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PHET ElectroMagnetism Key to this Document Instructions are in black. Experimental questions that you need to solve through experimentation with an online animation are in green highlighted. Important instructions are in red highlighted. Items that need a response from you are in yellow highlighted. Please put your answers to this activity in RED. Part I- Comparing Permanent Magnets and Electromagnets: 1. Select the simulation “Magnets and Electromagnets.” It is at this link: http://phet.colorado.edu/new/simulations/sims.php?sim=Magnets_and_Electromagnets 2. Move the compass slowly along a semicircular path above the bar magnet until you’ve put it on the opposite side of the bar magnet. Describe what happens to the compass needle. 3. Move the compass along a semicircular path below the bar magnet until you’ve put it on the opposite side of the bar magnet. Describe what happens to the compass needle. 4. What do you suppose the compass needles drawn all over the screen tell you? 5. Use page 10 in your book to look up what it looks like when scientists use a drawing to represent a magnetic field. Describe the field around a bar magnet here. 6. Put the compass to the left or right of the magnet. Click “flip polarity” and notice what happens to the compass. Using the compass needle as your observation tool, describe the effect that flipping the poles of the magnet has on the magnetic field. 7. Click on the electromagnet tab along the top of the simulation window. Place the compass on the left side of the coil so that the compass center lies along the axis of the coil. <--like this 8. Move the compass along a semicircular path above the coil until you’ve put it on the opposite side of the coil. Then do the same below the coil. Notice what happens to the compass needle. Compare this answer to the answer you got to Number 2 and 3. 9. Compare the shape of the magnetic field of a bar magnet to the magnetic field of an electromagnet. 10. Use the voltage slider to change the direction of the current and investigate the shape of the magnetic field the coil using the compass after you’ve let the compass stabilize. Summarize, the effect that the direction of current has on the shape of the magnetic field around an electrified coil of wires. 11. What happens to the current in the coil when you set the voltage of the battery to zero? 12. What happens to the magnetic field around the coil when you set the voltage of the battery to zero? Part II – Investigating relationships- No Answers are written on this document after this point. All three data tables, graphs and conclusion statements go on the Google Spreadsheet that you can download from Ms. Pogge’s website. Experimental Question #1: How does distance affect the strength of the magnetic field around an electromagnet? 1. Using the Electromagnet simulation, click on “Show Field Meter.” 2. Set the battery voltage to 10V where the positive is on the right of the battery (slide the switch all the way to the right). 3. Magnetic field strength (symbol B on the top line of the meter) is measured in gauss (G). You’ll only need to record the value on the top line of the Field Meter. 4. Position zero will be right on top of the coil. Negative number positions will be to the left and positive number positions to the right of the coil. 5. Move the field meter one compass needle to the right and record the value of B at position 1. 6. This data table below will be used to help you fill in the first spreadsheet you downloaded from Ms. Pogge’s website. You will end up with 3 data tables, 3 graphs and 3 conclusion statements in your document, one for each mini-experiment you are doing. a. NOTE: Be sure to take all of your values along the horizontal axis of the coil. You’ll know you’re on the axis because the B-y measurement of the magnetic field is zero along the axis. Compass position (no units) Magnetic Field Strength ( )<--Fill in units! -5 (5 needles to the left of coil) Don’t fill in the table here...do it on the Google Spreadsheet you downloaded -4 -3 -2 -1 0 (middle of coil) 1 2 3 4 5 (5 needles to right of coil) 7. In your Google Spreadsheet: Graph the compass position on the horizontal (x) axis and magnetic field magnitude on the vertical (y) axis. 8. Make sure to label the axes and title the graph. Share this spreadsheet with your teacher. 