...The single-phase induction motor can successfully be driven from a variable frequency power supply. Hence, the motor speed can be easily adjusted. The torque performance of the capacitor- connected motors can be enhanced at low frequency range by altering the V/f control law such that the internal power dissipation in the motor is held constant. VFD control provides efficient speed control the speed is controlled by varying the frequency not the stator voltage. The power factor is improved and the harmonic distortions were less. The simulation of a Modified SEPIC PFC converter fed induction motor drive is done using MATLAB. MATLAB is a high performance language for technical computing. It integrates computation, visualization and programming in an easier environment where problems and solutions are expressed in familiar mathematical notation. MATLAB is specially designed simulation software for power electronics and motor drive. By using MATLAB, various converter configurations can be modelled and compared. 4.1 Open Loop control Fig 4.1 Open loop control of Modified SEPIC converter Input voltage of 230V is given to the Modified SEPIC PFC Converter so that an output voltage of 400V DC is obtained. The input current waveform is of pure sinusoidal. Fig 4.2 Input Current Waveform Fig 4.3 Output Voltage Waveform Power factor of 0.98 above is obtained using the open loop control of the Modified SEPIC PFC converter. 4.2 Closed Loop Control Fig 4.4 Closed Loop Control...
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...crossover gives genetic algorithm much of their power. With crossover, beneficial mutations on two parents can be combined immediately when they reproduce. Mutation, on the other hand, randomly changes a bit in an individual from 0 to1 or vice versa, thereby introducing new material into the knowledge base. This operator is assigned a very low percentage of activation, causing it to function as a background operator. Figure 4 4 Two-point crossover Figure 4 5 Mutation Comparison of optimization strategies This study is not a comparative study of search and optimization techniques. Nonetheless, it is important to question whether GA is the best choice for this study. David E (1989) identifies three main types of search strategies: calculus-based, random, and enumerative as known as heuristic approaches. (See Figure 4-1) The methods can be applied depending on the type of the function one wants to optimize. In the following sub section, several different sorts of strategies will be explained. Figure 4 5 different optimization strategies Hill climbing strategy Hill climbing strategy is one of calculus-based strategies and is the intuitive method any wanderer would use to reach the peak of a mountain in a dense fog: always walk uphill. In the calculation process, the program seeks local optima by hopping on the function and moving in a direction related to the local gradient. The major problem with hill climbing is that the result strongly depends on the starting point...
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...1.5.1.1 Incandescent Lamp A tungsten filament bulbs were used to performed and verified the effect of voltage variations on the performance and efficiency of the lighting lamp. From the experimental setup, it was showed that the lamps (incandescent lamps) consumes more energy at higher voltages; as the voltage increase, the lamp brightness (intensity) increases. Similarly, as the voltage decreases the lamps brightness appear dim. It should worth saying here that as the brightness increase at a higher voltages, so it consumes more energy and it may lead to a shorter lifespan of the lamp. One of the foremost effect of voltage variations on the incandescent lamp was lamp flicker. Lamp flicker is an effect on a lamp brightness in which there is rapid visible changes or variations of the intensity or brightness level for the incandescent lamp. The fluctuations in the brightness or intensity of the lamps causes inconvenience or discomfort to the utility consumers. 1.5.1.2 Computer From the experimental setup, it was clearly showed that the computer (Laptop) consumes a constant power with voltage variations. As the voltage varies with the corresponding variation in current at 70volts, the laptop was still consuming the same power but one effect is noticed with the charger becoming hotter showing high current presences at the time of very low voltage which can damage the charger overtime. 1.5.1.3 Television The CRT (Cathode Ray Tube) television of 34cm, 14'' was used for this experimental...
