently. The temperature coefficient of the output power is −0.23%/°C for the optimum thickness monofacial cell at room temperature. The optimum thickness of silicon solar cells decreases strongly with temperature following a power law ${{\boldsymbol{T}}^{ - 7}}$ and thin cells have a lower temperature coefficient than thick cells. A surface recombination velocity of 1 cm/s is found to be a turning point below which surface recombination has a small effect on the efficiency.
Effect of Winding Configuration on Six-Phase Induction Machine Parameters and Performance

Six-phase induction machines have mostly shown promise in high-power electric drive applications as well as wind energy conversion systems. Different winding configurations for six-phase stators have been published, namely, dual three-phase (D3P), symmetrical six-phase (S6P), and asymmetrical six-phase (A6P) winding layouts. Although a body of research investigating six-phase machines and their control for different six-phase winding arrangements exists, a thorough comparative study between these different arrangements in terms of machine parameters and performance, has not been done so far. This paper employs a 12-phase stator with a configurable terminal box to compare different six-phase configurations by simply reconnecting the stator terminals of the twelve phases in different manners to obtain an equivalent six-terminal stator. This way, the same stator machine dimensions and copper volume will be assumed for all connections. The comparative study focuses on the effect of winding connection on machine parameters of the different subspaces, phase current quality and machine characteristic curves. Experimental validation has been carried out using a 1kW prototype system.
Synthesis and swelling characteristics of pH and thermoresponsive interpenetrating polymer network hydrogel composed of poly(vinyl alcohol) and poly(acrylic acid)

The swelling behavior of novel pH- and temperature-sensitive interpenetrating polymer networks (IPNs) composed of poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAAc) in water was investigated. The PVA/PAAc IPN hydrogels were synthesized by UV irradiation, followed by a repetitive freezing and thawing process by which PVA hydrogel networks were formed inside of cross-linked PAAc chains. The swelling behaviors of these IPNs were analyzed in buffer solution at various pH and temperature ranges. Swelling ratios of all IPNs were relatively high, and they showed reasonable sensitivity to both pH and temperature. Hydrogels showed both the positive and negative swelling behaviors depending on PAAc content. IPN46 showed the positive temperature-sensitive swelling behaviors and its stepwise changes in swelling ratio was about 1.8 and 2.0 obtained between 25 and 45°C at pH 7, and between pH 4 and 7 at 35°C, respectively. The positive temperature dependence is attributed to the formation and dissociation of hydrogen bonding complexes between PVA and PAAc. These IPNs are expected to show a pH- and temperature-sensitive drug release according to the stepwise behavior at this temperature region. © 1996 John Wiley & Sons, Inc.
LDPC Coded OFDM-IM Performance Evaluation Under Jamming Attack

Orthogonal frequency division multiplexing (OFDM) with index modulation (OFDM-IM) that carries part of the incoming bits by active subcarrier indices is a recently proposed multicarrier modulation technique. OFDM-IM is considered as a promising candidate for 5G and beyond, due to its superiority over OFDM. In this paper, we show that uncoded OFDM-IM can achieve better error performance than uncoded OFDM in the presence of barrage jamming (BJ). Low-density parity-check (LDPC) coding is used to further improve the robustness of OFDM-IM system against jamming attacks. We investigate the optimum log-likelihood ratio (LLR) values of index bits and modulation bits under a jamming attack. We also show the superior performance of coded OFDM-IM, when compared to classical OFDM, at a high code rate in the presence of BJ. We propose a new model for partial band jamming (PBJ) that can attack each subcarrier with different power by adjusting the jamming coefficients. Simulation results show that OFDM-IM is more robust against PBJ than BJ.
Reliable Reverse Engineering of Intel DRAM Addressing Using Performance Counters

The memory controller of a processor translates the physical memory address to hardware components such as memory channels, ranks, and banks. This DRAM address mapping is of interest to many researchers in the fields of IT security, hardware architecture, system software, and performance tuning. However, Intel processors are using a complex and undocumented DRAM addressing. The addressing can be different for every system because it depends on many aspects such as the processor model, DIMM population on the motherboard, and BIOS settings. Thus an analysis for every individual system is necessary. In this paper, we introduce an automatic and reliable method for reverse engineering the DRAM addressing of Intel server-class processors. In contrast to existing approaches, it is reliable, measurement errors are unlikely to occur, and can be detected if they occur. Our method mainly relies on CPU hardware performance counters to precisely locate the accessed DRAM component. It eliminates the problem of wrong attribution that is common in timing based approaches. We validated our method by reversing engineering the DRAM addressing of a diverse set of Intel processors. This set includes Broadwell, Haswell, and Skylake micro-architectures, with various core counts, DIMM arrangements, and BIOS settings. We show the correctness of the determined addressing functions using micro-benchmarks that access specific DRAM components.
Task Space Consensus of Heterogeneous Robots With Time-Delays and Without Velocity Measurements

