关于美国高铁的数学建模(全英文)
MCM美国大学生数学建模竞赛模板-公式
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由假设得到公式1.We assume laminar flow and use Bernoulli’s equation:(由假设得到的公式)公式Where符号解释According to the assumptions, at every junction we have(由于假设)公式由原因得到公式2.Because our field is flat, we have公式, so the height of our source relative to our sprinklers does not affect the exit speed v2 (由原因得到的公式);公式Since the fluid is incompressible(由于液体是不可压缩的), we have公式Where公式用原来的公式推出公式3.Plugging v1 into the equation for v2 ,we obtain(将公式1代入公式2中得到)公式11.Putting these together(把公式放在一起), because of the law of conservation of energy, yields:[]公式12.Therefore, from (2),(3),(5), we have the ith junction(由前几个公式得)公式Putting (1)-(5) together, we can obtain pup at every junction. In fact, at the last junction, we have公式Putting these into (1) ,we get(把这些公式代入1中)公式Which means that theCommonly, h is aboutFrom these equations, (从这个公式中我们知道)we know that ………引出约束条件4.Using pressure and discharge data from Rain Bird 结果,We find the attenuation factor (得到衰减因子,常数,系数)to be公式计算结果6.To find the new pressure ,we use the ( 0 0),which states that the volume of water flowing in equals the volume of water flowing out : (为了找到新值,我们用什么方程)公式Where() is ;;7.Solving for VN we obtain (公式的解)公式Where n is the …..8.We have the following differential equations for speeds in the x- and y- directions:公式Whose solutions are (解)公式9.We use the following initial conditions ( 使用初值) to determine the drag constant:公式根据原有公式10.We apply the law of conservation of energy(根据能量守恒定律). The work done by the forces is公式The decrease in potential energy is (势能的减少)公式The increase in kinetic energy is (动能的增加)公式Drug acts directly against velocity, so the acceleration vector from drag can be found Newton’s law F=ma as : (牛顿第二定律)Where a is the acceleration vector and m is massUsing the Newton’s Second Law, we have that F/m=a and公式So that公式Setting the two expressions for t1/t2 equal and cross-multiplying gives公式22.We approximate the binomial distribution of contenders with a normal distribution:公式Where x is the cumulative distribution function of the standard normal distribution. Clearing denominators and solving the resulting quadratic in B gives公式As an analytic approximation to . for k=1, we get B=c26.Integrating, (使结合)we get PVT=constant, where公式The main composition of the air is nitrogen and oxygen, so i=5 and r=1.4, so23.According to First Law of Thermodynamics, we get公式Where ( ) . we also then have公式Where P is the pressure of the gas and V is the volume. We put them into the Ideal Gas Internal Formula:公式Where对公式变形13.Define A=nlw to be the ( )(定义); rearranging (1) produces (将公式变形得到)公式We maximize E for each layer, subject to the constraint (2). The calculations are easier if we minimize 1/E.(为了得到最大值,求他倒数的最小值)Neglecting constant factors (忽略常数), we minimize公式使服从约束条件14.Subject to the constraint (使服从约束条件)公式Where B is constant defined in (2). However, as long as we are obeying this constraint, we can write (根据约束条件我们得到)公式And thus f depends only on h , the function f is minimized at (求最小值)公式At this value of h, the constraint reduces to公式结果说明15.This implies(暗示)that the harmonic mean of l and w should be公式So , in the optimal situation. ………5.This value shows very little loss due to friction.(结果说明)The escape speed with friction is公式16.We use a similar process to find the position of the droplet, resulting in公式With t=0.0001 s, error from the approximation is virtually zero.17.We calculated its trajectory(轨道) using公式18.For that case, using the same expansion for e as above,公式19.Solving for t and equating it to the earlier expression for t, we get公式20.Recalling that in this equality only n is a function of f, we substitute for n and solve for f. the result is公式As v=…, this equation becomes singular (单数的).由语句得到公式21.The revenue generated by the flight is公式24.Then we have公式We differentiate the ideal-gas state equation公式Getting公式25.We eliminate dT from the last two equations to get (排除因素得到)公式22.We fist examine the path that the motorcycle follows. Taking the air resistance into account, we get two differential equations公式Where P is the relative pressure, we must first find the speed v1 of water at our source: (找初值)公式自己根据计算所画的图:1、为了…….(目的),我们作了…….图。
介绍高铁的英语作文
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Highspeed rail,often referred to as highspeed train or bullet train,is a form of rail transport that operates significantly faster than traditional rail traffic.The development of highspeed rail has revolutionized the way we travel,offering a blend of speed,comfort, and efficiency that is unmatched by other modes of transportation.Here is an essay that introduces the concept,benefits,and impact of highspeed rail on modern society.Title:The Evolution of HighSpeed Rail:A Modern MarvelIn the21st century,the world has witnessed a remarkable advancement in transportation technology,with highspeed rail emerging as a key player in the global transportation network.Highspeed rail systems,characterized by their ability to travel at speeds exceeding200kilometers per hour,have transformed the way we perceive distance and time.Origins and DevelopmentThe concept of highspeed rail is not new it has evolved over decades of research and development.Japan was the first to introduce a highspeed rail system with the Shinkansen in1964,setting a precedent for the world.Since then,countries like France, Germany,and China have developed their own highspeed networks,each with unique features and technological advancements.Technological InnovationsThe technology behind highspeed rail is a testament to human ingenuity.It involves sophisticated engineering solutions for track design,train aerodynamics,and magnetic levitation where applicable.The trains are designed to minimize air resistance and reduce noise pollution,ensuring a smooth and quiet ride.Moreover,advanced signaling systems and safety measures are in place to maintain the high operational standards required for such speeds.Economic and Environmental BenefitsHighspeed rail has had a profound economic impact,stimulating regional development and reducing travel times between cities.It has become an essential tool for business travelers,tourists,and daily commuters alike.Economically,it has led to the creation of jobs,both directly and indirectly,and has boosted local economies along the rail routes.From an environmental perspective,highspeed rail is a sustainable mode of transport.It produces fewer greenhouse gas emissions compared to air and road travel,making it a preferred choice for ecoconscious travelers.The energy efficiency of highspeed trains is further enhanced by the use of regenerative braking systems,which convert kinetic energy back into electrical energy.Cultural and Social ImpactThe cultural and social impact of highspeed rail is equally significant.It has brought people closer together,fostering a sense of community and shared identity among regions. The accessibility of highspeed rail has also encouraged cultural exchange and tourism, allowing individuals to experience different parts of the country or the world with ease.Challenges and the FutureDespite its numerous advantages,highspeed rail faces challenges such as high initial investment costs,land acquisition issues,and competition with existing modes of transport.However,with continuous technological advancements and growing environmental concerns,the future of highspeed rail looks promising.In conclusion,highspeed rail is more than just a mode of transportation it is a symbol of progress and a catalyst for economic growth,environmental sustainability,and social cohesion.As the world moves towards a more interconnected future,the role of highspeed rail is set to expand,connecting people,places,and ideas at unprecedented speeds.This essay provides a comprehensive overview of highspeed rail,highlighting its technological,economic,environmental,and social significance in the modern world.。
高铁规划作文英语模板
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高铁规划作文英语模板英文回答:High-Speed Railway Planning: A Comprehensive Guide。
Introduction。
High-speed railways (HSRs) are integral to modern transportation systems, facilitating efficient and sustainable travel. Meticulous planning is crucial to ensure the successful implementation of HSR projects. This comprehensive guide outlines the key steps involved in HSR planning, providing a framework for professionals and policymakers to navigate the complex process.1. Define Project Scope and Objectives。
The initial step involves defining the scope and objectives of the HSR project. This includes:Identifying the origin and destination cities。
Determining the desired travel time and frequency。
Estimating passenger demand and revenue projections。
Establishing environmental and sustainability targets。
2. Conduct Route Analysis and Selection。
关于高铁发展的英语文章
