Monday, January 27, 2020
Current Voltage Relation of Different Memristor Models
Current Voltage Relation of Different Memristor Models Abstract: Memristor a two terminal passive non volatile device is considered as the fourth circuit element and can be used in many applications which includes memory, logic and neuromorphic systems. The memristor provides many advantages like scalability, compatibility with CMOS and offers no leakage current. Various models of memristor have been discussed in this paper. The main focus is on the Current-Voltage (IV) relation of different models and its simulation is done in Cadence Virtuoso. Index Terms- memristor, VerilogA, window function, SPICE, threshold. INTRODUCTION In 1971, L. O. Chua introduced the fourth passive circuit element named memristor which is two terminal non volatile device with a property of variable resistance known as memristance [1]. The memristance provides the relation in the time integrals of voltage and current. Originally, current controlled time invariant memristor is expressed as where w is state variable, v(t) is the device voltage, i(t) is the memristor device current, R(w, i) is the memristance and t is the time period. Since HP labs proclaimed the physical working model of memristor [2], it opens the doors to the new type of electronics. Some of the applications includes logic design [3] [4], memory [5], neuromorphic systems [6]. Different models of memristor have been deigned. Formally designed models does not contain threshold [2] [7] [8] (i.e. resistance changes for any current or voltage). The Threshold Adaptive Memristor model (TEAM )[9] and Voltage Threshold Adaptive Memristor model (VTEAM) [10] models exhibits the threshold current and threshold voltage respectively, are the most efficient models and less computational complexity. In this paper current-voltage relation of different models is implemented using VerilogA code. Section II describes the different types of memristor models. Comparison of memristor model is provided in section III. The paper is concluded in section IV. DIFFERENT MEMRISTOR MODELS Linear Ion Drift Model This is the first and basic model of memristor proposed by HP Labs [3]. This model has width which is splitted in two regions as shown in Figure 1. The region with width w is doped with positive oxygen ions (originally TiO2) and has low resistance therefore is more conductive and other side is undoped. Each region is modeled with resistor (in series). Various assumptions are considered i.e. ohmic conductance, uniform field and average ion mobility. RON is the resistance at w(t) = D and ROFF is the resistance at w(t) = 0 The state variable w(t) is bounded within the interval [0,D]. To prevent w from going beyond the physical dimensions of the device, the derivative of w is required to multiply by the window function. The IV relationship curve of linear ion drift model of memristor for sinusoidal input is shown in figure 2. Figure1: HP memristor model [1] Figure 2: IV curve of linear memristor model with 2-window function. (frequency=20MHz,source amplitude=0.003A, Ron=100ohm, Roff=2e5ohm, ÃŽ ¼v=10e-14m^2/Vs, D=10e-9m, P_coeff=2, initial state=0.5, j=1, w_multiplied=1e9, P_window_noise=1e-18) Non Linear Ion Drift Model Although the linear ion drift model of memristor is simple and satisfies the basic memristor equations. But as per the experiments of the fabricated device, it behaves differently i.e. it is highly non linear [11] [12]. The non linearity is desirable for logic circuits, therefore another memristor model have been proposed based on experimental results concluded in [11]. A model is [13] proposed. The relation between current and voltage for this model is Where ÃŽ ±, , are known as fitting parameters and parameter n describes the influence of state variable (w) on the currents. . Here, the state variable w is normalized within the interval [0,1]. The model shows asymmetric switching behavior, in a way that during the ON state, w is near one and the first term of, is the dominant part of the current, which is a tunneling phenomenon. During the OFF state, w is near zero and the second term, has the dominant part of the current, which is similar to an ideal diode equation. The state variable differential equation is written as where a, m are constants, f(w) is the window function and m is an odd integer. And there