Miracle-dz/UniFAR-FTUs huggingface dataset:
Input filter design for PWM current-source rectifiers

Pulse width modulated (PWM) rectifiers allow the elimination of low order harmonics. Filtering requirements for PWM current-source rectifiers are usually satisfied through the use of low-pass LC input filters. The design of LC filters involves the positioning of the resonant frequency to meet the harmonic attenuation requirements (THD), and the introduction of damping at the resonant frequency to avoid amplification of residual harmonics. The systematic approach proposed is focused on PWM rectifiers but can be extended to other classes of converters. Practical design considerations are detailed and design equations are derived. Simulated results are presented to validate the design approach. <<ETX>>
7.5.1 Capacity for Engineering Systems Thinking (CEST) and Project Success

Despite the vast amount of literature available on systems engineering and project management, about two‐thirds of all projects still fail. A review of both project management and systems engineering publications reveals that most of these works focus on processes. We suggest focusing on people – project managers and systems engineers. One of our previous studies dealt with project managers; the current paper focuses on systems engineers. The paper presents findings of a study aimed at exploring the relationship between systems engineers' capacity for engineering systems thinking (CEST), project types and project success. The study findings show that there is a significant correlation between CEST and project success. The extent of the project's novelty is a moderator variable that affects this correlation. The more innovative the project is, the higher the correlation between the subjects' CEST and project success.
VOXEL: cross-layer optimization for video streaming with imperfect transmission

Delivering videos under less-than-ideal network conditions without compromising end-users' quality of experiences is a hard problem. Virtually all prior work follow a piecemeal approach---either "tweaking" the fully reliable transport layer or making the client "smarter. " We propose VOXEL, a cross-layer optimization system for video streaming. We use VOXEL to demonstrate how to combine application-provided "insights" with a partially reliable protocol for optimizing video streaming. To this end, we present a novel ABR algorithm that explicitly trades off losses for improving end-users' video-watching experiences. VOXEL is fully compatible with DASH, and backward-compatible with VOXEL-unaware servers and clients. In our experiments emulating a wide range of network conditions, VOXEL outperforms the state-of-the-art: We stream videos in the 90th-percentile with up to 97% less rebuffering than the state-of-the-art without sacrificing visual fidelity. We also demonstrate the benefits of VOXEL for small-buffer regimes like the emerging use case of low-latency and live streaming. In a survey of 54 real users, 84% of the participants indicated that they prefer videos streamed using VOXEL compared to the state-of-the-art.
The CBR-PNN approach to real-time voltage security assessment of power systems

This paper presents the Case-based Reasoning (CBR) technique, a novel approach to voltage security assessment of power system in a real-time environment. The Probabilistic Neural Network (PNN) is used for determining the solution to a new case, using the old cases from the case base of the CBR system. A feature selection technique based on the information gained has been employed to identify the relevant input features for PNN. The CBR technique extracts the information of voltage security from large sets of possible operating conditions of the power system, generated by computer simulation. Also the ranking of contingencies is done by CBR as accurately as the one done by the Continuation Power Flow (CPF) method. Security classes are defined by the threshold value of maximum loadability margins, calculated by the CPF method. The effectiveness of the proposed approach is tested on IEEE test systems. The proposed method gives fast and accurate voltage security information for unknown patterns and it is found to be suitable for real-time monitoring of voltage security in energy management systems.
Measuring surface-wave overtone phase velocities using a mode-branch stripping technique

SUMMARY We present a method for the retrieval of the phase velocities of surface-wave overtones. The ‘single-station’ method is successful for several Love and Rayleigh overtone branches (up to at least four) in mode-specific period ranges between 40 and 200 s. It uses mode-branch cross-correlation functions and relies on adjusting the phase and amplitude of the mode branches one at a time. A standard statistical optimization technique is used. We discuss in detail the apriori information that is added to stabilize the retrieval procedure. In addition, we present a technique to estimate the reliability of individual phase and amplitude measurements. The retrieval method and the technique to estimate reliabilities can be used together in a highly automated way, making the methods especially suited for studying the large volume of digital data now available. We include several applications to synthetic and recorded waveforms. We will discuss in detail an experiment with 90 waveforms that have travelled along very similar paths from Vanuatu to California. For this path, we will present average overtone phase velocities and an average 1-D velocity structure.
A fast, scalable, and energy-efficient edge acceleration architecture based on FPGA cluster

