Miracle-dz/UniFAR-FTUs huggingface dataset:
Improved use of wind turbine kinetic energy for system frequency support

To ensure security operation of power systems with high wind penetration, wind turbines (WTs) are required to participate system frequency control. The amount of WT kinetic energy used for system frequency control is discussed and minimum rotor speeds according to different WT operation states are defined to avoid large drop of mechanical power during WT frequency control. The effect of different power shapes of releasing the kinetic energy on system frequency support is investigated and two methods are proposed. The first one is aimed at reducing the rate of change of frequency (ROCOF) whereas the second one aimed to reduce both the ROCOF and frequency nadir. The proposed strategies not only make full use of the available kinetic energy but also lead to a smooth transition when the rotor re-accelerates. The performance of the proposed strategies is validated by simulations using Matlab/Simulink. The results indicate significant improvement on system frequency control.
Selection on performance and tracking

ABSTRACT Tracking is widely used in secondary schools around the world. Some countries put more emphasis on the use of performance to place students into tracks (e.g. the Netherlands), while in other countries parents have more influence on the track their child will go to (e.g. Germany). This article examines whether selection into tracks based on performance has an effect on the relation between tracking and student performance and educational opportunities. Using data from the Programme for International Student Assessment for around 185 000 students in 31 countries, different estimation models are compared. The results indicate that a highly differentiated system is best for performance when schools always consider prior performance when deciding on student acceptance. In systems with a few tracks, there is no such impact. Equality of opportunity is best provided for in a system with many tracks when schools always consider prior performance.
Denitrogenation (or Oxyfuel Concepts)

Denitrogenation or oxyfuel combustion is ,based on separation of oxygen from nitrogen before combustion. The CO2 obtained is concentrated and easy to isolate after combustion. Oxyfuel combustion has been used in different industrial applications, although technological challenges have to be met for large scale power generation. An important area of improvement of this concept is to be found in the air separation unit, with the help of new technologies like membrane separation technologies, high temperature oxygen adsorption technologies, and improved cryogenic distillation.
Phytochemical and Antifungal Activity of Leaf Extracts of Corchorus olitorius and Gongronema latifolium on Fungi Associated with Post-Harvest Deterioration of Maize (Zea mays) Seeds in Oban Community, Nigeria

This study was carried out to investigate the fungal pathogens associated with post-harvest deterioration of maize seeds in storage in Oban community, Cross River State, Nigeria, determine the effect of the pathogens on the nutritional content of the maize seeds through biochemical analysis as well as evaluate the phytochemical contents and antifungal activity of ethanolic leaf extracts of Corchorus olitorius and Gongronema latifolium in controlling the isolated fungi in vitro. The fungal pathogens isolated as the causative agents of post-harvest deterioration of maize seeds in this study were Penicillium sp. , Fusarium sp. , Aspergillus sp. , and Rhizopus stolonifer. The result of biochemical analysis of fungal infected and non-infected maize seeds carried out showed a significant increase (P ≤ 0.05) in the moisture content of the fungal infected maize seeds as compared to healthy ones (control), while there was a significant decrease (P ≤ 0.05) in the crude fibre, fat, ash, protein and carbohydrate contents of the fungal infected maize seeds as compared to the healthy ones (control). For the in vitro antifungal assay, various concentrations of the extracts ranging from 20g/200ml, 40g/200 ml, 60g/200 ml, 80g/200 ml and 100g/200 ml were separately added to PDA media. Results shows that at 60g/200 ml and 80g/200 ml and 100g/200 ml concentrations, ethanolic leaf extracts of C. olitorius completely inhibited the radial growth of Penicillium sp. , Fusarium sp. , Aspergillus sp. , and R. stolonifer after seven days observation period while those of ethanolic extracts of G. latifolium completely inhibited the redial growth of the fungal pathogens at 40g/200 ml, 60g/200 ml, 80g/200 ml and 100g/200 ml concentrations. Results, however, shows that the extracts had a significant effect (P ≤ 0.05) on the World Scientific News 53(3) (2016) 157-177 -158radial growth of the fungal pathogens at all the different concentrations tested as compared with the control. Phytochemical screening of the extracts revealed the presence of cardiac glycosides, reducing sugars, flavonoids, saponnins, tannins, hydocyanin, and anthraquinones with traces of alkaloids.
Extracting News Events from Microblogs 1

