Miracle-dz/UniFAR-FTUs huggingface dataset:
Price volatility and service interruption risk-hedging by transmission contract

In this paper, we propose a transmission contract for reliability and risk-hedging in the deregulated power system. The proposed transmission contract, which is conducted by the transmission system operator (TSO), is a product of the agreements between the generation company (GENCO), the TSO, the distribution company (DISCO), and the large consumer. The proposed transmission contract results in a certain income of the GENCO and provides an incentive for new investments to meet demand in the future. Furthermore, it can help the DISCO and the large consumer hedge the risks, which are caused by the volatility of the price in the spot market. Additionally, for the large consumer, whose load needs high reliable electricity, the proposed contract gives a guarantee that his or her load will always be supplied, or otherwise, he or she will receive a compensation for the service interruption. The effectiveness, especially from the consumer's viewpoint, is shown by using the simulation based on two market models: pool model and mixed pool/bilateral model.
Process Optimization by a Response Surface Methodology for Adsorption of Congo Red Dye onto Exfoliated Graphite-Decorated MnFe2O4 Nanocomposite: The Pivotal Role of Surface Chemistry

Natural graphite, a locally available, eco-friendly, and low-cost carbonaceous source, can be easily transformed into exfoliated graphite (EG) with many surface functional groups via a chemical oxidation route. Combination between EG and magnetic MnFe2O4 is a promising strategy to create a hybrid kind of nanocomposite (EG@MnFe2O4) for the efficient adsorptive removal of Congo red (CR) dye from water. Here, we reported the facile synthesis and characterization of chemical bonds of EG@MnFe2O4 using several techniques such as Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). In particular, the quantity method by Boehm titration was employed to identify the content of functional groups: Carboxylic acid (0.044 mmol/g), phenol (0.032 mmol/g), lactone (0.020 mmol/g), and total base (0.0156 mmol/g) on the surface of EG@MnFe2O4. Through the response surface methodology-optimized models, we found a clear difference in the adsorption capacity between EG-decorated MnFe2O4 (62.0 mg/g) and MnFe2O4 without EG decoration (11.1 mg/g). This result was also interpreted via a proposed mechanism to elucidate the contribution of surface functional groups of EG@MnFe2O4 to adsorption efficiency towards CR dye.
A fully integrated Hall sensor microsystem for contactless current measurement

Contactless current measurement based on Hall-effect sensors can be performed in either closed- or open- loop configuration. In this paper an open-loop sensor system with a current-mode output is described. The system measures the magnetic field induced around the current path targeting high linearity, accuracy and speed. As the accuracy of the Hall sensor microsystem is affected by temperature-dependent offset and sensitivity of the sensing element, system-level solutions are developed to minimize these effects. The full system integration represents a design challenge as both voltage and current references are directly involved in the sensitivity calibration and both contribute to the system sensitivity drift. The measurements show a sensitivity drift lower than 80ppm/°C, the offset drifts less than 300nT/°C and the non-linearity is less than ±0.08%. The effects of the varying external field on the calibration loop are analyzed and the theoretical prediction is validated by measurement.
Conformity evaluation and L1-norm principal-component analysis of tensor data

Multi-modal tensor data sets arise with increasing frequency in modern day scientific and engineering applications, for example in biomedical sciences and autonomous engineered systems. Over the past twenty years, tensor-domain data analysis has been attempted primarily in the context of standard (L2-norm) eigenvector decompositions across tensor domains. The algorithms are not joint-tensor-domain optimal and exhibit the familiar sensitivity to faulty/corrupted/missing measurements that characterizes all L2-norm principal-component analysis methods. In this work, we present a robustified method to evaluate the conformity of tensor data entries with respect to the whole accessible data set. Conformity evaluation is based on a continuously refined sequence of calculated L1norm tensor subspaces. The theoretical developments are illustrated in the context of a multisensor localization application that indicates unprecedented estimation performance and resistance to intermittent disturbances. An electroencephalogram (EEG) data analysis experiment is also presented.
A Spectroscopic Study of Solid-Phase Chitosan/Cyclodextrin-Based Electrospun Fibers

