Machines Definition and 208 Threads

  1. G

    Live TV Captioning: Human or Machine Transcription?

    Are they really caption machines, or really well-trained stenographers? Like in an NFL or FIFA or other live broadcast. I took it that they might have been caption machines with highly advanced grammar compilers, but looking around, I guess they can just as well be very fast...
  2. winSOW32

    Protecting PCB, multiplexers and MCU in vending machines

    Hello everyone, I am working on a very low cost, small and basic vending machine ($300) with wooden cabinet for small neighborhood stores. As you may know, it is necessary to properly protect the components to prevent users from trying to steal money or damage the components. The PCB has a TFT...
  3. J

    Markov chains and production line comprising 3 machines

    I have tried solving this question, but I am not even sure where to start from and how to specify a state space for this question where it has a trick stating that a worker works overnight. However, for part a, is it the case that there are only 2 states to consider which are: {machine working...
  4. kunalvanjare

    Problem with different hydraulic connection sizes on CNC machines

    Hello guys, I am supplying a Venturi Vac to my clients which is installed directly on their CNC Machine Coolant Pumps (photo attached). This is done by introducing a Tee connection on the discharge end of the pump as shown. The straight line of the tee is connected to the hydraulic coolant...
  5. Lucas123

    Engineering Solve Motor Coil Current at Startup & Full Speed

    The question I'm in doubt about is The motor coil has a resistance of 10 Ω and is powered by a voltage of 120 V. When the motor is operating at rated speed, its emf is 70 V. Thus, it is questioned: a) What is the coil current when the motor is started? b) What is the coil current at rated...
  6. DDTG Global

    Why is life so much more resilient than machines?

    This might sound like a stupid question... Was installing something in my computer last night, gpu was stuck so I pulled with too much force, it just suffered a small chip on the PCB and is now dead. Made me think, humans/animals can lose limbs, organs, even half their brains, and still live...
  7. L

    Electrical Machines and Power Flow

    I have been studying the representation of generators in power flow studies and I would appreciate your comments in this thread. From the book Fitzgerald & Kingsley's Electric Machinery, I understand that there are unsaturated and saturated reactances. In section 5.3.2 of the book it is said...
  8. K

    Dirt, debris, dust, moisture and machines

    Is our home equipment and many other consumer's device usually designed to endure dust, debris, dirt or anything (even virus or bacteria) from the environment which is hard to avoid? What is the field of engineering or science that studies such issue?
  9. C

    I Feynman's reversible and irreversible machines

    I started reading "Feyman Lectures on physics" and stuck on his explanation about reversible and irreversible machines. I've tried to read other answers to this question, but I couldn't get the point. Here is the first thing: "If, when we have lifted and lowered a lot of weights and restored...
  10. Muhammad Usman

    Do soft errors still occur in today's machines?

    Hi, I was reading about the soft errors. I read that the soft errors are the one that basically caused by alpha particles and even some time thermal issues (Too much heat in the machines). Although I search lot of mitigation techniques but I am curious that are these errors still exist and are...
  11. W

    Disproving perpetual energy and perpetual motion machines.

    Hi, I was having a discussion with somebody who was trying to convince me of these things which I don’t believe. However I kept trying to think of the physics laws that make these things impossible. To my mind came resistance and friction. But I feel there are other science laws that I have...
  12. Athi Sankar

    Dynamics of Machines - Forced Vibration

    Summary: I need a help to solve problem asked in university exam I am looking for the answer for the above question. I solved almost except the last one "Force exerted by the spring and dashpot on the motor". Can anyone help me to find out the answer for it
  13. kunalvanjare

    Designing an Automatic Coolant Monitoring System for CNC Machines

    Hey guys, I am designing a system that would monitor the coolant tanks of about 10 CNC machines through a centralized system consisting of valves, a pump & a refractometer. The system would be connected to the tanks through fixed piping in the plant. A pump would draw small amount of liquid...
  14. M

    Hydraulic machines (Francis turbine)

    When my teacher was explaining about impulse-reaction inward Radial flow (Francis) turbine, he said that as the water moves from inlet to outlet tip of the blade, pressure energy of the water is used to do work and pressure reduces(reaction effect).Then he added that due to this decrease in...
  15. Jazzyrohan

    Perpetual motion machines can't exist (Feynman's lectures)

    I have been reading Feyman Lectures Volume 1 and I am stuck on the example or proof given in the book about how no machine can be more efficient than a reversible machine. http://www.feynmanlectures.caltech.edu/I_04.html Section 4-2 A very simple weight-lifting machine lifts weights three...
  16. M

    MHB How Many Handshakes Did the Hostess Make at the Party?

