Miracle-dz/UniFAR-FTUs huggingface dataset:
Voltage control of super high-speed reluctance generator system with a PWM voltage source converter

A voltage control system for a reluctance generator with a PWM voltage source converter is proposed. A phasor diagram of the generator is developed by introducing an iron loss conductance. A practical method for achieving optimal efficiency over the complete operating range is suggested. It is based on the optimal-efficiency current angle tracking by adjusting the voltage ratio of AC-to-DC voltage. The performance of the system is investigated by using the new phasor diagram. It is shown that a system with a PWM converter has wider operating range than one with a self-commutated six-pulse converter. The proposed control system is realized on a laboratory prototype, where control routines are mainly implemented by a 16 b single-board microcomputer. Experimental results show that 10% or more improvement compared with that of the system fed by a six-pulse converter is obtained at half full load. >
Film Bulk Acoustic Wave Resonator Filter for Ku-Band Applications

The design and analysis of Ku-band ladder-type filters based on film bulk acoustic wave resonator (FBAR) is presented. The proposed FBAR filter has an insertion loss of-3dB, out-of-band rejection of-12dB, centre frequency of 15.5GHz with 3dB bandwidth of 1.0GHz. Based on the characteristics of the FBAR filter, the expected characteristics of FBAR resonators are determined by using the Butterworth Van Dyke (BVD) equivalent circuit.
Energy consumption prediction from usage data for decision support on investments: the EnPROVE approach

Abstract When intending to renovate an existing building, with energy efficiency and greenhouse gas emissions in mind, a building owner is always questioning himself if the available investment resources are being directed to an effective return and if there are ways to improve this return? This paper presents the innovative approach from EnPROVE project that responds the previous question in a positive way. The approach is based on predicting the energy consumption of a specific building, with different scenarios implementing energy-efficient technologies and control solutions, based on actual measured performance and usage data of the building itself. The key hypothesis of EnPROVE is that it is possible, from adequate gathering and assessing data on how a structure performs and is being used by its occupants from an energy viewpoint, to build highly accurate and specific energy consumption models relevant for prediction of alternative scenarios. The EnPROVE software tools assess the energy-efficiency impact of alternative technologies for which available investment resources can be directed and, thus, support the decision maker finding the optimized set of energy-efficient solutions to be implemented. These results are tailored to the actual building itself, through automated measurements of building usage and energy consumption.
Lithographic evaluation of the EUV engineering test stand

Static and scanned images of 100 nm dense features were successfully obtained with a developmental set of projection optics and a 500W drive laser laser-produced-plasma (LPP) source in the Engineering Test Stand (ETS). The ETS, configured with POB1, has been used to understand system performance and acquire lithographic learning which will be used in the development of EUV high volume manufacturing tools. The printed static images for dense features below 100 nm with the improved LPP source are comparable to those obtained with the low power LPP source, while the exposure time was decreased by more than 30x. Image quality comparisons between the static and scanned images with the improved LPP source are also presented. Lithographic evaluation of the ETS includes flare and contrast measurements. By using a resist clearing method, the flare and aerial image contrast of POB1 have been measured, and the results have been compared to analytical calculations and computer simulations.
Development, Characterization, and Design Considerations of Ni19.5Ti50.5 Pd25Pt5 High-temperature Shape Memory Alloy Helical Actuators

Shape memory alloys (SMAs) have been used in various applications since their discovery. However, their use as actuation devices in high-temperature environments has been limited due to the temperature constraints of commercially available materials. Recently, SMAs that produce good work characteristics at elevated temperatures have been developed at NASA’s Glenn Research Center. One such alloy, Ni19.5Ti50. 5Pd25Pt 5, has shown repeatable strain recovery on the order of 2.5% in the presence of an externally applied stress at temperatures greater than 250°C. Based on these findings, potential applications for this alloy are being explored and further work is being done to assess the use of this alloy in various structural forms. In this article, the characterization of Ni 19.5Ti50. 5Pd25Pt5 helical actuators is reported, including their mechanical responses and how variations in their responses correlate to changes in geometric parameters and training loads. Finally, implementation of previously published SMA spring design methodology in future SMA helical actuator development is considered through comparison of the observed and predicted responses.
Determination of Railway Vertical Wheel Impact Magnitudes: Field Trials

