Miracle-dz/UniFAR-FTUs huggingface dataset:
What Retention Rate Is Expected For Your Institution?

Although a high retention ratio is desirable for institutions, not all colleges achieve that. Retention rate depends on many factors, and improving these factors may not always be possible. If the management knows that the institution’s retention can be improved significantly, it may be a good idea to allocate some resources for the improvement. If the institution’s retention ratio is already at the expected level, it might be better to facilitate resources for other obstacles the institution is facing. In this research, we tried to identify the most significant features that impact student retention in U.S. colleges using statistical methods, including random forest and linear regression. With these features, U.S. colleges’ retention rates can be estimated, so that management can compare their retention rate with the expected rate and develop a better action plan.
3D Ultrasound Parametric Modeling Imaging for Spine Deformity – A Preliminary Study

Ultrasound (US) imaging has been applied to the assessment of scoliosis. However, current ultrasound techniques cannot provide a good 3D visualization of spine structure, and the output images are difficult to interpret and measure for clinicians without ultrasound practice. The objectives of this study are to construct the 3D spine model image for scoliotic subject and to implement the model image for the proxy Cobb angle measurement. US measurement parameters including lamina indicator (LAI) and axial vertebral rotation (AVR) are used to generate the model. Coronal projection of the model are used as proxy radiograph to measure the scoliotic curvature. The result model visually shows the 3D deformity of spine and improves the spine curvature measurement result.
Single-Phase PFC Boost Converter Operating in CCM with Active Input Filter Using Linear Regulator Assistance

Hard switching (PWM) converters with input or output smoothing inductors provide small current ripple at CCM. PFC stages need additionally a passive input filter usually formed by LC-Filter. This passive filter was replaced by an active filter, formed by a linear regulator, that compensates the input current ripple by draining the inductor current ripple to ground potential [1]. A 150 Watts PFC boost converter for line voltage input of 230 V was designed and built using CCM operation mode to minimize the current ripple. The remaining peak inductor current ripple of about 77.4 mA was reduced by linear regulator compensation to 12.0 mA peak input current ripple, what means 84.5 % ripple reduction, while input filter inductors and input filter capacitors were avoided. The power factor was 0.991 and the efficiency of the boost converter with the presented linear regulator assistance was 91.1%.
Active-Damping for Digital Controlled LC-Type Voltage Source Inverter with Positive Proportional Feedback of Filter Capacitor Voltage

For the LC-type voltage source inverter (VSI), the negative derivative feedback of the filter capacitor voltage is often lieu of the negative proportional feedback of the filter capacitor current for damping the inherent resonance between the filter inductor and the filter capacitor without using additional current sensors. The doing so, however, weakens the noise immunity because of the derivative feedback. By taking advantage of the digital control delay, this paper proposes the positive proportional feedback of the filter capacitor voltage for implementing the digital active-damping. Compared to the one realized by the negative derivative feedback of the filter capacitor voltage, the proposed solution not only enhances the noise immunity performance but also extends the boundary frequency of the positive resistance region formed by the digital active-damping from 1/6 to 1/3 of the sampling frequency. The stability criterion has been derived. Also, the feasibility of the proposed work has been verified on a 3-kVA single-phase LC-type VSI.
A 120nW, 121 kHz, -20~100°C CMOS Relaxation Oscillator with Digital Current Comparator and On-Chip Voltage and Current Reference

A relaxation oscillator(RO) composed of a voltage and current reference (VCR) and a digital current comparator is presented in this paper. By using two different types of resistors with opposite temperature coefficient (TC) in the VCR, this design successfully stabilizes the operation frequency from -20 to 100° C with a very simple structure. Designed in a standard 180nm CMOS process, the proposed RO consumes 120nW under a 0.8V supply and operates at 121kHz, with a TC as low as 36.2 ppm/°C.
Bidirectional WDM Multi-Nodes Analog Radio-Over-Fiber Mobile Fronthaul Link Enhanced by Photonic Integrated Devices