    Hey! :o I am looking at the following problem: There are $k$ couples and the host and the hostess. (So, in total $k+1$ couples.) At the general greeting some people shake hands, others do not. Of course, nobody shakes hands with themselves or their spouse. The host asks everyone else in the...
  17. G

    I Can Turing Machines Understand Infinity?

    I had a conversation with someone once upon a time (it was quite a while back actually), and we came to the question of whether or not Turing machines could ever understand infinity. We agreed that we as humans are intimate with the extant and divisible infinities mainly through our...
  18. E

    Reporting my own post to bring this to the attention of a moderator.

    Does anybody have any references where Einstein speaks about Time Machines? From collected sources I found, he strongly rejected the idea of Time Machine but through his theory implied that time travel may be possible if wormholes existed. Something needs to be infinitely fast to do this? Have...
  19. cobalt124

    I Enumerate all 1-state Turing Machines

    Hi, using the definition of a TM from https://en.wikipedia.org/wiki/Busy_beaver a 1-state TM would have: one "operational" state a, plus the Halt State h a tape alphabet of 0,1 a tape initially all zeros Given this the possible 5-tuples a 1-state TM transition table could have are: (current...
  20. S

    Finite State Machines: Differences between Mealy and Moore Machines?

    There are two types of finite state machines (at least that I know about), mealy and Moore. What are the practical differences between them. I understand that mealy machines take the input into account for the output logic, but are the two machines used for different purposes? Or can the same...
  21. lc99

    Statics free body diagram (frames and machines)

    Homework Statement Homework Equations Trying to find the reaction forces at E. But, I am kinda confused about drawing the free body diagram for each member. I know that member AD and CB are two force members. What is wrong with my free body diagram then? The Attempt at a Solution i...
  22. SchroedingersLion

    Feynman: Reversible machines, no perpetual motion?

    Greetings, I have begun reading the Feynman Lectures to repeat the most important ideas from my undergraduate studies and to improve my intuitive understanding of physics. In one of the first chapters, the one about the conservation of energy, he demonstrates that the conservation of energy is...
  23. Meeeessttteeehh

    Operating cost for lights and coffee machines

    Had a bit of a hard time with this one. Anyone mind giving it a look over? 1. Homework Statement Find the total cost for a business that operates the following for one year. Assume that the rate is 6.4₵/kWh. · Fifteen 100 W light bulbs for an average of eight hours a day. ·...
  24. N

    Simple Machines Revisited + more - making 2.5 ton lift

    I always seem to get into "big" projects these days and need to whip out some math that has a lot of cobwebs. I'm not too worried about injuring myself... but I don't want to inadvertently have something break over a vehicle bed / trailer. I think most of the system components are good... I...
  25. Jacinta

    Can aeroplanes be technically used as time travel machines?

    So I'm currently on holidays somewhere, and it's one hour ahead of where i live. Since i went on the areoplane and landed to a new country where the time is an hour ahead, this also means i technically landed into the future, right?
  26. J

    Prerequisite Required for a Course in Electrical Machines

    I want to study "Electrical Machines" Course. I looked for online courses but they all had different prerequisites to study "Electrical Machines" course. Can anyone guide me about what prerequisites are needed to study "Electrical Machines" or any specific contents that i should study (e-book or...
  27. J

    Understanding Gears & Machines: Force & Distance

    Homework Statement I am really struggling to understand gears and how they can multiply force or speed. I was reading over this physics link (http://www.tutorvista.com/content/physics/physics-i/power-energy-machines/gears.php). Homework EquationsThe Attempt at a Solution I'm confused about the...
  28. A

    B Simple machines that are used in Weapons

    Do you know any weapons that use simple machines?
  29. Dimani4

    B Solve Feymann's Irreversible Machines Puzzle

    Hi all, I still have "a many times discussed" problem to understand Feymann's issue about irreversible/reversible machines example. Here is the part from the original text. Here is my questions: 1. Here Feymann talks about the situation when you are not applying any force to rise or lower...
  30. C

    Finding the Cost for Operating Coffee Machines

    Homework Statement Find the total cost for a business that operates the following for one year: - Fifteen 100 W light bulbs for an average of eight hours a day - Two 15 Ohm coffee makers connected to a 120 V power supply for two hours a day each The rate is 6.4 ¢/kWh Homework Equations ##...
  31. G

    Turing Machines: Classifying for Decidable Problems

    It's been a while since I've done this, but the question spurred on. Is there any sort of named class that a machine that can decide on all Turing decidable problems would belong to? Edit: Actually, I guess it would be Turing if you could program it to decide on a particular problem.
  32. Manoj Sahu

    Which is the best book for getting in-depth knowledge of Electrical Machines?