is a nonlinear dependency on voltage. The IV characteristics of this model is shown in figure 3. Figure3: IV curve of non linear ion drift model with 2-window function (frequency=20MHz,source amplitude=1V, P_coeff=1, initial state=0.5, j=1, Alpha=2, Beta=9, C=0.01, g=4, n=13, q=13,a=4, w_multiplied=1, P_window_noise=1e-18) Figure 4: IV curve of simmons tunnel barrier model. (frequency=20MHz,source amplitude=0.003A, Ron=100ohm, Roff=2e5ohm, D=3e-9m, initial state=0.5, aon=2e-9,aoff =1.2e-9, ion=8.9e-6, ioff=115e-6,con=40e-6, coff=3.5e-6,b=500e-6,Xc=107e-12 w_multiplied=1e9, P_window_noise=1e-18) Simmons Tunnel Barrier Model Another model having more accuracy than previous discussed model was proposed in [14]. The assumptions of this new model includes non-linearity and asymmetric switching behavior because of an exponential dependency of movement of ionized dopants i.e. changes in state variable. Physical model of this type has a resistor in series with electron tunnel barrier. The simmons tunnel barrier width x, is the state variable. So the derivative of x can be represented as oxygen vacancy drift velocity, and is: where b, con, coff, ion, ioff, aon, aoff are known as fitting parameters. Con is always greater than coff and they both effect the magnitude of change of x. The parameters ioff and ion define the current threshold. Another parameter aoff and aon gives the upper and lower bounds of x respectively. Within the range defined, the derivative of state variable x, is significantly smaller than state variable itself. Therefore, there is no need of window function that is the biggest advantage of this model. According to the simmons tunnel model, the relation between voltage and current can be expressed as: Where V is applied voltage and v is internal voltage of the device (it is not necessary that both voltages are equal [15] ). Based on the fitting parameters, the IV characteristics curve of the simmons tunnel barrier model is shown in figure 4. TEAM Model Before 2013, it was claimed that Simmons Tunnel Barrier model is the most accurate memristor model but it too has some limitations of complication, unexplicit relation in voltage and current and is not in general. Therefore a model with accuracy and simpler expressions is the main demand. The TEAM ( Threshold Adaptive Memristor model) is proposed by Shahar Kvatinsky [16]. This is simple and general model, physically similar to predefined model. Some assumptions can be made for analysis and for computational efficiency. Based on assumptions, state variable derivative of this model is expressed as where aon,aoff, kon,and koff are constants (koff is positive and kon is negative). foff(x) and fon (x) are the window functions, depends on state variable x. by assuming the current voltage relation is same as memristance of memristor which changes linearly in x. Therefore, but if Simmons Tunnel Barrier model is assumed then memristance changes exponentially and given as where ÃŽ » is the fitting parameter. The parameter Ron and Roff are resistances at bound and satisfies By tuning different parameters of the model, the VI curve of this model is showm in figure11. According to [9], it is claimed that the accuracy of TEAM model is more enough having mean error of 0.2%. VTEAM Model Many experiments on memristive devices shown the existence of threshold voltage [2] [16] [17] instead of threshold current. Therefore, Shahar Kvatinsky designs the new model i.e. VTEAM model [10] (Voltage Threshold Adaptive Memristor model), contains threshold voltage. Another reason for the existence of this model is that a memristor exhibiting threshold voltage is more desirable than the threshold current in many applications of memory and logic [10]. The advantages of TEAM model (i.e. general, accurate, simple, designer friendly) combines with threshold voltage in spite of threshold current gives the VTEAM model. Similar to the state variable derivative of TEAM model, the state variable derivative of VTEAM model is where koff, kon ÃŽ ±off and ÃŽ ±on are constants. Parameters voff and von are threshold voltages. The window functions fon and foff defines the dependency of state variable derivative on state variable w. for VTEAM model, the current voltage relation is not properly defined but the linear dependency of state variable and resistance can be attained, from where current voltage