In this study, chitosan (chi)/hydroxypropyl-β-cyclodextrin (HPCD) 2:20 and 2:50 Chi:HPCD fibers were assembled via an electrospinning process that contained a mixture of chitosan and HPCD with trifluoroacetic acid (TFA) as a solvent. Complementary thermal analysis (thermal gravimetric analysis (TGA)/differential scanning calorimetry (DSC)) and spectroscopic methods (Raman/IR/NMR) were used to evaluate the structure and composition of the fiber assemblies. This study highlights the multifunctional role of TFA as a solvent, proton donor and electrostatically bound pendant group to chitosan, where the formation of a ternary complex occurs via supramolecular host–guest interactions. This work contributes further insight on the formation and stability of such ternary (chitosan + HPCD + solvent) electrospun fibers and their potential utility as “smart” fiber coatings for advanced applications.
MEMS for automotive and consumer electronics

Micro-Electro-Mechanical Systems (MEMS) are sensing the environmental conditions and give input to electronic control systems. MEMS are miniature systems which usually combine tiny mechanical structures with electronic circuits. Typical MEMS structures have a size of a few micrometers. MEMS sensors make system reactions to human needs more intelligent, precise, and at much faster reaction rates than humanly possible. Today MEMS sensors can be found in nearly every motor vehicle, smart phone or laptop. Due to continuous product innovations, the sensors find their way into more and more applications in automotive and consumer electronics. According to IHS iSuppli an amount of 4.3 billion micromechanical sensors were sold in 2011 with an impressive increase to 9.8 billion sensors in 2015 - a growth rate of 23% per year! These growth rates are only possible with continuous efforts to improve the performance and to decrease the size, power consumption and costs of the sensors.
Designing an Instrument to Conduct a Survey on Requirement Reuse Practices in Malaysia

A set of questionnaire was designed to study the current state of requirement reuse practices in Malaysia. This paper describes the design of the survey on requirement reuse practice instrument, and the assessment of its reliability and validity. Cronbach’s Alpha test was used to check on its reliability and respondents’ feedback, to assess the level of understanding, the level of difficulty in responding and the level of relevancy to the subject area including the duration taken to complete the questionnaire. Results from the feedback suggested three main issues that need to be looked upon as a way to improve the instrument design. Future efforts will focus on improving the structure and contents of the questionnaire in order to achieve higher reliability and better number of responses to study on requirement reuse. Keywords—requirement reuse, requirement, engineering, software development, survey design
A polynomial-time approximation algorithm for the permanent of a matrix with nonnegative entries

We present a polynomial-time randomized algorithm for estimating the permanent of an arbitrary n × n matrix with nonnegative entries. This algorithm---technically a "fully-polynomial randomized approximation scheme"---computes an approximation that is, with high probability, within arbitrarily small specified relative error of the true value of the permanent.
Towards refined estimation of vegetation carbon stock in Auckland, New Zealand using WorldView-2 and LiDAR data: the impact of scaling

