A novel scheme for control by active and reactive power utilized in gearless variable speed wind turbine system with PMSG connected to the grid

Introduction. As a result of increasing fossil fuel price and state-of-the-art technology, more and more residential and commercial consumers of electricity have been installing wind turbines. The motivation being to cut energy bills and carbon dioxide emissions. Purpose. The main goal of this work is developing a control scheme for a variable speed wind turbine generator in order to produce utmost power from varying wind types, and variable wind speed. Novelty. This research paper presents an IGBT power converter control scheme for active power in relation to wind speed and reactive power by adjusting Q-reference (Qref) value in a gearless variable speed wind turbine with permanent magnet synchronous generator. Methods. An effective modelling and control of the wind turbine with the suggested power converter is executed by utilizing MATLAB/Simulink software. The control scheme consists of both the wind turbine control and the power converter control. Simulation results are utilized in the analysis and deliberation of the ability of the control scheme, which reveals that the wind turbine generator has the capability to actively sustain an electric power grid network, owing to its ability to independently control active and reactive power according to applied reference values at variable wind speed. Practical value. This research can be utilized for assessing the control methodology, the dynamic capabilities and influence of a gearless variable-speed wind energy conversion system on electric power grids. A case study has been presented with a (3×10 MW = 30 MW) wind farm scheme.Вступ. Внаслідок зростання цін на викопне паливо та використання найсучасніших технологій, дедалі більше побутових та комерційних споживачів електроенергії встановлюють вітряні турбіни. Мотивація полягає в тому, щоб скоротити рахунки за електроенергію та викиди вуглекислого газу. Мета. Основною метою цієї роботи є розробка схеми управління вітряним генератором зі змінною швидкістю для отримання максимальної потужності від різних типів вітру та змінної швидкості вітру. Новизна. У даній дослідницькій роботі представлена схема управління силовим IGBT перетворювачем для активної потужності в залежності від швидкості вітру та реактивної потужності шляхом регулювання значенняQ-еталона (Qref) у безредукторній вітровій турбіні з регульованою швидкістю та синхронним генератором із постійними магнітами. Методи. Ефективне моделювання та керування вітровою турбіною з запропонованим перетворювачем потужності здійснюється з використанням програмного забезпечення MATLAB/Simulink. Схема управління складається з управління вітряною турбіною і з управління силовим перетворювачем. Результати моделювання використовуються для аналізу та обговорення можливостей схеми управління, що показує, що генератор вітрової турбіни здатний активно підтримувати електроенергетичну мережу завдяки своїй здатності незалежно контролювати активну та реактивну потужність відповідно до застосовуваних еталонних значень при змінній швидкості вітру. Практична цінність. Це дослідження може бути використане для оцінки методології управління, динамічних можливостей та впливу безредукторної системи перетворення енергії вітру зі змінною швидкістю на електричні мережі. Наведено тематичне дослідження зі схемою вітряної електростанції (3×10 МВт = 30 МВт)

Enantioselective Gas Chromatographic Analysis of Cyclopropane Derivatives

Chirasil-β-Dex was used as chiral stationary phase for the enantioselective gas chromatographic analysis of several new chiral cyclopropane derivatives. The GC method provides information about the chemical yields of the cyclopropane products, enantioselectivity, substrate specifity, and catalytic activity of the chiral catalysts used in the inter- and intra-molecular cyclopropanation reactions and avoids time-consuming work-up procedure

Can large language model agents simulate human trust behaviors?

Large Language Model (LLM) agents have been increasingly adopted as simulation tools to model humans in applications such as social science. However, one fundamental question remains: can LLM agents really simulate human behaviors? In this paper, we focus on one of the most critical behaviors in human interactions, trust, and aim to investigate whether or not LLM agents can simulate human trust behaviors. We first find that LLM agents generally exhibit trust behaviors, referred to as agent trust, under the framework of Trust Games, which are widely recognized in behavioral economics. Then, we discover that LLM agents can have high behavioral alignment with humans regarding trust behaviors, particularly for GPT-4, indicating the feasibility to simulate human trust behaviors with LLM agents. In addition, we probe into the biases in agent trust and the differences in agent trust towards agents and humans. We also explore the intrinsic properties of agent trust under conditions including advanced reasoning strategies and external manipulations. We further offer important implications of our discoveries for various scenarios where trust is paramount. Our study provides new insights into the behaviors of LLM agents and the fundamental analogy between LLMs and humans

