Đang tải... (xem toàn văn)
3 Variable Types, Levels tài liệu, giáo án, bài giảng , luận văn, luận án, đồ án, bài tập lớn về tất cả các lĩnh vực kin...
COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services COPYRIGHT International Electrotechnical Commission Licensed by Information Handling Services 8/13/2012 Variable Types : • Qualitative/Categorical : variables are variables that are given category names instead of numbers two levels of categorical variables are • Nominal (Không thứ bậc): variables which is a purely classification variable, where there is no order or ranking such as color, yes or no items AB or C • Ordinal (Có thứ bậc) items are still placed in categories but the categories can now be ranked, for example “ strongly agree” “ agree” so on 8/13/2012 • Quantitative variables : require numerical response There are two levels of quantitative variables • Discrete: variables are numerical variables that can only increase in steps – usually they can only be integers for example, number of siblings, number of text messages – things you can count • Continuous : variables are variables that can increase or decrease continuously for example height, length, weight • When you rate something from – 1, you are putting something into categories that can be ranked The type will be qualitative, the level ordinal LBNL-5445E Changes in the Economic Value of Variable Generation at High Penetration Levels: A Pilot Case Study of California Andrew Mills and Ryan Wiser Environmental Energy Technologies Division June 2012 Download from http://eetd.lbl.gov/EA/EMP The work described in this paper was funded by the U.S. Department of Energy (Office of Energy Efficiency and Renewable Energy and Office of Electricity Delivery and Energy Reliability) under Contract No. DE-AC02-05CH11231. ERNEST ORLANDO LAWRENCE B ERKELEY NATIONAL LABORATORY Disclaimer This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, or The Regents of the University of California. Ernest Orlando Lawrence Berkeley National Laboratory is an equal opportunity employer. LBNL-5445E Changes in the Economic Value of Variable Generation at High Penetration Levels: A Pilot Case Study of California Prepared for the Office of Electricity Delivery and Energy Reliability Research & Development Division and Permitting, Siting and Analysis Division U.S. Department of Energy Washington, D.C. and the Office of Energy Efficiency and Renewable Energy Wind and Hydropower Technologies Program and Solar Energy Technologies Program U.S. Department of Energy Washington, D.C. Principal Authors: Andrew Mills and Ryan Wiser Ernest Orlando Lawrence Berkeley National Laboratory 1 Cyclotron Road, MS 90R4000 Berkeley CA 94720-8136 June 2012 The work described in this report was funded by the Office of Electricity Delivery and Energy Reliability (Research & Development Division and Permitting, Siting and Analysis Division) and by the Office of Energy Efficiency and Renewable Energy (Wind and Hydropower Technologies Program and Solar Energy Technologies Program) of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Acknowledgments The work described in this paper was funded by the Office of Electricity Delivery and Energy Reliabil- ity (Research & Development Division and Permitting, Siting and Analysis Division) and by the Office of Energy Efficiency and Renewable Energy (Wind and Hydropower Technologies Program and Solar Energy Technologies Program) of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. We would particularly like to thank Lawrence Mansueti, Patrick Gilman, and Kevin Lynn of the U.S. Depart- ment of Energy for their support of this work. For reviewing drafts of this report and/or for providing comments that helped shape our early thinking on this project Antonio Alvarez 2 -1 2 Wound Rotor Induction Generators: Transients and Control 2.1 Introduction 2 -1 2.2 The WRIG Phase Coordinate Model 2 -2 2.3 The Space-Phasor Model of WRIG 2 -5 2.4 Space-Phasor Equivalent Circuits and Diagrams 2 -7 2.5 Approaches to WRIG Transients 2 -12 2.6 Static Power Converters for WRIGs 2 -13 Direct AC–AC Converters • DC Voltage Link AC–AC Converters 2.7 Vector Control of WRIG at Power Grid 2 -18 Principles of Vector Control of Machine (Rotor)-Side Converter • Vector Control of Source-Side Converter • Wind Power WRIG Vector Control at the Power Grid 2.8 Direct Power Control (DPC) of WRIG at Power Grid 2 -34 The Concept of DPC 2.9 Independent Vector Control of Positive and Negative Sequence Currents 2 -39 2.10 Motion-Sensorless Control 2 -41 2.11 Vector Control in Stand-Alone Operation 2 -44 2.12 Self-Starting, Synchronization, and Loading at the Power Grid 2 -45 2.13 Voltage and Current Low-Frequency Harmonics