ABSTRACT It is necessary to estimate carbon (C) stored in urban vegetation for the purpose of carbon accounting and trading. This study aims to develop a refined method for reliably estimating above-ground carbon (AGC) stock of urban vegetation from integrated WorldView-2 imagery and Light Detection And Ranging (LiDAR) data in Auckland, New Zealand. Also assessed in this study is the impact of image resolution on regional AGC estimates by vegetation type. The integration of WorldView-2 imagery with a 2-m digital surface model produced from LiDAR data enables urban vegetation to be mapped into trees (101.5 km2), shrubs (64.9 km2), and grasses (172.2 km2) at a producer’s accuracy over 95.9%. The AGC stock of trees, shrubs and grasses is estimated at 1,134,287, 207,606, and 127,427 Mg C, respectively, from the vegetation map. Overall, the total AGC of all types of vegetation does not vary significantly with image spatial resolution over the range of 5 to 30 m if estimated using the same model. This is because high AGC densities are generalised at a coarser resolution, but the larger pixel size compensates for the decrease. Although the spatial resolution does not affect the most significant spectral predicators of plot-level AGC noticeably, it has an obvious effect on both model accuracy and complexity. Thus, the impact of image resolution on AGC would be pronounced if it were estimated using different models that were the best at a given resolution. Of the three vegetation types, the AGC of shrubs is the most variable with spatial resolution, followed by trees. Thus, the AGC of relatively small but more spatially fragmented vegetation parcels is more susceptible to change in image spatial resolution. The estimation model based on spectral features of vegetation has the lowest room-mean-square-error at 15 m. More research is needed to confirm whether it is true in other natural environments in future studies.
Environmentally Assisted Cracking Behavior of S420 and X80 Steels Containing U-notches at Two Different Cathodic Polarization Levels: An Approach from the Theory of Critical Distances

This paper analyzes, using the theory of critical distances, the environmentally assisted cracking behavior of two steels (S420 and API X80) subjected to two different aggressive environments. The propagation threshold for environmentally assisted cracking (i.e., the stress intensity factor above which crack propagation initiates) in cracked and notched specimens (KIEAC and KNIEAC) has been experimentally obtained under different environmental conditions. Cathodic polarization has been employed to generate the aggressive environments, at 1 and 5 mA/cm2, causing hydrogen embrittlement on the steels. The point method and the line method, both belonging to the theory of critical distances, have been applied to verify their capacity to predict the initiation of crack propagation. The results demonstrate the capacity of the theory of critical distances to predict the crack propagation onset under the different combinations of material and aggressive environments.
Control strategies for non‐sinusoidal multiphase PMSM drives in faulty modes under constraints on copper losses and peak phase voltage

In the context of future permanent magnet synchronous machines (PMSMs) with a high number of phases (>7) in integrated drives, this study proposes several control strategies when multiphase PMSMs with non-sinusoidal back electromotive forces (back-EMFs) operate in healthy and open-circuit faults. In all operation modes, the considered constraint on current is related to the maximum root mean square current allowable in one phase of the machine. The constraint on voltage limits the maximum peak value of the phase voltage determined by the DC-bus voltage of the converter. When one or two phases are open-circuited, to maximise torque and respect the constraints, new current references obtained by several proposed methods in rotating and natural frames are imposed to the machine. Owing to the non-sinusoidal waveform of back-EMFs and the considered constraints, numerical computations based on analytical formulations are required to obtain maximal torque-speed characteristics, including the flux-weakening operation. The usefulness of the proposed strategies is verified by numerical and experimental results.
Silicon Auditory Processors as Computer Peripherals

Several research groups are implementing analog integrated circuit models of biological auditory processing. The outputs of these circuit models have taken several forms, including video format for monitor display, simple scanned output for oscilloscope display, and parallel analog outputs suitable for data-acquisition systems. Here, an alternative output method for silicon auditory models, suitable for direct interface to digital computers, is described. As a prototype of this method, an integrated circuit model of temporal adaptation in the auditory nerve that functions as a peripheral to a workstation running Unix is described. Data from a working hybrid system that includes the auditory model, a digital interface, and asynchronous software are given. This system produces a real-time X-window display of the response of the auditory nerve model.
The impact of neglecting ice phase on cloud optical depth retrievals from AERONET cloud mode observations