The authors utilized both experimental and finite element modeling methods earlier to develop both a classical inverse approach as well as a root mean square (RMS) method to estimate the magnitude of wheel impact forces on railway track-like structures. This study presents some results from the field trials of the techniques developed in (Lee, M.L., Chiu, W.K. and Koss, L.L (2005). A numerical study into the reconstruction of impact forces on railway track-like structures. Structural Health Monitoring: An International Journal, 4(1), 19–45. Lee, M.L. and Chiu, W.K (2005). The reconstruction of dynamic impact forces on a railway track-like structure by using an inverse analysis technique. In: Proceedings of the 4th Australasian Congress of Applied Mechanics, pp. 605–610, Melbourne, Australia. Lee, M.L. and Chiu, W.K. (2005). A comparative study on impact force prediction on a railway track-like structure. Structural Health Monitoring: An International Journal, 4(4), 355–376. ). A length of track carrying freight rail traffic and situated along the Melbourne–Geelong line (Victoria, Australia) is instrumented with accelerometers and shear-bridges. The instrumentation consists of five rail cribs instrumented with a shear-bridge and an accelerometer on the rail foot at the midspan of each crib. Using the shear-bridge instrumentation as a check, it is found that the proposed inverse analysis method (IAM) shows potential in not only reconstructing clean impact strikes but also in reconstructing strikes occurring outside of the shear-bridge effective zone within a single crib. Furthermore, based on the principle of superposition governing linear systems, multiple impact strikes within a single crib of rail are also able to be reconstructed. Regarding the RMS method, it is found that while a good correlation (R ≈ 0.8) existed between wheel impact force and track response RMS, a significant spread existed in the data.
Adaptive Observer for Sensorless Control of Permanent Magnet Synchronous Motor Drives

This paper develops a sensorless control method for nonsalient permanent magnet synchronous motor drives. The position and speed estimations are based on the back electromotive force (emf) estimation in f g stator reference. Two equivalent solutions are developed to estimate the back emf (i.e., the adaptive filter technique), and alternatively, an extended disturbance observer, both being speed adaptive. The position estimation is computed directly from the back emf components. The speed estimation uses a model reference adaptive observer as a sinusoidal oscillator external synchronized by the back emf with (i) an amplitude adaptive correction speed depending, and (ii) a phase correction realized by an adaptive mechanism using a variable structure plus a proportional integral compensator. The speed sign is included. The speed and position observers can be independently tuned, and the estimations are robust to parameter deviations. A relatively large speed range of 1:100 is obtained. Extensive simulation results are given and discussed.
Optimize Engineering Processes With Simultaneous Engineering (SE) and Concurrent Engineering (CE)

The appropriate handling of time becomes one of the most important factors for industry to success because of globalization and market competition. Engineering processes should be optimized to achieve shorter “time to market”. This paper deals with Simultaneous Engineering (SE), which means parallelizing formerly serial executed product development processes, and Concurrent Engineering (CE), which means to cut processes into smaller sub processes or activities and parallelize them, both to achieve less product development time. The parallelization degree of processes depends on the dependencies between these processes. Therefore, the dependency between processes is defined and quantified. Processes are parallelized according to the result of the dependency calculation. Related concepts, methods and possible results are described in detail. An example is given about a home appliance product design processes to explain how the method works. The result shows that, with SE and CE, industry can reduce its product throughput time. The result depends also on how processes are modeled and how Concurrent Engineering is achieved.Copyright © 2005 by ASME
Two-step based sampling method for maximizing the capacity of V-belt driving in polymorphic uncertain environment

In this article, a two-step based sampling method is developed to solve the problem of maximizing the power transmission capacity in a system of V-belt driving with polymorphic uncertainties. The problem is first formulated as an optimization model, where there are a non-linear objective function and some linear or non-linear constraints associated with some parameters which are of uncertain nature. These uncertain parameters are interval parameters, random interval parameters, fuzzy parameters, or fuzzy interval parameters. To find a robust solution of the problem, the model of polymorphic uncertainty is converted into a non-linear interval programming problem; then, for a given satisfaction level, an interval solution for the original model is found by the developed two-step based sampling method. The proposed method is applied into a real-world design problem of V-belt driving, and numerical results indicate that both the model and the developed algorithm are useful to solve the maximization problem of the capacity in the system of V-belt driving.
Voltage dips at the terminals of wind power installations

This article gives an overview of the kind of voltage dips that can be expected at the terminals of a wind power installation. The overview is based on the study of those dips at the terminals of industrial installations and provides a guideline for the testing of wind power installations against voltage dips. For voltage dips due to faults, a classification into different types is presented. Five types appear at the terminals of sensitive equipment and thus have to be included when testing the wind power installation against disturbances coming from the grid. A distinction is made between installations connected at transmission level and those connected at distribution level. For the latter the phase angle jump has to be considered. Dips due to other causes (motor, transformer and capacitor switching) are briefly discussed as well as the voltage recovery after a dip. Finally some thoughts are presented on the way in which voltage tolerance requirements should be part of the design process for wind power installations. Copyright
Erbium-Doped Fiber Amplifiers For High-Speed Fiber-Optic Communication Systems