relation is where woff and won gives bounds of state variable w. The curve for the IV relation of VTEAM memristor model is depicted as in figure 6. Figure 5: IV curve of TEAM model with 4-window type. (frequency=20MHz,source amplitude=0.003A, Ron=100ohm, Roff=2e5ohm, ÃŽ ¼v=10e-14m^2/Vs, D=10e-9m, P_coeff=2, initial state=0.5, j=1.5, aon=2.3e-9, aoff =1.2e-9, ion=-1e-6, ioff=1e-6, kon=-8e-13, koff=8e13, xon=0, xoff=3e-9, aon=3,aoff=3, Xc =107e-12 w_multiplied=1e9, P_window_noise=1e-18) Figure6: IV curve of VTEAM model without window function. (frequency=20MHz,source amplitude=1V, Ron=100ohm, Roff=2e5ohm, ÃŽ ¼v=10e-14m^2/Vs, D=10e-9m, P_coeff=2, initial state=0.5, j=1.5, aon=2e-9, aoff =1.2e-9, von=-0.2 voff=0.02, kon=-8e-13, koff=8e13, xon=0, xoff=3e-9, aon=3,aoff=3, Xc =107e-12 w_multiplied=1e9, P_window_noise=1e-18) COMPARISON Comparison of different models of memristor is listed in table1. Table 1: Comparison between diffent memristor models. CONCLUSION In this paper, different models of memristor- linear ion drift model, non linear ion drift model, simmons tunnel barrier model, TEAM model and VTEAM model are described. Moreover the VI characteristics of each model is simulated. The VI curve for VTEAM model is most efficient and desirable. Also VTEAM and TEAM models are simple, general and accurate. The VI characteristics of each model is implemented by using verilogA code [18] because of its effiency regarding computational time than SPICE model. REFERENCES L. O. Chua, â€Å"Memristor – The Missing Circuit Element,†IEEE Transactions on Circuit Theory, Vol. 18, No. 5, pp. 507-519, 1971. D. B. Strukov, G. S. Snider, D. R. Stewart, and R. S. Williams, The Missing Memristor Found,†Nature, Vol. 453, No. 7191, pp. 80-83, 2008. G. Snider, â€Å"Computing with hysteretic resistor crossbars†, Applied Physics A, Material Science Process, vol. 80, page 1165-1172, 2005. S. Kvatinsky, E. G. Friedman, A. Kolodny, and U. C. Wieser, â€Å"Memristor-based IMPLY logic design procedure†, Proceedings IEEE International Conference Computational Design, page 142-147, 2011. G. M. Huang, Y. Ho, and P. Li, â€Å"Nonvolatile memristor memory: Device characteristics and design implication†, Proceedings IEEE International Conference Computer Aided Design, page 485-490, 2009. A. Ayatollahi, A. Afifi, and F. Raissi, â€Å"Implementation of biologically plausible spiking neural network models on memristor crossbar-based CMOS/Nano circuits,†Proceedings Eur. Conference Circuit Theory Design, page 563-566, 2009. E. Lehtonen and M. Laiho, CNN Using Memristors for Neighborhood Connections, Proceedings of the International Workshop on Cellular Nanoscale Networks and their Applications, pp. 1-4, February 2010. M. D. Pickett et al., Switching Dynamics in Titanium Dioxide Memristive Devices, Journal of Applied Physics, Vol. 106, No. 7, pp. 1-6, October 2009. S. Kvatinsky, A. Kolodny, U. C. Wieser, and E. G. Friedman, â€Å"TEAM: ThrEshold Adaptive Memristor Model†, IEEE Transactions on circuits and Systems 1: Regular Papers, page 211-221, 2013. S. Kvatinsky, M. Ramadan, E. G. Friedman, and A. Kolodny, â€Å"VTEAM – A General Model for Voltage Controlled Memristors†, IEEE Transactions on Circuits and Systems, page- 1-5, 2014. J. J. Yang, M. D. Pickett, X. Li, D. R. Stewart, and R. S. Williams, â€Å"Memristive switching mechanism for metal/oxide/metal nanodevice†, Nature Nanotechnology, page 429-433, 2008. R. S. Williams, and D. B. Strukov, â€Å"Exponential ionic drift: Fast switching and low volatility of thin- film memristor†, Applied Physics A. Material Sci. Process., page 515-519, 2009. M. Laiho, and E. Lehtonen, â€Å"CNN using memristors for neighborhood connections†, Proceedings International Workshop Cell. Nanoscale Network Their Applications, page 1-4, 2010. D. B. Strukov, J. J. Yang, M. D. Pickett, and J. L. Borghetti, â€Å"Switching dynamics in titanium dioxide memristive devices†, Journal Applied Physics, page 1-6, 2009. J. G. Simmons, â€Å" Generalized formula for the electric tunnel effect between similar electrodes separated by thin insulating film†, Journal Applied Physics, page 1793-1803, 1963. A. Chanthbouala, et al., A Ferroelectric Memristor., Nature materials, page 860-864, 2010. D. Liu, et al., Analog Memristors Based on Thickening/Thinning of Ag Nanofilaments in Amorphous Manganite Thin Films, ACS Applied Materials Interfaces, page 11258-11264, 2013.