Abstract. Clouds present many challenges to climate modelling. To develop and verify the parameterisations needed to allow climate models to represent cloud structure and processes, there is a need for high-quality observations of cloud optical depth from locations around the world. Retrievals of cloud optical depth are obtainable from radiances measured by Aerosol Robotic Network (AERONET) radiometers in “cloud mode” using a two-wavelength retrieval method. However, the method is unable to detect cloud phase, and hence assumes that all of the cloud in a profile is liquid. This assumption has the potential to introduce errors into long-term statistics of retrieved optical depth for clouds that also contain ice. Using a set of idealised cloud profiles we find that, for optical depths above 20, the fractional error in retrieved optical depth is a linear function of the fraction of the optical depth that is due to the presence of ice cloud (“ice fraction”). Clouds that are entirely ice have positive errors with magnitudes of the order of 55 % to 70 %. We derive a simple linear equation that can be used as a correction at AERONET sites where ice fraction can be independently estimated. Using this linear equation, we estimate the magnitude of the error for a set of cloud profiles from five sites of the Atmospheric Radiation Measurement programme. The dataset contains separate retrievals of ice and liquid retrievals; hence ice fraction can be estimated. The magnitude of the error at each location was related to the relative frequencies of occurrence in thick frontal cloud at the mid-latitude sites and of deep convection at the tropical sites – that is, of deep cloud containing both ice and liquid particles. The long-term mean optical depth error at the five locations spans the range 2–4, which we show to be small enough to allow calculation of top-of-atmosphere flux to within 10 % and surface flux to about 15 %.
Applying Event-Related Potentials to Measure Perceptual Experience toward the Navigation Interface of a Mobile Game for Improving the Design

High-level user experience has become the key factor that one game can be successful in the game market. The home page of mobile games, especially the design of the navigation interface, has a significant impact on users’ initial experience, which is an important determent to users’ preferences and purchase decision. Hence, measuring users’ perceptual experiences of the navigation interface can help designers understand real demands from users. Previous studies primarily used self-report scales or interviews to measure gamers’ perceptual experiences. However, it may not reflect gamers’ real perceptions that they are feeling as most of time the feeling is short-lived and implicit. To fill this gap, the current study attempted to combine subjective evaluation with event-related potentials (ERP) to objectively measure gamers’ perceptual experience evoked by the navigation interface of the mobile game. The navigation interfaces of mobile games with low, medium, and high perceptual experience were developed and the ERP experiment was conducted to detect the differences in users’ electroencephalograph (EEG) components when subjects were exposed to the different design levels of navigation interface. The results showed that N1 reaction showed asymmetry in brain regions, and P2 and N2 showed symmetry, and relative to the navigation interface with low and medium perceptual experiences, the high level of navigation interface induced a larger amplitude of N2 in the anterior scalp and P2 in the frontal scalp. These EEG components can, therefore, be regarded as significant indicators reflecting gamers’ perceptions of the navigation interface. The findings benefit game companies of navigation interface designs.
Towards the Guidelines for Requirements Change Management in Global Software Development: Client-Vendor Perspective

Currently, being deployed by organizations to develop high-quality software at a low cost, global software development (GSD) faces many challenges that make development activities more complex. These GSD challenges are mainly concerned with requirements to change management (RCM). RCM plays a key role in the successful execution of software projects. The objective of this paper is to identify the best practices of the RCM process by adopting a systematic literature review (SLR) and validate them using questionnaire survey with industry experts. A total of 46 best practices were identified through SLR and validated with industry experts. We have further classified the identified practices in the domain of client and vendor GSD organizations with the aim to provide a clear understanding of the RCM best practices in the context of both types of GSD organizations (client, vendor). Moreover, we have conducted a comparison analysis between SLR and questionnaire survey data and found a moderate positive correlation in the ranks of both data sets (rs = 0.522, p=0.003). In addition, the criticality of the identified best practices was assessed using the criteria of a practice having frequency ≥50%. The findings of this paper provide a framework that could help the GSD organizations to address the problems related to RCM in GSD environment.
Determinants of Capital Budgeting Practices and Risks Adjustment among Cambodian Companies