Serum transforming growth factor-beta1 in asthmatic children

Background: Transforming growth factor-beta1 is a multifunctional cytokine which has been linked to the pathogenesis of subepithelial fibrosis and airway wall remodeling in bronchial asthma. Objective: To outline the changes in serum TGF-beta1 in children with bronchial asthma in relation to severity of asthma and different treatment modalities. Methods: Twenty-three children with bronchial asthma recruited from the Pediatric Allergy and Immunology Clinic of Ain Shams University Children’s Hospital were enrolled in the study as well as 29 healthy controls. Asthmatic children were classified according to severity into two groups; the mild asthma group which included 12 children, 4 with mild intermittent and 8 with mild persistent asthma (none received steroid therapy), and the severe persistent asthma group which included 11 children (all were on steroid therapy). All patients were subjected to clinical evaluation and laboratory investigations including absolute eosinophilic count (AEC), total serum IgE% and biologically active serum TGF-beta1 by ELISA technique. All patients were studied during acute asthma exacerbations. Reevaluation during steady state asthma was carried out for 8 patients with mild persistent asthma and 9 with severe persistent asthma. Results: During acute asthma exacerbations, the mean serum TGF-beta1 was significantly elevated in mild asthma (77.04 ± 57.04 ng/ml) compared to controls (21.81 ± 22.09 ng/ml). However for severe persistent asthma , the mean serum TGF-beta1 was significantly lower (4.23 ± 0.85 ng/ml) than in controls. Comparison of paired observations of serum TGF-beta1 revealed a significant drop, during steady state, in patients with mild asthma, whereas in severe asthma, a significant rise was observed. The levels of both asthma groups during steady state were comparable to the control values. A positive correlation, of borderline significance, between serum TGF-beta1 and total serum IgE% was observed among mild asthamtics during acute exacerbations (r = 0.55). Conclusion: The behavior of serum TGF-beta1 in acute asthma exacerbations depends on asthma severity and is perhaps related to steroid inhalation therapy. The tendency towards normality of serum TGF-beta1 in steady state asthma is possibly a good prognostic sign.Keywords: TGF-beta1, bronchial asthma, children, remodelingEgypt J Pediatr Allergy Immunol 2004; 2(1): 46-5