This letter proposes a novel distributed control scheme for heterogeneous robot networks (kinematically and dynamically different), modeled as Euler-Lagrange systems, that solves the leaderless consensus problem in the Special Euclidean space of dimension three (SE(3)). The controller does not rely on velocity measurements and it is robust to variable time-delays in the communication channels. The solution employs a simple Proportional plus damping scheme that, since velocities are not available, injects damping through a dynamical controller. Using Barbalat’s Lemma, it is proved that velocities and pose (position and orientation) errors converge asymptotically to zero. A singularity-free representation, unit-quaternions, is used to describe the robots orientations and the network is modeled as an undirected and connected interconnection graph. Simulation results, with an heterogeneous robot network composed of five agents, are presented to illustrate the performance of the proposed control scheme.
Hand-in-Air (HiA) and Hand-on-Target (HoT) Style Gesture Cues for Mixed Reality Collaboration

In collaboration systems, collaborators often use hand gestures for showing information relating to a distant object. However, in viewer’s perspective, it is sometimes difficult to know where the conventional gesture cue (Hands-in-Air style: HiA) refers to because the conventional HiA gesture appears away from the distant object. In this paper, we investigate how two factors, distance to the object and view angle difference between collaborators, influence the understanding of HiA gesture by comparing the use of it at 25 positions with 5 distances and 5 view angles. In a user study, we found that the distance to the target object and view angle difference negatively influenced HiA gesture communication. The influence of the distance and view angle was more serious between smaller angles (0~30 degree) than larger angles (30~60 degree), and between shorter distances (1m $\sim 1.5\text{m}$ ) than between longer distance (1.5m $\sim 2\text{m}$ ). As a solution, we propose the Hands-on-Target (HoT) style which positions the hand gesture cue on the surface of the target object. The HoT style gesture cue dramatically reduces the negative effect of the distance and view angle difference. Participants completed the task 29.3 percent faster, selected the correct object 2.75 times more, and felt 63.1 percent less mental effort. For further investigation, we discuss on the extensibility of the HoT interface that it can be used not only for object selection but also for diverse type of gesture communication including gesture for object manipulation because the HoT interface can support all possible real world hand gestures.
Pockets in turbulent premixed flames

We address in this paper the problem of pocket formation in turbulent premixed flames. Pockets of unburnt gases inside the burnt gases, or of burnt gases inside unburnt gases have been observed in experiments, usually in tomographic cuts of a three-dimensional flame. We study here two effects (range of length scales and different time correlations) controlling the number and type of pockets created, on the basis of a two-dimensional numerical study of the thermal-diffusive model subjected to an external turbulent forcing (i.e. we neglect the retroaction of the flame on the flow field).
Rotation, tillage and seeder effects on winter wheat performance and soil moisture regime

The optimum management system for winter wheat (Triticum aestivum L.) production in southern Alberta has not been adequately defined. A 9-yr (1978–1986) study was conducted to determine the effects of three rotations (continuous winter wheat, winter wheat–fallow and winter wheat–barley (Hordeum vulgare L.)–fallow), two tillage systems (conventional tillage, zero tillage) and two seeder types (hoe-drill, disc drill) on winter wheat growth, yield and water use. Continuous cropping to winter wheat was terminated after 4 yr because of a heavy downy brome (Bromus tectorum L.) infestation. Soil moisture reserves to 1.5-m depth fell to only 61% of that under the wheat–fallow rotation. Wheat grown in the wheat–barley–fallow rotation yielded on average 4% higher than that in the wheat–fallow rotation. Yields under zero tillage were significantly higher in 3 of the 9 study years, and slightly higher in 5 yr, due to better soil moisture conservation once the zero-tillage treatment was established for 2 yr. Zero till.
Letter. Experimental study of radium partitioning between anorthite and melt at 1 atm