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...In the simulation result for VSWR is shown in the figure N065, where for the frequency of 5.8GHz have an excellent result with 0.10dB and for S-band was 1.08, both results are less that 2dB and this difference of matching is reflected in the graphic of return loss. Figure 65 Comparison of the VSWR between S & C-band before assembly Figure 66 Comparison of the Smith Chart between S & C-band before assembly In figures N066 of the Smith Chart shows that the frequency of 5.8GHz is very near to center of the Smith Chart, and is seen in the figure N067 where de input impedance is 49.96-j054 for 5.8 GHz but is 48.40-j081 for 2.4GHz and the C-band is matching with the port in 50Ω. This is the reason of the difference of the return loss between both frequencies. Figure 67 Comparison of the input impedance between S & C-band before assembly The requirement to apply microstrip antenna in the CubeSat is that have an excellent realized gain in comparison with the VHF and UHF antennas, when is applied a single patch has a little gain with 6.62dB for θ=00 in 2.4GHz but 10.43dB for θ=130 in 5.8GHz, as shown in figure N068. In the figure N069 is shown that the F/B is better in C-band. Figure 68 Comparison of the realized gain between S & C-band before assembly Figure 69 Comparison of the realized gain and F/B between S & C-band before assembly Directivity is other parameter that is improved when is used an array from 6.94dB until 10.64dB, see figure N070. Figure 70 Comparison...
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...detection vector of the k-th user within the target cell is hˆ1k.The average user rate is outlined by PROPERTIES OF BAYESIAN ESTIMATOR Before running simulations, we provide some discussions to understand the properties of Algorithm 1 (namely the Bayesian estimator). Specifically, our aim is to show how the MSE of the Bayesian estimator can be improved over the LS estimator. We begin by investigating the simplest case of not having pilot contamination, i.e., B = 1, and adopt the orthogonal pilot sequences. In that case, combining (2) with (8), we have the following equivalent channel In the higher than analysis, we have a tendency to didn't take into account the pilot interference from different users as a result of the pilot sequences area unit orthogonal. However, within the underdetermined system of interest, the pilot matrix isn't any longer orthogonal. Recent ends up in[23], [24] in contestable that once S is random and sufficiently large, near-minimum MSE (MMSE) estimation continues to be potential via the AMP algorithmic rule. For this reason, the pilot sequences are haphazardly generated for the Bayesian expert. it absolutely was illustrated in [39] that within the large-system limit,11 the output of AMPis comparable to the scalar channel (29) however with a rise inthe background level. Therefore, the MSE of the AMP algorithmic rule is identical to (32) however substitution Δn with an efficient background level Δeff. Recall that AMP is repetitious. Following [39], the effective...
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...Abstract – Lab 5 required the use of a new circuit which was created using a printed circuit board. This board acted as an ECG amplifier to output an ECG signal. We used a soldering iron to connect all components to the printed circuit board, allowing use to practice our soldering skills. A set of three leads were attached to a teammate. The board was then connected to the leads and an oscilloscope which displayed the signal. The lab was completed with some success, as our ECG amplifier briefly displayed a signal. However, we determined that our board is generally unreliable, and must do some troubleshooting before further use. I. Introduction The purpose of this lab was to refamiliarize ourselves with soldering, which we learned in ELE 202 last semester, and to create a functioning ECG amplifier. We were provided with an empty printed circuit board and were given a schematic and a photo of the complete circuit. We used the schematics to solder components onto the printed circuit board. There were no additions made to the...
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...V. SIMULATIONS AND RESULTS The output reference voltage drift of the proposed cross-coupled gain stage bandgap reference circuit as a function of temperature is as shown in Fig. 7.The output voltage is almost constant at 1.12V. From the simulation, the TC obtained for this circuit is 11.1ppm/°C. The VMAX is 1.1223V and VMIN is 1.12019V. For further minimizing the temperature coefficient value , piecewise curvature corrected current generator is added to the cross-coupled gain stage BGR. Fig.8. is the output voltage drift plot of the piecewise curvature corrected BGR as a function of temperature. The output voltage is almost constant at 1.09V From the simulation, the TC obtained for this circuit is 5.9ppm/°C. The VMAX is 1.098515V and VMIN is 1.07369V. The power supply rejection ratio obtained by this circuit is around -28 dB. The negative indicates that it is attenuation. So even if there is a voltage variation in the input power supply, it does not change the output reference voltage drastically. The Fig.10. proves that the proposed BGR can work at 1.6-V to 2.3-V supply voltage. The resistor value here was chosen accordingly to suit the 1.8-V supply voltage. It can be noted that the proposed BGR can function well at wide temperature range, without trimming the resistor value following supply voltage variation. Fig. 7: Output voltage drift plot of the cross coupled gain-stage BGR as a function of temperature. Fig. 8: Output voltage drift plot of the piecewise curvature...