Multimodal Fake News Detection with Textual, Visual and Semantic Information

[EN] Recent years have seen a rapid growth in the number of fake news that are posted online. Fake news detection is very challenging since they are usually created to contain a mixture of false and real information and images that have been manipulated that confuses the readers. In this paper, we propose a multimodal system with the aim to di erentiate between fake and real posts. Our system is based on a neural network and combines textual, visual and semantic information. The textual information is extracted from the content of the post, the visual one from the image that is associated with the post and the semantic refers to the similarity between the image and the text of the post. We conduct our experiments on three standard real world collections and we show the importance of those features on detecting fake news.Anastasia Giachanou is supported by the SNSF Early Postdoc Mobility grant under the project Early Fake News Detection on Social Media, Switzerland (P2TIP2 181441). Guobiao Zhang is funded by China Scholarship Council (CSC) from the Ministry of Education of P.R. China. The work of Paolo Rosso is partially funded by the Spanish MICINN under the research project MISMIS-FAKEnHATE on Misinformation and Miscommunication in social media: FAKE news and HATE speech (PGC2018-096212-B-C31)Giachanou, A.; Zhang, G.; Rosso, P. (2020). Multimodal Fake News Detection with Textual, Visual and Semantic Information. Springer. 30-38. https://doi.org/10.1007/978-3-030-58323-1_3S3038Boididou, C., et al.: Verifying multimedia use at MediaEval 2015. In: MediaEval 2015 Workshop, pp. 235–237 (2015)Castillo, C., Mendoza, M., Poblete, B.: Information credibility on Twitter. In: WWW 2011, pp. 675–684 (2011)Chollet, F.: Xception: deep learning with depthwise separable convolutions. In: CVPR 2017, pp. 1251–1258 (2017)Davidson, T., Warmsley, D., Macy, M., Weber, I.: Automated hate speech detection and the problem of offensive language. In: ICWSM 2017 (2017)Deng, J., Dong, W., Socher, R., Li, L.J., Li, K., Fei-Fei, L.: ImageNet: a large-scale hierarchical image database. In: CVPR 2009, pp. 248–255 (2009)Ghanem, B., Rosso, P., Rangel, F.: An emotional analysis of false information in social media and news articles. ACM Trans. Internet Technol. (TOIT) 20(2), 1–18 (2020)Giachanou, A., Gonzalo, J., Mele, I., Crestani, F.: Sentiment propagation for predicting reputation polarity. In: Jose, J.M., et al. (eds.) ECIR 2017. LNCS, vol. 10193, pp. 226–238. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-56608-5_18Giachanou, A., Ríssola, E.A., Ghanem, B., Crestani, F., Rosso, P.: The role of personality and linguistic patterns in discriminating between fake news spreaders and fact checkers. In: Métais, E., Meziane, F., Horacek, H., Cimiano, P. (eds.) NLDB 2020. LNCS, vol. 12089, pp. 181–192. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-51310-8_17Giachanou, A., Rosso, P., Crestani, F.: Leveraging emotional signals for credibility detection. In: SIGIR 2019, pp. 877–880 (2019)He, K., Zhang, X., Ren, S., Sun, J.: Deep residual learning for image recognition. In: CVPR 2016, pp. 770–778 (2016)Huang, D., Shan, C., Ardabilian, M., Wang, Y., Chen, L.: Local binary patterns and its application to facial image analysis: a survey. IEEE Trans. Syst. Man Cybern. Part C 41(6), 765–781 (2011)Khattar, D., Goud, J.S., Gupta, M., Varma, V.: MVAE: multimodal variational autoencoder for fake news detection. In: WWW 2019, pp. 2915–2921 (2019)Ojala, T., Pietikainen, M., Maenpaa, T.: Multiresolution gray-scale and rotation invariant texture classification with local binary patterns. IEEE Trans. Pattern Anal. Mach. Intell. 24(7), 971–987 (2002)Popat, K., Mukherjee, S., Yates, A., Weikum, G.: DeClarE: debunking fake news and false claims using evidence-aware deep learning. In: EMNLP 2018, pp. 22–32 (2018)Rashkin, H., Choi, E., Jang, J.Y., Volkova, S., Choi, Y.: Truth of varying shades: analyzing language in fake news and political fact-checking. In: EMNLP 2017, pp. 2931–2937 (2017)Shu, K., Wang, S., Liu, H.: Understanding user profiles on social media for fake news detection. In: MIPR 2018, pp. 430–435 (2018)Shu, K., Mahudeswaran, D., Wang, S., Lee, D., Liu, H.: FakeNewsNet: a data repository with news content, social context and spatialtemporal information for studying fake news on social media. arXiv:1809.01286 (2018)Simonyan, K., Zisserman, A.: Very deep convolutional networks for large-scale image recognition. arXiv:1409.1556 (2014)Szegedy, C., Vanhoucke, V., Ioffe, S., Shlens, J., Wojna, Z.: Rethinking the inception architecture for computer vision. In: CVPR 2016, pp. 2818–2826 (2016)Tausczik, Y.R., Pennebaker, J.W.: The psychological meaning of words: LIWC and computerized text analysis methods. J. Lang. Soc. Psychol. 29(1), 24–54 (2010)Vosoughi, S., Roy, D., Aral, S.: The spread of true and false news online. Science 359(6380), 1146–1151 (2018)Wang, Y., et al.: EANN: event adversarial neural networks for multi-modal fake news detection. In: KDD 2018, pp. 849–857 (2018)Zhao, Z., et al.: An image-text consistency driven multimodal sentiment analysis approach for social media. Inf. Process. Manag. 56(6), 102097 (2019)Zlatkova, D., Nakov, P., Koychev, I.: Fact-checking meets fauxtography: verifying claims about images. In: EMNLP-IJCNLP 2019, pp. 2099–2108 (2019

Production of monoclonal antibodies to Grapevine virus D and contribution to the study of its aetiological role in grapevine diseases

Six stable hybridoma cell lines secreting monoclonal antibodies (MAbs) to Grapevine virus D (GVD) were obtained by fusing spleen cells of immunized BALB/c mice with mouse myeloma cell line Sp 2/0-Ag 14, In ELISA all MAbs detected the virus in Nicotiana leaf extracts or cortical shavings from mature grapevine canes, The use of a polyclonal antiserum for coating plates and of monoclonal antibodies and antimouse-conjugated antibodies for antigen detection, gave highly efficient and reproducible results for identification of GVD in field-grown grapevines. The reliability of the ELISA kit was confirmed by GVD-transmission tests to herbaceous hosts, using in vitro explants as inoculum, 223 vines affected by one or more of the 4 syndroms of the rugose wood complex (Kober stem grooving, Corky bark, LN stem grooving and Rupestris stem pitting) were tested in ELISA for the detection of Grapevine virus A (GVA), Grapevine virus B (GVB) and GVD and by Western blot for the detection of Grapevine rupestris stem pitting associated virus (GRSPaV). The possible cause-effect relationship between GVA and KSG, GVB and Co, and GRSPaV and RSP was confirmed, but no consistent association was found between GVD and any of the 4 above syndromes, Intriguingly, a reduction in the expression of stem pitting symptoms in V. rupestris (from 90 % to 75 %) and of stem grooving symptoms in Kober 5BB (from 95 % to 70 %) was observed when vitiviruses and GRSPaV were contemporarily present in the same indicator. Preliminary data of a survey involving 676 grapevine samples showed a high incidence (31 %) of GVD, regardless of the geographical origin of samples.