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The Evolution and Impact of High-Speed Rail High-speed rail (HSR) has revolutionized modern transportation, offering a fast, efficient, and sustainable alternative to traditional rail and air travel. The development of HSR systems worldwide has not only transformed the way people commute but also significantly impacted economic growth, urban development, and environmental sustainability.Origins and DevelopmentThe concept of high-speed rail dates back to the mid-20th century. Japan pioneered the first HSR system with the introduction of the Shinkansen, or "bullet train," in 1964. This iconic train connected Tokyo and Osaka, drastically reducing travel time between these major cities and setting a new standard for rail travel. The success of the Shinkansen spurred interest in high-speed rail in other countries.Europe followed suit with the French TGV (Train à Grande Vitesse) in 1981. The TGV network expanded rapidly, linking major French cities and extending into neighboring countries. Other European nations, including Germany, Spain, and Italy, developed their own HSR systems, creating a continent-wide network that continues to grow.China entered the HSR arena in the 21st century, quickly becoming the global leader in high-speed rail infrastructure. Since the launch of its first HSR line in 2008, China has built an extensive network spanning over 38,000 kilometers, connecting most of its major cities. This rapidexpansion has made China’s HSR the most extensive and heavily used in the world.Technological AdvancementsHigh-speed rail technology has seen significant advancements since its inception. Modern HSR trains can travel at speeds exceeding 300 kilometers per hour (186 miles per hour), thanks to aerodynamic designs, lightweight materials, and powerful electric traction systems. Innovations in track construction, such as continuously welded rails and advanced signaling systems, ensure smooth and safe operations at high speeds.Moreover, the development of magnetic levitation (maglev) technology promises even faster travel. Maglev trains, which float above the tracks using powerful magnets, can reach speeds of over 600 kilometers per hour (373 miles per hour). While still in its early stages of commercial deployment, maglev technology represents the future frontier of high-speed rail.Economic and Social ImpactThe implementation of high-speed rail has had profound economic and social impacts. By significantly reducing travel times, HSR has made it easier for people to commute, facilitating greater mobility and access to job markets. This has led to the growth of "mega-regions," where cities within a few hours of each other form interconnected economic hubs.HSR also stimulates economic development by attracting businesses and tourists to areas along the rail lines. Cities with HSR stations often experience increased investment, rising property values, and enhanced regional competitiveness. Furthermore, the construction and maintenance of HSR systems create numerous jobs, contributing to local economies.Environmental BenefitsOne of the most compelling advantages of high-speed rail is its environmental sustainability. HSR systems are typically powered by electricity, which can be sourced from renewable energy. This reduces reliance on fossil fuels and lowers greenhouse gas emissions compared to car and air travel. Additionally, HSR's high capacity and efficiency make it a more sustainable option for mass transit, helping to alleviate congestion and reduce the carbon footprint of transportation.Challenges and Future ProspectsDespite its many benefits, the expansion of high-speed rail faces challenges. High initial costs for infrastructure development, land acquisition issues, and the need for substantial government investment can hinder HSR projects. Moreover, integrating HSR with existing transportation networks and ensuring interoperability between different countries' systems require careful planning and coordination.Looking forward, the future of high-speed rail appears promising. As technology continues to advance and the need for sustainabletransportation solutions grows, HSR is likely to play an increasingly vital role in global transit. Innovations such as maglev trains, autonomous operations, and smart infrastructure are set to further enhance the efficiency, speed, and appeal of high-speed rail.In conclusion, the development of high-speed rail has marked a significant milestone in the evolution of transportation. By providing a fast, efficient, and eco-friendly mode of travel, HSR has the potential to reshape the future of mobility, fostering economic growth, and contributing to a more sustainable world.。
关于中国和外国高铁的英语作文
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关于中国和外国高铁的英语作文High-speed trains, or "bullet trains," haverevolutionized the way we travel, connecting cities and countries with unprecedented speed and efficiency. In China, the development of high-speed rail has been nothing short of remarkable, with the network expanding rapidly over the past decade.China's high-speed rail system is the largest in the world, boasting a network that spans thousands of kilometers and serves millions of passengers daily. The trains are known for their punctuality and comfort, offering a seamless travel experience that has become a hallmark of modern China.In contrast, other countries have also embraced high-speed rail technology, albeit at a different pace. For instance, Japan, the birthplace of the bullet train, has a well-established system that has been in operation for over half a century. The Shinkansen is renowned for itsreliability and efficiency, setting a global standard for high-speed rail travel.Europe, too, has seen the growth of high-speed rail networks, with the Eurostar connecting London to mainland Europe and the TGV in France offering high-speed services across the country. These systems have transformed the way Europeans travel, reducing the reliance on air travel for shorter distances.The environmental impact of high-speed rail is another significant advantage. Compared to air and road transport, high-speed trains produce fewer emissions, making them a more sustainable choice for long-distance travel. This is particularly important in China, where the government is committed to reducing pollution and promoting greener modes of transport.Safety is a critical aspect of high-speed rail systems worldwide. With rigorous safety protocols and regular maintenance, high-speed trains have one of the lowest accident rates in the transportation sector. This is a testament to the engineering and operational excellence of these systems.Cultural exchange is another benefit of high-speed rail. The ease of travel has facilitated greater interaction between people from different countries, promoting understanding and cooperation. For example, the China-Europe Railway Express has become a vital link for trade andcultural exchange between Asia and Europe.In conclusion, high-speed rail has become a symbol of modern transportation, offering a fast, safe, and environmentally friendly way to travel. As these systems continue to expand and improve, they will undoubtedly play an even more significant role in connecting the world.。
高铁的发展史英语作文
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高铁的发展史英语作文The development of high-speed rail can be traced back to the 1960s, when Japan became the first country to operate a high-speed train service. The introduction of the Shinkansen, or "bullet train," revolutionized the way people traveled and set a new standard for speed and efficiency in rail transportation.In the 1980s, France followed suit with the development of the TGV, or Train à Grande Vitesse. This marked the beginning of high-speed rail in Europe and furthersolidified the importance of fast and reliable train travel in the modern world.As the demand for high-speed rail continued to grow, countries like China, Germany, and Spain began investing in their own high-speed rail networks. This led to the expansion of high-speed rail across the globe, with more and more countries recognizing the benefits of this mode of transportation.The advancements in technology have also played a crucial role in the development of high-speed rail. From improvements in train design to the implementation of advanced signaling systems, the continuous innovation has allowed for faster and safer travel on high-speed rail networks.Today, high-speed rail has become an integral part of many countries' transportation systems, offering a convenient and sustainable alternative to air travel and driving. With ongoing developments and investments, the future of high-speed rail looks promising, with the potential to further transform the way people travel around the world.。
关于高铁英语作文
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关于高铁英语作文Title: The Advantages of High-Speed Rail。
In recent years, high-speed rail has becomeincreasingly prevalent around the globe, revolutionizing the way people travel. This mode of transportation offers numerous advantages that make it an appealing choice for both commuters and tourists alike.First and foremost, high-speed rail provides unparalleled speed and efficiency. With trains capable of reaching speeds upwards of 300 kilometers per hour, travelers can reach their destinations in a fraction of the time compared to other modes of transportation such as cars or conventional trains. This not only saves valuable time but also reduces the overall carbon footprint by encouraging more people to choose a greener form of travel.Moreover, high-speed rail networks are often seamlessly integrated into existing transportation infrastructure,offering convenient connections to major cities and airports. This connectivity not only enhances regional mobility but also stimulates economic growth byfacilitating the flow of goods and people between urban centers.Another significant advantage of high-speed rail is its reliability and punctuality. Unlike air travel, which is often subject to delays and cancellations due to weather conditions or air traffic congestion, high-speed trains operate on dedicated tracks, minimizing the risk of disruptions. This reliability makes it an attractive option for business travelers who require punctuality and dependability.Additionally, high-speed rail is renowned for its safety standards and technological innovations. Trains are equipped with state-of-the-art signaling systems and safety features to ensure a smooth and secure journey for passengers. Moreover, stringent maintenance protocols and rigorous safety checks further contribute to the overall safety record of high-speed rail networks.Furthermore, high-speed rail promotes sustainable development by reducing reliance on fossil fuels and mitigating traffic congestion and air pollution. Byoffering a viable alternative to car travel, high-speedrail helps alleviate the strain on road infrastructure and reduces greenhouse gas emissions, thereby contributing to efforts to combat climate change.In terms of passenger experience, high-speed trains offer unparalleled comfort and amenities. Modern trains are equipped with spacious seating, onboard entertainment systems, and dining facilities, providing passengers with a comfortable and enjoyable travel experience. Additionally, the availability of Wi-Fi connectivity and charging outlets ensures that passengers can stay connected and productive during their journey.From an economic perspective, high-speed rail projects create job opportunities and stimulate investment in infrastructure development. The construction and operation of high-speed rail networks generate employmentopportunities in various sectors, including engineering, construction, and hospitality. Moreover, improved connectivity between cities and regions attracts investment and promotes economic growth by facilitating business transactions and tourism.In conclusion, high-speed rail offers numerous advantages ranging from speed and efficiency to safety and sustainability. By providing a fast, reliable, and environmentally friendly mode of transportation, high-speed rail has the potential to transform the way people travel and contribute to the sustainable development of society. As countries continue to invest in expanding and enhancing their high-speed rail networks, the benefits of this innovative mode of transportation will become increasingly apparent, ushering in a new era of mobility and connectivity.。
