How do we describe motion - University of Toledo
Mass Spring System(弹簧系统)
• Motion follows from
Newton’s 2nd Law
Fi mi ai
Research
Equations of Motion
Newton’s 2nd Law
Fi mi ai
Equations of motion for one mass point (3 equations) Equations of motion for system of mass points (3n equations)
F k l L
xj
Force in 3D
F
Fi k xi x j L
x x
i
xi x j
j
Initial spring length L Current spring length l Spring stiffness k
Research
Elastic Energy
Research
20
Dynamics
Force is known for every particle. How do we determine motion xi t ?
• Kinematic relations
Velocity
v i (t ) d x i (t ) dt
Acceleration 2 d v i (t ) d x i (t ) a i (t ) dt dt 2
l
xj
F
L
Elastic spring energy gradient of Force = – energy
1 E W k (l L) 2 2
E Fi xi
Research
2024-2025学年绵阳中学高三上学期英语月考试题卷
英语试题第一部分：听力（共两节，满分30分）第一节（共5小题；每小题1.5分，满分7.5分）听下面5段对话。
每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项。
听完每段对话后，你都有10 秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. What is the woman doing?A. Repairing a computer.B. Making a payment.C. Requesting a refund.2. Why does the man come to the woman?A. To invite her to dinner.B. To give her a present.C. To seek some advice.3. What is the man going to do first?A. Make reservations.B. Check with his wife.C. Work out a plan.4. What is the woman's opinion on the new building?A. Unattractive.B. Pretty.C. Unique.5. What is the probable relationship between the speakers?A. Salesman and customer.B. Householder and renter.C. Colleagues.第二节（共15小题；每小题1.5分，满分22.5分）听下面5段对话或独白。
每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项。
听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。
每段对话或独白读两遍。
听第6段材料，回答第6、7题。
6. What are the speakers discussing?A. The accommodations.B. The destination.C. The activities.7. What is the man's attitude towards the woman's words?A. Supportive.B. Disapproving.C. Unclear.听第7段材料，回答第8、9题。
Broadcast-文档资料
Stereo Multiplexing
• L+R Signal (Main Channel) • L-R Signal (Stereo Channel) • 19 kHz Pilot Subcarrier (FM)
Waveform Sketch of a Video Signal
A simple video waveform
One Line
Waveform of Sync Pulses
IRE Measurement Scale
Vertical Blanking Interval (VBI)
• Lines 1-21 of each field
Wavelength Example
WTHR Television
Meters: Lambda = 300/211.25 = 1.46 meters Miles: Lambda = .186/211.25 = .00088 miles Feet: 1 meter = 3.28 feet
Lambda = 1.46 meters x 3.28 = 4.79 feet
Video Standards
• Standards and Principals
– Persistence of Vision
The rapid presentation of frames of video information to give you the illusion of smooth motion.
motion
motion英['məʊʃ(ə)n] 美['moʃən] n. 动作；移动；手势；请求；意向vi. 运动；打手势vt. 运动；向…打手势动议原来，一个建议，必须首先由具表决权的代表提交会议，成为动议（Motion），经讨论后，有代表附议（Second）,即同意这个动议,方可成为提议进行表决。
提议最新随笔... end up as a failure 一辈子失败motion 提议denounce 谴责...短语Motion Capture 动作捕捉; 运动捕捉; 动态捕捉; 动作捕获Brownian motion 布朗运动; 布朗活动; 布朗勾当; 第一章reciprocating motion [机] 往复移动; [机] 往复运动; 住复式动作; 往来来往移动rotary motion [机] 旋转运动; [物] 转动; [机] 回转运动; [机] 旋转活动parabolic motion 抛物线运动; 等加等减速运动规律; 抛物线活动; 等加等减速活动纪律proper motion 自行运动; [天] 自行; [物] 固有运动; 正常运动oscillatory motion [力] 振荡运动; 振动; 振荡周期Motion Detection 移动侦测; [自] 运动检测; 动态侦测; 移动侦帧thermal motion [热] 热运动motion [ 'məuʃən ] n. 0.a natural event that involves a change in the position or location of something 同义词：movement.the use of movements (especially of the hands) to communicate familiar or prearranged signals 同义词：gesture.a change of position that does not entail a change of location "the reflex motion of his eyebrows revealed his surprise"同义词：movement move motility.a state of change "they were in a state of steady motion".a formal proposal for action made to a deliberative assembly for discussion and vote "he made a motion to adjourn"同义词：question.the act of changing location from one place to another "police controlled the motion of the crowd"同义词：movement move.an optical illusion of motion produced by viewing a rapid succession of still pictures of a moving object "the cinema relies on apparent motion"同义词：apparent motion apparent movement movementv. show, express or direct through movement 同义词：gesticulate gesture1.动；运动；移动2.动作；举动；姿态；步态；手势；眼色3.提议；动议；会议提案4.意向，意愿5.(生物的)运动能力6.【法律】(诉讼人向法院提出的)请求，申请7.【音乐】(一个或几个声部的)进行8.(钟、表的)机械装置，转动装置；机械装置的运转9.[复数]活动，行动10.[主英国英语]大便；[亦作复数]粪便11.[废语]木偶；木偶戏vi. 1.做手势；点(或摇)头示意：She motioned to the waiter.她向侍者招手。