FPGA-based acceleration has been emerged to avoid the cloud computing overload problem by accelerating the compute-intensive workload on edge networks. Though existing studies for FPGA-based edge acceleration have focused on optimizing the computing time, they did not address the burden of the FPGA-aided server under an enormous computing requests circumstance. The massive computing requests can cause delays in transmission and processing at the FPGA-aided server, leading to long response times and high system energy consumption. Therefore, we propose an emerging edge acceleration architecture based on FPGA cluster over the low-latency RDMA-based network. Preliminary simulation results demonstrate that our architecture is fast, scalable, and energy-efficient in comparison with the FPGA-aided servers cluster.
c-di-GMP Homeostasis Is Critical for Heterocyst Development in Anabaena sp. PCC 7120

c-di-GMP is a ubiquitous bacterial signal regulating various physiological process. Anabaena PCC 7120 (Anabaena) is a filamentous cyanobacterium able to form regularly-spaced heterocysts for nitrogen fixation, in response to combined-nitrogen deprivation in 24h. Anabaena possesses 16 genes encoding proteins for c-di-GMP metabolism, and their functions are poorly characterized, except all2874 (cdgS) whose deletion causes a decrease in heterocyst frequency 48h after nitrogen starvation. We demonstrated here that c-di-GMP levels increased significantly in Anabaena after combined-nitrogen starvation. By inactivating each of the 16 genes, we found that the deletion of all1175 (cdgSH) led to an increase of heterocyst frequency 24h after nitrogen stepdown. A double mutant ΔcdgSHΔcdgS had an additive effect over the single mutants in regulating heterocyst frequency, indicating that the two genes acted at different time points for heterocyst spacing. Biochemical and genetic data further showed that the functions of CdgSH and CdgS in the setup or maintenance of heterocyst frequency depended on their opposing effects on the intracellular levels of c-di-GMP. Finally, we demonstrated that heterocyst differentiation was completely inhibited when c-di-GMP levels became too high or too low. Together, these results indicate that the homeostasis of c-di-GMP level is important for heterocyst differentiation in Anabaena.
An efficient waveguide photodetector fabricated in an InP-based amplifier layer stack

This article describes the fabrication and characterization of a waveguide pin-photodetector (WGPD) based on butt-joint integration of a passive waveguide and photodetector. The WGPD is fabricated in a layer stack that is designed to be used for an optical amplifier, which now acts as a detector by reversely biasing the pin-diode. The device is fabricated in active-passive material with a technology that uses two epitaxial regrowth steps. The static and high-frequency behavior of the photodetector are characterized and demonstrate a very low dark current of 20 nA at -4 V and an internal efficiency of more than 65% for a 60 µm long device at -5 V bias voltage around a wavelength of 1.5 µm. The output reflection coefficient shows more than 20 GHz bandwidth for a 70 µm long device.
Dynamic Compensation of Cutting Forces Measured From the Spindle Integrated Force Sensor System

This paper presents a dynamically compensated Spindle Integrated Force Sensor (SIFS) system to measure cutting forces. Piezo-electric force sensors are integrated to the stationary spindle housing. The structural dynamic model between the cutting forces acting on the tool tip and the measured forces at the spindle housing is identified. The system is first calibrated to compensate the influence of spindle run-out and unbalance at different speeds. Using both the cutting force and acceleration sensor signals measured at the spindle housing, a Kalman Filter is designed to filter the influence of structural modes on the force measurements. The frequency bandwidth of the proposed sensor system is expanded from 300 Hz to about 800 Hz with the proposed sensing and the signal processing method.Copyright © 2002 by ASME
Black-box testing in motor sequence learning

During learning of novel motor sequences, practice leads to the consolidation of hierarchical structures, namely motor chunks, facilitating the accurate execution of sequences at increasing speeds. Recent studies show that such hierarchical structures are largely represented upstream of the primary motor cortex in the motor network, suggesting their function to be more related to the encoding, storage, and retrieval of sequences rather than their sole execution. We isolated different components of motor skill acquisition related to the consolidation of spatiotemporal features and followed their evolution over training. We found that optimal motor skill acquisition relies on the storage of the spatial features of the sequence in memory, followed by the optimization of its execution and increased execution speeds (i.e., a shift in the speed-accuracy trade-off) early in training, supporting the model proposed by Hikosaka in 1999. Contrasting the dynamics of these components during ageing, we identified less-than-optimal mechanisms in older adults explaining the observed differences in performance. We applied noninvasive brain stimulation in an attempt to support the aging brain to compensate for these deficits. The present study found that anodal direct current stimulation applied over the motor cortex restored the mechanisms involved in the consolidation of spatial features, without directly affecting the speed of execution of the sequence. This led older adults to sharply improve their accuracy, resulting in an earlier yet gradual emergence of motor chunks. The results suggest the early storage of the sequence in memory, largely independent of motor practice, is crucial for an optimal motor acquisition and retrieval of this motor behavior. Nevertheless, the consolidation of optimal temporal patterns, detected as motor chunks at a behavioral level, is not a direct consequence of storing the sequence elements, but rather of motor practice.
Regulation of dctA and DctA by cAMP-CRP and EIIAGlc at the transcriptional and post-translational levels in E. coli: Consequences for aerobic uptake and metabolism of C4-dicarboxylates