A bidirectional wavelength division multiplexing (WDM) analog radio-over-fiber (A-RoF) mobile fronthaul (MFH) link is enhanced using photonic integrated devices. Two key photonic integrated devices are combined in the A-RoF link: an 8-channel InP directly modulated laser (DML) transmitter and a 32×100-GHz silicon array waveguide grating (AWG). The DML transmitter has 8 parallel monolithically integrated distributed feedback lasers, enabling cooperative and reconfigurable downlink analog transmission. Moreover, the 32×100-GHz AWG is featured by low insertion loss (<4.5-dB) and low crosstalk (<−20.4-dB), to achieve a high-density WDM system. In the distributed field experiments, we have successfully demonstrated a bidirectional A-RoF MFH over 10-km standard single mode fiber, providing an 8×5-Gbit/s 4-quadrature amplitude modulation (QAM) orthogonal frequency division modulation (OFDM) downlink transmission and a 3×12-Gbit/s 16-QAM uplink transmission.
Maximizing Information Usefulness in Vehicular CP Networks Using Actor-Critic Reinforcement Learning

Cooperative Perception (CP) allows Connected and Autonomous Vehicles (CAVs) to enhance their Environmental Awareness (EA) by sharing locally perceived objects through CP messages (CPMs). European Telecommunications Standards Institute (ETSI) has recently defined a set of CPM generation rules to achieve a trade-off between EA and Channel Busy Ratio (CBR) despite massive perception data. Nonetheless, these rules still lack the consideration of information usefulness, resulting in a considerable volume of useless information transmitted in the CP network. This limitation could increase CBR and thus decrease EA due to the loss of CPMs in the network. This paper introduces CloudAC-IU, a cloud-based deep reinforcement learning approach to lean CAVs to maximize perception information usefulness in the network. Simulation results highlight that the CloudAC-IU enhances EA by decreasing CBR and increasing CPM reception for CAVs compared to state-of-the-art works.
Vibration energy extraction method of power transformer based on PMN-PT piezoelectric ceramics with series and parallel configuration

In order to realize the passive vibration monitoring of power transformer, a vibration energy extraction method of power transformer based on PMN-PT piezoelectric ceramic series and parallel structure, is proposed in this paper. The piezoelectric chip collects the vibration energy of the power transformer and converts it into electrical energy to supply power to the low-power vibration sensor. At the same time, the vibration sensor collects the surface vibration signal and uses the vibration analysis method to judge the operation status of the iron core and winding. The experimental and simulation results showed that the center frequency of the vibration signal of the power transformer was concentrated at 200 Hz, and the vibration amplitude of the lower part of the transformer was the largest; The actual output power of the piezoelectric energy collection device was greater than 500 µW. The energy recovery control circuit could greatly improve the energy recovery power, and the maximum output power was independent of the load. It could stably provide 3.6 V voltage for the back end, which was enough to meet the power supply demand of the vibration sensor.
Research on Hybrid Modulation Strategy of Bidirectional LLC Resonant Converter in Distributed Energy Storage System

In order to increase the input and output voltage range of the energy storage system, this paper will conduct in-depth research on the modulation strategy of the bidirectional DC/DC module of the energy storage system. In this paper, the LLC resonant converter with bidirectional operation is used as the connection port between the battery and the DC bus in the energy storage system. The working principle of this topology and the commonly used modulation strategies are briefly described, and then the hybrid modulation strategy is analyzed in detail, which can ensure the normal operation of the DC bus voltage in the range of 310V to 380V. The correctness and effectiveness of the strategy are verified by experiments.
Development of a Wearable Ultrasound Transducer for Sensing Muscle Activities in Assistive Robotics Applications