    Hi. I am preparing for IES (Indian Engineering Services ) exam. I have basic knowledge of electrical machines both ac and dc. For the examination point of view I need to have in depth knowledge of each and every topic in electrical machines (both ac and dc). Can you suggest me some really good...
  33. gilakmesum

    Exploring the Possibility of Warp Machines for Space Travel

    Is it possible now that we can built a warp machine and put inside the spacecraft and traveling around the universe?
  34. W

    Networking Virtual Machines: Best Practices

    Hi just curious, Are there standard methods for putting several Virtual Machines in a network?
  35. dkotschessaa

    Leonardo’s Perpetual Motion Machines

    Obviously they don't work, perpetually, but they're really cool anyway: http://www.leonardodavincisinventions.com/mechanical-inventions/leonardo-perpetual-motion-machine/
  36. E

    Sparsity of Support vector machines over an RKHS

    Im trying to solve the following problem from the book 'Learning with kernels', and would really appreciate a little help. Background information - Let $\{(x_{1},y_{1}),...,(x_{N},y_{N})\}$ be a dataset, L a Loss function and $H(k)$ a reproducing kernel Hilbert space with kernel $k$. The...
  37. E

    Engineering Electrical Machines DC Shunt Motor

    An 8.25 kW shunt DC motor is supplied with a terminal DC voltage of 300 V. The armature resistance of the motor Ra is 0.25 , and the field resistance Rf is 40 . The field winding consists of 1500 turns. An adjustable resistance Radj is connected in series to the field winding. Radj may be...
  38. F

    Operation of mechanisms and machines

    Is it possible for a mechanical engineer or even a mechanical engineering student to know how a mechanism or a machine works only through an image (photography, drawing ...)? And if so, what subjects should I study to have this ability ?
  39. kolleamm

    Machines taking our jobs and possible solutions

    In an attempt to try and decide my future career in computers I have come across the topic of machines taking our jobs. What will happen when society reaches the point at which a machine can do even highly skilled jobs that require years of college education and creativity? The typical...
  40. DrClaude

    Nobel prize: molecular machines

    The Nobel prize in chemistry for 2016 has been awarded "for the design and synthesis of molecular machines." These are fascinating constructions made up of just a few molecules, so they are the smallest machines possible. It is far from trivial to get these things working, especially since...
  41. S

    Setting up FBDs for Frames & Machines: Tips & Tricks

    Hi everyone, I did a search and couldn't find any useful information on frames and machines for statics (unless I missed it for which I apologize if I did) Does anyone have a few steps that they follow when setting up a FBD of a frame/machine. I'm having trouble being able to efficiently set up...
  42. S

    Understanding the operation of the Lathe

    During the operation of a lathe, why does the work-piece revolve anticlockwise as seen from the tailstock?
  43. marcophys

    What lives in washing machines and eats aluminium alloy?

    The washing machine stopped spinning, so I dismantled it. Here's what I found: I'm thinking it might have become a big battery, as the steel drive shaft was embedded in the alloy drive bracket, which in turn had 6 studs bolting it to the stainless steel drum. It was all enclosed in the sealed...
  44. thegreengineer

    Analyzing Structural Forces: Understanding Reactions and Moments in Mechanics

    <<Mentor note: Missing template due to being moved from other forum.>> I took this problem from Vector Mechanics for Engineers by Beer et al. The reason why I am writing this is because I don't understand where I am wrong in this problem, yet I know I am wrong. This is problem 6.123 and it's a...
  45. AndresPB

    Medical Electron Acceleration and X-Ray Emission in X-Ray Machines

    Good morning all, I was just wondering the following question. When an electron is accelerated it emits electromagnetic radiation, depending on how much it is accelerated the energy varies so the frecuency does and the electromagnetic wave emitted would be of different colors or maybe even...
  46. S

    Hydraulic system used in cnc machines

    I have found some uses of hydraulic systems in cnc machines in http://www.trendingtop5.com/hydraulic-system-used-in-cnc-machine/ . But those are not enough for me. please suggest some another uses in the modern industry.
  47. defaultusername

    Is the Tension Force in an Atwood Machine Only Transmitted Between Blocks?

    Homework Statement When talking about an Atwood machine, a student states: Is the student correct or incorrect? Why? Homework Equations Tension = mg + ma The Attempt at a Solution This is how it is making sense in my mind, but correct me if I'm wrong. I am thinking that the student is...
  48. Syed Taha ahmed

    I Why does back EMF in DC machines deviate from a pure sine wave?

    Why voltages out of the rotating loop is constant positive and negative **Why nOT varying like sinusoidal **. Like it has a wave form of O to 2*vBL and then it maintain its value there for some time before failing to zero and changing direction. I have attach the image file from my book...
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