The expression of dctA, encoding the aerobic C4-dicarboxylate (C4-DC) transporter DctA of Escherichia coli, and its use in the presence of alternative carbon sources was characterized. dctA is regulated by cAMP-CRP and substrates that control cAMP levels, either through the phosphotransferase system (PTS), or through their metabolic link to PEP synthesis. The data indicates that phosphorylation of the regulator EIIAGlc of the glucose-specific PTS represents the mediator for regulation. The dctA promotor region contains a class I CRP-binding site (position -81.5) and a DcuR-binding site (position -105.5). The response regulator DcuR of the C4-DC-activated DcuS-DcuR two-component system is known to stimulate expression of dctA, and cAMP-CRP is known to stimulate expression of dcuS-dcuR. Thus, activation of dctA expression by cAMP-CRP and DcuR is organized in a coherent feed-forward loop (FFL) where cAMP-CRP positively regulates the expression of dctA by direct stimulation and by stimulating the expression of dcuR. Stimulation by DcuR is presumed to require DNA bending by cAMP-CRP. In this way, CRP-FFL integrates carbon catabolite control and C4-DC-specific regulation. Moreover, EIIAGlc of the glucose-specific PTS strongly interacts with DctA, which could lead to substrate exclusion of C4-DCs when preferred carbon substrates such as sugars are present. Since C4-DCs are perceived in the periplasmic space by the sensor DcuS, the substrate exclusion is not linked to inducer exclusion, contrasting classical inducer exclusion known for the lactose permease LacY. Thus, aerobic C4-DC metabolism is tightly regulated at the transcriptional and post-translational levels, whereas uptake of L-aspartate by DcuA is essentially unaffected. Overall, transcriptional and post-translational regulation of dctA expression and DctA function efficiently fine-tunes C4-DC catabolism in response to other preferred carbon sources.
Max-Min Fair Bandwidth Allocation in Millimeter-Wave Radio Clusters

Enabling ultra high speed wireless communication, Extreme High Frequency (EHF) or Millimeter Wave (mmWave) bands will play a significant role for the 5G. Apart from speed, 5G will be very useful for handling great amounts of data simultaneously and serving bandwidth hungry applications as well. Ultra high quality and ultra fast video streaming will be one of those applications that will be made possible by 5G. While serving bandwidth hungry applications with ease will be an important development and maximizing throughput is most of the time the main goal in a network, it is also important to make sure that no other application starves. In order to prevent such a situation, fair bandwidth allocation should be considered in wireless communications. We simulated a max-min fair bandwidth allocation scenario in a mmWave radio cluster, where a radio cluster is a set of base stations connected to a main hub over 60 GHz radio links. We ran experiments with different path loss exponent values with increasing number of base stations to examine the effects of topology complexity and radio signal loss on the optimization time and on the overall network throughput while maintaining max-min fair allocation. The results showed that as the topology becomes more complex, the problem takes longer to solve. However, the overall network throughput increases. In addition, our model has achieved a decent quantitative fairness level as shown by Jain's index values, which are always more than 0.5 on a scale of 0 to 1 with respect to the topology complexity and the number users.
LADRC Current Control Based On LTCL Filter

This paper focuses on the grid connected inverter system based on LTCL filter. On the basis of stability analysis, the inherent resonance of the filter is compensated and suppressed. After the analysis, it is equivalent and simplified. The linear active disturbance rejection control method and the phase-locked loop of the front filter are adopted to ensure the robustness of the system. Finally, the simulation results show that the proposed control method is effective.
Fast and Robust Ground Surface Estimation from LiDAR Measurements using Uniform B-Splines

We propose a fast and robust method to estimate the ground surface from LiDAR measurements on an automated vehicle. The ground surface is modeled as a uniform B-spline which is robust towards varying measurement densities and with a single parameter controlling the smoothness prior. We model the estimation process as a robust Least-Squares optimization problem which can be reformulated as a linear problem and thus solved eﬃciently. Using the SemanticKITTI data set, we conduct a quantitative evaluation by classifying the point-wise semantic annotations into ground and non-ground points. Finally, we validate the approach on our research vehicle in real-world scenarios.
Network Slicing in 5G Edge Networks with Controlled Slice Redistributions