Sunday, January 19, 2020
Thomas Jefferson Essay example -- essays research papers fc
Thomas Jefferson      Table of Contents      Page I.     Early Life and Childhood     1 II     Through Collage and Into the world     2 III     Revolutionary Politics     3 IV     Pre-Presidential Posts and Accomplishments     4 V     Presidency and post presidency     5 VI     Picture     6 VII     Works Cited     7                Thomas Jefferson      I. Early life and childhood A simple log cabin located in now what is commonly known as Albemarle County, Virginia, was the birthplace of Thomas Jefferson, the third President of the United States of America. He was born on April 13, 1743 to Peter and Jane Randolph Jefferson. Thomas Jefferson was borne into what we might define today as an upper middle class. His mother, Jane Randolph, came from one of the leading families of Virginia and his father Peter Jefferson, although not considered poor, was considerably less well off than his wife. (Malone 1)      When Thomas was only two years old he and his family, which now consisted of three Sisters, himself and his mother moved to a new house called Tuckahoe. His father provided for his family by working as a planter owning more than 200 slaves but as his children grew he expanded and moved further from raising tobacco and made a name for himself by eventually becoming a well known surveyor and getting the popular reputation as a conqueror of the Virginian wilderness. (Malone 22)      When Tom was nine he and his family moved back to the home of his birth where his father died five years later. Tom spent the rest of his childhood as a typical Virginian boy would. He developed a not overwhelming yet real affection for the out doors as any boy would. He attended the Latin School of the Reverend William Douglas who was the min... ...term he won the election by a complete landslide winning every state with the exception of Connecticut and Delaware. He commissioned the Lewis and Clark Expedition, arrested Aaron Burr for engaging in a conspiracy to try and establish Louisiana as an independent Republic, and ended the Tripolitan war, which was the first fighting ever done by the American Navy. As he continued to lead the country in these new times of suffering and change he continued to fight to reform many of the country’s faults e.g. tax supported elementary system.           Jefferson lived 17 years after his second term. In which time he founded the University of Virginia in Charlottesville. He died on the 50th anniversary of the signing of his very own Declaration of Independence on July 4, 1826 at his home in Monticello. http://www.monticello.org/jefferson/biography.html      VI. Picture VII. Works cited Malone, Dumas. Jefferson the Virginian. New York: McClelland and Stewart Limited, 1948 Thomas Jefferson. [online] Nov 28, 2004 A brief Biography of Thomas Jefferson. [online] Nov 30, 2004
Saturday, January 11, 2020
Environmental Influences on Performance
1. â€Å"Marathon race organizers should be mindful of weather conditions during the race ‘ Discuss the above statement on a scientific marathon footrace is among the most physiologically demanding endurance events in the world. Competitive runners typically maintain a pace corresponding to 70-90% of their maximal aerobic capacity [3,15,20] for more than 2 h. At maximal mechanical efficiency, more than 80% of the energy required for this task is transferred as heat to the body core [9]. Moreover, the rate of endogenous heat production associated with a 2-h 10-min marathon estimated from ordinary heat-balance equations [9] is approximately 1400 kcal ·h-1. This metabolic heat must be dissipated to the surrounding environment, or body temperature will rise to physiologically dangerous levels. Lind [13] has demonstrated that core temperature is independent of climate over a temperature range he has termed the â€Å"prescriptive zone. †It has been demonstrated that the width of the prescriptive zone progressively narrows as metabolic rate increases. Thus, climate begins to affect physiological responses to exercise at relatively cooler temperatures during activities that elicit high metabolic rate compared with those eliciting lower metabolic rates. More recently, it has been demonstrated that endurance performance is indeed impaired when exercising in warm versus more temperate laboratory conditions and that air temperatures of approximately 10 °C seem optimal for endurance exercise [10]. One criticism of these and other laboratory findings is that typical airflows used for indoor testing situations are well below those encountered when running or cycling outdoors ver the ground. The lack of appropriate airflow substantially reduces the combined heat transfer coefficient [9] and may overestimate physiological strain [2]. Few field studies have examined the effect of weather conditions on endurance running performance[16,17,22]. Although it is generally observed that race performances worsen as weather warms, there are current