...Noise may be defined as any unwanted form of energy tending to interfere with the proper and easy reception and reproduction of signals. It may be subdivided according to type, source, effect, relation to the speaker, depending on circumstances. 1. External Noise. * Atmospheric Noise – consist of spurious radio components distributed a wide range of frequencies. Majority of these radio signals come from the natural sources of disturbance generally called static. * Extraterrestrial Noise * Solar Noise * Cosmic Noise * Industrial Noise – the intensity of noise made by humans easily outstrips that created by any other source, internal or external to the receiver. 2. Internal Noise * Thermal agitation noise – it is due to the rapid and random motion of molecules, atoms and electrons of which any such resistor is made up. Vn = 4kTδƒ R Example a. An amplifier operating the frequency rate from 18 to 20 MHz has a 10-kΩ input resistor. What is the rms noise voltage at the input to this amplifier if the ambient temperature is 27° C? Vn = 4kTδƒ R =4 x 1.38 x 3 x 2 x 10-11 = 1.82 x 10-5 = 18.2 μV * Shot noise – it is caused by random variations in the arrival of electrons at the output electrode of an amplifying device and thus as a randomly varying noise current superimposed on the output. 1.6 x 10-19 C in =2eip δf * Transmit Time Noise – if the time taken an electron to travel from the emitter to...
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...Noise 1. Calculate for the noise power if the temperature of the conductor is 290 K, the bandwidth is 200kHz. PN=kTB PN=1.38x10-23290(200kHz) PN=8.004x10-16 W 2. With a resistance of 200k ohms, a bandwidth of 500khz and a temperature of 500 K calculate for the noise voltage. VN=4kTBR VN=41.38x10-23500(500k) VN=1.17x10-7 V 3. Given a noise power of 3000kW and a bandwidth of 2.5Mhz. Compute for the noise density No=PNB No=3000kW2.5Mhz No=1.2 WHz 4. Given a noise temperature of 350K calculate for the noise factor. Teq=ToF-1 F=TeqTo+1 F=350290+1 F=2.2 5. With a bandwidth of 450 hz and a current of 50mA. Compute for the shot noise. IN=2BIq IN=(2(450)(50mA)(1.6x10-19) IN=2.68 nA 6. Calculate for the Bandwidth if the noise power is 500kW and the temperature is 279K PN=kTB B=PNkT B=500kW1.38x10-23279 B=1.3x1026Hz 7. If the noise voltage is 20V and the resistance and temperature is 200 ohms and 273 K respectively, calculate for the bandwidth. VN=4kTBR B=Vn24TR B=2024200(273) B=1.83x10-3Hz 8. Given a signal voltage of 55V and a noise voltage of 35 V calculate for the signal-to-noise ratio in decibel form. SNdB=20logVsVN SNdB=20log5535 SNdB=3.93 dB 9. Given a signal power 60W and a noise power of 43W. Calculate for the signal-to-noise ratio in decibel form. SNdB=10logPsPN SNdB=10log6043 SNdB=1.45 dB 10. Given a signal power 80W and a noise power of 33W. Calculate for...
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...Name: Tutor: Course: Date: Communication Quistion1 Noise is one of the obstacles to effective listening, and we define noise as any unwanted sound in any environment. Noise is a barrier to effective listening, and we can overcome this obstacle by one avoiding conversations in a noisy place secondly eliminating the source of the noise. Quistion2 Collaboration as a method of conflict management strategy refers to bringing together all the conflicting parties to find out the most appropriate solution to solve the problem. This method of conflict resolution is appropriate since it prevents further conflicts or advancing the level of conflict to a level that will be difficult to solve. Additionally collaboration is effective since it ensures all parties that were involved are satisfied in terms of the decision made to solve the conflict. Quistion3 Nonverbal communication can be used to pass information even without us knowing it, especially about our personality, thus none verbal communication can be used to enhance our self-confidence for example when giving a speech or talking to a single individual maintaining eye contact this shows that you have a strong personality and also a sense of responsibility in terms of believing in yourself. Quistion4 The first type of perceptual processing is sound this is the ability to distinguish sounds by detecting vibrations using our ears. Secondly, we will define speech, and we can say that speech is the process by which the sound...