9. Analyze your graph to discover how the two variables are related, and report the relationship between magnetic field strength and position using 1-3 complete sentences. Experimental Question #2: How does the number of coils affect the strength of the magnetic field around an electromagnet? Design an experiment to test how field strength varies with the number of coils. Enter your data, graph your results and write your conclusion statement on the Google Spreadsheet. Experimental Question #3: How does the amount of current affect the strength of the magnetic field around an electromagnet? Design an experiment to test how field strength varies with the Current. (Recall that voltage is directly proportional to current….Ohm’s Law.) Enter your data, graph your results and write your conclusion statement on the Google Spreadsheet.SUPPLY CHAIN MANAGEMENT AT BOSE CORPORATION Bose Corporation, headquartered in Framingham, Massachusetts, offers an excellent example of integrated supply chain management. Bose, a producer of audio premium speakers used in automobiles, high-fidelity systems, and consumer and commercial broadcasting systems, was founded in 1964 by Dr. Bose of MIT. Bose currently maintains plants in Massachusetts and Michigan as well as Canada, Mexico, and Ireland. Its purchasing organization, while decentralized, has some overlap that requires coordination between sites. It manages this coordination by using conference calls between managers, electronic communication, and joint problem solving. The company is moving toward single sourcing many of its 800 to 1,000 parts, which include corrugated paper, particle board and wood, plastic injected molded parts, fasteners, glues, woofers, and fabric. Some product components, such as woofers, are sourced overseas. For example, at the Hillsdale, Michigan, plant, foreign sourcing accounts for 20% of purchases, with the remainder of suppliers located immediately within the state of Michigan. About 35% of the parts purchased at this site are single sourced, with approximately half of the components arriving with no incoming inspection performed. In turn, Bose ships finished products directly to Delco, Honda, and Nissan and has a record of no missed deliveries. Normal lead time to customers is 60 working days, but Bose can expedite shipments in one week and airfreight them if necessary. The company has developed a detailed supplier performance system that measures on-time delivery, quality performance, technical improvements, and supplier suggestions. A report is generated twice a month from this system and sent to the supplier providing feedback about supplier performance. If there is a three-week trend of poor performance, Bose will usually establish a specific goal for improvement that the supplier must attain. Examples include 10% delivery improvement every month until 100% conformance is achieved, or 5% quality improvement until a 1% defect level is reached over a four-month period. In one case, a supplier sent a rejected shipment back to Bose without explanation and with no corrective action taken. When no significant improvement occurred, another supplier replaced the delinquent supplier. Bose has few written contracts with suppliers. After six months of deliveries without rejects, Bose encourages suppliers to apply for a certificate of achievement form, signifying that they are qualified suppliers. One of the primary criteria for gaining certification involves how well the supplier responds to corrective action requests. One of the biggest problems observed is that suppliers often correct problems on individual parts covered by a corrective action form without extending these corrective actions to other part families and applicable parts. Bose has adopted a unique system of marrying just-in-time (JIT) purchasing with global sourcing. Approximately half of the dollar value of Bose’s total purchases are made overseas, with the majority of the sourcing done in Asia. Because foreign sourcing does not support just-in-time deliveries, Bose “had to find a way to blend low inventory with buying from distant sources,” says the director of purchasing and logistics for Bose. Visualizing itself as a customer-driven organization, Bose now uses a sophisticated transportation system—what Bose’s manager of logistics calls “the best EDI system in the country.” Working closely with a national less-than-truckload carrier for the bulk of its domestic freight movements, including shipments arriving at a U.S. port from oversees, Bose implemented an electronic data interchange (EDI) system that does much more than simple tracking. The system operates close to real time and allows two-way communication between every one of the freight handler’s 230 terminals and Bose. Information is updated several times daily and is downloaded automatically, enabling Bose to perform shipping analysis and distribution channel modeling to achieve reliable lowest total cost scenarios. The company can also request removal from a terminal of any shipment that it must expedite with an air shipment. This state-of-the-art system provides a snapshot of what is happening on a daily basis and keeps Bose’s managers on top of everyday occurrences and decisions. Management proactively manages logistics time elements in pursuit of better customer service. The next step is to implement this system with all major suppliers rather than just with transportation suppliers. In the future, Bose plans to automate its entire materials system. Perhaps one of the most unique features of Bose’s procurement and logistics system is the development of JIT II. The basic premise of JIT II is simple: The person who can do the best job of ordering and managing inventory of a particular item is the supplier himself. Bose negotiated with each supplier to provide a full-time employee at the Bose plant who was responsible for ordering, shipping, and receiving materials from that plant, as well as managing on-site inventories of the items. This was done through an EDI connection between Bose’s plant and the supplier’s facility. Collocating suppliers and buyers was so successful that Bose is now implementing it at all plant locations. In fact, many other companies have also begun to implement collocation of suppliers. Assignment Questions The following assignment questions relate to ideas and concepts presented throughout this text. Answer some or all of the questions as directed by your instructor. 