ly no data quantifying the magnitude of performance reduction. In addition, these studies relied only on data from elite male runners; thus, the implications for slower competitors or women runners are only speculative. COLD WEATHER BEST FOR MARATHON PERFORMANCE Every runner knows that cool weather is better than hot weather for marathon performance. But a recent study from the U. S. Army Research Institute of Environmental Medicine suggests that relatively cold weather is better than merely cool weather. Researchers gathered many years' worth of results and weather data from six major North American marathons and performed stastical analyses to determine the effect of air temperature on finishing times among runners at various levels of performance. Specifically, they looked at year-to-year comparative finishing times of the top three male and female runners at each event, as well as the 25th, 50th, 100th, and 300th finishers. The results showed a clear trend toward faster times at colder temperatures. For example, the finishing times of male races winners were, on average, 1. 7% slower than the course record when the air temperature was between 34 and 50 degrees. The finishing times of the top male runners were 2. 5% slower than the course record, however, when the temperature was between 51 and 59 degrees. And at higher temperatures, finishing times fell off even more dramatically. Runners at all levels were slowed by warmer air, but higher temperatures had a smaller effect on faster runners. The ideal marathon temperature, according to these analyses, was a bone-chilling 41 degrees. Think about that when you sign up for your next marathon! 2. Divers who collect ornamental fish have to work in a hostile environment. Discuss how the SCUBA apparatus helps these divers to meet the challenge of the deep sea environment. SCUBA diving is an exciting and first-hand way for scientists to study the underwater environment. It is one among the most effective ways for executing underwater experiments that require high quality precise measurements. SCUBA as the name suggests stands for Self Contained Underwater Breathing Apparatus. It literally means that all divers carry all of required breathing equipment’s and gases with them. Hence they are subjected to water temperature, pressure, currents, and other factors revolving oceans present at the diving depth. The NURP program approximately supports about 10,000 SCUBA Divers for Scientific Research work. NURP provides all the necessary equipments and finances for scientists and technical assistance to conduct diving operations. They use both open circuit as well as closed circuit breathing apparatus. The difference between them primarily relies upon what happens to the exhaled gas. In open system the gas is exhaled in to the water. A closed system apparatus has recycling abilities and thus lasts longer underwater as it reduces carbon-dioxide and adds oxygen in a cyclic manner inside the container. It reduces the amount of gas required in the container and also allows the diver to remain streamlined. The breathing gas provided by NURP involves compressed air, NITROX and TRIMIX. NITROX is a composition of nitrogen and oxygen whilst TRIMIX is a composition of oxygen, nitrogen and helium. NITROX is of special interest to NOAA. It was in introduced in late 1970’s which allows the divers to stay longer underwater when compared to compressed air alone. Each of these gases is of different properties which enables the diver to dive at maximum depths. 3. The year 1968 marked the emergence of high altitude trained long distance runners from Kenya. Discuss the scientific basis of high altitude training and how it helps to perform better in long distance events. The theory underlying the belief that training at high altitude can enhance athletic performance sounds reasonable enough. Work out in an environment that causes the body to produce more oxygen-carrying red blood cells and an athlete will be able to perform better than he or she can when trained at a lower elevation. Proponents of this theory point to East African runners, who have dominated long-distance events in recent years, as proof that training at high altitudes pays off. But if that’s the case, why don’t runners from other high altitude countries such as Peru and Mexico perform equally well? And why do some athletes excel in endurance sports despite having never trained at high altitude? â€Å"[High-altitude training has] had so much press that certain athletes feel like they’re at a disadvantage if they’re not doing altitude training,†says Andrew Subudhi, a researcher at the Altitude Research Center in Denver and assistant professor of biology at the University of Colorado in Colorado Springs. There’s a big movement for endurance athletes to move to high altitude if they’re serious about [improving their performance]. †Into Thin Air But does it really help? Answering that question is harder than one might think, despite numerous scientific studies on the relationship between altitude and athletic performance. The issue reached prominence at the 1968 summer Olympics in Mexico City (elevation 7, 349 feet), when questions arose about the best way to prepare for competing in the thin air, Subudhi says. Thin air†is a term used to describe air that contains less oxygen than air at sea level (20. 