People who suffer from the amputation of limbs or with mobility impairment due to methodological disorder sometimes require assistive robotics (AR), such as robotic prostheses and exoskeletons, to function satisfactorily and productively in daily life. Dynamic measurements of muscle voluntary activities are widely used to control AR, and sensors used to control AR should be non-invasive, effective, and wearable. Ultrasound (US) imaging is an effective method for measuring muscle activity. Nevertheless, conventional US transducers are cumbersome and inflexible, making them inconvenient for continuous monitoring of muscle activity for AR control. In light of no report available about using a flexible transducer for detecting muscle activities for AR, this work aims to develop a novel wearable US device for detecting muscle activities. In specific, a 16-element 10 MHz flexible sparse array was designed, fabricated, and characterized. The feasibility of monitoring muscle activity in different regions was demonstrated by an in vivo human experiment.
A Self- Reliant finite Automata for Reduplication Detection

Reduplication is a common phenomenon in almost all human languages. It implies the repetition of the smallest linguistic unit partially (e.g. flip flop) or fully (e.g. bye bye). Symbolically it can be written as $W_{i} W_{j}$, where $W_{i}$, and $W_{j}$ are similar or almost similar and $W_{i}$ is any linguistic unit or token or sequence of symbols. Identifying such reduplication in a text is an important aspect of various language processing tasks. Several researchers have tried to address the issue and solve using various techniques like the heuris-tic approach, 1-way / 2-way finite-state transducers, etc. This paper presented a sophisticated generic (Nondeterministic Finite Automata i.e. NFA-based) automaton that is self-reliant generates dynamically and identifies all the reduplicated words from the text.
Towards multi-probe high frame rate volumetric vector Doppler imaging: a feasibility study

The Doppler approach more frequently used for estimating two components of the velocity vector is based on the use of the “dual beams” associated with either two single-element probes or two sub-apertures of a linear array. With the diffusion of high frame rate (HFR) sequences, these methods have been adapted to the investigation of a planar region of interest (ROI). In this study, we evaluate the feasibility of using multiple 2-D sparse array probes to extend HFR vector Doppler imaging to a 3-D ROI. The results of this work confirm that accurate estimations of the velocity can be obtained. Our results show bias and standard deviation errors below 4.5 % and 13.0 %, respectively, and an achievable rate of 750 volumes per second.
Intelligent Video Analysis System for Railway Station

Manually monitoring the railway station can not guarantee efficiency and accuracy. Therefore, this paper proposes a novel intelligent video analysis system. The main innovation is that the system introduces the passenger production plan to train intelligence analysis algorithm. This system mainly focuses the the platform and waiting hall in the railway station. It can accomplish the platform crossing, end intrusion, loitering detection, standardized operation detection, on duty detection, passenger flow density, queue detection, etc. The effect of Zhengzhou-Airport station proves that it can provide accurate decision-making data for staff, and ensure passenger travel safety and passenger station management level in real time.
Towards Dense Point Correspondence with PatchMatch in Low-Resolution Sonar Images

Robust feature correspondences between 2D sonar imagery are important for perception tasks in the underwater domain such as 3D reconstruction but involve open challenges, in particular, low-resolution as well as the fact that object appearance is view-dependent. Although sonars in the MHz range would allow for higher resolution imagery, in this paper we focus on scenarios with a lower frequency kHz sensor, in which the longer visual range is gained at the sacrifice of image resolution. To this end, we first propose to solve the correspondence task using the PatchMatch algorithm for the first time in sonar imagery, and then propose a method for feature extraction based on IC. We then compare the proposed methods against conventional methods from computer vision. We evaluate our method on data from a lake experiment with objects captured with an FLS sensor. Our results show that the proposed combination of IC together with PatchMatch is well-suited for point feature extraction and correspondence in sonar imagery. Further, we also evaluate the different methods for point correspondence with a 3D object reconstruction task.
Determination of Initial Rotor Position of PMaSynRM Based on DC Current Injection

