baseband transmission and line coding

... Digital Transmission Sampling (a) Analog signal (b) Sampled version of the signal The sampling theorem is also known as the Nyquist theorem of Sampling in case of a band limited signal And the ... And the sampling rate is also known as Nyquist rate Nyquist Theorem of Sampling for a band limited signal: A band-limited signal of W Hz may be completely recovered from its samples taken at the ... Modulation, the amplitude of the sound wave is sampled at regular intervals, and is translated into a binary number (encoding) as shown in figure 111 = 110 = 101 = 100 = 011 = 010 = 001 = 000 =...

Ngày tải lên: 09/12/2013, 16:15

... Transform and Lapped Transform Coding of Images 7.3.2 Pyramid Coding of Images 7.3.3 Subband and Wavelet Coding of Images 7.3.4 Advanced Methods in Subband and Wavelet ... Compression and Subband Coding 7.1 Compression Systems Based on Linear Transforms 7.1.1 Linear Transformations 7.1.2 Quantization 7.1.3 Entropy Coding ... wavelets and their discretetime cousins, filter banks or subband coding From work in harmonic analysis and mathematical physics, and from applications such as speech/image compression and computer...

Ngày tải lên: 03/01/2014, 23:54

... months Chapter 2: Transmission and Pathogenesis of Tuberculosis 42 References American Thoracic Society and CDC Diagnostic standards and classification of tuberculosis in adults and children Am ... any fluoroquinolone and at least one of three injectable second -line drugs (i.e., amikacin, kanamycin, or capreomycin) Because XDR TB is resistant to first -line and second -line drugs, patients ... isoniazid and rifampin, plus any fluoroquinolone, and at least one of three injectable second -line drugs A MDR TB B XDR TB 2.26 Resistant to at least the two first -line drugs, isoniazid and rifampin...

Ngày tải lên: 15/02/2014, 12:20

... economic and environmental reasons, transmission lines are situated in areas of sparse population making them subject to the vagaries of man and nature, tailor made for assaults by vandals and saboteurs ... of standard methods and equipment, but also on operating and maintenance procedures, and its impact on other utilities And all are subject to further modification to provide for load growth and ... saboteurs Finally, with transmission lines connected together in a grid, supposedly for better reliability and economy, failures causing the outage of a line may cause another of the lines to trip open...

Ngày tải lên: 18/02/2014, 22:20

... with global guidelines and latest research WHO and UNICEF should support this process and also regularly assess implementation of these guidelines in the field and consistently and publicly release ... have both quantitative and qualitative targets, milestones and deadlines UNAIDS and UNICEF should assess these plans and give feedback to countries on their strengths and weaknesses All these ... HIV-related stigma and discrimination and providing support (including nutrition and clothes) to children infected with and affected by HIV Impact of violence and stigma HIV-related stigma and discrimination...

Ngày tải lên: 05/03/2014, 13:20

... quantity of proapoptotic and antiapoptotic mRNAs The mRNA expression levels of genes hSK4, bcl-2 and p53 in HEKhSK4 cells untreated and treated with 15 lM binase for 24 h and 48 h and rRNA in SKOV-3 ... RNA fragments observed after the digestion of a single-stranded and a double-stranded hSK4 mRNA sample with binase, the nontoxic RNase Sa, and its highly cytotoxic cationic mutant 5K RNase Sa [20], ... nuclear and cytosolic fractions of FDC-P1 cells (A–C) and FDC-P1iR1171 cells (D–F) untreated (blank columns) and treated (filled columns) with 40 lM binase for 24 h (A, D), 48 h (B, E), and 72...

Ngày tải lên: 06/03/2014, 09:22

Ngày tải lên: 13/03/2014, 11:07

... load currents during peak and emergency conditions, performing coordination studies that include source and low side protection equipment, and expected transformer size and winding configuration ... maintenance and cost advantages found with power fuses Protection and control devices, circuit breakers, and station batteries are required The overcurrent relays are a small part of the total cost and ... aging, contamination, cracking, internal moisture, and loss of oil can all cause a bushing to fail Two other possible reasons are vandalism and animals that externally flash over the bushing Transformer...

Ngày tải lên: 21/03/2014, 12:08

... above a small set-value SET_4 and the negative and zero sequence currents I2 and I2 not exceed a small set-value SET_3, then a fuse failure condition will pick up to one and remain in that state thanks ... recommended by the ANSI=IEEE guides and standards Fig 2.10 represents a typical dual definite-time characteristic whereas Fig 2.11 represents a combined definite and inverse-time characteristic One ... in case of a loss of VT signal and contrary to a fault condition, there should not be any change in the current’s magnitudes and phases Therefore, the negative and zero sequence currents should...

Ngày tải lên: 21/03/2014, 12:08

... Voltages Transmission lines will be those lines operating at 138 kV and above, subtransmission lines are 34.5 kV to 138 kV, and distribution lines are below 34.5 kV These are not rigid definitions and are only ... ‘‘medium,’’ and ‘‘long’’ is not precise A short line is one in which the ratio of the source to the line impedance (SIR) is large (>4 e.g.), the SIR of a long line is 0.5 or less and a medium line s ... voltage, and a compensated faulted phase current must be used Ex ¼ Z1 Ix þ mI0 (3:2) where m is a constant depending on the line impedances, and I0 is the zero sequence current in the transmission line...