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...known as central auditory processing disorder (CAPD) is a hearing problem that affects about 5% of school-aged children. They may have a hard time tuning out background noise and find loud noises overwhelming. It may affect your ability to pinpoint a sound, tell which sound comes before another, distinguish similar sounds from one another (such as "seventy" and "seventeen") and enjoy music. DIAGNOSES: A pediatrician rules out other possibilities such as hearing loss related to an ear infection. A speech-language pathologist or school psychologist may also give your child tests that measure receptive language or listening comprehension skills as well as cognitive abilities. But only a trained audiologist can conduct the tests needed to make a diagnosis of APD. No matter how many symptoms of APD a child may have, only careful and accurate diagnostics can determine the underlying cause. It typically isn’t diagnosed until grade school, but there are some warning signs that can be detected in preschool. SIGNS AND SYMPTOMS: Auditory discrimination, auditory figure-ground discrimination, auditory memory, and auditory sequencing. Find it hard to follow spoken directions, especially multi-step instructions, saying “huh?” or “what?” often, easily distracted especially by background noise or loud and sudden noises, trouble with reading and spelling, they struggle with word math problems, trouble following conversation, poor musical ability, trouble learning songs or nursery rhymes...
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...Financial Time Series Analysis Jiajing Sun University of Chinese Academy of Sciences 22 September 2013 J. Sun (UCAS) ARMA(1) 22 September 2013 1 / 23 Review As pointed out in the last week, the objective of studying …nancial time series analysis is to predict future values of some …nancial variable. This objective is achieved by following methodology based on: 1 2 3 4 Model Speci…cation; Model Estimation; Model Validation; Forecasting (or prediction) Note: The model to be used for forecasting is in fact estimated from history, i.e. data from the past is used to make probabilistic statements about future values. J. Sun (UCAS) ARMA(1) 22 September 2013 2 / 23 Stationarity Historical values are used to identify the dynamic properties of the time series (relationship between current and past values) and these are used to forecast the future. A critical assumption behind the methodology that we develop …rst in this course is that such dynamics do not change over time. In a heuristic sense, we require the future to be like the past in a probabilistic sense. This requirement is formalized by the concept of stationarity. J. Sun (UCAS) ARMA(1) 22 September 2013 3 / 23 Stationarity Strict Stationarity A time series Y is strictly stationary if its probabilistic distribution does not change over time. That is, for any k, the joint distribution of (Yt , Yt 1 , ..., Yt k +1 ) does not depend on t. In other words, the joint...
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...Rollin Luis NETW320 Professor Antoniou Week 2 HW assignment Silent suppression is a technique used to improve bandwidth utilization of voice circuits. Through silence suppression, a mechanism senses periods of inactivity in a voice conversation and simply ceases sending data associated. Silent suppression can be enabled to monitor signals for voice activity so that when silence is detected for a specified amount of time, the application informs the Packet Voice Protocol and prevents the encoder output from being transported across the network. To help understand silence suppression technology, consider this example: Some people talk all the time. Even they have to take a breath and they sometimes listen and are quiet. On a phone call, it is quite common that there is silence in one direction of the call while there is speech carried in the other direction. The public switched telephone network does not take advantage of this condition. The PSTN opens up a path in both directions, between the speakers, and allocates 100% of the path capacity to the call, even when there is silence. Silent suppression is the application of this IP network principle to VoIP calls. When there is silence, you don't send voice packets full of silence. Silence suppression can save bandwidth, especially on IP trunks. The savings can be 40% to 50%. The packet-sending phone or gateway implements the VAD function in the codec. When you think of silent suppression think of it as speech door. It opens...
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...Stochastic Resonance of FHN Model 1 Introduction Deterministic, nonlinear systems with excitable dynamics, e.g. the FitzHugh Nagumo (FHN) Model, undergo bifurcation from stable focus to limit cycle on tuning the system parameter. However, addition of uncorrelated noise to the system can kick the system to the limit cycle region, thus exhibiting spiking behaviour if the parameter is hold on the fixed point side. Thus the system exhibits intermittent cyclic behaviour, manifesting as spikes in the dynamical variable. It is interenting to note that at an optimal value of noise, the seemingly irregular behaviour of the spikes becomes strangely regular. The interspike interval τp becomes almost regular and the Normal√ p ized Variance of the interspike interval, defined by VN = exhibits τp a minima as a function of noise strength (D). The phenomenon is termed as Coherence Resonance. Coherence Resonance is a system generated response to the noise. However, there is another form of resonance that is found at lower level of noise in response to a subthreshold signal, known as Stochastic Resonance. Subthreshold signals that are in general undetectable can often be detected in presence of noise. There is an optimal level of noise at which such information transmission is optimal. Stochastic resonance has been investigated in many physical, chemical and biological systems. It can be utilised for enhancing signal detection and information transfer. SR has been obversed for subthreshold input...