This study uses a sample survey to analyse the capital budgeting practices of Cambodian companies in the manufacturing sector. The findings show that payback period, NPV, discounted payback period and accounting rate of return are the most popular evaluation techniques. The study also finds that interest rate risk as well as business cycle risk are mainly adjusted with a discount rate, and the commonly used method for calculating cost of capital is the after tax cost of debt and the weighted average cost of capital (WACC). Furthermore, the finding suggests that the longer the existence of a company, the more likely for it to use NPV method. The finding also reveals that the higher the amount of capital investment, the more it is likely to use the NPV method, while the smaller the amount of capital investment, the more likely the payback method will be used. With higher educational background, NPV and ARR are most likely the methods to be used in capital budgeting among the Cambodian firms.
Cardiovascular adverse events during treatment with darunavir-based regimens in an Italian observational study

Background: The protease inhibitor (PI) darunavir (DRV) has proven to be highly effective and well tolerated for HIV treatment. The DAD (Data collection on Adverse Effects of Anti-HIV Drugs) cohort showed an increased 5-year cumulative cardiovascular (CV) risk in patients given various PIs, including DRV, whereas two other recent studies found no association between DRV and CV diseases. Methods: We performed a post-hoc analysis of CV adverse events (CVAEs) in an Italian cohort, the TMC114-HIV4042 observational study, where 875 patients treated with ritonavir-boosted DRV-based regimens were followed for a total of 1,566 patient-years. Results: We observed 23 CVAEs of any type, including 17 [12 (95%CI, 7–19) per 1,000 patient-years] primary; 14 [10 (95%CI, 5–17) per 1,000 patient-years] were primary Framingham-type general CVAEs, close to what expected according to the Framingham algorithm based on traditional risk factors. Age and systolic blood pressure (SBP) at the time of study enrolment were the only relevant (p<0.01) independent predictors of CVAEs in all models; patients with any CVAE were on average 10 years older and had an SBP 14 mmHg higher than patients without CVAEs. When controlling for age and SBP, the association with other traditional factors, including serum lipids, and with HIV-specific factors was not statistically significant (p>0.05). Models that also adjusted for previous ARV exposure showed no statistically significant association between any-type CVAEs and either DRV doses, 1,200 or 800 mg/daily (as also suggested by propensity score stratification), or previous DRV exposure duration. Conclusion: We found no evidence of a relationship between DRV use and increased CV risk.
Flow Origins of Labor Force Participation Fluctuations

We investigate the origins of cyclical and trend movements in the labor force participation rate (LFPR) using a three-state flow decomposition. The procyclicality of LFPR can be traced to cyclical flows between employment and unemployment. By contrast, labor force entry and exit explain virtually all of the trend movements. Among men, rising labor force exit rates account for two-thirds of the trend decline in male LFPR since the 1990s. For women, trend increases in female LFPR during the 1990s were dominated by declining exit rates, while the trend decline since the Great Recession can be traced to declining entry rates.
Fringing Field Impedance Sensor for Hydration Monitoring and Setting Time Determination of Concrete Material

This paper deals with the development of a simple, low-cost, fringing field impedance sensor suitable for early age hydration monitoring and setting time determination of hydraulic cement paste. An impedance technique using a double-sided copper-cladded printed circuit board substrate as a sensor is proposed. Different batches of sensors with different probe sizes and substrate thickness have been fabricated and tested for hydraulic cement paste. The cement samples having different water-to-cement ratios (w:c) by weight are considered to study the effectiveness of the sensor. The purpose of this study is to develop a simple yet effective measurement system to determine the change in impedance of the cement paste with hydration time and thus to correlate the impedance change to determine the critical initial and final setting times. Initial and final hydration times of different cement samples are compared with the results of the commercial Vicat apparatus (VA). The values of the setting times closely match the Vicat values (the average value at 100 kHz differs by 4 m). Therefore, the proposed sensor-based system can be used in place of conventional VA to determine the hydration condition. The output of the sensor can be electronically processed further to develop a prototype system.