“你觉得怎么样”可不是Howdoyouthink,一句话暴露你的英语水平！
“你觉得怎么样”可不是Howdoyouthink,⼀句话暴露你的英语⽔平！“你觉得怎么样？”千万不要说成How do you think?最近刷抖⾳视频的时候，发现有不少⼩姐姐⼩哥哥给⾃⼰的作品配⽂“How do you think？” ⼩编默默点上⼀颗⼩红⼼后，皱起了眉头。
不只是抖⾳，⽣活中也常常听到⼀些同学脱⼝⽽出 HOW do you think？乍⼀听没什么问题...你-you，觉得-think ，怎么-how你觉得怎么样？How do you think？完美翻译！Em...如果你也觉得没有问题，那就说明已经掉⼊中式思维的坑啦。
今天⼩编就来帮⼤家避坑，说出更地道的英语～How do you think?为什么不对How 这个英语疑问词通常指的是 in what way or by what methods，也就是⽅式或过程，所以问：'how do you think？'就相当于在问：“你是怎么进⾏思考的？”这问题⼀抛，⼋成让对⽅蒙圈，不知道该怎么回答你。
（除⾮...你们真的要探讨“⼈是如何思考的？”这么⼀个涉及⽣物科学和哲学的专业问题。
）最简单的地道问法中⽂问的“你觉得怎么样?”这句话⾥的“怎么样”指的其实是“你的看法是什么”(think 思考过后得到的观点)。
所以，简单⼜地道的问法只要把how换成'What'就可以啦！What do you think?What do you think？通常是在⼀段话的结尾。
也就是当我们说完了⼀件事，或者发表了观点之后，想知道其他⼈的看法，就会在最后问这句话。
e.g.A: Both shirts fit me well. I can't decide which to buy. What do you think?两件衬衫都挺合⾝的，我决定不了买哪件了。
你觉得呢？B: I think the blue one looks better.我觉得蓝⾊的这件看起来更好。
Thecmumotionofbody（mobo）database
The CMU Motion of Body(MoBo)DatabaseRalph Gross Jianbo ShiCMU-RI-TR-01-18June2001Robotics InstituteCarnegie Mellon UniversityPittsburgh,Pennsylvania15213c Carnegie Mellon UniversityAbstractIn March2001we started to collect the CMU Motion of Body(MoBo)database. To date the database contains25individuals walking on a treadmill in the CMU3D room.The subjects perform four different walk patterns:slow walk,fast walk,incline walk and walking with a ball.All subjects are captured using six high resolution color cameras distributed evenly around the treadmill.In this technical report we describe the capture setup,the collection procedure and the organization of the database.Contents1Introduction1 2Capture Setup and Data Collection Procedure22.1Camera Setup (2)2.2Capture Procedure (3)3Database Organization43.1Available Images (4)3.2File Structure (6)4Obtaining the MoBo database6 5Usage of MoBo images in publications7II1IntroductionIn general,locomotion is the process by which an animal moves itself from one geo-graphic position to another[14].In contrast to the majority of mammals which move on four legs,humans are bipedal.The bipedal locomotion appears to be simpler,yet it requires greater neural control.Humans therefore spend up to thefirst15months of their life acquiring this skill.While the basic pattern of bipedal locomotion are iden-tical between healthy humans,individuals walk differently.The human gait depends on a multitude of factors including physical build and body weight,but also heel hight, clothing and the emotional state of mind of the walker.Nevertheless there is ample anecdotal evidence about people being able to identify acquaintances only based on their manner of walking.Most studies on human locomotion have been conducted from a biomedical point of view[1].Recently,the research community has begun to investigate gait as a biometric [4].While there is a rich body of work describing computer vision systems for model-ing and tracking human bodies(see[7]for a review),only a few publications deal with the problem of automatically identifying people from the way they walk[13,11,5]. Similarly the knowledge about the human performance on this task is sparse.A num-ber of studies found that humans can recognize gender from gait at greater than chance level[10,3,6].The work by Stevenage et.al.