Twitter stream has become a large source of information for many people, but the magnitude of tweets and the noisy nature of its content have made harvesting the knowledge from Twitter a challenging task for researchers for a long time. Aiming at overcoming some of the main challenges of extracting the hidden information from tweet streams, this work proposes a new approach for real-time detection of news events from the Twitter stream. We divide our approach into three steps. The first step is to use a neural network or deep learning to detect news-relevant tweets from the stream. The second step is to apply a novel streaming data clustering algorithm to the detected news tweets to form news events. The third and final step is to rank the detected events based on the size of the event clusters and growth speed of the tweet frequencies. We evaluate the proposed system on a large, publicly available corpus of annotated news events from Twitter. As part of the evaluation, we compare our approach with a related state-of-the-art solution. Overall, our experiments and user-based evaluation show that our approach on detecting current (real) news events delivers a state-of-the-art performance.
Macromodeling of High Frequency Interconnects Based on Accurate Delay Identification

This paper presents the rational modeling of a transmission line interconnect system from the Scattering-Parameter data using minimum-phase-all-pass (MPAP) decomposition and a system identification algorithm. Vector Fitting Algorithm (VFA) is used for system identification and it is found that delay extraction before application of VFA enables us to reduce model identification errors. The efficiency of the algorithms has been tested through examples of several lengths of lossy and lossless transmission lines under matched and mismatched terminations.
Discrimination Based on Marital Status, Gender, and Sexual Orientation: Implications for Employment Hiring Decisions

Marital status and sexual orientation discrimination has been largely underresearched and has not been researched using working professionals, or with the incorporation of sexual orientation, marital status, and gender interactions. Additionally, with the growing acceptance of same-sex relationships, marriages, and partnerships, the interaction of marital status (i.e., applicants with or without a spouse) and sexual orientation bias in the workplace needs to be examined. Our study used an experimental design that manipulated gender, marital status, and sexual orientation in interview simulations and examined participants’ (N 365 working adults) hiring decisions. A significant 3-way interaction was found such that single lesbian women received significantly higher ratings when compared with married lesbian women, and married heterosexual women received significantly higher ratings compared with single heterosexual women. The study revealed that sexual orientation interacted with marital status in women’s ratings, but not for men. This research updates current knowledge about discrimination in employment settings and provides updated information on a topic for which the existing research has been largely outdated and underresearched.
The Effect of Communication Technologies on Firm Productivity in a Difficult Business Environment: Evidence from Kenya

Kenyan firms rely on communication technologies such as email, websites, and the internet to overcome obstacles associated with excessive regulations, poor infrastructure, rampant insecurity, an uneducated workforce, widespread corruption, and inadequate finance. This study shows that such reliance has significant positive impacts on productivity mainly for firms with one or more female owners. Using a sample of enterprises in relatively low-skilled industries with few barriers to entry, the exogenous component of technology use is isolated by using information on the regional presence of mission, private, and government schools from colonial Kenya, as well as a geographical indicator which measures rainfall shocks. These instruments pass a series of robustness checks on relevance, and they satisfy the exclusion restriction. Results indicate that for firms with female owners, a 10% increase in technology use results in a 1.69 percentage point increase in value-added per worker. For male-owned firms, a positive effect is evident but significantly more muted.
Diagnosing inter-model variability of 20 th century Northern 1 Hemisphere Jet Portrayal in 17 CMIP 3 Global Climate Models

4 The present study focuses on diagnosing inter-model variability of non-zonally averaged 5 jet stream portrayal in 17 global climate models (GCMs) from the CMIP3 dataset. 6 Compared to the reanalysis, the ensemble mean 300 hPa Atlantic jet is too zonally 7 extended and located too far equatorward in GCMs. The Pacific jet varies significantly 8 between modeling groups, with large biases in the vicinity of the jet exit region that cancel 9 in the ensemble mean. After seeking relationships between 20th century model wind biases 10 and (1) the internal modes of jet variability or (2) tropical sea surface temperatures (SSTs), 11 it is found that biases in upper-level winds are strongly related to an ENSO-like pattern in 12 winter mean tropical Pacific SST biases. 13 The temporal variability of the upper-level zonal winds in the 20th century is found to 14 be accurately modeled in nearly all 17 GCMs. Also, it is shown that Pacific model biases in 15 the longitude of EOF 1 and 2 are strongly linked to the modeled longitude of the Pacific jet 16 exit, indicating that the improved characterization of the mean state of the Pacific jet will 17 positively impact the modeled variability. 18 This work suggests that improvements in model portrayal of the tropical Pacific mean 19 state may significantly advance the portrayal of the mean state of the Pacific and Atlantic 20 jets, which will consequently improve the modeled jet stream variability in the Pacific. To 21 complement these findings, a second paper is in progress that examines 21st century GCM 22 projections of the non-zonally averaged NH jet streams. 23
Indirect Field Oriented Control of an Unbalanced Nine-Phase Induction Motor due to Open Phases