The bandwidth, gain, saturation power and noise of the erbium-doped fiber-amplifier (EDFA) are reviewed in the context of high-speed optical communication systems. Recent experiments which have used EDFA postamplifiers, repeaters and preamplifiers to enhance the performance of fiber-optic systems are discussed.
Factors influencing public sector employee’s intention to work on projects

Public sector employees often have discretion as to whether to work on projects or to perform routine jobs. The motivational factors which encourage employees to work on projects have not been adequately investigated in the literature. For effective project human resource management it is important to examine the motivating factors to work in projects. To explore these factors, this study develops a model based on the theory of planned behaviour to identify public employees' intention to work on projects. To empirically verify the model, we collect 108 data from New Zealand public employees. The significant findings show that public employees are more motivated to work on projects when they believe that: project management tools and techniques will improve their job performance and quality of work; a project position does not require radical changes in the way they usually work; their colleagues have a positive opinion about project-based work and want them to work on projects; and when a project position is associated with high social status and prestige. Overall, the findings have managerial implications, and suggest ways for public sector organisations to develop human resource strategies that will help improve the recruiting process for public sector projects.
The processes of ICT diffusion in technology projects

Abstract Delivering technology projects on time with a specified budget and resources has emerged as a strategic imperative in the highly competitive business world. One of the project challenges is increasingly tied to diffusion (spread) of Information and Communication Technology (ICT) innovation. This paper presents an empirical study that examines how ICT innovation is diffused within technology projects. Based on the case study methodology within 12 organisations in Australia and Germany, it emerged that ICT innovation is diffused formally alongside standard project management phases and informally within informal networks. The findings are synthesised in a new framework that seeks to inform theory and practice about formal and informal processes of ICT diffusion in technology projects.
Towards a more rigorous and practical unit commitment by Lagrangian relaxation

A Lagrangian relaxation algorithm for power system generator unit commitment is proposed. The algorithm proceeds in three phases. In the first phase, the Lagrangian dual of the unit commitment is maximized by standard subgradient techniques. The second phase finds a reserve-feasible dual solution, followed by a third phase of economic dispatch. A mathematically based, systematic and generally applicable procedure to search for a reserve-feasible dual solution is presented. The algorithm has been tested on systems of up to 100 units to be scheduled over 168 hours, giving reliable performance and low execution times. Both spinning and time-limited reserve constraints are treated. >
Remaining Useful Life Early Prediction of Batteries Based on the Differential Voltage and Differential Capacity Curves

Accurate prediction of the remaining useful life (RUL) of batteries is of great importance for the health management of different equipment and machines, such as electric vehicles and smartphones. It gives operators information about when the battery should be replaced. Predicting the batteries’ RUL using the data only from early cycles can also be beneficial for manufacturers. For example, it can reduce the batteries’ testing costs during the research and development phase. This article focuses on batteries’ RUL early prediction using data-driven methods. The differential capacity (<inline-formula> <tex-math notation="LaTeX">$dQ/dV)$ </tex-math></inline-formula> and differential voltage (<inline-formula> <tex-math notation="LaTeX">$dV/dQ)$ </tex-math></inline-formula> curves can reveal the potential capacity and voltage of a battery, respectively, and they are known to be indicators of the batteries’ degradation. We will present a practical method for batteries’ RUL early prediction using features extracted from those two curves. Accordingly, 19 features generated from the <inline-formula> <tex-math notation="LaTeX">$dQ/dV$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$dV/dQ$ </tex-math></inline-formula> curves are analyzed and extracted. The Sparse Bayesian Learning (SBL) method is a popular machine learning method in the field of RUL prediction, and it is used to achieve an RUL early prediction for batteries. In the end, the training and test errors are investigated to evaluate the presented method’s efficiency. Moreover, we compared our results with two other methods (lasso and elastic net), which have been recognized as best performing methods in this field so far, and the comparisons showed our proposed method outperforms those two methods in the term of accuracy. The presented method is generic and can be used for RUL early prediction of different batteries.
Experimental investigation of an atmospheric-open cyclone solar reactor for solid-gas thermochemical reactions

This paper reports that a solar receiver-reactor has been designed to conduct solid-gas chemical reactions, using concentrated solar radiation as the energy source of high-temperature process heat. It consists of a conical cyclone gas-particle separator that has been modified to let concentrated solar energy enter the cavity through a windowless (atmospheric-open) aperture. It combines the advantages of cavity receivers and volumetric reactors, and permits continuous mode of operation. A small-scale prototype reactor to conduct the thermal decomposition of calcium carbonate at 1300 K was experimentally investigated in a solar furnace. Its thermal performance was evaluated. The mean energy absorption efficiency, based on the optically measured power incident on the receiver aperture, was 43 percent. Reaction products showed high degree of calcination.
Characterizing sources of high surface ozone events in the southwestern US with intensive field measurements and two global models

