Miracle-dz/UniFAR-FTUs huggingface dataset:
Rendering of Arbitrary and Stable Stiffness Using a Series Elastic Actuator

Accurate and stable stiffness control is required for robots that need to interact safely with human or the environment. Accurate stiffness control can be achieved using a series elastic actuators (SEA). An SEA includes an elastic spring in series with an actuator to provide more accurate force control than conventional rigid actuators. Although impedance and admittance controllers have both been developed for series elastic actuators to render virtual stiffness, the stable virtual stiffness is still largely limited by the stiffness of the elastic spring in the SEA. Increasing the stiffness of the spring can allow a larger range of stable virtual stiffness. However, the accuracy of the stiffness control would be compromised. Adding a virtual damper can also improve the stability, but the stability range would highly depend on the environmental parameters. To overcome the limitations, this paper proposes a novel control strategy such that the stable range of the virtual stiffness does not depend on the spring stiffness and the environmental parameters. Both impedance and admittance controllers will be modified based on this new control strategy. The stability analysis of the modified controllers will show that the virtual stiffness can be arbitrarily selected and is unrelated to the spring stiffness and environmental parameters. It is expected that the new control strategy can be used for SEAs when wide-range and accurate virtual stiffness is required.
ON THEIR FIRST YEAR TEACHING

Kimberly Rogers, Advisor Mathematics teaching assistants (MTAs) play a critical role in the instruction of undergraduate mathematics students and may go on to become faculty members. Although the literature addressing teaching and learning of mathematics at the K-12 level is extensive, very little is known about MTAs’ teaching practices, beliefs, challenges, and understandings of mathematics and teaching. The two major goals of this study were to better understand how MTAs, who were in their first year teaching expressed mathematical knowledge for teaching (MKT) and pedagogical successes and shortcomings in reflecting on their teaching practices. We coded and analyzed the weekly reflections of 21 participants for five distinct MKT categories and twenty-three pedagogical themes across the reflections. This study presents an initial investigation of mathematical knowledge for teaching at the collegiate level, has professional development implications, and suggestions for future research into this topic.
SMART : Stock Market Analyst Rating Technique Using Naive Bayes Classifier

Currently there are a lot of analysts and experts who give out recommendations to laymen regarding the operations of the stock market and answering the when and where of investments in the stock market. The system developed aims to create an unbiased rating system that will analyze and quantify the performance of stock market analysts. Our system will keep these analysts’ reliability in check by analyzing their performance and providing a rating for each of these analysts on a 5 star rating system. The recommendations given by the analysts will be analyzed and factors relevant to the success/failure of the recommendation will be stored. The system will then use the Naive Bayes classifier to provide a rating on the factors thus extracted. The project will help curtail problems like incompetent analysts and simultaneously provide a system of reference to see how good an analyst is at his/her job.
How Much to Share in Resource Pooling

Resource pooling between two service providers, each having a fixed number of resources is considered. Each of the providers commit some of their resources to the common pool, and use the other providers’ resources (committed by it to the common pool) if available to service their clients if all of their own resources are completely occupied. Each such request requires a fixed payment to the other provider. The standard model of exponentially distributed occupancy time for each resource request is assumed. Assuming transferable utilities, Shapley value based inter-provider payoff keeps the coalition stable, and the problem is to find the optimal number of resources to commit to the common pool by each provider that maximizes the sum of the revenues of the two service providers. An exact solution is derived for the problem that depends on the prices charged by each provider to its clients. In case of equal prices, either full sharing or no sharing is shown to be optimal. Otherwise, the service provider with lower price commits all its resources, while the other provider commits resources depending on the solution of a recursive equation.
A Study of Gain Improvement of a Slot Antenna Using Curved Metallic Holes Structure

Nowadays, a microstrip slot antenna is widely used in the modern wireless communication systems because it has more advantages such as compact, easy fabrication, low cost, and wide bandwidth. However, it also has the drawback such low gain, because of its resonant nature of microstrip. Therefore, this paper presents a method to increase and improve the gain of slot antenna, a bandwidth of 1,800 MHz to 6,000 MHz, to apply for a modern wireless communication system. The new technique of metamaterial utilized for improving the gain of slot antenna is presented. From this study, the proper metamaterial, the curved metallic holes structure, is competent to improve the performance of slot antenna by increasing it directivity, gain, and radiation efficiency. Moreover, a behavior of gain characteristic, reflection coefficient (S11), and radiation pattern of slot antenna with and without a metallic holes structure are examined in this paper. From simulated results by simulation software, it noted that the gains of all the operating frequencies of a slot antenna with a metallic holes structure have been increased around 1.7 dB of all operating frequencies when compared to a slot antenna without a metallic holes structure.
Substrate Integrated Waveguide (SIW) Diplexer with Novel Input/Output Coupling and No Separate Junction