9% at sea level compared with 15. 3% at higher altitudes). The number of red blood cells found in the body of an endurance athlete who does not live and train at high altitudes may be insufficient to supply the amount of oxygen needed at higher altitudes. To help deal with this problem, athletes may live and train at high altitudes several weeks before a competition to increase the number of red blood cells, which are produced in response to greater release of the hormone erythropoietin. More red blood cells allows a person’s blood to carry more oxygen, which partly makes up for the shortage of oxygen in the air. Studies have found that athletes do perform better in competitions held at high altitudes if they live and train at high altitudes prior to competition, Subudhi says, but training at high altitudes does not necessarily help athletes perform better at low altitudes as one might assume. â€Å"When you’re at altitude, you can’t train as hard, and when you’re not training as hard, you’re not getting the same training stimulus,†he says. â€Å"Training at altitude doesn’t mean you’ll do well at sea level. Then again, that doesn’t mean that you won’t, says Jack Daniels, PhD, head distance coach at the Center for High Altitude Training at Northern Arizona University. Daniels says the key benefit to training at higher than normal altitudes is that it teaches an athlete how to hurt, and learning to tolerate pain can help athletes push themselves harder than they would otherwise. â€Å"It’s good for an athlete to learn to really lay it out there, and it’s easy to do that [in high altitude] without working quite as hard,†says Daniels, who has coached 31 individual3/22/13 Printer-friendly article page www. motionsports. com/blog/training at altitude. htm 2/3 NCAA national champions in his career. Although there are benefits to training at altitude, Daniels says, the advantages one might gain are unimportant when compared with more mundane factors. No matter where people train, he says, they want comfortable housing, healthy food, a friendly atmosphere, good training facilities, desirable weather, and adequate medical and therapy attention. â€Å"In other words, you train best where you are happiest,†Daniels says. If you c an have that at altitude, that's good, but if you do altitude-type things and don't have those other things, then you are wasting your time. It is very disturbing to me to hear people say, ‘If you don't train at altitude you may as well not bother trying. ’ I think we have all the things an athlete would want right here, but anyone who comes here and is not happy, I encourage to leave. †Live High, Train Low Daniels also doesn’t believe in another philosophy that has gained considerable support in recent years from researchers who have studied the altitude-performance relationship. Known as â€Å"live high, train low,†this philosophy holds that endurance athletes benefit most from living in high-altitude conditions but training at low altitude where they are able to push themselves harder. The term â€Å"live high, train low†came into being in 1996 when researchers James Stray-Gundersen and Benjamin Levine studied the relationship between altitude, training, and performance using three groups of endurance athletes. One group lived and trained in Park City, Utah, (elevation 7,000 feet) while another group lived there and trained at a lower altitude. A third group lived and trained in San Diego (elevation 72 feet). After the four-week training period ended, all were tested at a low altitude. â€Å"They found that the group that lived high but trained low got the best benefit; that was measured in 5-kilometer time trials. †Subudhi says. The reason for the improved performance among the live-high, train-low group, researchers hypothesized, is that by living in high-altitude conditions, their bodies produced more red blood cells in response to the lower concentration of oxygen. And because these athletes trained at a lower elevation, they were able to push themselves harder than they would have at higher altitudes, resulting in a higher training stimulus. The results of this and other studies received so much media attention that companies began manufacturing masks, tents, and rooms that would allow athletes to live anywhere in high-altitude conditions. Devices cost anywhere from hundreds to thousands to tens of thousands of dollars. Some companies convert entire houses to these conditions, and both Finland and the United States have outfitted dormitories in this way. Manufacturers claim benefits can occur from as little as six to eight hours of exposure. But those claims are not supported by research, Subudhi