Edge computing with network slicing enables 5G networks to meet the diverse and stringent requirements of new services and applications. We study the problem of admitting network slice requests and serving currently active slices in the 5G edge network, while avoiding active slice redistributions in the network. We pose it as a constrained optimization problem that seeks to maximize the total reward or revenue to the network operator from serving the new and active slices minus a term that penalizes slice redistributions in the network. We propose a three-phase polynomial-time, greedy, heuristic approach called RESET to solve this NP-hard problem. The first phase employs a cost function that determines the order in which new slice requests and a fraction of the active slices are served. It takes into account the bandwidth, storage, and computing requirements of a slice request. The second phase selects an edge cloud (EC) to assign an admitted request based on the residual bandwidth of its incoming links, and storage and computing resources at the EC. The last phase determines the forwarding path to route the traffic associated with the slice request to the selected EC. Extensive simulation results show that RESET achieves a total reward that is competitive with the optimal solution and is higher than benchmark schemes, while requiring far fewer slice redistributions.
A Greedy Algorithm for Minimum Cut into Bounded Sets Problem

Finding critical links and weak points is an important task in almost all types of networks. Minimum cuts provide useful information about the critical links. However, finding a minimum cut of a network may provide insufficient or misleading information on critical links since the number of disconnected nodes in the residual network is not taken into account in this problem. In this work, we study the minimum cut into bounded sets problem, which limits the number of nodes in portioned sets. Finding the minimum cut into bounded sets can provide useful information on important critical links in a different network, whose failure has a hard and unacceptable effect. The minimum cut into bounded sets problem is an open NP-Complete problem. We propose a greedy algorithm for this problem with $O\left(c \times n^{2}\right)$ time complexity and present computational results on random networks. To the best of our knowledge, the proposed algorithm is the first heuristic for the minimum cut into bounded sets problem.
Coupled transmission lines revisited

The author presents a very satisfying and disarmingly simple way of introducing students to the parallel line coupler, which derives its S matrix directly from a knowledge of its eigenvectors and eigenvalues. For a pair of symmetrical coupled lines, the eigenvectors can be found by inspection, and the eigenvalues determined easily by means of flow graphs. The elements of the S matrix are then known, being linear combinations of the eigenvalues. >
Fault tolerant operation of induction motor drives with automatic controller reconfiguration

Proper operation of vector controlled induction motor drives over the entire speed range critically depends upon reliable operation of the feedback sensors. In the event of sensor failures, it is desirable that the induction motor system continues to operate, even if under a diminished performance capacity. This paper describes the development of a fault tolerant control system for an induction motor with automatic controller reconfiguration. The system adaptively reorganizes itself in the event of sensor loss or sensor recovery to sustain the best control performance given the complement of the remaining sensors. Theoretical and experimental results are presented.
Chromatic dispersion compensation of a ferroelectric liquid crystal modulator for optical switching applications

In this work we present a characterization of the phase shift chromatic dispersion introduced by a ferroelectric liquid crystal modulator. Maximum optical contrast is obtained when the proper design wavelength illuminates the device. In this situation the modulator acts as a perfect half-wave plate. However, for many applications the illuminating sources available are different from the design one and the optical contrast is reduced. In a previous work we proposed an optimization method to increase the optical contrast ratio by illuminating the device with an optimal elliptically polarized light. Here, we explore further the optimization of the ferroelectric modulator performance as an optical switching device for different monochromatic and polychromatic sources. For that purpose we use an achromatic quarter wave-plate placed in front of the modulator. For the optimal situations, the two output states of the modulator will be almost linear and orthogonal providing a highly contrasted modulated optical signal. Experimental results are obtained using a commercially available single pixel ferroelectric liquid crystal modulator from CRL-Opto, model LCS2N-G, with an active area of 25.5×25.5 mm2.
40.1: Invited Paper: Active Matrix Low Temperature Poly‐Si TFT / OLED Full Color Displays: Development Status

In October 1999, Eastman Kodak and Sanyo Electric jointly announced the development of a high quality, 2.4 inch diagonal Full Color active matrix Organic Light Emitting Diode (OLED) display. This technology demonstration resulted from the successful integration of Kodak's organic electroluminescence display technology and Sanyo's low temperature polysilicon TFT technology. Commercial samples are expected to reach the market in 2001. The active matrix OLED displays feature a wider viewing angle and a faster response speed than conventional LCDs. With its low power consumption, high brightness and thin design, these OLED displays when incorporated in digital cameras, personal digital assistants (PDA), videophones and other portable imaging devices, will offer a superior value proposition to consumer electronics products. Several OLED display designs are under development now to serve various market segments. This paper will summarize the status of active matrix full color OLED display development, the key technical challenges, and the path ahead.