A microwave diplexer implemented by using the twenty-first century substrate integrated waveguide (SIW) transmission line technology is presented. No separate junction (be it resonant or nonresonant) was used in achieving the diplexer, as the use of an external junction for energy distribution in a diplexer normally increases design complexity and leads to a bulky device. The design also featured a novel input/output coupling technique at the transmit and receive sides of the diplexer. The proposed SIW diplexer has been simulated using the full-wave finite element method (FEM), Keysight electromagnetic professional (EMPro) 3D simulator. The design has also been validated experimentally and results presented. Simulated and measured results show good agreement. The measured minimum insertion losses achieved on transmit and receive channels of the diplexer are 2.86 dB and 2.91 dB, respectively. The measured band isolation between the two channels is better than 50 dB.
Mixing Efficiency Analysis on Droplet Formation Process in Microchannels by Numerical Methods

Liquid–liquid two-phase flow in microchannels has attracted much attention, due to the superiority of mass transfer enhancement. One of the biggest unresolved challenges is the low mixing efficiency at the microscale. Suitable mixing efficiency is important to promote the mass transfer of two-phase flow in microchannels. In this paper, the mixing efficiency in three junction configurations, including a cross-shaped junction, a cross-shaped T-junction, and a T-junction, is investigated by the volume of fluid (VOF) method coupled with user-defined scalar (UDS) model. All three junction configurations are designed with the same hydraulic diameter of 100 μm. Mixing components are distributed in the front and back parts of the droplet. The mixing efficiency in the droplet forming stage and the droplet moving stage are compared quantitatively. Results show that different junction configurations create very different mixing efficiencies, and the cross-shaped T-junction performs best, with relatively lower disperse phase fractions. However, with an increase of the disperse phase fraction, the cross-shaped junction is superior.
Asymptotic properties and approximation of Bayesian logspline density estimators for communication-free parallel computing methods

In this article we perform an asymptotic analysis of parallel Bayesian logspline density estimators. Such estimators are useful for the analysis of datasets that are partitioned into subsets and stored in separate databases without the capability of accessing the full dataset from a single computer. The parallel estimator we introduce is in the spirit of a kernel density estimator introduced in recent studies. We provide a numerical procedure that produces the normalized density estimator itself in place of the sampling algorithm. We then derive an error bound for the mean integrated squared error of the full dataset posterior estimator. The error bound depends upon the parameters that arise in logspline density estimation and the numerical approximation procedure. In our analysis, we identify the choices for the parameters that result in the error bound scaling optimally in relation to the number of samples. This provides our method with increased estimation accuracy, while also minimizing the computational cost.
GlaucoVIZ: Assisting System for Early Glaucoma Detection Using Mask R-CNN

Glaucoma is a chronic eye disease which is the second leading cause of blindness all over the world and a great number of people have been experiencing it. Glaucoma is a group of diseases that cause the damage to the optic nerves which leads to irreversible partial or full vision loss. Currently, its causes cannot be identified; hence, early detection of glaucoma is critical and highly beneficial in preventing further deterioration. One of the most valuable methods of structural diagnosis in the glaucoma screening is the measurement of the Cup-to-Disc Ratio (CDR). To segment optic cup and optic disc, and the determination of the CDR currently require specialists and this process is very time consuming. Therefore, automated screening solution will be very useful in this situation. Due to this, GlaucoVIZ is proposed as an automated system to assist in the preliminary glaucoma screening process to help general ophthalmologists by calculating the CDR with the use of the deep leaning technique, Mask Regional - Convolutional Neural Network (Mask R-CNN). With the use of four public datasets available, we conduct two experiments to understand the characteristics of the datasets and train our model to be more generalize by combining all public datasets together. With the use of the interpolated mean Average Precision (mAP) as our evaluation criteria, our model trained from the combined datasets can achieve mAP of 0.78 by using the original fundus images and the augmented images in the total of about 3,390 images.
How trade liberalization affected productivity in Morocco