of WRIG 2 -49 2.14 Summary 2 -51 References 2 -53 2.1 Introduction Wound rotor induction generators (WRIGs) are used as variable-speed generators connected to a strong or a weak power grid or as motors in the same conditions. Moreover, WRIGs may operate as stand-alone generators for variable speed. In all these operational modes, WRIGs undergo transients. Transients may be caused by the following: • Prime mover torque variations for generator mode • Load machine torque variations for motor mode 5715_C002.fm Page 1 Tuesday, September 27, 2005 1:46 PM © 2006 by Taylor & Francis Group, LLC 2 -2 Variable Speed Generators • Power grid faults for generator mode • Electric load variations in stand-alone generator mode During transients, in general, speed and voltage, current amplitudes, power, torque, and frequency vary in time, until eventually, they stabilize to a new steady state. Dynamic models for typical prime movers (Chapter 3, Synchronous Generators ), such as hydraulic, wind, or steam (gas) turbines or internal combustion engines, are needed to investigate the complete transients of WRIGs. An adequate WRIG model for transients is imperative, along with close-loop control systems to provide stability in speed, voltage, and frequency response when the active and reactive power demands are varied. Typical static power converters capable of up to four-quadrant operation (super- and undersynchro- nous speed) also need to be investigated as a means for WRIG control for constant stator voltage and frequency, for limited variable speed range. Vector or direct power control methods with and without motion sensors are described, and sample transient response results are given. Behavior during power grid faults is also explored, as, in some applications, WRIGs are not to be disconnected during faults, in order to contribute quickly to power balance in the power grid right after fault clearing. Let us now proceed to tackle the above-mentioned issues one by one. 2.2 The WRIG Phase Coordinate Model The WRIG is provided with laminated stator and rotor cores with uniform slots in which three-phase windings are placed (Figure 2.1). Usually, the rotor winding is connected to copper slip-rings. Brushes FIGURE 2.1 Wound rotor induction generator (WRIG) phase circuits. θ er ω r I a V a V cr V ar V br V b V c I b I c i cr i br i ar 5715_C002.fm Page 2 Tuesday, September 27, 2005 1:46 PM © 2006 by Taylor & Francis Group, LLC Wound Rotor Induction Generators: Transients and Control 2 -3 on the stator collect (or transmit) the rotor currents from (to) the rotor-side static power converter. For the time being, the slip-ring–brush system resistances are lumped into rotor phase resistances, and the converter is replaced by an ideal voltage source. distribution in the rather uniform airgap (slot openings are neglected). Consequently, the main Expression of uncoupling protein-3 in subsarcolemmal and intermyofibrillar mitochondria of various mouse muscle types and its modulation by fasting Maria Jimenez, Cedric Yvon, Lorenz Lehr, Bertrand Le ´ ger, Patrick Keller, Aaron Russell, Franc¸oise Kuhne, Pierre Flandin, Jean-Paul Giacobino and Patrick Muzzin Department of Medical Biochemistry, Faculty of Medicine, University of Geneva, Switzerland Uncoupling protein-3 (UCP3) is a mitochondrial inner- membrane protein abundantly expressed in rodent and human skeletal muscle which may be involved in energy dissipation. Many studies have been performed on the metabolic regulation of UCP3 mRNA level, but little is known about UCP3 expression at the protein level. Two populations of mitochondria have been described in skeletal muscle, subsarcolemmal (SS) and intermyofibrillar (IMF), which differ in their intracellular localization and possibly also their metabolic role. To examine if UCP3 is differen- tially expressed in these two populations and in different mouse muscle types, we developed a new protocol for isolation of SS and IMF mitochondria and carefully valid- ated a new UCP3 antibody. The data show that the density of UCP3 is higher in the mitochondria of glycolytic muscles (tibialis anterior and gastrocnemius) than in those of oxi- dative muscle (soleus). They also show that SS mitochondria contain more UCP3 per mg of protein than IMF mito- chondria. Taken together, these results suggest that oxida- tive muscle and the mitochondria most closely associated with myofibrils are most efficient at producing ATP. We then determined the effect of a 24-h fast, which greatly increases UCP3 mRNA (16.4-fold) in muscle, on UCP3 protein expression in gastrocnemius mitochondria. We found that fasting moderately increases (1.5-fold) or does not change UCP3 protein in gastrocnemius SS or IMF