1. Discuss how the strategy development process might work at a company like Bose. 2. What should be the relationship between Bose’s supply management strategy and the development of its performance measurement system? 3. Why is purchased quality so important to Bose? 4. Can a just-in-time purchase system operate without total quality from suppliers? 5. Why can some components arrive at the Hillsdale, Michigan, plant with no incoming inspection required? 6. Discuss the reasons why Bose has a certificate of achievement program for identifying qualified suppliers. 7. Bose is moving toward single sourcing many of its purchased part requirements. Discuss why the company might want to do this. Are there any risks to that approach? 8. Discuss some of the difficulties a company like Bose might experience when trying to implement just-in-time purchasing with international suppliers. 9. Why does Bose have to source so much of its purchase requirements from offshore suppliers? 10. What makes the JIT II system at Bose unique? Why would a company pursue this type of system? 11. Why is it necessary to enter into a longer-term contractual arrangement when pursuing arrangements like the one Bose has with its domestic transportation carrier? 12. Why is it important to manage logistics time elements proactively when pursuing higher levels of customer service? 13. What role does information technology play at Bose? 14. What advantages do information technology systems provide to Bose that might not be available to a company that does not have these systems? 15. Why has Bose developed its supplier performance measurement system? 16. Do you think the performance measurement systems at Bose are computerized or manual? Why?Biomedical Signal and Image Processing (4800_420_001) Assigned on September 12th, 2017 Assignment 4 – Noise and Correlation 1. If a signal is measured as 2.5 V and the noise is 28 mV (28 × 10−3 V), what is the SNR in dB? 2. A single sinusoidal signal is found with some noise. If the RMS value of the noise is 0.5 V and the SNR is 10 dB, what is the RMS amplitude of the sinusoid? 3. The file signal_noise.mat contains a variable x that consists of a 1.0-V peak sinusoidal signal buried in noise. What is the SNR for this signal and noise? Assume that the noise RMS is much greater than the signal RMS. Note: “signal_noise.mat” and other files used in these assignments can be downloaded from the content area of Brightspace, within the “Data Files for Exercises” folder. These files can be opened in Matlab by copying into the active folder and double-clicking on the file or using the Matlab load command using the format: load(‘signal_noise.mat’). To discover the variables within the files use the Matlab who command. 4. An 8-bit ADC converter that has an input range of ±5 V is used to convert a signal that ranges between ±2 V. What is the SNR of the input if the input noise equals the quantization noise of the converter? Hint: Refer to Equation below to find the quantization noise: 5. The file filter1.mat contains the spectrum of a fourth-order lowpass filter as variable x in dB. The file also contains the corresponding frequencies of x in variable freq. Plot the spectrum of this filter both as dB versus log frequency and as linear amplitude versus linear frequency. The frequency axis should range between 10 and 400 Hz in both plots. Hint: Use Equation below to convert: Biomedical Signal and Image Processing (4800_420_001) Assigned on September 12th, 2017 6. Generate one cycle of the square wave similar to the one shown below in a 500-point MATLAB array. Determine the RMS value of this waveform. [Hint: When you take the square of the data array, be sure to use a period before the up arrow so that MATLAB does the squaring point-by-point (i.e., x.^2).]. 7. A resistor produces 10 μV noise (i.e., 10 × 10−6 V noise) when the room temperature is 310 K and the bandwidth is 1 kHz (i.e., 1000 Hz). What current noise would be produced by this resistor? 8. A 3-ma current flows through both a diode (i.e., a semiconductor) and a 20,000-Ω (i.e., 20-kΩ) resistor. What is the net current noise, in? Assume a bandwidth of 1 kHz (i.e., 1 × 103 Hz). Which of the two components is responsible for producing the most noise? 9. Determine if the two signals, x and y, in file correl1.mat are correlated by checking the angle between them. 10. Modify the approach used in Practice Problem 3 to find the angle between short signals: Do not attempt to plot these vectors as it would require a 6-dimensional plot!