Miracle-dz/UniFAR-FTUs huggingface dataset:
An inrush mitigation technique of load transformers for the series voltage sag compensator

Survey results suggest that 92% of interruption at industrial facilities is voltage sag related. The voltage sag compensator, based on a transformer-coupled series- connected voltage source inverter, is among the most cost- effective solution against voltage sags. Transformers are often installed in front of critical loads for electrical isolation purposes. When voltage sags happen, the transformers are exposed to the disfigured voltages and a DC offset will occur in its flux linkage. When the compensator restores the load voltage, the flux linkage will be driven to the level of magnetic saturation and severe inrush current occurs. The compensator is likely to be interrupted because of its own over-current protection, and eventually the compensation fails, and the critical loads are interrupted by the voltage sag. This paper proposes an inrush current mitigation technique together with a state feedback controller for the voltage sag compensator. The operation principles of the proposed method are specifically presented, and experiments are provided validate the proposed approach.
A Salvaging Strategy Enables Stable Metabolite Provisioning among Free-Living Bacteria

Recycling gives new life to old things. Bacteria have the ability to recycle and reuse complex molecules they encounter in their environment to fulfill their basic metabolic needs in a resource-efficient way. ABSTRACT All organisms rely on complex metabolites such as amino acids, nucleotides, and cofactors for essential metabolic processes. Some microbes synthesize these fundamental ingredients of life de novo, while others rely on uptake to fulfill their metabolic needs. Although certain metabolic processes are inherently “leaky,” the mechanisms enabling stable metabolite provisioning among microbes in the absence of a host remain largely unclear. In particular, how can metabolite provisioning among free-living bacteria be maintained under the evolutionary pressure to economize resources? Salvaging, the process of “recycling and reusing,” can be a metabolically efficient route to obtain access to required resources. Here, we show experimentally how precursor salvaging in engineered Escherichia coli populations can lead to stable, long-term metabolite provisioning. We find that salvaged cobamides (vitamin B12 and related enzyme cofactors) are readily made available to nonproducing population members, yet salvagers are strongly protected from overexploitation. We also describe a previously unnoted benefit of precursor salvaging, namely, the removal of the nonfunctional, proliferation-inhibiting precursor. As long as compatible precursors are present, any microbe possessing the terminal steps of a biosynthetic process can, in principle, forgo de novo biosynthesis in favor of salvaging. Consequently, precursor salvaging likely represents a potent, yet overlooked, alternative to de novo biosynthesis for the acquisition and provisioning of metabolites in free-living bacterial populations. IMPORTANCE Recycling gives new life to old things. Bacteria have the ability to recycle and reuse complex molecules they encounter in their environment to fulfill their basic metabolic needs in a resource-efficient way. By studying the salvaging (recycling and reusing) of vitamin B12 precursors, we found that metabolite salvaging can benefit others and provide stability to a bacterial community at the same time. Salvagers of vitamin B12 precursors freely share the result of their labor yet cannot be outcompeted by freeloaders, likely because salvagers retain preferential access to the salvaging products. Thus, salvaging may represent an effective, yet overlooked, mechanism of acquiring and provisioning nutrients in microbial populations.
Optical system for the supervision of the operation of a induction motor

In this work we present an optical system for the supervision of the operation of an induction motor. We used a Cyclic interferometer for the measurement of the vibrations produced by the motor motion and obtain a frequency spectrum via a Fourier transform of the signal. According to the spectrum, we can know the operation conditions of the induction motor. The optical system consists of a Cyclic Interferometer, a data acquisition board and virtual instrument.
Analysis and design of a LCC resonant inverter for high intensity discharge lamps

A complete study of the clamped-mode LCC resonant inverter together with some of the control-to-output characteristics are presented in the first part of this paper. In the second part, a new control method for the clamped-mode LCC resonant inverter is introduced. With this method the inverter is forced to operate with optimum commutations and without handling reactive energy, thus minimizing both switching and conduction losses. The corresponding design procedure is illustrated with a design example. Finally, some experimental results obtained from a prototype at the laboratory are also shown to validate the analysis and evaluate the proposed control method.
Evaluation of product-platform decisions based on total supply chain costs

Over the past decades, several companies have introduced product platforms in the design of their products in order to produce a large product variety in a cost-efficient way. However, for some companies, the introduction of platforms ended up being more costly than expected, leading them to reconsider their platform decisions. In this paper, we develop a model to support companies in determining (1) how many platforms to develop, (2) which platforms to develop and (3) which products to derive from which platforms. The model takes into account the impact of these product-platform decisions on a company’s relevant supply chain activities and costs. The model shows how the optimal product-platform decisions depend on the trade-off between the costs of platforms versus the costs of customising these platforms to final product variants. We propose a simulated annealing algorithm to solve large problem instances within reasonable time. The practical validity of our model is shown through its application in a global technology company specialised in the development and production of medical screens.
Motives and risk perceptions of participants in a phase 1 trial for Hepatitis C Virus investigational therapy in pregnancy