says, who contends 15 to 16 hours per day exposure is supported by research. Exercise rooms designed to mimic high-altitude conditions can benefit athletes who live at low altitudes and are planning to compete at a high altitude, he says: â€Å"If your competition is at altitude, then you need to train at altitude. †Altitude Advantage The only danger associated with the use of such devices is reducing oxygen levels too quickly, and almost everyone will experience more difficulty sleeping, Subudhi says. However, it’s rare to see athletes suffering from acute mountain sickness, commonly known as altitude sickness, or from high-altitude pulmonary or cerebral edema among those who live at an 8,000- to 9,000-foot altitude, he says. Plus, benefits are temporary: An athlete who stops living under high-altitude conditions will begin to see a loss in benefits in about two weeks as extra red blood cells die off, he says. Bob Cranny, PT, owner of Altitude Physical Therapy and Sports Medicine in Boulder, Colo. , is a big believer in the benefits of training at altitudes of 2,500 feet or greater. He and his wife are both triathletes and marathon runners who moved to Boulder (elevation 5,430 feet) 12 years ago from Long Beach, Calif. , because they believed the higher altitude would enhance their performance. Many athletes in the area follow the live-high, train-low philosophy, although it might more accurately be described as â€Å"live high, train lower. †That’s because many athletes who train in Boulder live at elevations of3/22/13 Printer-friendlyarticlepage www. kmotionsports. com/blog/training at altitude. htm 3/3 round 9,000 feet and travel to Boulder’s 5,430-foot elevation to train, as opposed to sea level. â€Å"If you could live at 9,000 feet and train at sea level, that would be even better  that would be wonderful,†Cranny says. So the answer to the question of whether training at high altitude will enhance an athlete’s performance is: maybe. Training at altitude will help some, while other athletes might benefit best fro m alternate training methods. â€Å"I see altitude as a type of training, and if this type suits you then it is good,†Daniels says.
Friday, January 3, 2020
Assignment 2 Water Park Essay example - 933 Words
Chasidy Lovett Instructor: Nancy Blair TV and the American Family HUM-110HM-CL03 24 August 2014 Water Parks The question of what does integrity mean to me? Integrity is within a person and how they show themselves to the world. A person with integrity is more righteous or has higher morals then others; they are honest even when it is not in their best interest. This person would also have strong ethics like being trustworthy or truthful. I definitely understand a family vacation and how important it can be but when it comes to Hal and Lois’ decision to get a babysitter for Dewey no matter what, does not matter who it is as long as we can go on our vacation mind frame is horrible and I do not see any type of integrity in this part of†¦show more content†¦I was at a water park with my family, the attendant at the bottom of one of the water slide told me I could not wait at the bottom of the slide where my 2 year old was coming down, he almost fell off the raft when it hit the water and fell off because the attendant was not paying attention so from that point on, to me it did not matter what the attendants said because they were not worried about my son’s safety, so basically it was let me catch him or face the issue of me going to the people in charge. Course as I am writing this I am thinking maybe I should have so it did not happen to someone else, again I am not perfect either but I do watch my kids. When it comes to integrity in Francis and Spangler’s decision to play badly so that they lose the game of pool, I would have to say I do not find integrity in this situation either, they are basically lying, definitely not being truthful in this circumstance. I can understand losing on purpose, I do it sometimes so my kids think they have won but not with someone my age or someone older. Usually people play to win. This event is horrible and would be very scary if anything like ever really happened. I find it completely disconcerting, imagine coming home from the family vacation at the water park to find your home empty, you ha d found a babysitter at any cost, have no clue where anyone isShow MoreRelatedSunday Field Trip And Sketch / Photo Essay1626 Words  | 7 Pagesto create an illustrated essay that uses imagery and short blurbs to talk about some of the ideas discussed in the readings and that you observe. The purpose of the assignment is to explore how combining imagery and short blurbs can be used to narrate the history of a site, its design, and how its design has been received. The assignment is meant to get you thinking about how photos can be used to promote ideas and represent experience, as well as how photos found in blogs and magazines can be deceptiveâ€â€Read MoreMeet Ppr s New Director Of Urban Forestry1148 Words  | 5 