[15]suggests that humans are able to learn the gait characteristics of individuals unknown to them.However,many of these findings are based on a small number of subjects.It is not clear how these results scale to larger databases.To advance research on human gait as a biometric,we collected the CMU Motion of Body(MoBo)database.To date,we recorded25subjects performing four different walking activities on a treadmill.We used six cameras evenly distributed around the treadmill capturing more than8000images per subject.The sequences are each11 seconds long,recorded at full frame rate(30frames/second).Table1gives an overview of the collected data.Figure1shows all six views of the database with extracted silhouettes.Walking IndoorLocation TreadmillViews6Walk styles4Pixel height500Size uncompressed[GB]175Figure1:All six views of the CMU MoBo database with corresponding silhouettes.An open question remains on biomechanical differences between overground and treadmill walking.So far no conclusive result has been reached with studiesfinding differences[12]and studies reporting minimal or no differences[2,8]between the two conditions.In the reminder of this report we describe the setup of the capture apparatus,the capture procedure and the organization of the database.2Capture Setup and Data Collection Procedure2.1Camera SetupHuman locomotion is a complex process that involves nearly all the major parts of the body.The visual appearance of the different body parts is view dependent which makes capturing of the complete human body a difficult task.We were able to adapt the CMU3D Room[9]to capture multiview walk sequences.To keep the data volume per sequence at a manageable level and still be able to compute a full3D reconstruction, we determined that six cameras evenly distributed around the subject on the treadmill are sufficient.The cameras are high quality(3CCD,progressive scan)Sony DXC 9000’s.The resulting images are640x480in size with24-bit color resolution.As the subjects in our database are spatially more or less stationary on the treadmill,we were able to capture a high resolution image of the person.Furthermore,all the cameras are calibrated and synchronized.Figure2depicts the position of the cameras with respect to the treadmill in the room.Figure3shows a panoramic view of the3D room.2Figure2:Camera setup in the3D room for the data collection.Figure3:Panoramic view of the CMU3D room.2.2Capture ProcedureWe instructed each subject to wear light colored shoes to facilitate the task of segment-ing the feet from the black treadmill.In order to obtain a wide spectrum of different gaits each subject had to perform four different activities on the treadmill:slow walk, fast walk,incline walk and walking with a ball.Prior to the recording the subjects were given time to accustom themselves with walking on the treadmill.Most of the subjects3had no previous experience in exercising or walking on a treadmill.Nevertheless the majority of the subjects indicated that they feel comfortable walking on the device after practicing for a few minutes.The subjects were then recorded in the following order: Slow walkThe speed of the treadmill was adjusted to be at a comfortable walking speed for the subjects.Figure4shows examples from all six cameras.Average walking speed:2.06mphFast walkHere the directions asked for a fast but still comfortable walk.Average walking speed:2.82mphIncline walkThe treadmill was set to the maximum incline of.The speed was adjusted to be comfortable for the individual subject.Figure5shows example images from all views.Average walking speed:1.96mphWalking with a ballFinally the subjects were asked to hold a ball in front of their body while walking at a comfortable speed.The objective behind this sequence was to immobilize the arms and analyze how this affects their gait pattern.Figure6contains exam-ple images from all cameras.Average walking speed:2.04mphOn average the complete recording session took about15minutes per subject.Each sequence is340frames long,recorded at a speed of30frames per second.During this 11second period we can typically observe about10full gait cycles.We record8160 images for each subject,totaling more than7GB of data.At the beginning of every recording session for each subject we capture a background image with each camera to facilitate background subtraction.With25subjects captured the database is about175 GB in size(uncompressed).Figure7shows15images of a fast walk sequence which spans half a walking cycle as seen from the sagittal perspective.For each subject we also recorded a number of basic informations