Limited research has been done among pregnant people participating in investigational drug trials. To enhance the ethical understanding of pregnant people’s perspectives on research participation, we sought to describe motives and risk perceptions of participants in a phase 1 trial of ledipasvir/sofosbuvir (LDV/SOF) treatment for chronic Hepatitis C virus (HCV) during pregnancy. Pregnant people with chronic HCV infection enrolled in an open-label, phase 1 study of LDV/SOF participated in semi-structured, in-depth interviews to explore their reasons for participation and experiences within the study. Pregnant people took 12 weeks of LDV/SOF and were interviewed at enrollment and at the end of study. We recorded the interviews, transcribed them verbatim, coded them using NVivo software, and performed inductive thematic analysis. Nine women completed the study yielding 18 interview transcripts. We identified two themes regarding motives and one regarding risk perception. Motives—(1) Women conceptualized study participation as part of the caregiving role they associate with motherhood; participating was viewed as an act of caregiving for their infants, their families, themselves, and other pregnant women with chronic HCV. (2) Women also noted that they faced multiple barriers to treatment prior to pregnancy that created a desire to receive therapy through trial participation. Risk perception—(3) Women acknowledged personal and fetal risk associated with participation. Acceptance of risk was influenced by women’s concepts of motherhood, preexisting knowledge of HCV and medical research, family members, intimate partners, or by the study design. Women enrolled in a phase 1 trial for chronic HCV therapy during pregnancy acknowledged risks of participation and were motivated by hopes for fetal and personal benefit and by lack of prenatal access to treatment. Ethical inclusion of pregnant people in research should acknowledge structural factors that contribute to vulnerability and data deficiencies for treatment in pregnancy.
Investigation of 60GHz technology for onboard avionics applications

The technology of the protocol 802.11ad is a cutting edge since it is one of the protocols promoted by Wireless Gigabit Alliance, an association that promoted and developed multi-gigabit speed wireless communications technology. This protocol operates over the 60 GHz frequency band and it provides transfer rates up to 7 Gbit/s. One of the possible applications using this protocol is the transfer of in-flight entertainment content in aircrafts. For instance, multimedia applications like video-on-demand. Nowadays, the technology used for this transmission is based on wired systems that increase the complexity and the weight of the aircraft. This kind of applications require high data rates which can not be satisfied by the existing \ac{Acro:WLAN} solutions operating at 2.4 GHz and 5GHz band. The protocol 802.11ad is fairly recent and there are no channel models that approach the onboard avionics scenarios. Therefore, a channel model has been designed and developed further considering the path loss, the multipath effect, the phase shift and the beamforming.
Time-of-flight sensing using time-correlated single-photon counting

Time-correlated single-photon counting techniques using individual optimized detectors have been applied to time-of-flight ranging and depth imaging. This paper describes recent progress in photon-counting systems performing surface mapping of non-cooperative targets. This includes systems designed for short ranges of the order of 1-50 meters, and longer ranges of up to ten kilometers. The technique has also been applied to distributed surfaces. We describe the measurement approach, techniques used for scanning, as well as the signal analysis methodology and algorithm selection. The technique is fundamentally flexible: the trade-off between the integrated number of counts (or acquisition time) against range repeatability or depth resolution allows its application in a number of diverse fields. The inherent time gating of the technique, allied to the spatial filtering provided by small active area single-photon detectors, can lead to operation under high ambient light conditions even with low average optical power pulsed sources. We have demonstrated three-dimensional imaging of meter-dimensioned objects where reverse engineering methods using cooperative targets cannot be routinely employed: e.g. delicate objects, or objects with more than one reflective surface. Using more advanced signal processing algorithms, we have been able to improve the system performance significantly, as measured by the depth resolution at short and long ranges. Furthermore, the application of these methodologies has allowed us to characterize the positions and amplitudes of multiple returns. Hence, the approach can be used for characterization of distributed non-cooperative targets at kilometer ranges, even in environments where low-light level and and/or eye-safe operation is necessary. The technique has also been applied in conjunction with a rapid scanning approach, to acquire three-dimensional information of a target scene with frame times of approximately 1 second.
Analytic Calculation of Noise Power Robbing, NPR, and Polarization Isolation Degradation