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...11/5/2004 Noise Margins 1/12 Noise Margins The transfer function of a digital inverter will typically look something like this: vO V+ d vO = −1 dv I Transition Region d vO = −1 dv I vO = f (vI ) I III II V+ vI Note that there are essentially three regions to this curve: I. The region where vI is relatively low, so that the output voltage vO is high. II. The region where vI is relatively high, so that the output voltage vO is low. III. The transition region, where the input/output voltage is in an indeterminate state (i.e, an ambiguous region between high and low. Jim Stiles The Univ. of Kansas Dept. of EECS 11/5/2004 Noise Margins 2/12 Note that the transition region is rather arbitrarily defined by the points on the transfer function where the magnitude of the slope is greater than one (i.e., where d vO dv I > 1.0 ). Although this transfer function looks rather simple, there are actually several parameters that we use to characterize this transfer function—and thus characterize the digital inverter as well! 1. First of all, let’s consider the case when vI=0. The output of the digital inverter in this condition is defined as VOH (i.e., OH “output high”), i.e.: VOH vO when v I = 0 Thus, VOH is essentially the “ideal” inverter high output, as it is the output voltage when the inverter input is at its ideal low input value vI=0. Typically, VOH is a value just slightly less than supply voltage V+. 2. Now, let’s consider the...
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...My family is deaf. All my aunts and uncles are deaf. We like to get together and have a good time while making a lot of noise, but it doesn't mean anything to us. My husband is deaf and we had a daughter who was born hearing. We were surprised that she was born hearing. That meant that we had to learn about how sound is interpreted by hearing people. I remember a funny story that I'd like to tell you now. One day, my hearing daughter brought her hearing friends over. They were all sitting in the living room while I was in the kitchen doing dishes and putting them away. My daughter came to me concerned and asked me “Mom, are you okay?” I looked at her confused and said “Yeah, I'm okay.” She said “Well, are you mad?” I said “No, I'm not mad.” She asked “Are you not feeling well?”. I said “No, I feel fine. Why do you ask?” My daughter said that they thought I was mad because I was making loud noises in the kitchen. I said “What do you mean?” She said “You were closing the drawers very hard and putting the dishes away very loudly. My friends said you were angry at me for not helping you clean.” I said “Oh, okay.” The next time she brought her friends over, I told myself “Okay, I got to be careful putting things away.” I cleaned everything very quietly and put everything away carefully, very different from my usual way of doing things in the past. When I was finished doing that, I was exhausted. My daughter came in and asked “Are you okay? You are being very quiet.” I...
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...On one of my many expeditions with 4 of my closest friends to the Andes, I had lost my amazing, waterproof camera in the snow. Once I realized it wasn’t in my bad, I suited back up and set off in search of it. It was early afternoon, and contrary to the forecast I had listened to, it was extremely foggy. Suddenly, I heard the noise of a plane. I looked around to see one flying unusually low. I knew it was way too close to the mountain top to be safe. I could barely see through the fog. There was a huge crash and now the plane was spinning downwards without its right wing and tail, both plummeting to the ground below. As the plane hit another mountain top, its other wing broke away. My whole body shook as I watched the wreck take place. Things were flying out of the back of the plane, and I was sickened as I realized there were people hurtling out of there. Even at the speed it was falling at, I managed to see that the plane was Uruguayan. I cringed as I thought of the people inside the plane that was charging toward the ground. With an ear-splitting sound, the plane hit snow, in a valley a ways away from where I was crouching, in complete shock. I could smell smoke and burning all the way from my vantage point. My hands were still shaking as I gathered my supplies. I looked around for the camera I had come for and spotted it. After hearing nothing but absolute silence for a whole two minutes, I started to hear yelling and screaming. The cries for help got louder, as more people...
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...Topic # 3: Random Variables & Processes & Noise T1. B.P. Lathi, Modern Digital and Analog Communication Systems, 3rd Edition, Oxford University Press, 1998: OR 4th Edition 2010 Chapter 8, 9 & 12 T2. Simon Haykin & Michael Moher: Communication Systems; John Wiely, 4th Edition OR 5th Edition, 2010, 5/e. : Chapter 5 R1.DIGITAL COMMUNICATIONS Fundamentals and Applications: ERNARD SKLAR and Pabitra Kumar Ray; Pearson Education 2009, 2/e. : ( Section 5.5) August 11- 18, 2014 1 What is Noise ? Desired Signal : The one that is needed. Effect of Noise : Since the noise adds to the signal, it lives with it. Neither amplification nor the filtering can alleviate the effect of noise on the desired signal. Undesired Signal : The one that gets added to the desired signal when the desired signal is passing through the medium, amplifiers, mixers, filters and other parts of the communication channel between the source and the destination. Noise : The undesired signal that adds to the desired signal and reaches the destination. The only way to keep away from the effects of noise is to see that less amount of noise, relative to the desired signal, is present at the destination Interference: Intentional or unintentional un desired signals that interfere with communication process. 2 ELECTRICAL ELECTRONICS COMMUNICATION INSTRUMENTATION Noise Sources Externally Generated Internally Generated Thermal noise : Random Motion of electrons due to temperature in...