including:sex, age,weight,and the treadmill speed for the different walking sequences.3Database Organization3.1Available ImagesWe store the database in two formats:uncompressed in PPM format(175GB)and compressed in JPG format(9.9GB).We also provide the body silhouettes for all im-ages extracted using simple background subtraction and thresholding.Note that the extracted silhouettes are not particularly clean-silhouettes can contain holes,the sil-houette boundary can be interrupted,and static background pixels can be mistakenly included.Figure8shows one silhouette example for each subject in the database.4Figure4:Slow walk sequence.Figure5:Incline walk sequence.5Figure6:Ball walk sequence.Calibration information as computed using Tsai’s[16]algorithm is available for all six cameras.3.2File StructureThe CMU MoBo database is organized as a collection of images for each subject.The subjects are identified by their unique5-digit subject ID.For each subject the images are stored in subdirectories according to the different activities“ball”,“fastWalk”,“in-cline”and“slowWalk”.The background images are kept in a separate subdirectory.In the respective subdirectories the images are further organized according to the cameras they were recorded by.The camera labels are vr037,vr077,vr16 7as shown in Figure2.Table2illustrates the organization of the database. 4Obtaining the MoBo databaseDetailed instructions on how to obtain the MoBo database can be found on the HID project web page: under“databases”.6Subject ID View03292400.ppm03292401.ppm703293509.ppmball7vr07040067vr167Figure 7:Half of a fast walk cycle seen from camera vr03Figure8:The CMU MoBo database contains six simultaneous motion sequences of25subjects(23male,2female)walking on a treadmill.The3CCD progressive scan images have a resolution of640x480.Each subject is recorded performing four different types of walking:slow walk,fast walk,inclined walk,and slow walk holding a ball(to inhibit arm swing).Each sequence is11seconds long,recorded at30frames per second.More than8000images are captured per subject.Thefigure shows silhouette examples for all subjects in the database.9References[1]T.Andriacchi and E.Alexander.Studies of human locomotion:past,present andfuture.Journal of Biomechanics,33:1217–1224,2000.[2]A.B.Arsenault.Treadmill versus walkway locomotion in human:An emg study.Ergonomics,29(5):665–676,1986.[3]C.D.Barclay,J.E.Cutting,and L.T.Kozlowski.Temporal and spatial factors ingait perception that influence gender recognition.Perception and Psychophysics, 23:145–152,1978.[4]D.Cunado,M.S.Nixon,and J.N.Carter.Gait as a biometric,via phase-weighted magnitude spectra.In Proceedings of1st Int.Conf.on Audio-and Video Based Biometric Person Authentication,AVBPA,pages95–102,Crans-Montana, Switzerland,March1997.[5]D.Cunado,M.S.Nixon,and J.N.Carter.Extracting a human gait model for use asa biometric.In IEE Colloquium Computer Vision for Virtual Human Modelling,1998.[6]J.E.Cutting and D.R.Proffitt.Gait perception as an example of how we perceiveevents.In R.D.Walk and H.L.Pick,editors,Intersensory perception and sensory integration.Plenum Press,London,1981.[7]D.M.Gavrila.The visual analysis of human movement:A puterVision and Image Understanding:CVIU,73(1):82–98,1999.[8]J.Isacson,L.Gransberg,and E.Knutsson.Three-dimensional electrogoniomet-rical gait recording.J.Biomech.,19(8):627–635,1986.[9]T.Kanade,H.Saito,and S.Vedula.The3D Room:Digitizing time-varying3Devents by synchronized multiple video streams.Technical Report CMU-RI-TR-98-34,Robotics Institute,Carnegie Mellon University,Pittsburgh,PA,December 1998.[10]L.T.Kozlowski and J.E.Cutting.Recognizing the sex of a walker from a dynamicpoint-light display.Perception and Psychopysics,21:575–580,1977.[11]H.Murase and R.Sakai.Moving object recognition in eigenspace representation:gait analysis and lip reading.Pattern Recognition Letters,17:155–162,1996. [12]R.C.Nelson,C.J.Dillman,gasse,and P.Bickett.Biomechanics of over-ground versus treadmill running.Med.Sci.Sports,4(4):233–240,1972.[13]S.A.Niyogi and E.H.Adelson.Analyzing and recognizing walkingfigures inxyt.In CVPR,pages469–474,1994.[14]J.Rose and J.Gamble,editors.Human Walking.Williams and Wilkins,2ndedition,1994.10[15]S.Stevenage,M.Nixon,and K.Vince.Visual analysis of gait as a cue to identity.Applied Cognitive Psychology,13:513–526,1999.[16]Roger Tsai.An efficient and accurate camera calibration technique for3d ma-chine vision.In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition,pages364–374,Miami Beach,FL,1986.11。