Three Geostationary Operational Environmental Satellite (GOES) R transponders (services) required analysis and measurements to develop an accurate link budget. These are a) Search and Rescue transponder which suffers from power robbing due to thermal uplink noise, b) the Data Collection Platform Report which suffers from degradation due to NPR (Noise Power Ratio), and c) GOES Rebroadcast transponder which uses a dual circular downlink L band for which there was no depolarization data. The first two services required development of extended link budget to analytically calculate the impact of these degradations which are shown to have a significant impact on the link budget. The third service required measurements of atmospheric L band CP depolarization as there were no known previous measurements and results are reported her
High‐Precision Earthquake Location Using Source‐Specific Station Terms and Inter‐Event Waveform Similarity

Earthquake monitoring and many seismological studies depend on earthquake locations from phase arrival‐times. We present an extended, arrival‐time earthquake location procedure (NLL‐SSST‐coherence) which approaches the precision of differential‐timing based, relative location methods. NLL‐SSST‐coherence is based on the probabilistic, global‐search NonLinLoc (NLL) location algorithm which defines a probability density function (PDF) in 3D space for hypocenter location and is highly robust to outlier data. NLL‐SSST‐coherence location first reduces velocity model error through iteratively generated, smooth, source‐specific, station travel‐time corrections (SSST). Next, arrival‐time error is reduced by consolidating location information across events based on inter‐event waveform coherency. If the waveforms at a station for multiple events are very similar (have high coherency) up to a given frequency, then the distance separating these “multiplet” events is small relative to the seismic wavelength at that frequency. NLL‐coherence relocation for a target event is a stack over 3D space of the NLL‐SSST location PDF for the event and the PDF's for other multiplet events, each weighted by its waveform coherency with the target. NLL‐coherence relocation requires waveforms from only one or a few seismic stations, enabling precise relocation with sparse networks, for foreshocks and early aftershocks of significant events before installation of temporary stations, and for older data sets with few waveform data. We show the behavior and performance of NLL‐SSST‐coherence with synthetic and ground‐truth tests, and through application and comparison to relative locations for California earthquake sequences with dense and sparse station coverage.
Probiotic Fermented Beverage From Macroalgae

We have tested the hypothesis that a fermented beverage from the macroalgae Hydropuntia eucheumatoides exhibits antioxidant and enzymatic activity. The macroalga was hydrolyzed (maximum hydrolysis yield: 78%) with a mixture of the enzymes viscozyme and lactozyme. Then, the hydrolyzate was fermented with Lactobacillus casei and Saccharomyces boulardii. This beverage contained oligosaccharide prebiotics. The lactic acid, acetic acid, ethanol, methanol, cell count, pH, and heavy metal content of the beverage were determined. All tested heavy metals were either not detected (eg, As) or within the US Food and Drug Administration limits (eg, Fe).
Biodiesel production from linseed oil and performance study of a diesel engine with diesel bio-diesel

The use of biodiesel is rapidly expanding around the world, making it imperative to fully understand the impacts of biodiesel on the diesel engine combustion process and pollutant formation. Biodiesel is known as "the mono alkyl esters of long chain fatty acids derived from renewable lipid feedstock, such as vegetable oils or animal fats, for use in compression ignition (diesel) engines. " Biodiesel was made by transesterification from linseed oil. In aspect of Bangladesh linseed can play an important role in the production of alternative diesel fuel. The climatic and soil condition of our country is convenient for the production of linseed (Linum Usitatissimum) crop. In the first phase of this work optimization of different parameters for biodiesel production were investigated. In the second phase the performance study of a diesel engine with diesel biodiesel blends were carried out. The results showed that with the variation of catalyst, methanol and reaction time; variation of biodiesel production was realized. About 88% biodiesel production was experienced with 20% methanol, 0.5% NaOH catalyst and at 550C. The results also showed that when compared with neat diesel fuel, biodiesel gives almost similar thermal efficiency, lower carbon monoxide (CO) and particulate matter (PM) while slightly higher nitrogen oxide (NOx) emission was experienced. Â Keywords: Biodiesel, linseed oil, catalyst, alcohol and diesel emissions. doi:10.3329/jme.v39i1. 1832 Journal of Mechanical Engineerin g, vol. ME39, No. 1, June 2008 40-44
A novel bulk micromachined electrostatic microvalve with a curved-compliant structure applicable for a pneumatic tactile display