Multiphase machines have several advantages when compared to three-phase machines. Their inherently higher reliability makes them attractive in several applications. For instance, the nine-phase motor can operate with up to six open phases in its stator. However, in order to allow the multiphase machine to work magnetically balanced even in open phase conditions, an adequate current control can be employed. To develop this control scheme, it is necessary a synchronous-frame modeling of a nine-phase induction motor (9PIM) under open phase faults, which is developed here. Using it, indirect field oriented control is derived, still using proportional controllers in the current loops. This is possible due to the use of an appropriate voltage decoupling considering the fault condition. Hence, the unbalanced multiphase induction motor can be controlled very similarly as a balanced one, additionally resulting in torque ripple minimization. Simulation results show the success of the proposed control scheme.
Predictions and simulations of surrounding traffic for automated highway driving of long-combination vehicles

Long combination vehicles (LCVs) are modular heavy trucks which can make the transport sector more effective. Due to the size and complex dynamics of these vehicles, automated driving (AD) functionality has the potential to improve traffic safety and prevent accidents. Lane changes on highways with very dense traffic is an example where traffic predictions are important in order for AD functionality to act safely. For LCV-sized vehicles, situations can occur where it simply is not possible to find a large enough gap in dense traffic which can accommodate the vehicle, and so communication with the surrounding traffic is necessary. This thesis examines the simulation of dense highway traffic situations where the traffic participants are able to react on intention signals such as turning indicators, as well as a method for predicting how the traffic situation will develop in the near future. This is done by introducing a concept of independent and dependent drivers in order to handle expected and emergency scenarios. Three highway traffic scenarios are identified for testing the functionality. It is shown that the system for automated driving becomes more risk-averse by considering the potential for emergency situations.
Surface Morphology and Magnetic Properties of Isolated Cylindrical Nickel Nanowires

In this article, the surface morphology and magnetic properties of isolated cylindrical nickel (Ni) nanowires fabricated by electrodeposition have been thoroughly investigated using scanning electron microscopy and Magneto-Optical Kerr Effect (MOKE) magnetometry, respectively. The surfaces of most nanowires were found to be homogenous, uniform, and cylindrical in shape. Some others show different diameters and surface features, including; protrusions and branches along their length. The diameter distribution of a wide range of nanowires was found to differ from their template pore diameters. These all variations are more likely due to defects exist in the internal surfaces of the pores within the template itself, or may be associated with the trapped air pockets within the pores during nanowires growth or due to the oxide formation or residual contaminants which may cover these wires. The nanowires lengths were found to differ from their actual lengths estimated during deposition growth. This was attributed to the breakage of nanowires into small sections during releasing process. The hysteresis loops obtained by applying a magnetic field at different angles with respect to the nanowires long axis showed square hysteresis loops with a sharp jump of Kerr signal during switching behaviour, as well as a high squareness ratio, indicating the dominance of shape anisotropy. These results are quite different from the measurements of high density templated nanowires reported in the literature, due to the small number of nearest neighbour nanowires, and hence no magneto-static interaction. The magnetisation reversal of such wires is well described by the non-uniform rotation of the curling model of domain reversal.
Rewriting Ontology-Based Mappings

Data translation consists of the task of moving data from a source database to a target database. This task is usually performed by developing mappings, i.e. executable transformations from the source to the target schema. However, a richer description of the target database semantics may be available in the form of an ontology. This is typically defined as a set of views over the base tables that provides a unified conceptual view of the underlying data. We investigate how the mapping process changes when such a rich conceptualization of the target database is available. We develop a translation algorithm that automatically rewrites a mapping from the source schema to the target ontology into an equivalent mapping from the source to the target databases. Then, we show how to handle this problem when an ontology is available also for the source. Differently from previous approaches, the language we use in view definitions has the full power of non-recursive Datalog with negation. In the paper, we study the implications of adopting such an expressive language. Experiments are conducted to illustrate the trade-off between expressibility of the view language and efficiency of the chase engine used to perform the data exchange.
Identification of a small HSP gene from hard clam Meretrix meretrix and its potential as an environmental stress biomarker