高铁的英语作文
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高铁的英语作文In the era of rapid technological advancements, high-speed railways have emerged as a symbol of modern transportation. They are not just a means of travel, but a testament to human ingenuity and engineering prowess.The concept of high-speed rail began in Japan in the 1960swith the introduction of the Shinkansen, which revolutionized the way people thought about train travel. Today, high-speed railways are a staple in many countries, connecting citiesand regions at unprecedented speeds.One of the most notable features of high-speed railways istheir efficiency. With top speeds reaching over 300kilometers per hour, they cut down travel time significantly. This has a profound impact on both business and tourism, asit allows for easier and quicker access to various destinations.Another advantage is their environmental friendliness. High-speed trains produce far less carbon emissions compared to airplanes, making them a more sustainable choice for long-distance travel. Moreover, they are powered by electricity, which can be sourced from renewable energy, further reducing their environmental footprint.Safety is also a key aspect of high-speed railways. With advanced signaling systems and rigorous maintenance protocols,these trains are among the safest modes of transportation available. This is particularly important for passengers who prioritize safety in their travel choices.The economic benefits of high-speed rail are undeniable. They stimulate regional economies by improving accessibility and fostering business opportunities. Additionally, the construction and operation of high-speed rail networks create numerous jobs, contributing to economic growth.However, the implementation of high-speed railways is not without challenges. The initial cost of infrastructure can be high, and the return on investment may take years to realize. Furthermore, there are concerns about the displacement of communities and the environmental impact of construction.In conclusion, high-speed railways represent a significant leap forward in transportation technology. They offer a blend of speed, efficiency, and environmental responsibility thatis hard to match. As the world continues to evolve and grow, it is likely that high-speed rail will play an increasingly important role in connecting people and places, shaping the future of travel.。
美国数学建模比赛历年试题
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2003 MCM ProblemsPROBLEM A: The Stunt PersonAn exciting action scene in a movie is going to be filmed, and you are the stunt coordinator! A stunt person on a motorcycle will jump over an elephant and land in a pile of cardboard boxes to cushion their fall. You need to protect the stunt person, and also use relatively few cardboard boxes (lower cost, not seen by camera, etc.).Your job is to:•determine what size boxes to use•determine how many boxes to use•determine how the boxes will be stacked•determine if any modifications to the boxes would help•generalize to different bined weights (stunt person & motorcycle) and different jump heightsNote that, in "Tomorrow Never Dies", the James Bond character on a motorcycle jumps over a helicopter.PROBLEM B: Gamma Knife Treatment PlanningStereotactic radiosurgery delivers a single high dose of ionizing radiation to a radiographicallywell-defined, small intracranial 3D brain tumor without delivering any significant fraction of the prescribed dose to the surrounding brain tissue. Three modalities are monly used in this area; they are the gamma knife unit, heavy charged particle beams, and external high-energy photon beams from linear accelerators.The gamma knife unit delivers a single high dose of ionizing radiation emanating from 201 cobalt-60 unit sources through a heavy helmet. All 201 beams simultaneously intersect at the isocenter, resulting in a spherical (approximately) dose distribution at the effective dose levels. Irradiating the isocenter to deliver dose is termed a “shot.” Shots can be represented as different spheres. Four interchangeable outer collimator helmets with beam channel diameters of 4, 8, 14, and 18 mm are available for irradiating different size volumes. For a target volume larger than one shot, multiple shots can be used to cover the entire target. In practice, most target volumes are treated with 1 to 15 shots. The target volume is a bounded, three-dimensional digital image that usually consists of millions of points.The goal of radiosurgery is to deplete tumor cells while preserving normal structures. Since there are physical limitations and biological uncertainties involved in this therapy process, a treatment plan needs to account for all those limitations and uncertainties. In general, an optimal treatment plan is designed to meet the following requirements.1.Minimize the dose gradient across the target volume.2.Match specified isodose contours to the target volumes.3.Match specified dose-volume constraints of the target and critical organ.4.Minimize the integral dose to the entire volume of normal tissues or organs.5.Constrain dose to specified normal tissue points below tolerance doses.6.Minimize the maximum dose to critical volumes.In gamma unit treatment planning, we have the following constraints:1.Prohibit shots from protruding outside the target.2.Prohibit shots from overlapping (to avoid hot spots).3.Cover the target volume with effective dosage as much as possible. But at least 90% of thetarget volume must be covered by shots.e as few shots as possible.Your tasks are to formulate the optimal treatment planning for a gamma knife unit as a sphere-packing problem, and propose an algorithm to find a solution. While designing your algorithm, you must keep in mind that your algorithm must be reasonably efficient.2002 Contest ProblemsProblem AAuthors: Tjalling YpmaTitle: Wind and WatersprayAn ornamental fountain in a large open plaza surrounded by buildings squirts water high into the air. On gusty days, the wind blows spray from the fountain onto passersby. The water-flow from the fountain is controlled by a mechanism linked to an anemometer (which measures wind speed and direction) located on top of an adjacent building. The objective of this control is to provide passersby with an acceptable balance between an attractive spectacle and a soaking: The harder the wind blows, the lower the water volume and height to which the water is squirted, hence the less spray falls outside the pool area.Your task is to devise an algorithm which uses data provided by the anemometer to adjust the water-flow from the fountain as the wind conditions change.Problem BAuthors: Bill Fox and Rich WestTitle: Airline OverbookingYou're all packed and ready to go on a trip to visit your best friend in New York City. After you check in at the ticket counter, the airline clerk announces that your flight has been overbooked. Passengers need to check in immediately to determine if they still have a seat.Historically, airlines know that only a certain percentage of passengers who have made reservations on a particular flight will actually take that flight. Consequently, most airlines overbook-that is, they take more reservations than the capacity of the aircraft. Occasionally, more passengers will want to take a flight than the capacity of the plane leading to one or more passengers being bumped and thus unable to take the flight for which they had reservations.Airlines deal with bumped passengers in various ways. Some are given nothing, some are booked on later flights on other airlines, and some are given some kind of cash or airline ticket incentive.Consider the overbooking issue in light of the current situation:Less flights by airlines from point A to point BHeightened security at and around airportsPassengers' fearLoss of billions of dollars in revenue by airlines to dateBuild a mathematical model that examines the effects that different overbooking schemes have on the revenue received by an airline pany in order to find an optimal overbooking strategy, i.e., the number of people by which an airline should overbook a particular flight so that the pany's revenue is maximized. Insure that your model reflects the issues above, and consider alternatives for handling "bumped" passengers. Additionally, write a short memorandum to the airline's CEO summarizing your findings and analysis.MCM2000Problem A Air traffic ControlTo improve safety and reduce air traffic controller workload, the Federal Aviation Agency (FAA) is considering adding software to the air traffic control system that would automatically detect potential aircraft flight path conflicts and alert the controller. To that end, an analyst at the FAA r traffic control system that would automatically detect potential aircraft flight path conflicts and alert the controller. To that end, an analyst at the FAA has posed the following problemsRequirement A: Given two airplanes flying in space, when should the air traffic controller ld the air traffic controller consider the objects to be too close and to require intervention?Requirement B: An airspace sector is the section of three-dimensional airspace that one air traffic controller controls. Given any airspace sector, how we measure how plex it is from an air traffic workload perspective? To what extent is plexity determined by the number of we measure how plex it is from an air traffic workload perspective? To what extent is plexity determined by the number of aircraft simultaneously passing through that sector (1) at any one