196,518 research outputs found
Harmonics Mitigation and Non-Ideal Voltage Compensation Utilizing Active Power Filter Based On Predictive Current Control
No full textIt is well-known that the presence of nonlinear loads in the distribution system can impair the power quality. Furthermore, the problem becomes worse in microgrids (MGs) and power electronic-based power systems as the increasing penetration of single-phase distributed generation may result in more unbalanced grid voltage. Shunt active power filters (SAPFs) are used forimproving the power quality and compensating the unbalance grid voltage. This paper presents a modification of the classical control structure based on the finite control set model predictive control (FCS-MPC). The proposed control structure can retain all the advantages of finite control set MPC, while improving the input current quality. Furthermore, a computationally efficient cost function based on only a single objective is introduced, and its effect on reducing the current ripple is demonstrated. The presented solution provides a fast response to the transients and as well as it compensates for the unbalanced grid voltageconditions. A straightforward single loop controller is compared to the conventional way of realizing the APFs, which is based on space vector pulse width modulation (SVPWM). Moreover, the proposed control solution is compared with some of the control structures in the literature. The comparison has been done in terms of dynamic response, input current total harmonic distortion(THDi), and controller structure complexity. The simulation results have been obtained from MATLAB/SIMULINK environment, while the obtained experimental results, utilizing a 15 kVA power converter, highlight the effective performance of the proposed control scheme and verifies the introduced MPC based method as a viable control solution for SAPFs
Imparipes dilatatus Mahunka & Zaki 1982
No full text<i>Imparipes dilatatus</i> Mahunka & Zaki, 1982 <p> <b>World distribution</b> – This species was described from Hungary and reported from Ukraine (Khaustov 2008).</p> <p> <b>Material examined</b> – Two females were found in soil sample of Galogah-Damghan forestry road, 36.38° N, 53.49° E, and altitude 1000 m a.s.l., June 12, 2021, coll. M. Davari.</p> <p> <b>Remarks</b> – This species is new for mite fauna of Iran.</p>Published as part of <i>Rahiminejad, Vahid, Hakimitabar, Masoud, Davari, Milad & Yahyapour, Eliye, 2023, Scutacarid mites (Acari: Heterostigmata: Scutacaroidea) of Mazandaran province, northern Iran, pp. 159-163 in Persian Journal of Acarology 13 (1)</i> on page 160, DOI: 10.22073/pja.v13i1.84210, <a href="http://zenodo.org/record/10943170">http://zenodo.org/record/10943170</a>
Model predictive control of grid forming converters with enhanced power quality
No full textThis paper proposes an enhanced finite control set model predictive control (FCS-MPC) strategy for voltage source converter (VSC) with a LC output filter. The proposed control scheme is based on tracking the voltage reference trajectory by using only a single-step prediction within the controller horizon. Besides, the suitability of different frequency control schemes with the proposed scheme to prevent from inherent variable switching behaviour of conventional FCS-MPC is investigated. Based on that, the proposed method targets two major factors influencing power quality in grid forming applications by enhancing the output voltage harmonic distortion and also preventing variable switching behaviour of FCS-MPC. Although compared to multi-step prediction approaches, only a single-step multi-objective cost function to improve computation efficiency is utilized, the introduced control schemes are able to deliver higher power quality compared to its counterpart methods as well. Furthermore, the effect of different applied cost functions on the transient response of the system is studied and investigated for the future use of the VSC in microgrids (MGs). The effectiveness of the proposed scheme was assessed by simulation using MATLAB/SIMULINK and experiment using a 5.5 kVA VSC module and the results were in good agreement
Scutacarus (Scutacarus) echidna Soil