Heat shock proteins (HSPs) are molecular chaperones that help organisms cope with stressful conditions. In this study, a novel small HSP (sHSP) gene was identified from the hard clam Meretrix meretrix (designated as Mm-HSP20). The full length of the cDNA is 1222 bp, con- sisting of a 5'-terminal untranslated region (5'UTR) of 103 bp, a 3'UTR of 565 bp, and a 522 bp open reading frame encoding a polypeptide of 173 amino acids. Sequence comparison showed that Mm-HSP20 had a moderate degree of homology to the sHSP of other organisms. A sHSP feature domain, an alpha-crystallin domain, and a V/IXI/V motif in the C-terminal extension were identified in the Mm-HSP20 amino acid sequence, indicating that Mm-HSP20 is a new member of the sHSP family. The Mm-HSP20 transcript was constitutively expressed in 6 different test tissues, with the highest expression level detected in the digestive gland by fluorescent quantitative real- time PCR. The temporal expression of Mm-HSP20 mRNA in the digestive gland and hemocytes was evaluated after exposure to cadmium (Cd) (40 µg l �1 CdCl2) and benzo(a)pyrene (50 µg l �1 B(a)P) individually, and in combination (40 µg l �1 CdCl2 +5 0 µg l �1 B(a)P). Mm-HSP20 expression level increased significantly after Cd and B(a)P exposure in both tissue types. Conversely, signifi- cant Mm-HSP20 transcript repression was detected in the 24 h B(a)P-treated digestive gland sam- ples. Considerable up-regulation of Mm-HSP20 mRNA level was observed after multiple expo- sures. These results indicate that Mm-HSP20 plays a role in mechanisms involved in coping with environmental stress in hard clams. Mm-HSP20 may be suitable for use as a biomarker for heavy metal and B(a)P contamination.
What do festinos at a national arts festival regard as value for money

This research attempts to provide guidelines for the management of the Klein Karoo National Arts Festival by determining factors and identifying the determinants of value for money for this unique tourism product. A survey was conducted during the duration of the festival that was held from 31 March 2012 to 7 April 2012. Seven hundred questionnaires were distributed while 600 completed questionnaires were returned. Statistical analysis consisted of three stages: descriptive statistics to analyse the socio-demographic profile of respondents; after which a factor analysis, focusing on factors influencing value for money perceptions, and a regression analysis were performed. Four factors were identified: experience, amenities, quality and price and event attributes. Of these, it was found that event attributes is the premier factor contributing to value for money at a festival. This study could add to the body of knowledge regarding the travel behaviour of visitors as well as pinpointing what festival attendees perceive as value for money. Consequently, this article can be used to assist managers in providing value for money and in obtaining a competitive advantage in the industry by revising management structures and marketing campaigns.
Atmospheric CO2 inversion validation using vertical profile measurements: Analysis of four independent inversion models

[1] We present the results of a validation of atmospheric inversions of CO2 fluxes using four transport models. Each inversion uses data primarily from surface stations, combined with an atmospheric transport model, to estimate surface fluxes. The validation (or model evaluation) consists of running these optimized fluxes through the forward model and comparing the simulated concentrations with airborne concentration measurements. We focus on profiles from Cape Grim, Tasmania, and Carr, Colorado, while using other profile sites to test the generality of the comparison. Fits to the profiles are generally worse than to the surface data from the inversions and worse than the expected model-data mismatch. Thus inversion estimates are generally not consistent with the profile measurements. The TM3 model does better by some measures than the other three models. Models perform better over Tasmania than Colorado, and other profile sites bear out a general improvement from north to south and from continental to marine locations. There are also errors in the interannual variability of the fit, consistent in time and common across models. This suggests real variations in sources visible to the profile but not the surface measurements.
Deterministic and Probabilistic Investigation on Multiple Crack Interactions in a Semi-Infinite Domain

The investigation of multiple crack interactions in fracture mechanics is important to predict the safety and reliability of structures. This study aims to investigate the interactions of multiple parallel cracks in a semi-infinite domain in both deterministic and probabilistic ways by using an automated finite element modeling procedure and the Monte Carlo simulation. The stress intensity factor is considered as an indicator of failure and accurately evaluated by using the domain integral technique. The variation of the stress intensity factor according to the position, the length, and the number of cracks is demonstrated. In a probabilistic investigation, the effects of the number of cracks, the random distribution of the crack lengths, and the crack interactions to the failure probability are studied for a semi-infinite domain. The stress redistribution among multiple cracks, the effect of unevenly distributed crack lengths, and the combined effect of crack length uncertainties and a crack shielding effect have been examined.
An Accuracy-Enhanced Stemming Algorithm for Arabic Information Retrieval

This paper provides a method for indexing and retrieving Arabic texts, based on natural language processing. Our approach exploits the notion of template in word stemming and replaces the words by their stems. This technique has proven to be effective since it has returned significant relevant retrieval results by decreasing silence during the retrieval phase. Series of experiments have been conducted to test the performance of the proposed algorithm ESAIR (Enhanced Stemmer for Arabic Information Retrieval). The results obtained indicate that the algorithm extracts the exact root with an accuracy rate up to 96% and hence, improving information retrieval.