instant? (2) During any given interval of time? (3) During particular time of day? How does the number of potential conflicts arising during those periods affect plexity?Does the presence of additional software tools to automatically predict conflicts and alert the controller reduce or add to this plexity?In addition to the guidelines for your report, write a summary (no more than two pages) that the FAA analyst can present to Jane Garvey, the FAA Administrator, to defend your conclusionsProblem B Radio Channel AssignmentsWe seek to model the assignment of radio channels to a symmetric network of transmitter locations over a large planar area, so as to avoid interference. One basic approach is to partition the region into regular hexagons in a grid (honeyb-style), as shown in Figure 1, where a transmitter is located at the center of each hexagon.An interval of the frequency spectrum is to be allotted for transmitter frequencies. The interval will be divided into regularly spaced channels, which we represent by integers 1, 2, 3, ... . Each transmitter will be assigned one positive integer channel. The same channel can be used at many locations, provided that interference from nearby transmitters is avoided. Our goal is to minimize the width of the interval in the frequency spectrum that is needed to assign channels subject to some constraints. This is achieved with the concept of a span. The span is the minimum, over all assignments satisfying the constraints, of the largest channel used at any location. It is not required that every channel smaller than the span be used in an assignment that attains the span.Let s be the length of a side of one of the hexagons. We concentrate on the case that there are two levels of interferenceRequirement A: There are several constraints on frequency assignments. First, no two transmitters within distance of each other can be given the same channel. Second, due to spectral spreading, transmitters within distance 2s of each other must not be given the same or adjacent channels: Their channels must differ by at least 2. Under these constraints, what can we say about the span in,Requirement B: Repeat Requirement A, assuming the grid in the example spreads arbitrarily far in all directions.Requirement C: Repeat Requirements A and B, except assume now more generally that channels for transmitters within distance differ by at least some given integer k, while those at distance at most must still differ by at least one. What can we say about the span and about efficient strategies for designing assignments, as a function of k?Requirement D: Consider generalizations of the problem, such as several levels of interference or irregular transmitter placements. What other factors may be important to consider?Requirement E: Write an article (no more than 2 pages) for the local newspaper explaining your findingsMCM2000问题A 空间交通管制为加强安全并减少空中交通指挥员的工作量,联邦航空局(FAA)考虑对空中交通管制系统添加软件,以便自动探测飞行器飞行路线可能的冲突,并提醒指挥员。
关于高铁的英语作文范文
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关于高铁的英语作文范文Title: The Advancements and Impact of High-Speed RailIn the realm of transportation, high-speed rail stands as a testament to human ingenuity and progress. Since its inception, it has revolutionized travel, commerce, and connectivity, ushering in a new era of efficiency and convenience. This essay delves into the advancements and impact of high-speed rail, exploring its technological marvels, economic implications, environmental benefits, and social significance.Technological Advancements:High-speed rail epitomizes the pinnacle of technological achievement in transportation. Utilizing cutting-edge engineering and innovation, it achieves remarkable speeds while ensuring safety and comfort for passengers. Advanced signaling systems, aerodynamic designs, and precisionengineering enable trains to traverse vast distances in record time, rivaling the speed and efficiency of air travel. Furthermore, continuous research and development efforts continually push the boundaries of speed and efficiency, promising even greater advancements in the future.Economic Implications:The introduction of high-speed rail networks has profound economic implications, stimulating growth, and fostering development in regions served by these systems. By reducing travel times and improving accessibility, high-speed rail enhances business opportunities, facilitates trade, and attracts investment. It creates employment opportunities in construction, operation, and maintenance while supporting ancillary industries such as tourism and hospitality. Moreover, the seamless connectivity offered by high-speedrail integrates regional economies into larger markets, fostering innovation and competitiveness on a global scale.Environmental Benefits:High-speed rail represents a sustainable alternative to traditional modes of transportation, offering significant environmental benefits. Compared to automobiles and airplanes, trains emit fewer greenhouse gases per passenger-kilometer, thereby mitigating air pollution and reducing carbon emissions. Additionally, high-speed rail systems oftenutilize renewable energy sources such as electricity, further minimizing their environmental footprint. By promoting modal shift from carbon-intensive modes of transport, high-speedrail plays a crucial role in combating climate change and advancing sustainability goals.Social Significance:Beyond its technological and economic aspects, high-speed rail holds profound social significance, reshaping lifestyles, and fostering social cohesion. By connecting urban centerswith peripheral regions, it reduces disparities in access toopportunities and services, promoting inclusivity and equality. High-speed rail enhances mobility for individuals, facilitating leisure travel, family visits, and cultural exchanges. Moreover, by alleviating congestion on roads and airports, it enhances the overall quality of life by reducing travel stress and improving safety.In conclusion, high-speed rail stands as a symbol of human achievement, embodying our relentless pursuit of progress and innovation. With its technological prowess, economic vitality, environmental stewardship, and social impact, it continues to redefine the landscape of transportation in the 21st century. As we look to the future, high-speed rail remains poised to play a central role in shaping a more connected, sustainable, and prosperous world.。
介绍高铁的英语作文
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介绍高铁的英语作文英文回答:IntroductionImagine a world where distances melt away, and time becomes irrelevant. Picture yourself soaring through picturesque landscapes, enveloped in a cocoon of speed and comfort. Welcome to the realm of high-speed rail, the epitome of modern transportation that has revolutionized the way we travel.The Genesis of High-Speed RailThe seeds of high-speed rail were first sown in the early 20th century, with Japan's dream of connecting its bustling metropolises with lightning-fast trains. In 1964, the first high-speed rail line, the Shinkansen, was unveiled, capable of reaching speeds of up to 125 mph. Thesuccess of the Shinkansen sparked a global race towards developing high-speed rail systems, with countries worldwide vying to push the boundaries of speed and innovation.Technological AdvancementsThe development of high-speed rail has been propelled by relentless technological advancements. From aerodynamic bullet trains to sophisticated signaling systems, each innovation has pushed the limits of what was once thought impossible. Advanced materials, such as lightweight aluminum and carbon fiber, have enabled the construction of trains that are both strong and sleek. Energy-efficient engines and regenerative braking systems have minimized environmental impact, making high-speed rail a greener mode of transportation.Economic BenefitsHigh-speed rail has emerged as a catalyst for economic growth and development. By connecting major cities and unlocking access to remote areas, high-speed rail has fostered trade, stimulated tourism, and created new job opportunities. The reduced travel time has allowed businesses to expand their reach, fostering collaboration and innovation. Moreover, high-speed rail has reduced congestion on roads and airports, easing traffic flow and improving air quality.Social ImpactBeyond its economic benefits, high-speed rail has a profound social impact. It has bridged geographical divides, connecting communities that were once separated by distance. The increased accessibility has fostered cultural exchange, promoting understanding and breaking down barriers. High-speed rail has also improved mobility for all, providing convenient and affordable transportation options for people from all walks of life.Environmental SustainabilityIn an era marked by climate change, high-speed rail offers a sustainable alternative to air travel and road transportation. Electrically powered high-speed trains produce significantly lower greenhouse gas emissions compared to other modes of transport. The energy efficiency of these trains, coupled with the reduction in road congestion, makes high-speed rail an environmentally friendly choice.ConclusionHigh-speed rail is more than just a mode of transportation; it is a testament to human ingenuity and our relentless pursuit of progress. Its transformative impact on economies, societies, and the environment has cemented its place as a cornerstone of modern infrastructure. As we continue to push the boundaries of technology and innovation, the future of high-speed railholds endless possibilities, promising a future where distance is no longer an obstacle, and time is harnessed for the benefit of humanity.中文回答:引言想象一个距离消失,时间变得无关紧要的世界。
最伟大的发明英语高铁作文