Ngày tải lên: 21/03/2014, 12:08

... the transmission lines, varying the operating conditions such as voltage profile and generation dispatch, coordinating relays and controls, and load shedding Most utilities rely on planning and ... bandwidth, usually expressed in bits per second (BPS), latency in data transmission, reliability, and communication error handling Presently, electrical utilities use a combination of analog and ... cascading overload of many more elements, mostly transmission lines, and ultimately, it may lead to a complete power system blackout A quick, simple, and reliable way to reestablish active power...

Ngày tải lên: 21/03/2014, 12:08

... ANSI=IEEE Standard C37.90, provides the standard for the Surge Withstand Capability (SWC) to be built into protective relay equipment The standard consists of both an oscillatory and transient ... in time and Eq (5.44) represents the measurements The terms wk and vk are discrete time random processes representing state noise, i.e., random inputs in the evolution of the parameters, and measurement ... as half the line time constant and different Ks for voltage and current The Kalman filter estimates phasors for voltage and current as the DFT algorithms The filter must be started and terminated...

Ngày tải lên: 21/03/2014, 12:08

... X Y LINE D Z C A LINE OSC LINE CURRENT BUS PT X FAULT B R OSC REV TRAL OSC A-G FAULT BUS PT A B LINE CURRENT C A B C DEAD TIME LINE LOAD CURRENT CHARGING NEUTRAL ... line On lines that have flat spacing, the two outside voltages transfer energy between each other that FAULT X A B R R LINE PT BUS PT FAULT CURRENT BUS VOLTAGE LINE VOLTAGE FIGURE 6.7 Bus or line ... thirteen 161 kV lines, and three 500-kV lines The reason for the extensive loss was the result of burning oil that drifted up into adjacent busses steel causing multiple bus and line faults that...

Ngày tải lên: 21/03/2014, 12:08

... Security Assessment and Control Dynamic Phenomena of Interest Timescales Transient Stability Modeling Criteria and Methods Recent Activity Off -Line DSA On -Line DSA Status and Summary 16 Power ... also exists and has been experienced at least on one system (Van Cutsem and Mailhot, 1997) It can occur when EHV transmission lines are loaded significantly below surge impedance loading and underexcitation ... rotor angle instability and voltage instability go hand in hand One may lead to the other, and the distinction may not be clear However, distinguishing between angle stability and voltage stability...

Ngày tải lên: 21/03/2014, 12:08

... traditional positive sequence powerflow model, which defines the transmission topology, line reactances, connected loads and generation, and predisturbance voltage profile Generators can be represented ... models that capture their speed torque characteristics and connected loads There are a myriad of other devices, such as HVDC lines and controls and static Var devices, which may require detailed ... Defines system topology and initial operating state Dynamic data: Includes model types and associated parameters for generators, motors, protections, and other dynamic devices and their controls Program...

Ngày tải lên: 21/03/2014, 12:08

... function of initial angle, and thus tie -line loading Thus, in the absence of mitigating means, tie -line oscillations are very likely to occur, especially at heavy -line loading (and they have on numerous ... usually predictable by simulation, its nonlinear character and vast size lead to challenging demands on system planners and operating engineers The experience and intuition of these engineers is generally ... variations and required parametric studies become tedious and prohibitively expensive for some linear analysis techniques and control design methods in general use today A good understanding of...

Ngày tải lên: 21/03/2014, 12:08

... in Fig 10.7 In this model (Xu and Mansour, 1994), x is the state variable Pt(V ) and Ps(V ) are the transient and steady-state load characteristics, respectively, and can be expressed as Pt ¼ ... these Jacobians, and their sensitivities with respect to various system parameters Bus voltage profiles and their sensitivity to variations in active and reactive power of the load and generators, ... by generators, synchronous condensers, and static-var compensators and its sensitivity to variations in load bus active and= or reactive power These indices and sensitivities, as well as their associated...

Ngày tải lên: 21/03/2014, 12:08

... (1994) and Chadalavada et al (1997), has resulted in an online tool which has been implemented and used to rank contingencies based on their severity Another online approach implemented and being ... studies and is limited to the analysis of first swing transients For more details regarding the model, the reader is referred to Anderson and Fouad (1994), Fouad and Vittal (1992), Kundur (1994), and ... engines, and use the qualitative measure provided by the direct methods to derive preventive and corrective control actions and estimate limits This line of investigation has great potential and could...

Ngày tải lên: 21/03/2014, 12:08

... stability and transfer capability problems must be solved by new controls and new substation equipment, rather than by new transmission lines Different ownership of generation, transmission, and distribution ... operating conditions and disturbances Recently, however, on -line dynamic (or transient) stability and security assessment software have been developed State estimation and on -line power flow provide ... preplanned binary logic rules and employ programmable logic controllers For example, if line A and line B trip, then disconnect sending-end generators at power plants C and D These schemes can be...

Ngày tải lên: 21/03/2014, 12:08

... equivalent circuit, and Ll represent the resistance and leakage inductance of the generator stator, Lad and Laq represent the mutual inductance between stator and rotor, and the remaining elements ... modeled as a single line with charging capacitance equal to total of the individual collector lines=cables and with series R and X adjusted to give approximately the same P and Q output at the ... analysis, the transient and steady-state variation of the load P and Q with changes in bus voltage and frequency must be modeled Accurate load modeling is difficult due to the complex and changing nature...

Ngày tải lên: 21/03/2014, 12:08