mitochondria, respectively. These results show that modu- lation of UCP3 expression at the mRNA level does not necessarily result in similar changes at the protein level and indicate that UCP3 density in SS and IMF mitochondria can be differently affected by metabolic changes. Keywords: fasting; intermyofibrillar mitochondria; muscle type; subsacorlemmal; uncoupling protein-3 (UCP3). The first uncoupling protein described, uncoupling protein-1 (UCP1), is an inner-mitochondrial membrane protein, which, by dissipating the mitochondrial proton gradient driven by the respiratory chain, uncouples oxidation from phosphorylation and therefore produces heat instead of ATP. UCP1 was found to be exclusively expressed in brown adipose tissue (for review see [1]). The novel UCP3, discovered in 1997, is abundantly expressed in rodent and human skeletal muscle. Its high sequence homology with UCP1 suggested that it had similar uncoupling activities [2]. In fact, using heterologous yeast and mammalian cell expression systems, UCP3 was shown to decrease the mitochondrial membrane potential, as measured by uptake of potential sensitive fluorescent dyes (reviewed in [3–5]). Also recent data obtained using muscle mitochondria of UCP3 knockout (UCP3KO) mice [6,7] and of transgenic mice overexpressing UCP3 in their skeletal muscle [8] confirmed the uncoupling activity of UCP3. A more recent study clearly established that UCP3 is, like UCP1, a H + transporter sensitive to nucleotides and fatty acids [9]. Many studies have been performed This Provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon. Low ficolin-3 levels in early follow-up serum samples are associated with the severity and unfavorable outcome of acute ischemic stroke Journal of Neuroinflammation 2011, 8:185 doi:10.1186/1742-2094-8-185 George Fust (fustge@kut.sote.hu) Lea Munthe-Fog (lea.munthe.fog@rh.regionh.dk) Zsolt Illes (zsolt.illes@aok.pte.hu) Gabor Szeplaki (szeplaki.gabor@gmail.com) Tihamer Molnar (tihamermolnar@yahoo.com) Gabriella Pusch (pusch@aok.pte.hu) Kristof Hirschberg (hirschbergkristof@gmail.com) Robert Szegedi (szrobert@kut.sote.hu) Zoltan Szeplaki (szeplaki@kut.sote.hu) Zoltan Prohaszka (prohoz@kut.sote.hu) Mikkel-Ole Skjoedt (moskjoedt@gmail.com) Peter Garred (garred@post5.tele.dk) ISSN 1742-2094 Article type Research Submission date 7 September 2011 Acceptance date 29 December 2011 Publication date 29 December 2011 Article URL http://www.jneuroinflammation.com/content/8/1/185 This peer-reviewed article was published immediately upon acceptance. It can be downloaded, printed and distributed freely for any purposes (see copyright notice below). Articles in JNI are listed in PubMed and archived at PubMed Central. For information about publishing your research in JNI or any BioMed Central journal, go to http://www.jneuroinflammation.com/authors/instructions/ For information about other BioMed Central publications go to Journal of Neuroinflammation © 2011 Fust et al. ; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. http://www.biomedcentral.com/ Journal of Neuroinflammation © 2011 Fust et al. ; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1 Low ficolin-3 levels in early follow-up serum samples are associated with the severity and unfavorable outcome of acute ischemic stroke George Füst 1 , Lea Munthe-Fog 2 , Zsolt Illes 3 , Gábor Széplaki 1 , Tihamér Molnar 4 , Gabriella Pusch 3 , Kristóf Hirschberg 5,7 , Robert Szegedi 6 , Zoltán Széplaki 6 , Zoltán Prohászka 1 , Mikkel- Ole Skjoedt 2 , Peter Garred 2 1 3rd Department of Internal Medicine, Semmelwies University, Budapest, Hungary, 2 Laboratory of Molecular Medicine, Department of Clinical Immunology-7631, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark, 3 Division of Clinical and Experimental Neuroimmunology, Department of Neurology, University of Pecs, Pecs, Hungary, 4 Institute of Anaesthesia and Intensive Therapy, Faculty of Medicine, University of Pecs, Pecs, Hungary, 5 Heart Center, Semmelweis University, Budapest, Hungary, 6 Department of Neurology, Kútvölgyi Clinical Centre, Semmelweis University, Budapest, Hungary, 7 Experimental Laboratory of Cardiac Surgery, University of Heidelberg, Germany Address correspondence to Dr George Füst 3rd Dept Internal Medicine Semmelweis University Budapest Kútvölgyi út 4 Phone: 361-212-9351, fax: 361-225-3899 ...8/ 13/ 2012 • Quantitative variables : require numerical response There are two levels of quantitative variables • Discrete: variables are numerical variables that can only... example, number of siblings, number of text messages – things you can count • Continuous : variables are variables that can increase or decrease continuously for example height, length, weight •