The paper proposes the rotor parking procedure upgraded with actual rotor parking position error detection suitable for permanent magnet assisted synchronous motor drives. The approach is based on the well know DC current based rotor parking, but takes into account an expected parking position error due to the confrontation of the synchronous and the reluctant torque during the parking. The paper shows that the difference between the actual rotor parking position, and referent zero position of stator current vector, can be predicted and compensated by taking into account DC current level and motor parameters, with core saturation included.
Effects of Imitation Training Methods on Chinese EFL Learners’ Production of English Intonation

Intonation plays an important role in speech intelligibility and is difficult to be acquired by L2 learners. Previous studies exploring L2 intonation have generally focused on the learners' intonational performance in perception and/or production tasks. Imitation has been known as one of the significant approaches for L2 learners to master intonation. Listen-and-repeat (LAR) and repetitive synchronous imitation (RSI) have been fully studied and applied before, while there have been fewer studies on delayed repeating task (DRT) and a lack of comparisons with other methods. The current study explored whether the three imitation training methods help Chinese EFL learners improve their production of English intonation. Sixty non-English majors were randomly divided into three groups for three training methods, i.e., LAR, RSI, and DRT. The results indicate that: 1) Chinese EFL learners' English intonation was improved immediately after the training regardless of training methods; 2) There were improvements in the three training methods regardless of their proficiency of oral English; 3) There was not extended improvement on selective question and enumeration in the retention test.
Energy Consumption Simulation and Economic Benefit Analysis for a Light Duty Urban Commercial Electric Vehicle

Electrification of the conventional propulsion system revolution has been taking place in the automotive industry to seek a cleaner and safer transportation network across cities. The electrified powertrain has significantly reduced fossil fuel dependence and improved fuel economy. Moreover, optimal energy consumption as a trade-off between the conflicting demand to prolong driving mileage and the need for the vehicle to operate within the limit of the battery capacity is quite critical. This paper simulates the energy consumption per 1 kilometer and 100 kilometers of the distance covered by a VW Crafter with a 2.0 CR DTI Diesel Engine Vehicle. The traditional Combustion Engine (CI) system as a front-wheel-drive was replaced by a comparative study between a complex and simplified electrified drivetrain-based a 4-pole, Y-connected Three-Phase Permanent Magnet Brushless DC Motor (PMBLDCM) propulsion system. The energy consumed using the New European Drive Cycle (NEDC) test procedure was 0.15 kWh/km and 10.53 kWh/100km, respectively. Furthermore, this research proposes a Proportional Integral (PI) baseline control algorithm to regulate Motor and vehicle speeds. In this manner, the execution of the PI controller was confirmed by implementing a PID Control scheme. However, the performance of the traditional controls is not realistic and, therefore, not reliable due to the nonlinear nature of the system. Accordingly, performance integral criteria such as “Integral Square Error (ISE),” “Integral Absolute Error (IAE)” etc., were used to ascertain the optimal gains of the proposed control techniques.
The Response of Prefrontal and Parietal Lobes to Acoustoelectric Signal

Acoustoelectric brain imaging (ABI), a high spatiotemporal resolution neural imaging method, has been achieved in living rats. Based on the coupling of acoustic field and electric field, acoustoelectric (AE) signal can be generated within the focal zone of focused ultrasound (FUS) and AE signal is the foundation of the ABI. Although experiment results reveal AE signal could be detected in the non-focal brain regions, the response of different non-focal regions to AE signal remains unclear. In this study, applying FUS and visual stimulus to living rat, the AE signal and stable state visual evoked potential (SSVEP) signal were simultaneously collected in the prefrontal and parietal lobe. For decoded-AE signal and SSVEP, the consistent spectra with obvious amplitude response at 8Hz were observed. Then, the amplitude and energy of the AE signal on different brain cortex were compared. We found that the intensity of AE signal on the contralateral side of the FUS focuses was stronger than that on the ipsilateral side. And compared to the parietal lobe, the prefrontal lobe had a stronger response to AE signal. Experiment results validate that the conduction of AE signal is not only due to the volume conductor effect in the brain. Moreover, the further away from the source, the stronger the response of AE signal was. This study may provide a prospect for the processing mechanism of AE signal.
Preventing Soft Errors and Hardware Trojans in RISC-V Cores