Abstract We present the first experimental radium mineral/melt partitioning data, specifically between anorthite and a CMAS melt at atmospheric pressure. 226Ra disequilibria are an important chronometer of recent magmatic activity. Ion microprobe measurement of coexisting anorthite and glass phases produces a molar DRa = 0.040 ± 0.006 and DRa/DBa = 0.24 ± 0.05 at 1400 °C. Our results indicate that lattice strain partitioning models fit the divalent (Ca, Sr, Ba, Ra) partition coefficient data of this study well, supporting previous work on crustal melting and magma chamber dynamics that has relied on such models to approximate radium partitioning behavior in the absence of experimentally determined values
More Space may be Cheaper: Multi-Dimensional Resource Allocation for NVM-based Cloud Cache

Cloud cache has been crucial to promoting the performance of I/O intensive applications. Due to the capacity and cost advantages over DRAM, NVM has been gradually utilized in cloud cache. However, NVM usually has limited write endurance, resulting in a frequent device replacement and a high cost. Cloud cache also needs to ensure Service-Level Agreement (SLA) such as an enough cache capacity, but there are few existing approaches that deal with the NVM writing problem without breaking SLA. Therefore, we propose a new SLA-aware cloud cache framework called MECC to extend the NVM lifetimes and thus reduce the total system cost with performance ensurance. Through dynamically allocating the two kinds of resources, i.e., NVM cache space and cache updating quota, to tenants according to their characteristics, MECC achieves the same performance for all tenants with a 56.3% cost reduction on average.
CORPORATE GOVERNANCE AND PERFORMANCE OF UNIVERSITIES IN KENYA

Although strategic management literature strongly acknowledge the existence of a relationship between corporate governance and the overall organizational performance, some studies have reported mixed results about the relationship between the variables. The inconsistency in findings point to the need for further investigations on the ongoing debate about this relationship. This study therefore sought to establish the effect of corporate governance on performance of universities in Kenya. We adopted an explanatory survey research design with 248 respondents formed of universities’ management board members and senior management academic staff (deans/directors/HoDs). Structured questionnaire was used to collect data analyzed using both descriptive and inferential statistics. Findings revealed that corporate governance significantly influences organizational performance at R= 0.213, F= 43.410, p-value<0.05. We, thus, concluded that putting in place an effective corporate governance framework enhances corporate performance. The results present important implications to managers of higher learning institutions, other corporate entities, policy makers, and stakeholders in the higher education sector in Kenya and beyond.
Accuracy Analysis of the Geometrical Approximation of MIMO Channels Using Ray-Tracing

Channel characterization is one of the most important steps in the design and performance evaluation of a communication system. With the adoption of larger antenna arrays (up to the hundreds, in massive MIMO systems) and millimeter waves, measurement campaigns require expensive equipment to be performed. An alternative approach is to use ray-tracing techniques to accurately obtain MIMO channel responses. For time-varying scenarios, the simulation can be very computationally expensive. An alternative method is to obtain SISO channel responses, and then use the geometric channel model to generate the full MIMO channel for uniform linear or planar antenna arrays. This works analyses the impact of this approximation in the estimated channel capacity and NMSE (normalized mean square error).
RED CLOVER SILAGE FOR MILK PRODUCTION

Nine wilted silages made from tetraploid red clover were fed in four winter-feeding experiments to 32 Ayrshire cows. The DM content of the silages averaged 23±5% (range 15±8–27±1) and contained an average of 19±6% crude protein, 14±2% digestible crude protein and 52±0% digestible organic matter. The pH values varied from 4±0–6±2, depending on the DM content and mechanical treatment of the crop, and the rate of application of formic add. The silages were fed ad lib.with supplementary concentrates and the average daily intakes of silage DM ranged from 16±0–24±0 Ib/cow (7±3–10±9 kg). The highest daily intakes were obtained with double-chopped silage containing 24–26% DM with a pH of 4±0. Although the red-clover silage had a high content of N and apparently provided a balanced ration with the addition of barley, yields of milk were increased significantly by substituting 1 Ib (0±4 kg) groundnut cake for 1 Ib barley in the daily ration of the cow. The silage contained oestrogenic compounds but the breeding pattern and fertility of the cows were not affected adversely. The tetraploid red clover produced approximately 9000 Ib DM/ac (10 100 kg/ha) in the 1st-harvest year and it is concluded that a safe and highly palatable silage with high intake characteristics can be made if the clover is wilted to about 24% DM, double chopped, and formic acid is applied at the rate of 0±5 gal/ton.