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最伟大的发明英语高铁作文In the annals of human ingenuity, few inventions have revolutionized transportation as profoundly as the high-speed train. This remarkable mode of transportation has not only transformed the way we travel but has also reshaped the economic, cultural, and environmental landscapes of the world.The high-speed train, often referred to as the "bullet train" or "HSR" (High-Speed Rail), is a testament to the boundless possibilities of human innovation. With speeds that can exceed 350 kilometers per hour (over 200 miles per hour), these trains have缩短了distances and reduced travel times, making it possible to traverse vast distances in a fraction of the time it would take by car or plane.The impact of the high-speed train is felt across all sectors of society. In the economic realm, it has fostered economic growth and integration by connecting cities and regions, allowing businesses to expand their reach and markets. The convenience and efficiency of HSR have also made it a popular mode of transportation for commuters,reducing congestion on roads and in airports while cutting down on carbon emissions.Culturally, the high-speed train has served as a catalyst for cultural exchange and tourism. By making it easier for people to travel between cities, it has opened up new opportunities for cultural experiences and exploration. Visitors can now easily traverse the length and breadth of a country, taking in the sights and sounds of diverse regions and cultures.Environmentally, the high-speed train offers a sustainable alternative to fossil fuel-dependent modes of transportation. By reducing the need for air travel and long-distance road trips, HSR helps to mitigate the impact of climate change by cutting down on greenhouse gas emissions.The development of the high-speed train is a testament to the power of human ingenuity and innovation. It represents a triumph of engineering and technology, as well as a profound understanding of human needs and aspirations. As we look to the future, the potential of the high-speedtrain to revolutionize transportation and transform our world is limitless.**高铁:最伟大的发明**在人类智慧的编年史中,很少有发明能像高铁一样彻底改变交通方式。
介绍超级高铁英语作文
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介绍超级高铁英语作文Super Hyperloop: Revolutionizing Transportation The concept of the Super Hyperloop is an exciting development in the field of transportation. It is a revolutionary mode of travel that promises to change the way we move people and goods from one place to another.The Super Hyperloop is a high-speed transportation system that uses magnetic levitation technology to propel pods through a low-pressure tube. These pods can reach incredibly high speeds, potentially traveling at several times the speed of a commercial airplane. This would drastically reduce travel times, making it possible to travel long distances in a matter of minutes.One of the key advantages of the Super Hyperloop is its energy efficiency. The system is designed to minimize air resistance and friction, which results in a significant reduction in energy consumption compared to traditional transportation methods. Additionally, the use of renewable energy sources to power the system makes it a more sustainable option for the future.Another benefit of the Super Hyperloop is its potential to reduce traffic congestion. By providing a fast and efficient alternative to traditional modes of transportation, it could encourage people to leave their cars at home and opt for this greener and more convenient option. This could have a positive impact on the environment and quality of life in urban areas.However, there are also some challenges associated with the development of the Super Hyperloop. The technology is still in its early stages, and there are many technical and engineering hurdles that need to be overcome. Additionally, the cost of building and maintaining such a system is likely to be very high, which could pose a significant barrier to its widespread implementation.Despite these challenges, the potential of the Super Hyperloop is too great to ignore. With continued research and development, this innovative transportation system could one day become a reality, transforming the way we travel and shaping the future of transportation.In conclusion, the Super Hyperloop represents a bold vision for the future of transportation. While there are still many obstacles to overcome, the potential benefits of thistechnology make it an area worth exploring. As we look towards a more sustainable and efficient future, the Super Hyperloop could play a crucial role in meeting our transportation needs.。
讲高铁的英语作文
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讲高铁的英语作文Title: The High-Speed Rail: A Game-Changer in Transportation。
Introduction:The advent of high-speed rail (HSR) has revolutionized the way people travel, offering swift and efficient transportation across vast distances. This essay delvesinto the significance of high-speed rail systems, their benefits, and their impact on society and the environment.Development:High-speed rail, often referred to as bullet trains, exemplifies cutting-edge technology in the realm of transportation. These trains operate at speeds exceeding conventional trains, providing passengers with a rapid and comfortable journey. The implementation of HSR networks has brought about numerous advantages.Firstly, high-speed rail enhances connectivity, linking major cities and regions within a country. Thisconnectivity fosters economic growth by facilitating the movement of people and goods, thereby stimulating trade and commerce. Moreover, HSR reduces travel time significantly, offering commuters a time-efficient alternative to other modes of transportation such as cars or airplanes.Furthermore, high-speed rail contributes to environmental sustainability by reducing carbon emissions. Compared to air travel, trains produce fewer greenhouse gases per passenger-kilometer, making them a more eco-friendly option for long-distance travel. Additionally, the efficient use of energy in high-speed rail systems further mitigates environmental impact.In terms of social impact, high-speed rail promotes social inclusion by making travel more accessible to a wider population. It enables individuals from diversesocio-economic backgrounds to commute between cities for work, education, or leisure, thereby fostering culturalexchange and societal cohesion. Moreover, HSR enhances mobility for elderly and disabled individuals, ensuring equitable access to transportation services.Another significant aspect of high-speed rail is its role in urban development and regional planning. The construction of HSR stations stimulates economic activityin surrounding areas, leading to the development of commercial and residential complexes. This phenomenon, known as the "railway effect," spurs investment and revitalizes urban centers, creating employmentopportunities and improving living standards for residents.Additionally, high-speed rail plays a pivotal role in reducing traffic congestion and alleviating strain on existing transportation infrastructure. By diverting a portion of passenger traffic from roads and airports torail networks, HSR helps mitigate congestion, resulting in smoother traffic flow and reduced travel delays. This not only enhances the overall efficiency of the transportation system but also reduces the need for costly infrastructure expansion projects.Conclusion:In conclusion, high-speed rail represents a paradigm shift in transportation, offering a myriad of benefits ranging from enhanced connectivity and environmental sustainability to social inclusion and urban development. As nations continue to invest in expanding and modernizing their HSR networks, the transformative impact of this mode of transportation will undoubtedly shape the future of mobility on a global scale.。
关于高铁的初中英语作文
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关于高铁的初中英语作文High-speed rail has become an increasingly popular mode of transportation around the world in recent decades. This advanced rail system offers a fast, efficient, and environmentally-friendly way to travel between cities and regions. As a student, I have had the opportunity to experience the convenience and comfort of high-speed rail, and I believe it has significant benefits for individuals, communities, and our planet.One of the primary advantages of high-speed rail is its speed and efficiency. High-speed trains can reach top speeds of over 200 miles per hour, allowing passengers to travel long distances in a fraction of the time it would take by car or traditional rail. This makes high-speed rail an attractive option for both business and leisure travelers who value their time and want to arrive at their destination quickly. The speed of high-speed rail also reduces congestion on roads and in the air, as more people choose to travel by train instead of driving or flying.In addition to its speed, high-speed rail is also known for itsreliability and punctuality. High-speed rail systems are designed with advanced signaling and control systems that ensure trains run on time and with minimal delays. This is particularly beneficial for business travelers who need to arrive at their meetings or events on schedule. The reliability of high-speed rail also makes it a more attractive option for commuters who rely on public transportation to get to work or school.Another significant advantage of high-speed rail is its environmental sustainability. Compared to other modes of transportation, such as cars and airplanes, high-speed trains produce significantly lower greenhouse gas emissions and have a smaller carbon footprint. This makes high-speed rail an important part of efforts to reduce the environmental impact of transportation and combat climate change. Additionally, high-speed rail can reduce the need for new highway construction and airport expansions, which can have a significant impact on the environment.High-speed rail also has the potential to promote economic development and social connectivity. By connecting cities and regions, high-speed rail can facilitate the movement of people, goods, and ideas, which can lead to increased economic activity and job creation. High-speed rail can also make it easier for people to access educational, cultural, and recreational opportunities in other parts of the country, fostering greater social integration andreducing regional disparities.Despite these benefits, the development of high-speed rail infrastructure can be a significant challenge, requiring substantial investments in new track, signaling systems, and rolling stock. Additionally, the construction of high-speed rail lines can be disruptive to local communities and may face opposition from residents who are concerned about the impact on their neighborhoods. Nonetheless, many countries around the world have made significant investments in high-speed rail, recognizing its long-term benefits for their citizens and their economies.In conclusion, high-speed rail is a transformative mode of transportation that offers a range of benefits for individuals, communities, and the environment. Its speed, reliability, and environmental sustainability make it an attractive option for both business and leisure travelers, while its potential to promote economic development and social connectivity make it a valuable investment for countries and regions. As we continue to grapple with the challenges of sustainable transportation and climate change, high-speed rail will likely play an increasingly important role in shaping the future of mobility around the world.。