Swept-source optical coherence tomography changes and visual acuity among Palestinian retinitis Pigmentosa patients: a cross-sectional study

Background: Retinitis pigmentosa (RP) is a heterogeneous group of inherited ocular diseases that result in progressive retinal degeneration. This study aims to describe different Swept-source Optical Coherence Tomographic (SS-OCT) changes in Palestinian RP patients and to explore possible correlations with Visual Acuity (VA). Methods: A cross-sectional observational study was conducted on Retinitis Pigmentosa patients diagnosed with RP in a tertiary eye hospital. Full history and ocular examination were made. SS-OCT imaging was done for all eyes assessing the presence of cystoid macular edema, epiretinal membrane, macular holes, and external limiting membrane, ellipsoid zone status. Also, central macular thickness and choroidal vascular thickness were measured. // Results: The study was run on 161 eyes of 81 patients; 53 males and 28 females. The average age at examination was 26.1 (6–78) years. Twenty-six eyes (16.1%) were of syndromic RP patients, mostly Usher syndrome; 20 eyes (12.4%). The mean Logaritmic minimal angle of resolution (LogMAR) of Best Corrected Visual Acuity (BCVA)of the study sample was 0.66 ± 0.7. The most prevalent change was cystoid macular edema [28 eyes, (17.4%)], followed by epiretinal membrane [17eye, (10.6%)]. A macular hole was noted only in one eye (0.6%). Ellipsoid zone and external limiting membrane were absent in 55 eyes (35.0%) and 60 eyes 37.5%. Vitreous hyperreflective foci were found in 35 eyes (43.8%). LogMAR of BCVA was associated significantly with cystoid macular edema (p = 0.001), ellipsoid zone(p = 0.001), and external limiting membrane (p = 0.001). // Conclusions: Detailed SS-OCT assessment in Palestinian patients diagnosed with RP identified different morphologies from other populations. Cystoid macular edema and vitreous hyperreflective foci may reflect signs of early or intermediate stages of the disease. Disease progression can be monitored by measuring the length/width (area) of ellipsoid zone +/− external limiting membrane and choroidal vascular thickness, which should be evaluated serially using high-resolution OCT

Exhaustive and Efficient Constraint Propagation: A Semi-Supervised Learning Perspective and Its Applications

This paper presents a novel pairwise constraint propagation approach by decomposing the challenging constraint propagation problem into a set of independent semi-supervised learning subproblems which can be solved in quadratic time using label propagation based on k-nearest neighbor graphs. Considering that this time cost is proportional to the number of all possible pairwise constraints, our approach actually provides an efficient solution for exhaustively propagating pairwise constraints throughout the entire dataset. The resulting exhaustive set of propagated pairwise constraints are further used to adjust the similarity matrix for constrained spectral clustering. Other than the traditional constraint propagation on single-source data, our approach is also extended to more challenging constraint propagation on multi-source data where each pairwise constraint is defined over a pair of data points from different sources. This multi-source constraint propagation has an important application to cross-modal multimedia retrieval. Extensive results have shown the superior performance of our approach.Comment: The short version of this paper appears as oral paper in ECCV 201

The Power to Resist: Mobilization and the Logic of Terrorist Attacks in Civil War

Existing research has argued that terrorism is common in civil war because it is "effective." Surprisingly, however, only some groups use terrorism during civil wars, while many refrain altogether. We also see considerable variation in the use of terrorism over time. This article presents a theory of terrorism as a mobilization strategy in civil war, taking into account benefits, costs, and temporal dynamics. We argue that the choice and the timing of terrorism arise from the interaction between conditions for effective mobilization and battlefield dynamics. Terrorism can mobilize support when it provokes indiscriminate government repression or when it radicalizes rebels' constituency by antagonizing specific societal groups. The timing of attacks, however, is in uenced by battlefield losses, which increase rebels' need to rally civilian support. The analyses of new disaggregated data on rebels' terrorist attacks during con icts (1989-2009) and of ISIS tactics in Iraq and Syria support our theoretical argument