Pagesher career with Philadelphia Parks Recreation (PPR) as a Penn State summer student intern, June of 1981. Due to family circumstances, Lori had to get a job immediately. As a result of her internship experience, Lori decided to take the Grounds Maintenance Worker 1 test and passed. One of Lori’s proudest moments was that she began working with PPR when she was 21 years-old. After permanent appointment, she was able to advance within PPR as a Grounds Maintenance Worker 2, and Grounds Maintenance WorkerRead MoreA Qualitative Methodological Approach Through Field Research1209 Words  | 5 Pageswith a time-lapse coverage of a cross-section of spaces consisting of 14 plazas and 3 small parks. The main technique employed was simple and direct observation. The entities under study are referred to in social research as units of analysis (Singleton and Straits, 2010, p. 81). Entities can range from individual, groups, organization, objects or events. In the film, Whyte observes plazas, play areas, parks and open spaces in New York City. The explanatory variables that were present in Whyte’s studyRead MoreA Report On The Fire924 Words  | 4 PagesWritten Assignment #1 1. Risk: Risk is identified by each situation that could potentially bring harm to the town, and that may bring damage if the risk is very hazardous. a. In Stone Park even though we are a small community, we have a serious water pressure issue with the water that supplies the fire hydrants. This community could have problems when fighting a fire and not being supplied enough water, therefore, the fire could grow quickly due to not enough water. Our village did talk to theRead MoreUniversity Of New South Wales1397 Words  | 6 Pages University of New South Wales CVEN9611 –Urban Hydraulic Structures Assignment Stefan Felder Submitted by: Garth Cooper Student Number – z3189074 â€Æ' Question 1 Toowoomba City is located 125km from Brisbane in Queensland on the Western side of the Great Dividing Range. It consists of two main creek catchments, east creek and west creek catchments. In January 2011 there was a main flooding event which caused a large flood event that is described as an â€Å"Inland Tsunami†. Figure 1 - Catchment mapRead MoreOrting, Washington Essay711 Words  | 3 Pagesflow, it is currently in resting state. The last eruption of this massive volcano occurred more than 115 years ago in 1884. The eruptions of Mount Rainier produce lahar mudflows which are similar to pyroclastic flows except they contain more water. These mudflows carry debris of volcanic ash and boulders that produce lava flows and have the consistency of concrete flowing down a mountain (C.M. Riley). Lahars can flow up to 100 kilometers per hour and can extend out to more than 300 kilometersRead More Tescos Customer Service Essay1603 Words  | 7 Pagesinformation for this assignment. The investigation can help me provide evidence, true information and do the assignment easier. Structure Part one of my assignment is the research of the customer service practices in tesco. I will talk about the customer types, the customers’ needs, the organisation’s aims and policy and my conclusion. In this part, I will put some of the information in table and bullet point. Therefore the points are more clearly. The second part of this assignment is about theRead MoreTesco - Customer Service Essay1619 Words  | 7 Pagesinformation for this assignment. The investigation can help me provide evidence, true information and do the assignment easier. Structure Part one of my assignment is the research of the customer service practices in tesco. I will talk about the customer types, the customers needs, the organisations aims and policy and my conclusion. In this part, I will put some of the information in table and bullet point. Therefore the points are more clearly. The second part of this assignment is about theRead MoreChallenges Essay822 Words  | 4 Pagesdocument and organize it in your Drive account. I recommend having an ELA folder with subfolders for each marking period, 1, 2, 3 and 4. Read the prompt, read the articles, and type your response below. Upload this document to BlackBoard to submit it: On this document, select â€Å"File - Download as - Microsoft Word†and save it to your Chromebook. In Blackboard, click on the assignment link and follow the directions there to upload it. Links are not accepted in this class, and I am not digging around onRead MoreWindshield Survey1376 Words  | 6 Pagesand grading rubric found in Doc Sharing for specific instructions in order to complete the information below. This assignment is worth 150 points. Type your name above and your answers below directly on this form. Click Save as and save the file with the assignment name and your last name (e.g., â€Å"NR443 Windshield Survey Form_Smith†). When you are finished, submit the form to the Week 2 Caring for Populations: Windshield Survey Dropbox by the deadline indicated in your guidelines. Your Name: Jessica
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