物理英语翻译
物理英语翻译Physics is called the fundamental science because it provides the foundation for studying all other natural sciences. Through physics, we can understand how the universe works at the most basic level, from the smallest particles to the largest galaxies. Physics is concerned with the laws and principles that govern the behavior of matter and energy, as well as their interactions.One of the fundamental concepts in physics is motion. The studyof motion is known as mechanics, and it involves understanding the factors that affect the motion of objects, such as force, acceleration, and energy. For example, Newton's laws of motion describe how an object will move when acted upon by a force.Another important topic in physics is energy. Energy is the ability to do work, and it can exist in many forms, such as kinetic energy (energy of motion), potential energy (stored energy), and thermal energy (heat energy). Conservation of energy is a fundamental principle in physics, which states that energy cannot be created or destroyed, but can only be converted from one form to another.Electromagnetism is another branch of physics that deals with the interaction between electricity and magnetism. It explains phenomena such as the behavior of electric and magnetic fields, electromagnetic waves, and the generation of electricity. Maxwell's equations are a set of mathematical equations that describe the behavior of electromagnetic fields and are fundamental to the study of electromagnetism.Quantum mechanics is a branch of physics that deals with thebehavior of matter and energy at the atomic and subatomic level. It introduces the concept of wave-particle duality, which suggests that particles such as electrons can exhibit both wave-like and particle-like properties. Quantum mechanics has revolutionized our understanding of the microscopic world and has led to the development of technologies such as lasers and transistors.In addition to these topics, physics also encompasses other areas such as thermodynamics (study of heat and energy flow), optics (study of light), and nuclear physics (study of atomic nuclei and their interactions). These are just a few examples of the wide range of topics covered by physics.In conclusion, physics is a fundamental science that seeks to understand the fundamental principles that govern the behavior of matter and energy. It provides the foundation for studying all other natural sciences and has led to numerous technological advancements. The study of physics allows us to explore the mysteries of the universe and better understand the world around us.。
人大版研究生英语提高级13
Structure of the text
Introduction 1. What is Bertrand Russell’s description of universe?
The earth orbits around the sun and the sun, in turn, orbits around the center of a vast collection of stars called our galaxy.
About the author and the text
1. Bertrand Russell (1872-1970) British philosopher, mathematician, and Nobel laureate, whose emphasis on logical analysis influenced the course of 20th-century philosophy.
People mentioned in the text
6. Empedocles (490 BC?-430 BC) Greek philosopher, statesman, and poet.
People mentioned in the text
7. Karl Popper (1902-1994) Austrian-born British philosopher of science, known for his theory of scientific method and criticism of historical determinism.
E= mc
2
This was the theory of relativity, which was puple mentioned in the text
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What determines the strength of gravity?