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...Amazon 5 Bullet Points: ELIMINATE CONFUSION: Conveniently manage pills for the entire week MULTIPLE DIVIDERS: Each tray has four sections for morning, noon, evening and bedtime COLOR-CODED DAYS: Each day has a designated color to eliminate missed pills COMPACT DESIGN: Pill tower is compact for use at home, at work or while traveling CONVENIENT PILL SPLITTER: Easy to use pill splitter is also included Product Description: Organize and manage pills easily and efficiently with the Vive plastic pill organizer. Conveniently manage medications and supplements with the easy to use Vive pill organizer. The durable plastic pill box contains seven color-coded trays with sliding lids, one for each day of the week. Each tray is divided into four compartments:...
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...This was the circuit’s input voltage. The Tektronix TDS 2014B oscilloscope was then used to verify the accuracy of the output wave by making sure that the amplitude was 10V peak-to-peak, with a frequency of .5 Hz and a mean value of zero. Subsequently, this square wave was then applied to the input of the RC circuit. The functionality of the circuit was also verified when the left two LEDs lit up in pairs and then right two LEDs lit in pairs successively. SignalExpress was used to record and graph the input of the system, which was a square wave, and the output of the RC circuit. This graph verified the functionality of the of circuit and also aided in calculating the time constant of the system. Next, the circuit was modified by a adding another 0.1 μF capacitor in parallel to the first capacitor and by replacing the 470kΩ resistor with an 820kΩ resistor. This is shown in Figure 10. The second, third and fourth LEDs were disabled by disconnecting...
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...CHAPTER 6 SIMULATION RESULTS 6.1 Introduction The passive filters were designed according to the specifications of Table 2. The precharge method and the pre-charge sequence are an important and not trivial design step of the iUPQC due to the power flow characteristics of the system. During the start-up, the voltage supplied to the load cannot be distorted, and the iUPQC coupling in the circuit shall not affect the load. The pre-charge method developed allows the start-up of the iUPQC with no need of load power disconnection. The used pre-charge sequence is shown in Fig. 6.1.The pre-charge circuit has three contactors, namely, Ks, Kp, and Kp2, and one in-rush resistor Rpc. The switches sw1 and sw2are used symbolically to show the switching turn-on time. The Kp1 and Kp2 contactors are initially opened, while the Ks contactor is initially closed, and the switching of both active filters is initially disabled. Fig 6.1 Precharge sequence of the iUPQC The pre-charge sequence starts when the contactor Kp1 is turned on, providing the charge of the dc link capacitors through antiparallel diodes present in the PAF power circuit. After 340 ms, the switching of the SAF sw1 is enabled, causing a voltage unbalance on the dc link during a short period of time due to the stabilization time of the SAF unbalanced-voltage control loop. After 1s, the Ks contactor is turned off, allowing the increase of the dc link voltage by SAF operation. After 10 ms, the switching of the PAF sw2 is enabled, starting...
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...To begin the voltage measurement procedure, we made sure that the DC Power supply cables (positive and negative) were plugged into the power supply source so we could obtain a precise and accurate measurement. After we secured our cables into our power supply, we turned our power supply source on. We discovered that it was not directly plugged into the electrical outlet, so we connected it to the outlet and the digital numbers on the power supply appeared. Our next step was to tune the power supply’s current knob to barely above the 0 value, this gave us a minimal amount of potential electrons in our cable. When our current knob was perfectly tuned, we began to adjust our voltage knob to 6.5 volts. Obtaining the 6.5 volts on the power supply was a bit tedious. We had to be extremely delicate with the knob to acquire the 6.5 volt reading. After minutes of adjusting, the 6.5 volt reading finally appeared. In order to check and see if the power supply source was revealing an accurate reading, we turned on the digital multimeter and adjusted the switch to DC voltage. We connected both sets of cables from each device. For the first measurement, our reading was almost 100% percent accurate. We obtained 6.431 volts which was almost perfect. Since we got off to a fast start we went ahead and calculated the percent error for our measurements. We calculated a 1.1% error. To continue the experiment, we went ahead and repeated the same procedure but adjusted the volt knob to...