The economic literature now accepts theoretical arguments that liberal, outward-oriented trade policy is better than restrictive, inward-oriented policies. Traditionally such arguments for the gains from trade have rested on the concept of allocative efficiency. But a new argument for liberal trade has emerged: increased technical efficiency or productivity. The best-known attempts to link trade policy and productivity are based on X-efficiency, economies of scale, capacity use, increased competition, and technological catch-up. The author estimates total factor productivity (TFP) at the firm level using panel data from the Moroccan industrial census in a production-funtion framework during Morocco's period of trade liberalization (1984-89). The author corrected for several problems that usually bias the estimate of productivity. The use of panel data allowed her to take into account the heterogeneity across firms. These firm-specific effects were tested for randomness. Differences between large firms and small firms were checked. She also corrected for errors in measuring capital stock, so common in data from developing countries, and for simultaneity bias because of the endogeneity of factor inputs or because managers have some knowledge about the noise in the production function. The author then estimated the effect of various trade and market-structure variables on the level of TFP, as well as on the deviation of firm TFP from the efficiency frontier. The results are not very sensitive to the different measures of TFP and show that trade openness has a significant positive effect on firm productivity through: outward orientation from export promotion; import liberalization; and more direct foreign investment. By splitting the sample into protected and unprotected sectors, the author showed lower productivity in protected sectors. The results are clear. Trade liberalization in Morocco improved productivity in manufacturing firms, so they could exploit their comparative advantage and compete better with foreign firms.
Acceptance Towards Digital Payments and Improvements in Cashless Payment Ecosystem

"Faceless, Paperless, Cashless". ‘Digital India’ is a flagship programme of the Government of India that envisions India as a digitally empowered knowledge economy. As India emerges a global competitor in innovative population-scale payment systems, various digital payment methods have been introduced nation-wide, including Micro ATMs, Banking Cards, Internet Banking, UPI (Unified Payment Interface), Mobile Banking, and Mobile Wallets. However, the Indian economy identifies an unapparent barrier between the growth of Digital India and complete acceptance towards Digital Payment System. India’s present usage of cash as a payment mode can be measured in the terms of India’s cash to GDP (Gross Domestic Product) ratio of 11.4 percent, as of 2019, which is considerably higher than several other developing and developed countries. This also includes costs of cash, such as costs of printing, maintaining cash supply to ATMs, incurred interest and costs due to counterfeit currency, which round up to 10 to 30 percent of India’s GDP. This research studies prior literature and consumer behaviour via ground-level surveys and interviews. We also analyse the cryptic challenges faced by users belonging to different age groups towards complete acceptance of digital payments and modes. For instance, a significant proportion of digital users are minors which spurs the need of shared wallets to allow governed transactions by dependent users. Also, symmetric inter-app transactions, intelligent resolution for effective redressal, credible incentivisation, short-term loans, etc. are proposed. As an outcome, a more reliable, secure, and contemporary working model for a Digital Payment Wallet service using Blockchain Technology has been developed.
Can We Distinguish Genuine Minutiae from Imposter Minutiae

we propose a novel method to differentiate genuine minutiae from impostor minutiae of an enhanced latent fingerprint. Because poor-quality latent fingerprints are deposited on uncontrolled backgrounds with noises, the imposter minutiae are incorrectly detected by a conventional fingerprint enhancement process. As a result, these imposter minutiae decrease identification performance. We introduce a histogram of the spectrum difference between the original latent fingerprint and its enhanced image. This new feature is suitable for distinguishing between genuineness and imposter. The minutiae set from the NIST SD27 latent fingerprint database is used as ground truth to evaluate the performance of the proposed method and the existing quality assessment methods. The experimental results show that the proposed method outperforms the current methods in terms of precision and F-measure.
Bipedal Walking Based on Improved Spring Loaded Inverted Pendulum Model with Swing Leg (SLIP-SL)

This paper proposes a new template model called Spring Loaded Inverted Pendulum with Swing Legs (SLIP-SL) which improves on the popular SLIP model by adding passive swing leg dynamics. It is shown that SLIP-SL can be used to realize cyclic walking on multi-body bipedal systems using the proposed controller. SLIP model has some excellent properties for realizing a natural locomotion but it doesn’t have swing leg dynamics. Thus, SLIP requires additional methods to find a swing foot trajectory. This might cause difficulties since adding this dynamics later on might prove difficult to synchronize with SLIP model and even be considered as disturbance. In this paper, we present the dynamics of the SLIP-SL model which is passive and actuated only by springs. We show how to find proper spring parameters using Direct Collocation methods, which is key for realizing cyclic gait with SLIP-SL. Then, a feedback linearization controller is described that can track the trajectories obtained from the template model. Finally, we present numerical simulation results that illustrate a 5 link fully actuated bipedal robot model’s gait based on the the proposed SLIP-SL model.
Decentralized AP selection using Multi-Armed Bandits: Opportunistic ε-Greedy with Stickiness