高铁技术的英语作文初一
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高铁技术的英语作文初一High-speed rail technology, also known as bullet train technology, has revolutionized the way people travel. It is a marvel of engineering and innovation that has brought about numerous benefits to society.The first thing that comes to mind when thinking about high-speed rail technology is its incredible speed. These trains can reach speeds of up to 350 kilometers per hour, allowing passengers to travel long distances in a fraction of the time it would take by car or conventional train.It's like flying on the ground!Not only are high-speed trains fast, but they are also incredibly comfortable. The seats are spacious and plush, and the cabins are equipped with modern amenities such as Wi-Fi and power outlets. Passengers can relax and enjoy the journey while being able to stay connected to the outside world.One of the most impressive aspects of high-speed rail technology is its safety record. These trains are equipped with state-of-the-art safety features, including advanced braking systems and sophisticated signaling systems. The tracks are also built to the highest standards, ensuring a smooth and secure ride for passengers.In addition to speed and comfort, high-speed rail technology is also environmentally friendly. These trains run on electricity, which means they produce zero emissions during operation. This helps reduce air pollution and combat climate change, making high-speed rail a sustainable mode of transportation.Furthermore, high-speed rail technology has had a significant impact on local economies. The construction of high-speed rail lines creates jobs and stimulates economic growth in the areas where they are built. It also promotes tourism and facilitates business travel, bringing more opportunities for businesses and boosting local economies.In conclusion, high-speed rail technology hastransformed the way we travel. Its incredible speed, comfort, safety, environmental friendliness, and economic benefits make it a game-changer in the transportation industry. Whether for business or leisure, high-speed rail offers a convenient and sustainable way to get from one place to another.。
介绍一个高铁英语作文
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介绍一个高铁英语作文High-speed rail, also known as bullet train, is a popular mode of transportation in many countries. It is fast, convenient, and comfortable. The high-speed rail network connects major cities and reduces travel time significantly.The high-speed rail is equipped with advanced technology, such as magnetic levitation and aerodynamic design, which allows it to travel at speeds of up to 300 kilometers per hour. This makes it a time-efficient option for travelers who want to reach their destinations quickly.One of the advantages of high-speed rail is its punctuality. It rarely experiences delays and cancellations, which is a common occurrence in air travel. Passengers can rely on the high-speed rail to arrive at their destination on time.The interior of the high-speed rail is designed forcomfort. The seats are spacious and adjustable, and the train is equipped with modern amenities such as Wi-Fi, power outlets, and clean restrooms. Passengers can relax and enjoy the journey in a comfortable environment.High-speed rail is also environmentally friendly. It consumes less energy and produces lower emissions compared to other modes of transportation. This makes it a sustainable option for long-distance travel.Overall, high-speed rail offers a fast, convenient, and comfortable travel experience for passengers. It is a reliable mode of transportation that connects major cities and contributes to a sustainable environment.。
高铁技术的英语小作文
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高铁技术的英语小作文High-speed rail technology has revolutionized the way we travel. It offers a swift and efficient mode of transport, connecting cities and regions in a matter of hours instead of days.The comfort and convenience of high-speed trains are unmatched. Passengers can enjoy a smooth ride with minimal noise, making long journeys a pleasure rather than a chore. The spacious seating and amenities on board further enhance the travel experience.Safety is a paramount concern in high-speed rail systems. Advanced signaling and braking technologies ensure that these trains operate with utmost reliability. The rigorous maintenance and inspection schedules contribute to the safety record of high-speed rail.Economically, high-speed rail has a significant impact.It stimulates regional development by bringing people and businesses closer together. The reduced travel time encourages trade and tourism, boosting local economies.Environmental benefits are another advantage of high-speed rail. Compared to air and road transport, trains produce fewer emissions, making them a greener choice for long-distance travel. This aligns with global efforts to combat climate change.The future of high-speed rail is promising, with ongoing research and development aimed at increasing speeds and reducing costs. Innovations in materials and design are pushing the boundaries of what is possible in rail transportation.In conclusion, high-speed rail technology is a testament to human ingenuity and progress. It offers a blend of speed, comfort, safety, and environmental responsibility, making it an ideal choice for modern travel.。
英语作文关于高铁
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英语作文关于高铁Title: The High-Speed Rail: A Marvel of Modern Transportation。
Introduction:The high-speed rail, often dubbed as a marvel of modern transportation, has revolutionized the way people travel. With its speed, efficiency, and environmental benefits, it has become a cornerstone of many countries' transportation systems. In this essay, we will delve into the various aspects of high-speed rail and explore its significance in today's world.History and Development:The concept of high-speed rail dates back to the early 20th century, but it wasn't until the late 20th and early 21st centuries that it truly flourished. Countries like Japan, France, and Germany were pioneers in developinghigh-speed rail networks, with the introduction of the Shinkansen in Japan in 1964 marking a significant milestone. Since then, many countries around the world have investedin high-speed rail infrastructure, leading to a global network of fast and efficient train services.Advantages of High-Speed Rail:One of the primary advantages of high-speed rail is its speed. High-speed trains can travel at speeds exceeding 300 kilometers per hour, allowing passengers to reach their destinations in a fraction of the time compared to conventional trains or other modes of transportation. This not only saves time for travelers but also increases productivity and efficiency in business and commerce.Moreover, high-speed rail is environmentally friendly compared to other modes of transportation such as airtravel or road transport. High-speed trains produce fewer greenhouse gas emissions per passenger kilometer, making them a more sustainable option for long-distance travel. Additionally, high-speed rail helps alleviate congestion onroads and reduce the need for domestic flights, thereby contributing to a reduction in air pollution and carbon emissions.Furthermore, high-speed rail promotes economic development by improving connectivity between cities and regions. It facilitates the movement of people and goods, which stimulates economic activity and fosters growth in both urban and rural areas along its routes. High-speedrail stations become hubs of economic activity, attracting businesses, tourism, and investment.Challenges and Considerations:Despite its numerous advantages, high-speed rail also faces challenges and considerations. One of the main challenges is the high initial cost of infrastructure development. Building and maintaining high-speed rail lines require significant investment in land acquisition, construction, and technology. Governments and private investors must weigh the long-term benefits against the upfront costs when deciding to invest in high-speed railprojects.Additionally, high-speed rail projects often face logistical and regulatory hurdles. Coordinating between multiple stakeholders, including government agencies, railway operators, and local communities, can be complex and time-consuming. Moreover, ensuring safety and security standards is paramount for high-speed rail systems, requiring rigorous planning and implementation of safety measures.Future Prospects:Looking ahead, the future of high-speed rail appears promising. Many countries are expanding their existing networks and investing in new technologies to further improve the speed, efficiency, and sustainability of high-speed trains. Advances in materials, propulsion systems, and infrastructure design hold the potential to make high-speed rail even faster and more cost-effective.Furthermore, the integration of high-speed rail withother modes of transportation, such as urban transit systems and autonomous vehicles, could enhance its connectivity and accessibility. This multimodal approach would offer passengers seamless and convenient travel options, further incentivizing the use of high-speed rail for both domestic and international travel.Conclusion:In conclusion, high-speed rail has emerged as a vital component of modern transportation systems, offering numerous benefits in terms of speed, efficiency, and sustainability. Despite facing challenges, its continued development and expansion hold great promise for the future of global mobility. By investing in high-speed rail infrastructure and embracing innovation, countries can create a more interconnected and sustainable world for generations to come.。