Abstract. The detection and attribution of high background ozone (O3) events in the southwestern US is challenging but relevant to the effective implementation of the lowered National Ambient Air Quality Standard (NAAQS; 70 ppbv). Here we leverage intensive field measurements from the Fires, Asian, and Stratospheric Transport−Las Vegas Ozone Study (FAST-LVOS) in May–June 2017, alongside high-resolution simulations with two global models (GFDL-AM4 and GEOS-Chem), to study the sources of O3 during high-O3 events. We show possible stratospheric influence on 4 out of the 10 events with daily maximum 8 h average (MDA8) surface O3 above 65 ppbv in the greater Las Vegas region. While O3 produced from regional anthropogenic emissions dominates pollution events in the Las Vegas Valley, stratospheric intrusions can mix with regional pollution to push surface O3 above 70 ppbv. GFDL-AM4 captures the key characteristics of deep stratospheric intrusions consistent with ozonesondes, lidar profiles, and co-located measurements of O3, CO, and water vapor at Angel Peak, whereas GEOS-Chem has difficulty simulating the observed features and underestimates observed O3 by ∼20 ppbv at the surface. On days when observed MDA8 O3 exceeds 65 ppbv and the AM4 stratospheric ozone tracer shows 20–40 ppbv enhancements, GEOS-Chem simulates ∼15 ppbv lower US background O3 than GFDL-AM4. The two models also differ substantially during a wildfire event, with GEOS-Chem estimating ∼15 ppbv greater O3, in better agreement with lidar observations. At the surface, the two models bracket the observed MDA8 O3 values during the wildfire event. Both models capture the large-scale transport of Asian pollution, but neither resolves some fine-scale pollution plumes, as evidenced by aerosol backscatter, aircraft, and satellite measurements. US background O3 estimates from the two models differ by 5 ppbv on average (greater in GFDL-AM4) and up to 15 ppbv episodically. Uncertainties remain in the quantitative attribution of each event. Nevertheless, our multi-model approach tied closely to observational analysis yields some process insights, suggesting that elevated background O3 may pose challenges to achieving a potentially lower NAAQS level (e.g., 65 ppbv) in the southwestern US.
Conditions for the Rupture of a Lubricating Film. Part I: Theoretical Model

Abstract : An analysis is made to determine the shape of the film-vapor interface when a thin liquid film separates from a stationary surface and is swept away on an opposing moving surface. Situations in which variations of this phenomenon occur include cavitation in bearings, the spreading of thin films, and the movement of bubbles in narrow spaces. The results of the analysis show that for a fixed attachment height the flow carried in the separating film decreases with decreasing N = (3mu(U)/T) to the 1/3rd power. Stagnation points occur on the interface (with upstream recirculation) at a film height of 3F/U where F is the flow per unit film width and U is the plate velocity. As N decreases, the flow decreases; and the stagnation point moves down the interface toward the moving plate. A second stagnation point always occurs at the point of film attachment. A second important result is that film separation occurs in a distance of about one plate clearance. Because this transition distance is very small, the analysis is applicable to situations in which the plate velocity is not normal to the film edge, e.g. striated cavitation in bearings. The upstream transition distance is shown to be a few plate clearances.
OptiCoS - A New Optical Co-registration System for Multimodal Integration

Since it is usually not possible to detect modality specific markers (MRI, PET, MEG, etc.) in the environment of any other modality, problems arise with multimodal mapping techniques. Especially MEG mapping asks for the combination of the resulting data with the morphological data provided by MRI. Simple marker substitution for the appropriate modality at identical positions would introduce an error source to the overall system. Simultaneous detection of different types of markers in an optical manner and registration in a common 3D coordinate system could help to solve the outlined problem. To adjust the anatomy to the MEG system for example, at least 3 MRI markers at anatomically significant locations and 3 MEG markers have to be optically detected and registered. We have developed and built an optical co-registration system (OptiCoS) that allows for optical detection of markers of different modalities. The system utilizes six color video cameras, homogenously distributed over a sphere sector. The overlapping of the recording segments allows for a 3D reconstruction by transforming the 2D coordinates of the appropriate camera image into 3D coordinates of the specific modality (MRI, PET, MEG). This transformation is possible as the camera locations are defined and the optical axis of each camera is adjusted.