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...Sorry for the Loss * by Bridget Keehan The novel “Sorry for the Loss” by Bridget Keehan is about a woman called Evie who is prison chaplain. In the text she is about to tell an inmate that a relative of his died. This is the first time she is going to do this. The text is about the expectations she has towards telling him the grim news and how people can surprise you. She had her expectations and maybe even prejudices going into that cell. By analyzing symbols and reactions in the novel, this essay will look deeper on the reaction of the inmate Victor. This essay will also look at Evie’s workplace and how she feels about her work. Last, it will look at some of the symbols in the text and how they are used to make us understand certain points in the text. Victor reacts differently than Evie expected because he understand his situation. Victor seems to care very little about his grandmother’s death. At least compared to what you would expect but there is one thing you need to understand. Victor is in for murder and has done 5 years. He will be doing a lot more years and there is no point in becoming soft now. He knows the rules in the prison. “Is there anything you’d like me to do? I can find out the time of the funeral if you like?” “I won’t be able to go though will I, Miss?” (p. 4 l. 140-141). He would like to go if he could but he knows that he cannot so he does not want to seem like he cares. Prison is tough and when you are behind bars for as long as a man with...
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...What could be in a graveyard? As it turns out, everything. There was the sound of a church bell, and zombies came out and about everywhere. Bats were flying overhead, and I could feel the gust of wind they created, the noise of wings beating. I heard a medley of odd noises. I thought they were the false cries of others, but as it turns out, a medley of noises equated to a medley of really odd gross things. Apart from the zombies and bats, there where ghouls, vampires, weird green things that looked like blobs, and off in the distance, what appeared to be a manticore. At this point, I was beyond screaming and crying and closing my eyes, I was wondering what was wrong with my...
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...Impact of Noise on Recall of Advertisements Author(s): Bob T. Wu and Stephen J. Newell Source: Journal of Marketing Theory and Practice, Vol. 11, No. 2 (Spring, 2003), pp. 56-65 Published by: Taylor & Francis, Ltd. Stable URL: http://www.jstor.org/stable/40470111 Accessed: 30-11-2015 10:58 UTC REFERENCES Linked references are available on JSTOR for this article: http://www.jstor.org/stable/40470111?seq=1&cid=pdf-reference#references_tab_contents You may need to log in to JSTOR to access the linked references. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Taylor & Francis, Ltd. is collaborating with JSTOR to digitize, preserve and extend access to Journal of Marketing Theory and Practice. http://www.jstor.org This content downloaded from 27.251.83.10 on Mon, 30 Nov 2015 10:58:27 UTC All use subject to JSTOR Terms and Conditions THE IMPACT OF NOISE ON RECALL OF ADVERTISEMENTS Bob T. Wu BowlingGreenStateUniversity J. Stephen Newell Western MichiganUniversity that referred inmarketing to to and is a literature, hasbeenthe Noise,a barrier...
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...running out of things to say so I am just typing whatever voice is in my head right now. Freaking people cannot drive. I am people are too loud, and don’t get me started on my cousin.. they don’t even trust their own kind.. family will be family. Ok ok ok you are right. It seems like no matter where you go, how much you shell out for rent, or how great the area is - there is almost always that one noisy, rude neighbor who is either completely oblivious of the world around them, or they're just flat out inconsiderate of others. While there are some noisy days that can be forgiven (New Year's Eve, for example) - frequent noise disturbance can become more than just a nuisance, and in some cases it can become an extremely serious issue. Tip #1 - Keep A Record! When having issues with a noisy neighbor - you should keep a record of dates and times when the noise was an issue - whether it was too loud, a minor annoyance or just plain overwhelming. While it's wishful thinking that the issue won't escalate to a true point of seriousness - it is better to be prepared and safe, rather than sorry later on. Tip #2 - Remain Polite At All Times! In some cases, your neighbor may simply be unaware that they're being too loud. Perhaps they simply have a heavy foot when walking across their floor (which may be your ceiling,) or they are unaware that their music is being heard through your shared wall (if they live above you, next to you, or below you.) If this is the first offense and...
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