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28号交流的时间10:00----10:10 How should the national rail system be built?what the nation high speed rail will bring to American?SummaryFirst of all, we select the top 20 states through the rankings of the total GDP of the U.S. states divided into seven economic zones in each economic region between First select total GDP and GDP per capita, the top row and a total population of more citiesdesign of high-speed rail line. After we are through the high-speed rail line to connect each economic zone, and eventually form a complete high-speed rail network. In the design of high-speed rail line, we use the prim algorithm. By constructing a minimum spanning tree to determine the railway between which two points is the best.The construction of high-speed rail manufacturing relationship with the economy, tourism, Select economically developed regions reasons.First, according to the economic divide block, we get seven economic blocks through the analysis of GDP of 20 states, and then consolidated the top of the urban population and 50 selected priority to the construction of high-speed rail city, and finally we decided the 31 cities priority the construction of high-speed rail.The second year the main purpose is to connect some of the blocks, integrated urban population in 100 cities elected before connecting the city and some of the more populous city, and finally selected 26 new high-speed rail city.The third and fourth years of the connection of the eastern and western regions of the central region.The first five years the construction of the difficulty of some larger and some minor high-speed rail construction.The impact of the aircraft on the high-speed railway, we assume that its effect is linear.800 miles ago, the choice of high-speed rail and aircraft are fixed, the number of aircraft in the 800 miles increased linearly select number of high-speed rail will decrease linearly.Key wordsThe prim algorithm, Economic zones Linear effectsContents1. Introduction (3)1.1 Why does toll way collects toll? (3)1.2 Toll modes (3)1.3 Toll collection methods (3)1.4 Annoyance in toll plazas (3)1.5 The origin of the toll way problem (3)1.6 Queuing theory (4)2. The Description of Problem (5)2.1 How do we approximate the whole course of paying toll? (5)2.2 How do we define the optimal configuration? (5)2.2.1 From the perspective of motorist (5)2.2.2 From the perspective of the toll plaza (6)2.2.3 Compromise (6)2.3 Overall optimization and local optimization (6)2.4 The differences in weights and sizes of vehicles (7)2.5 What if there is no data available? (7)3. Models (7)3.1 Basic Model (7)3.1.1 Symbols and Definitions (7)3.1.2 Assumptions (8)3.1.3 The Foundation of Model (9)3.1.4 Solution and Result (11)3.1.5 Analysis of the Result (11)3.1.6 Strength and Weakness (13)3.2 Improved Model (14)3.2.1 Extra Symbols (14)3.2.2 Additional Assumptions (14)3.2.3 The Foundation of Model (14)3.2.4 Solution and Result (15)3.2.5 Analysis of the Result (18)3.2.6 Strength and Weakness (19)4. Conclusions (19)4.1 Conclusions of the problem (19)4.2 Methods used in our models (19)4.3 Application of our models (19)5. Future Work (19)5.1 Another model (19)5.2 Another layout of toll plaza (23)5.3 The newly- adopted charging methods (23)6.References (23)7.Appendix (23)Programs and codes (24)I. IntroductionAmerican has it’s well developed highway system already,the reason why we are on track to creating a modern ,high-speed and interconnected rail system is that the rail system will support sustained economic growth,move people and goods with greater speed and efficiency, relieve growing congestion,and provide another choice for the public’s mobility needs.1.1 More people, more fright, more challengeThe United States and world economies are experiencing an increased demand for rail.Expanding U.S.passenger and freight mobility will require a networked railroad system that is able to modernize and increase capacity.With an estimated U.S.population growth of 70 million people over the next 25 years,mostly centered in metropolitan regions,a national rail plan is needed to ensure a coordinated and intelligent system that provides safe,reliable,and efficient passenger and freight rail service.1.2 T ask and ApproachesThe United States now faces new challenges spurred by unprecedented population growth,economic transformations,and technological innovations. High-speed rail, now established in marry developed nations, is positioned to benefit the United States as the States’plans mature and projects are implemented. With FY2009 kick starting U.S. High-speed rail investment and planning,follow-on funding and strategic investment will bring us closer to realizing the vision outlined by Congress and the Administration.The ext American transformation will require an interconnected and balanced transportation network that maximizes the benefits of every mode. A key to integrating these systems is higher-performing rail, including the full spectrum of high-speed and intercity passenger rail, commuter rail,and freight rail.These interconnected rail systems will relieve congestion,promote livable communities, facilitate economic expansion, respect environmental sustainability and provide choices for the American public. This investment will set set the stage for job creation, sustainable economic competitiveness, a more resilient infrastructure and a lasting prosperity.In order to construct a reasonable rail system ,we plan to accomplish goals as follows:⑴To find the economically developed region ,and assign this area as the strongly construct area.⑵To find the metropolitan areas as the strongly construct area;⑶To consider the developed and intensive area as the megaregions, there will have the densely railway network.⑷To design the railway in the megaregions.⑸To connect the different megaregions.II. Basic Assumptions⑴In the future, the developed regions remain developed.⑵The inhabitants will live in these metropolitan areas and most of the population growth will occur there.⑶The data we used is accurete and reliable.⑷Assuming the railway between cities is straight.⑸The state with less people do not construct.III. The different megaregions3.1 To certain the metropolitan①According to the relevant references,we get the Figture 1②According to the relevant references,we get Figure 2③integrate economic and population ,we can get the megaregionsPart I: Washington State; (northwest)Part II: California (western)Part III: Minnesota, Wisconsin, Michigan; (North)Part IV: New Y ork, Pennsylvania, Massachusetts, Massachusetts, Pennsylvania, New Jersey, Maryland (Eastern)Part V: Illinois, Tennessee, Missouri, West V irginia, V irginia, North Carolina, South Laizhou (Central)Part VI: Florida, Georgia (southeast)Part VII: Texas, Mississippi, Louisiana (South)District of Columbia as the fourth, fifth part of the point of contact.In every part of the city economy, population ranked each part of the center of the city:Part I: SeattlePart II: Los AngelesPart III: MinneapolisPart IV: New Y orkPart V: ChicagoPart VI: AtlantaPart VII: DallasIV. The best route modelThere are six megaregions in the map,and every magaregion has different circumstance,if there are less than three cities in one magaregion, then we can connect them into a triangle. If the number bigger than three, we can use prim algorithm to find the shortest way .What we have construct was our five years plan, next we will base on the per capita GDP to certain the timing.4.1 Certain the route in every part4.1.1 Part oneIn part one, there are only three bigger cities,as we wanted we connect them as a trianglePart IStarting point Ending point The distance(in miles)Seattle Portland 144.990Portland Kennewick 170.753Seattle Kennewick 172.4814.1.2 Part twoIn part two, the densely cities are on a line, maybe it ’s the best answer that we want,we connect them like a line.4.1.3 Part sixIn part six, there are only four cities in there ,it ’s also easy to find the best route.Part VIStarting point Ending point The distant(in miles) Jacksonville Orlando 125.600 Orlando Tampa 77.272 OrlandoMiami203.8804.1.4 The rest partThe rest is harder to railroad, because the city is intensive, and there are densely population. Now we try to use prim algorithm to find the shortest route. According to the relevant reference,we obtain T able 3.We can see from T able 3, we find the cities ’s position, then we get the distant between different cities, now we base the thoughts of prim algorithm , to find the shortest way. (i ) { P = v1} ,Q = Φ;(ii )while P ~=V ;find the shortest edge pv , p ∈ P ,v ∈V − PStarting point Ending point The distance(in miles) San Francisco Sacramento 76.2114 San Francisco Los Angeles 350.793 Los AngelesSan Diego113.002P = P +{v}Q = Q +{pv}endNow we start the MA TLAB simulation .Results and discussions of the simulation1 2 3 17 16 15 5 142 3 17 16 15 5 14 121.19282.5708 1.5621 0.2791 1.1207 1.4416 1.5997 0.8004 12 3 11 13 10 8 7 710 11 13 4 8 7 9 61.581 1.6658 1.6878 0.8344 3.33892.1544 0.7281 1.36784From the conclusion, we can get that the path is that 1→2→3→17→16→15→5→14→12→10; 3→11→13→4; 10→8→7→9; 7→6;The final answer is shown as the following figure4.1.5 Optimize the networkWe take the first year construct city as the center ,year by year ,we can connect the vice city, eventually we will get a whole network.4.2 The whole networkAfter we get the separate route, we can use the next few years to finish the rest route.The red line indicates the first year of laying railway.The blue line represents the second year of laying railway.The yellow line represents the third year of laying railway.The green line represents the fourth year of laying railway.The brown line represents the fifth year of laying railway.4.3 Evaluation of the model4.3.1 Strengths①prim algorithm can precisely find the shortest way. It build up an equation to calculate the shortest path in the magaregions.② prime algorithm has a strong flexibility. It can be applied to other region .4.3.2 weaknesses① prim algorithm get the routine too ideally and it can not consider the other factors.