No full text<i>Scutacarus</i> (<i>Scutacarus</i>) <i>echidna</i> (Berlese, 1905) <p> <b>World distribution</b> – Previously, this species was recorded from Italy, Germany, Greece, Hungary, France, Russia, Korea and Ukraine (Khaustov 2008).</p> <p> <b>Material examined</b> – Four females were extracted from soil samples and forest litter under old trees of Galogah-Damghan forestry road, 36.08° N, 53.48° E, and altitude 1000 m a.s.l., June 12, 2021, coll. M. Davari.</p> <p> <b>Remarks</b> – This species is new for mite fauna of Iran.</p>Published as part of <i>Rahiminejad, Vahid, Hakimitabar, Masoud, Davari, Milad & Yahyapour, Eliye, 2023, Scutacarid mites (Acari: Heterostigmata: Scutacaroidea) of Mazandaran province, northern Iran, pp. 159-163 in Persian Journal of Acarology 13 (1)</i> on page 160, DOI: 10.22073/pja.v13i1.84210, <a href="http://zenodo.org/record/10943170">http://zenodo.org/record/10943170</a>
Modelling ripple effect propagation and global supply chain workforce productivity impacts in pandemic disruptions
No full textAn increasing number of disruptions in ports, plants and warehouses have generated ripple effects
over supply networks impacting economic activity. We demonstrate how the spread of the pan-
demic geographically expands the ripple effect by reducing the workers’ participation in production,
so undermining the ability of firms and, as a result, the entire cross-border sup- ply chain network
to satisfy customers’ demands. Our model of the spatio-temporal dynamics of the propagation of
Covid-19 infection for supply networks contributes toward ripple effect visualisation and quantifi-
cation by combining the flow of goods and materials through a typical global supply chain with
an epidemiological model. The model enables prospective analyses to be performed in what-if sce-
narios to simulate the impact on the workforce in each node. The outcome should be helpful tools
for managers and scholars. Results from this research will help mitigate the impact and spread of a
pandemic in a particular region and the ability of a supply network to overcome the ripple effect. A
stylised case study of a cross-border supply chain illustrates the ripple effect by showing how waves
with crests at varying dates impact the ability to serve demand showing how a supply chain manager
can obtain a forward-looking picture
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Fall detection for elderly people using depth video data obtained by kinect
No full textAutomatic detection of unusual events such as falls is very important especially for elderly people living alone. Real-time detection of these events can reduce the health risks associated with a fall. There has been a series of ongoing researches in the ?eld of unusual event detection using the Microsoft`s depth sensor Kinect. It has been applied in areas like fall detection using only the depth images and features derived from skeletal data having exaggerated dimensionality. This thesis will propose a novel method for automatic detection of fall event by using depth cameras. Depth images generated by these cameras are used in estimating the skeletal data of a person. The contribution here is to use features extracted from this data to form a strong set of features which can help us achieve an increased precision at low redundancy. The achievements indicate that the calculated features which are derived from skeletal data are moderately powerful for detecting unusual events such as fall.Düşme gibi anormal durumlarda otomatik algılama, özellikle yaşlı ve yalnız yaşayan insanlar için çok önemlidir. Bu durumların gerçek zamanlı algılanması düşmeyle alakalı sağlık risklerini azaltabilir. Hali hazırda Microsofts depth sensor Kinect kullanılarak anormal durumların algılanması alanında bir seri araştırmalar mevcuttur. Aşırı boyutlara sahip olan iskelet verilerinden elde edilen yalnızca derinlik görüntüleri ve özellikleri kullanılarak düşme algılama gibi alanlarda uygulandı. Bu tez derinlik kameraları kullanarak düşme olaylarının otomatik algılanmasıyla ilgili yeni bir yöntem sunuyor. Bu kamaralardan elde edilen derinlik görüntüleri, kişinin vücut lekesi ve iskelet verilerin hesaplanmasında kullanılır. Buradaki katkı ise güçlü bir özellik kümesi oluşturmak için bu verilerden alınan özellikleri kullanmaktır. Düşük sayıda fazlalıkla, bu bize doğruluğu başarmamıza yardım eder. Bu başarı gösteriyor ki insan vücudundaki leke ve iskelet verilerinin ikisinden de elde edilerek hesaplanan özellikler, düşme gibi anormal durumların algılanmasında kısmen güçlüdür
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
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