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...The RED [13] queue is very sensitive to parameters setting. Suppose, if wq is too small then it responds too slowly to short-lived congestion. On the other side, if wq is too large then the average queue size reacts too slowly to instantaneous queue size. Again, the values of two thresholds are also responsible for controlling average queue delay and packet loss rate. Therefore, after appropriate assessment of RED parameters as shown in Table 2.1 the following values are used in our simulation. Initially, the simulation of RED queue is all run using a buffer size of 100 packets with minth ranges from 5 to 50 packets. The maxth is set to 5 times minth with average queue length as wq=0.002 and maxp=1/50. The calculated average queue size avg changes fairly slowly compared to q. Upon setting these values the RED controls the average queue size, and actual queue size to prevent or reduce packet loss to minimum possible. Again, the behavior of the RED queue is also analyzed at regular intervals of timeslot even at a bottleneck link with the various arrival rate, average queue length and instantaneous queue length. The same simulation is again run with the Drop Tail queuing technique by varying buffer sizes. Their results are evaluated as below. Table 3.1 Evaluation of RED parameters The queueing performance of an IQ switch is concern the first factor is to consider is queueing delay. The queueing delay mainly depends on the parameters like buffer size, maxth, and minth. These...
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...Fig. 5. Simplified block diagram of the test setup for assessing the absolute and relative pulse response of the measuring receivers The RF generator provides a continuous wave signal at the different frequencies selected for bands C and D. Then, the AWG produces the gating signal that modulates the carrier by switching on and off the CW signal, creating a pulse according to CISPR16-1-1 requirements. Finally, the modulated pulse is feed directly to the EMI measuring receiver. The amplitude of the CW signal and the gating duration are defined in Table IV for bands A to D. TABLE IV. REFERENCE PULSE DURATION AND AMPLITUDE SPECIFICATION Frequency Band Td (μs) Urms (mV) A 100 95,5 B 2,2 101,6 C 0,167 186,3 D 0,167 186,3 The specific carrier frequency...
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...2. The data is presented using three tables and four figures. The first table examined the LC50 values for species S. endius and U. rufipes under forced exposure. The LC50 values were taken of the three active ingredients, imidacloprid, dinotefuran and methomyl, found in fly granular bait. The second table further examines both fly species and displays the mean, standard error, t-test, and difference for the times spent in the area with and without the active ingredients. The third table lists data for both species of flies, but this time documenting the mean and standard error difference in time spent at arenas with a medium or large amount of fly pheromone. The first figure displayed data obtained for the species Spalangia endius. The data was represented in a bar graph. The first bar graph was comparing the proportion of replicates contacted for the three bait types and control. The second bar graph compared the number of grooming events per replicate for each bait type and control. The flies were exposed for ten minutes. The same experiment was repeated for the second fly species for which the data is displayed in figure two. The second figure organized the data in the same fashion and compared the same variables except the data displayed was collected for the Urolepis rufipes species. Figure three was used to measure the “proportion of S. endius females surviving when exposed to bait residue”. Figure four displayed the similar data but taken for the U. rufipes females. 3...
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...Once the sample is processed, the samples are tested for the presence of various pathogenic viruses. In my placement laboratory this is usually done by using the real time fast PCR instrument. This is a quick and reliable method, generating results by the end of the day. However, since the principle of PCR is molecular amplification of nucleic acid, it has a disadvantage of getting contaminated quite easily. If a sample even gets slightly contaminated by a few virus particles or previously amplified material, at the end of the test the nucleic acid of that virus will be greatly amplified in number, thus it will give a false positive result. It is very important to be careful when transferring materials from one place to another (pipettes into the wells), as chances of contamination are high during this stage. In reviewing the test results, it is always wise to suspect a contamination whenever a low positive sample is located next to a high positive one in a well plate or a strip of tubes. The low positive sample should be re-extracted and retested separately, if necessary using manual extraction. The original extract can also be retested and compared to the new extract, to deduce the point where contamination occurs. For instance there was a situation where a cerebrospinal fluid (CSF) sample was found to be positive for Herpes simplex virus 2 (HSV-2). CSF samples are really important in nature as they are quite difficult to obtain, thus they are always tested in duplicates....
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