Newton’s Insight
A big question in the 18th century is what physics governs the orbits of the planets around the Sun. Newton’s insight is that the gravity on Earth should continue to extend into space. Came up with a Universal Law of Gravitation which could explain gravity on Earth and the motions of the planets.
Fearth = m (kg) x 6.67 x 10-11 x 5.97 x 1024 kg / (6378000 meter)2 Fmoon = m (kg) x 6.67 x 10-11 x 7.36 x 1022 kg / (1738000 meter)2 Fitokawa = m (kg) x 6.68 x 10-11 x 3.51 x 1010 kg / (357 meter)2
Sir Isaac Newton (1642-1727)
How can you explain the expansion of the universe?
Newton’s second law of motion
Force = mass × acceleration
No force means no acceleration, and an object continues on with the same speed. What is mass? If the force is 1 g, what is the acceleration? How do you measure mass?
How is mass different from weight?
• Mass – the amount of matter in an object • Weight – the force that acts upon an object
Does your mass depend on whether the elevator is moving up or down? You are weightless in free-fall!
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1. Newton’s three laws of motions
2. Newton’s Universal Law of Gravity
example: speed of 10 m/s • Velocity: Speed and direction example: 10 m/s, due east • Acceleration: Any change in velocity units of speed/time (m/s2)
The Universal Law of Gravitation: 1. Every mass attracts every other mass. 2. Attraction is directly proportional to the product of their masses. 3. Attraction is inversely proportional to the square of the distance between their centers.
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Acceleration by Gravity
Distance falling by an object is: D = 1/2 g t2 Where g = 9.8 meter/second2 Thus if you drop any object: In one second it will fall 4.9 meters In two seconds it will fall 19.6 meters Leaning tower of Pisa Independent of Mass Attributed to Galileo (17th claw go back to the 14th century.
3. Conservation laws: I. Conservation of momentum II. Conservation of angular momentum III. Conservation of energy
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How did Newton change our view of the universe?
Galileo’s Intuition Motion can be separated into two components, a horizontal component and a vertical component. The vertical component is accelerated by gravity at the same rate, independent of the horizonal motion.
What are Newton’s three laws of motion?
Newton’s first law of motion: An object moves at constant velocity unless a net force acts to change its speed or direction. This is also called the law of inertia Imagine a spacecraft moving through space. What happens to its speed, velocity and acceleration if the rocket engine is off? How do you slow down a rocket ship?
What keeps a planet rotating and orbiting the Sun?
Centrifugal Force
Gravity
/phys_anim/PA.html
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Lecture 3: The Laws of Motion and Universal Gravitation Astronomy 2020, Prof. Tom Megeath To be ignorant of motion is to be ignorant of nature
weight of a 68 kg mass 150 lb weight on earth 24 lb weight on the Moon 0.0003 lb weight on Itokawa
Asteroid Itikawa
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Centrifugal Force: F = Mass x Velocity2 / radius
Hammer and Feather on the Moon Apollo 15, Astronaut David Scott
/alsj/a15/video15.html#landing
The Acceleration of Gravity
• All falling objects accelerate at the same rate (not counting friction of air resistance). • On Earth, g ≈ 10 m/ s2: speed increases 10 m/s with each second of falling.
• Realized the same physical laws that operate on Earth extended to the Moon and beyond. • Discovered laws of motion and gravity - published in Principia in 1687 at the urging of Edmond Halley. • Much more: Experiments with light; first reflecting telescope, calculus… • Held Lucasian Chair of Mathematics at Cambridge University, the Chair now occupied by Stephen Hawking
-Aristotle
Overview of Today’s Lecture
How do we describe motion?
Precise definitions to describe motion: • Speed: Rate at which object moves speed = distance units of m s time
http://faraday.physics.utoronto.ca/GeneralInterest/Harrison/Flash/ ClassMechanics/Projectile/Projectile.html
http://faraday.physics.utoronto.ca/GeneralInterest/Harrison/Flash/ ClassMechanics/MonkeyHunter/MonkeyHunter.html
Question: does this predict that acceleration is independent of mass?