WiFi densification leads to the existence of multiple overlapping coverage areas, which allows user stations (STAs) to choose between different Access Points (APs). The standard WiFi association method makes the STAs select the AP with the strongest signal, which in many cases leads to underutilization of some APs while overcrowding others. To mitigate this situation, Reinforcement Learning techniques such as Multi-Armed Bandits can be used to dynamically learn the optimal mapping between APs and STAs, and so redistribute the STAs among the available APs accordingly. This is an especially challenging problem since the network response observed by a given STA depends on the behavior of the others, and so it is very difficult to predict without a global view of the network. In this paper, we focus on solving this problem in a decentralized way, where STAs independently explore the different APs inside their coverage range, and select the one that better satisfy its needs. To do it, we propose a novel approach called opportunistic $\varepsilon$-greedy with Stickiness that halts the exploration when a suitable AP is found, then, the STA remains associated to that same AP while it is satisfied, only resuming the exploration after several unsatisfactory association periods. With this approach, we reduce significantly the network response variability, improving the ability of the STAs to find a solution faster, as well as achieving a more efficient use of the network resources.
A Test Sensitization State Compaction Method on Controller Augmentation

One of the challenges on VLSI testing is to reduce the area overhead of design-for-testability and to maintain the high fault efficiency. To solve the challenge, a design-for-testability method using partial scan design and controller augmentation to execute the behaviors of easily testable functional time expansion models was proposed. In this method, when test operation control-status signal sequences (TCSSs) to execute the behaviors of easily testable functional time expansion models are given, the state transitions on invalid states in controllers are designed such that the sequences are supplied to control signals of data-paths. When the total sum of the lengths for TCSSs is large, it is required to increase the number of state registers in controllers to increase the number of invalid states. In this paper, we propose a compaction method of TCSSs to reduce the area overhead of controllers. Experimental results for high-level benchmark circuits show that our proposed method reduced the area overhead by 27 to 70% compared with that without the compaction of TCSSs.
Simulating Reliability of IoT Networks with RelIoT

The Internet of Things (IoT) networks are expected to operate reliably for many years while meeting the needs of a growing range of applications. However, a dependable operation may not always be maintained due to the reliability degradation of IoT devices. From low-power sensors to multi-core platforms, IoT devices age and degrade, leading to failures that necessitate maintenance. Reliability-aware design and management were shown to delay failures and improve the lifetime of individual devices. Even though the IoT networks can also radically benefit from this, the unavailability of network simulators that provide reliability modeling makes it impossible to assess reliability-aware strategies. To bridge this gap and enable reliability analysis at an early design phase, we introduce an integrated reliability framework called RelIoT for IoT networks, implemented in the ns-3 simulator. The framework also includes modeling of power, performance, and temperature, which are required to model reliability. We validate the simulations done using our framework and demonstrate that RelIoT accurately captures the power, temperature, and reliability dynamics of real networked IoT devices.
Comprehensive Optimization of the Unmanned Tilt-Wing Cargo Aircraft With Distributed Propulsors

The unmanned tilt-wing cargo aircraft using distributed propulsors is an emerging aircraft significantly different from traditional types. This paper proposes an aerodynamic, propulsion, noise, weight integrated optimization design method for this new aircraft. The method consists of several functional modules specially developed or adjusted targeting the aircraft’s characteristics, such as the boundary state analysis, propeller/rotor oblique inflow analysis, waked wing analysis, propeller/rotor noise evaluation, multi-state wing mass analysis, multi-objective genetic algorithm optimization. It comprehensively considers the impact of various complex factors on the optimization results, such as the impact of distributed propulsors on the wing aerodynamics, the effect of wingtip propellers on the induced drag reduction, the coupling between wing aerodynamics and structure, the propeller/rotor aerodynamics optimization, and noise control. With the proposed method, it is possible to directly translate the top-level design requirements into the design scheme with the optimal specific system performance (such as the lowest delivery cost and highest delivery efficiency) at the very initial aircraft design stage, thereby greatly shortening the development cycle. A case study was presented. The results show that the introduction of distributed propulsors can increase the delivery efficiency by 28.2% and reduce the delivery cost by 15%; suppressing the wingtip vortices using propellers can increase the wing lift-drag ratio by 5.43%-6.65%; the slipstream generation efficiency and thrust efficiency are significantly different between different distributed propulsor schemes. To maximize the overall efficiency, it is necessary to balance between the slipstream generation efficiency and the overall thrust efficiency when optimizing the tilt-wing cargo aircraft.