Soft errors in embedded systems’ memories like single-event upsets and multiple-bit upsets lead to data and instruction corruption. Therefore, devices deployed in harsh environments, such as space, use fault-tolerant processors or redundancy methods to ensure critical application dependability. Another rising concern in secure, critical space applications is the possible introduction of hardware Trojans in an untrusted phase of the manufacturing process. Besides environmental side-effects, an adversary that has injected a malicious mechanism e.g., in the processor or memory can trigger unwanted behavior or leak sensitive information. Techniques to prevent or mitigate hardware Trojans are important to ensure hardware security. Leveraging the openness of the RISC-V ISA, this paper introduces a novel solution to improve the security and dependability of softcores with a low area and latency overhead. The instruction validator which is the first part of this solution can effectively detect hardware Trojans and multiple-bit upsets in the instruction memory by checking instruction/address pairs using a Bloom filter probabilistic data structure. The second part of the solution is the proposal of an error correction code instruction memory using Hamming single-error correction to detect and correct single-event upsets. It has also been proven that the Hamming decoder improves the detection performance of the instruction validator.
A Perturbation and Observation Based Sawtooth Carrier Modulation Strategy of Parallel Converters

Phase shift pulse width modulation (PS-PWM) has been a common approach in parallel converters to improve the quality of the total output current in many applications. However, additional internal communication between different converters is typically required to maintain the phase shift angles synchronized. Furthermore, the phase shift angles of the PS-PWM still need to be reset when part of the converters in the parallel system is not working. To overcome the above drawbacks, a perturbation and observation based sawtooth carrier modulation strategy is proposed based on the harmonic distribution of output current and circulating current. The phase shift angle for each converter is obtained by analyzing the root mean square value of its own circulating current, and be applied in the sawtooth carrier modulation strategy to achieve output current harmonics attenuation, with the advantage of no additional communication and adapting to different numbers of converters. The effectiveness of the proposed method is verified by experiment results.
High quality Ge on Si by epitaxial necking

We show that pure Ge grown selectively on SiO2/Si substrates in 100 nm holes is highly perfect at the top surface compared to conventional Ge lattice-mismatched growth on planar Si substrates. This result is achieved through a combination of interferometric lithography SiO2/Si substrate patterning and ultrahigh vacuum chemical vapor deposition Ge selective epitaxial growth. This “epitaxial necking,” in which threading dislocations are blocked at oxide sidewalls, shows promise for dislocation filtering and the fabrication of low-defect density Ge on Si. Defects at the Ge film surface only arise at the merging of epitaxial lateral overgrowth fronts from neighboring holes. These results confirm that epitaxial necking can be used to reduce threading dislocation density in lattice-mismatched systems.
Modelling Second-Life Batteries as the Energy Storage System for EV Charging Stations

This paper introduces a model for using second-life batteries (SLBs), retired from electric vehicles (EVs), as the energy storage system (ESS) in order to improve the profitability of a public charging station. Furthermore, the introduced model significantly flattens the peak loads to the grid introduced by the operation of charging stations. The reinforcement learning algorithm used here does not depend on forecast data, and learns to make optimal scheduling decisions for charging the ESS and the EVs online, either charging from the ESS or from the power grid. The implemented model is simulated using real data and compared to another charging scheduler. The resulting charging station system proves to be more profitable with the inclusion of the ESS and also helps flatten the electrical energy load on the power grid during on-peak times. Additionally, by modelling the battery degradation of the SLBs for each charge and discharge cycle, it is shown that the life time of these batteries can be extended. Therefore, it is a viable use for these batteries as they can fulfill the requirements of the ESS for a year before their charge capacity falls below the 50% mark that defines their end of life.