②V. The influence nation rail system will bring toOn one hand, The high-speed and interconnected rail system will support sustained economic growth, move people and goods with greater speed and efficiency, relieve growing congestion,ang provide another choice for the public’s mobility needs. On the other hand,it’s unpleasant for the airline, because someone will take train nor plane in the future. Obviously, it will do harm to their benefit.VI. Prediction of the airline passenger lossHaving analyzed the two sides influence, we can sure that it’s bad news for the airline.But why do not the passenger to take the high-speed rail for the rail more punctual and comfortable, Y es,that’s many of the passenger’s thought. But what proportion will the passenger to take high-speed rail instead of plane. And how many losses the airline will have?6.1 liner Equation Model6.1.1 Basic AssumptionSuppose there are N passengers to travel with high-speed rail or plane throughout a year, and if the distance is less than 800km, then eighty percent of the passenger will take the high-speed rail, if the distance is greater than 800km, then the number of passenger decreased by 20% per 200km,the same time ,the number of passenger by plane will increase 20%. And suppose the travel distance X~U[600,1600].6.1.2 Finding the distance that harm the airline mostAccording to the basic assumption,we can get the following figure ,the high-speed rail curve and the plane curve .we can also get it’s equations:⑴ 1y =0.8N (X<=800)1y =0.8N-N*(X-800)/1000 (X>=800)⑵ 2y =0.2N (X<=800)2y =0.2N+N*(X-800)/1000 (X>=800) For X~U[600,1600], ix P =1/1000 ;P(600<=X<=800)=200*1/1000=0.2; P(800<=X<=1600)=800*1/1000=0.8;So the passenger loss L=0.2*0.8N+0.8*(0.8N-N*(X-800)/1000)=0.8N-0.8*(N*(X-800)/1000); The conclusion:When the travel distance is 800km, the passenger loss is biggest.Then from the map ,we can find several route, in these routes 80% of the passenger was lost.6.2 Evaluations of our module6.2.1 strengths ① Linear model has enormous edibility. For instance, not only it can be applied to the transportation, but it can also be used to simulate the other situations. ② Linear model is easy to calculate. It ’s the feature of linear equation. 6.2.2 weakness① Linear model can not to predict precisely, because the passenger ‘s change with the distance can not be linear ,it can be complex, so the outcome we finally get was roughly② the parameter of the model is subjective ,it is not through the actual survey . ③If the distance is shorter than 400km ,there will not be plane , but in our model,we suppose there plane still be there.VII Contribution to the American economicAs we have analyses before ,the construction of high-speed rail will play a great role to theVIII ConclusionIX future workReferences[1]Albert.R & Barabasi, A.-L.(2002). Statistical mechanics of complex networks. Reviews of Modern Physics, 74,47-97.[2]American Radio Relay League (2008). The Arrl Operating Manual for Radio Amateurs. ARRL OPERA TING MANUAL. Amer Radio Relay League.[3]Barclay,L, & Institution of Electrical Engineer(2003). Propagation of radiowaves. Electromagnetic Waves. Institution of Electrical Engineers.[4]Federal Communications Commission (2011). About the fcc.URL /aboutus.html[5]/[6]/wiki/%E7%BE%8E%E5%9B%BD%E5%90%84%E5%B7%9E%E5%9 B%BD%E5%86%85%E7%94%9F%E4%BA%A7%E6%80%BB%E5%80%BC%E5%88%97%E8%A1%A8[7]Straw, R, Cebik, L. Hallidy, D, & Jansson, D. (2007). The ARRL Antenna Book .ARRL ANTENNA BOOK. ARRL.[8]ukrepeaters, The UK Amateur Radio Repeater Resource (2011). 2 metres band repeaters(coverage)Appendix 1American GDP per stat ranking (2010)GDPstate GDPpercentage ofnationalGDPpopulationGDP percapitaGDP percapitarankingsranking(milliordollor)(millior) (dollor) United States14,657,80100 308.7 47,4821 California1,936,400 13.34 37.3 51,914 122 Texas 1,207,432 7.95 25.1 45,940 243 New York 1,156,500 7.68 19.4 57,423 74 Florida 754,000 5.2 18.8 40,106 405 Illinois 644,200 4.44 12.8 50,328 156 Pennsylvania 575,600 3.97 12.7 45,323 257 New Jersey 497,000 3.42 8.8 56,477 88 Ohio 483,400 3.33 11.5 42,035 339 Virginia 427,700 2.95 8 53,463 910 North Carolina 407,400 2.81 9.5 42,884 3111 Georgia 404,600 2.79 9.7 41,711 3512 Massachusetts 377,700 2.6 6.5 58,108 613 Michigan 372,400 2.57 9.9 37,616 4214 Washington 351,100 2.42 6.7 52,403 1015 Maryland 300,000 2.07 5.8 51,724 1316 Indiana 267,600 1.84 6.5 41,169 3617 Minnesota 267,100 1.84 5.3 50,396 1418 Arizona 261,300 1.8 6.4 40,828 3919 Colorado 259,700 1.79 5 51,940 1120 Wisconsin 251,400 1.73 5.7 44,105 2921 Tennessee 250,300 1.72 6.3 39,730 41Table 1. the American per stat ranking(source:U.S. Census Bureau)Appendix 2The first yearStarting point Ending point The distant(in miles) Seattle Portland 144.990San Francisco Sacramento 76.2114San Francisco Los Angeles 350.793Los Angeles San Diego 113.002Phoenix Coctus 109.391Houston Dallas 230.225Houston San Antonio 186.698Dallas Austin 182.682Austin San Antonio 76.4823Jacksonville Orlando 125.600Orlando Tampa 77.272Orlando West Palm Beach 149.751West Palm Beach Miami 67.1118Atlanta Charlotte 224.081Charlotte Raleigh 130.743Nashville Atlanta 215.622Minneapolis Milwaukee 302.516Milwaukee Chicago 83.601Chicago Indianapolis 161.628Chicago Detroit 259.963Chicago Springfield 177.601Springfield St Louis 86.056Indianapolis Columbus 168.986New Y ork Philadelphia 80.326Philadelphia Washington 123.266The first year of the total length of the laying of high-speed rail:3904.5985milesThe second yearStarting point Ending point The distant(in miles) Portland San Francisco 532.850Los Angeles Phoenix 356.266Denver Pueblo 108.682Pueblo Santa Fe 188.330 Albuquerque Santa Fe 55.2531 Oklahoma City Tulsa 94.297Toledo Fort Wayne 92.8754Fort Wayne Indianapolis 107.213 Indianapolis Cincinnati 97.127 Indianapolis Louisville 104.933Louisville Lexington 70.166Cincinnati Lexington 73.706Cleveland Akron 31.818Akron Pittsburgh 89.693Pittsburgh Washington 190.470 Philadelphia Allentown 51.050Atlanta Macon 77.543Atlanta Birmingham 137.838Memphis Nashville 194.249Nashville Louisville 156.843Louisville Lexington 71.592 Montgomery Birmingham 83.9005 Montgomery Atlanta 146.289 Birmingham Atlanta 140.149 Birmingham Savannah 225.946 Savannah Jacksonville 130.365 Jacksonville Montgomery 311.175Raleigh Washington 233.375Boston New Y ork 191.973The second year of the total length of the laying of high-speed rail:4345.967milesThe third yearStarting point Ending point The distant(in miles) Denver Salt Lake City 368.745 Albuquerque Tucson 316.996 Albuquerque Dallas 586.689Dallas Oklahoma City 188.002Wichita Kansas City 181.989 Louisiana New Orleans 80.628New Orleans Mobile 128.703Mobile Tallahassee 224.573 Tallahassee Jacksonville 161.590Mobile Montgomery 155.973Birmingham Jackson 213.116Jackson Louisiana 145.713Columbus Charleston 133.827Cleveland Buffalo 173.795Buffalo Boston 399.072The thirty year of the total length of the laying of high-speed rail:3459.411miles The forth yearStarting point Ending point The distant(in miles) Sacramento Reno 109.336Reno Salk Lake City 427.061Los Angeles Flagstaff 380.012Flagstaff Phoenix 127.505Kansas City Hays 385.565Hays Denver 309.963Kansas City Lowa 212.521Lowa Minneapolis 192.885Dallas Little Rock 293.249Little Rock St Louis 289.804Lexington Parkersburg 178.301Parkersburg Washington 244.502Richmond Norfolk 76.779Raleigh Charlotte 126.143Charlotte Charleston 176.901New Y ork Watertown 242.678The fourth year of the total length of the laying of high-speed rail:3773.205milesThe fifth yearStarting point Ending point The distant(in miles) Seattle Kennewick 172.481Kennewick Boise 229.268Boise Salt Lake City 299.174San Diego Las V egas 253.996Memphis Little Rock 129.070Memphis Birmingham 216.322St Louis Nashville 253.171Roanoke Greensboro 87.004Raleigh Norfolk 153.169Boston Augusta 151.061Boston Montpelier 152.706The fifth year of the total length of the laying of high-speed rail:2097.422milesAppendix 3clc;clear;a=zeros(17);a(1,2)=1.1928;a(1,3)=3.7065;a(1,4)=4.9103;a(1,5)=5.7873;a(1,6)=14.0866;a(1,7)=13.1131;a(1,8)=11.6331;a(1,9)=12.6520;a(1,10)=8.3259;a(1,11)=3.3859;a(1,12)=6.9160;a(1,13)=4.5627;a(1,14) =6.3636;a(1,15)=5.4361;a(1,16)=6.0495;a(1,17)=5.2392;a(2,3)=2.5708;a(2,4)=4.6055;a(2,5)=5.0081;a(2,6)=13.6692;a(2,7)=12.6168;a(2,8)=11.0061;a(2,9) =12.2062;a(2,10)=7.7681;a(2,11)=2.6129;a(2,12)=6.4720;a(2,13)=4.0805;a(2,14)=5.8336;a(2,15)=4.4466;a(2,16)=4.9533;a(2,17)=4.0736;a(3,4)=4.0330;a(3,5)=3.1663;a(3,6)=12.1817;a(3,7)=11.0016;a(3,8)=9.1665;a(3,9)=10.7029;a(3,1 0)=6.2005;a(3,11)=1.6658;a(3,12)=5.2830;a(3,13)=3.2225;a(3,14)=4.5046;a(3,15)=2.1130;a(3,16) =2.3976;a(3,17)=1.5621;a(4,5)=2.3645;a(4,6)=9.1800;a(4,7)=8.2365;a(4,8)=6.9241;a(4,9)=7.7514;a(4,10)=3.5900;a(4,11) =2.4363;a(4,12)=2.0540;a(4,13)=0.8344;a(4,14)=1.7307;a(4,15)=3.4125;a(4,16)=4.5332;a(4,17)= 4.8947;a(5,6)=9.0212;a(5,7)=7.8400;a(5,8)=6.0604;a(5,9)=7.5371;a(5,10)=3.0409;a(5,11)=2.4140;a(5,12) =2.3874;a(5,13)=1.7855;a(5,14)=1.5997;a(5,15)=1.4416;a(5,16)=2.4444;a(5,17)=3.2468;a(6,7)=1.3784;a(6,8)=3.5308;a(6,9)=1.4842;a(6,10)=5.9925;a(6,11)=11.1360;a(6,12)=7.2016;a(6, 13)=9.5919;a(6,14)=7.8494;a(6,15)=10.2716;a(6,16)=10.8269;a(6,17)=12.0084;a(7,8)=2.1544;a(7,9)=0.7281;a(7,10)=4.8600;a(7,11)=10.0434;a(7,12)=6.2037;a(7,13)=8.5668;a(7 ,14)=6.7846;a(7,15)=9.0345;a(7,16)=9.5353;a(7,17)=10.7355;a(8,9)=2.3046;a(8,10)=3.3389;a(8,11)=8.3951;a(8,12)=4.8852;a(8,13)=7.0832;a(8,14)=5.2881;a(8 ,15)=7.1220;a(8,16)=7.5143;a(8,17)=8.7484;a(9,10)=4.5091;a(9,11)=9.6681;a(9,12)=5.7488;a(9,13)=8.1341;a(9,14)=6.3786;a(9,15)=8.7934;a( 9,16)=9.3691;a(9,17)=10.5352;a(10,11)=5.1843;a(10,12)=1.5810;a(10,13)=3.7639;a(10,14)=1.9626;a(10,15)=4.3674;a(10,16)=5. 1045;a(10,17)=6.1632;a(11,12)=3.9926;a(11,13)=1.6878;a(11,14)=3.2890;a(11,15)=2.2128;a(11,16)=3.1135;a(11,17)=2. 8942;a(12,13)=2.3917;a(12,14)=0.8004;a(12,15)=3.8277;a(12,16)=4.8043;a(12,17)=5.6203;a(13,14)=1.8013;a(13,15)=2.6303;a(13,16)=3.7481;a(13,17)=4.0583;a(14,15)=3.0352;a(14,16)=4.0345;a(14,17)=4.8218;a(15,16)=1.1207;a(15,17)=1.8152;a(16,17)=.2791;a=a+a';a(find(a==0))=inf;result=[];p=1;tb=2:length(a);while length(result)~=length(a)-1temp=a(p,tb);temp=temp(:);d=min(temp);[jb,kb]=find(a(p,tb)==d);j=p(jb(1));k=tb(kb(1));result=[result,[j;k;d]];p=[p,k];tb(find(tb==k))=[];endresult。