Recent success of microelectromechanical systems (MEMS) in projection displays have raised similar expectation for an efficient, low power, affordable, full-page and pneumatic tactile display. Such design has not been achieved by the conventional technology but could bring significant improvement to current refreshable Braille displays. This paper demonstrates a novel bulk-micromachined electrostatic microvalve suitable for a pneumatic tactile display. The microvalve, a silicon perforated diaphragm juxtaposed to a silicon inlet orifice, requires relatively low closing voltage against a large supply differential pressure and flow rate, i.e., 72.9 V-rms for 19.3 kPa and 85 mi/min. Such an attractive characteristic is due to its unique curved-compliant structure that has, unlike other electrostatic microvalves, no tolerance for any initial air gap between its electrodes. As a design tool, a mechanical model of the microvalve is introduced based on the lubrication theory and large plate deflection theory. The model is established on a steady-state coupled field problem of fluid-solid mechanics. Reynolds and von-Karman equations were simultaneously solved for the microvalve geometry by finite difference approximation and double Fourier series expansion. The results of the model and experiments are compared and found to be in good agreement with a relative error less than 10%.
Organizational learning, innovativeness, and organizational performance: a qualitative investigation

In a knowledge-based economy, organizational learning and innovation are the most critical intangible assets that a manufacturer needs to acquire and exploit to achieve superior organizational performance. In this research we propose a model seeking to understand the links between organizational learning and innovativeness, and organizational performance measures. We postulate the impact of organizational learning on innovativeness, internal efficiency, customer satisfaction, and financial performance, and elaborate how such impacts are contingent on the organizational contexts of a firm. Case research was then carried out in three manufacturing companies to examine our proposed conceptual model. Our case studies showed that organizational learning happens when it is valued by senior management, and supported by an appropriate learning infrastructure and culture, leading to organizational efficiency. However, relationships among learning, innovativeness, and performance are unlikely to be established for a manufacturer pursuing a low-cost strategy or producing mature products. The proposed model and the empirical evidence provide an important foundation to develop a comprehensive theory for formulating effective learning strategies contingent on organizational context.
Statistical Analysis of Driver Behavior Data in Different Regimes of the Car-Following Stage

An instrumented vehicle has been used to study car-following behavior on Swedish motorways. In this study, the previous data collection and preprocessing work were briefly reviewed. To understand the driving behavior in the car-following stage more clearly, the collected time series were classified into a number of regimes using unsupervised fuzzy clustering methods. Then, the statistical relations between the driver acceleration response and the perceptual variables in each regime were analyzed using correlation and regression methods. It was found that regime classification helps discern the behavioral variance between those regime clusters. According to the data analysis, some of the car-following regimes, for example, opening and braking, can be described adequately in the statistical sense by a linear regression model (Helly's model). Therefore, a multiple regime car-following model with simple model forms, for example, linear models, has the potential to robustly represent the general car-following behavior in most regimes.
A new power distribution strategy for area array bonded ICs and packages of future deep sub-micron ULSI

Signal and power distribution of deep sub-micron ULSI ICs compete for on-chip wiring resources because of increasing chip power dissipation, reduced supply voltage, increased signal wiring demand, higher operating frequency and interconnect delay limitations. We propose a novel cascaded power/ground ring approach for on-chip power distribution, which simultaneously addresses power and signal distribution. Three power distribution approaches have been analyzed and compared. It will be shown that substantial packaging support for on-chip power distribution is imperative for future deep sub-micron ULSI IC's. Simulation results indicate that the cascaded power/ground ring power distribution approach reduces total on-chip metal interconnect levels compared to conventional power distribution methods, while meeting both signal and power distribution goals. The benefit of reducing the total on-chip metal interconnect levels carries significant implications for reducing manufacturing cost and the design of future deep sub-micron ASIC and microprocessor IC's and their packages.
Comparison of two robust PCA methods for damage detection in presence of outliers

Statistical methods such as Principal Component Analysis (PCA) are suffering from contaminated data. For instance, variance and covariance as vital parts of PCA method are sensitive to anomalous observation called outliers. Outliers, who are usually, appear due to experimental errors, are observations that lie at a considerable distance from the bulk of the observations. An effective way to deal with this problem is to apply a robust, i.e. not sensitive to outliers, variant of PCA. In this work, two robust PCA methods are used instead of classical PCA in order to construct a model using data in presence of outliers to detect and distinguish damages in structures. The comparisons of the results shows that, the use of the mentioned indexes based on the robust models, distinguish the damages much better than using classical one, and even in many cases allows the detection where classic PCA is not able to discern between damaged and non-damaged structure. In addition, two robust methods are compared with each other and their features are discussed. This work involves experiments with an aircraft turbine blade using piezoelectric transducers as sensors and actuators and simulated damages.