What is sd: Definition and 47 Discussions

Standard-definition television (SDTV, SD, often shortened to standard definition) is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing specification for broadcast (and later, cable) television in the mid- to late-20th century, and compatible with legacy analog broadcast systems.
The two common SDTV signal types are 576i, with 576 interlaced lines of resolution, derived from the European-developed PAL and SECAM systems, and 480i based on the American NTSC system. Common SDTV refresh rates are 25, 29.97 and 30 frames per second. Both systems use
a 4:3 aspect ratio.
Standards that support digital SDTV broadcast include DVB, ATSC, and ISDB. The last two were originally developed for HDTV, but are also used for their ability to deliver multiple SD video and audio streams via multiplexing. In North America, digital SDTV is broadcast in the same 4:3 aspect ratio as NTSC signals, with widescreen content often being center cut. However, the aspect ratio of widescreen content may be preserved in a 4:3 frame through letterboxing. In other parts of the world that used the PAL or SECAM color systems, digital standard-definition television is now usually shown with a 16:9 aspect ratio, with the transition occurring between the mid-1990s and late-2000s depending on region. Older programs with a 4:3 aspect ratio are broadcast with a flag that switches the display to 4:3.Digital SDTV eliminates the ghosting and noisy images associated with analog systems. However, if the reception has interference or is poor, where the error correction cannot compensate one will encounter various other artifacts such as image freezing, stuttering or dropouts from missing intra-frames or blockiness from missing macroblocks.

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  1. 1

    MCNP6.2: F6:N and F6:P tallies vs +F6 tallies?

    Hi, I am checking whether, in case of a MODE:N P, tallies can be compared. In theory, is +F6=F6:N+F6:P? If so, my numbers do not add up. But maybe it's due to the role of SD card, so here there is an aside question: how does SD card affect the F6 tallies? Is it exactly like for F4 and F2? For...
  2. amyy

    A Does 15F Qualify as an sd Shell Nucleus?

    If we call a nucleus a sd shell nucleus, should its last proton and last neutron both lie in the sd shell or just one lies in the sd shell? For example, 15F, whose proton number is 9 and neutron number is 6. Then the last proton lies in the 1d5/2 orbit and the last neutron lies in the 1p3/2...
  3. M

    New menu has disappeared in my external sd card

    Hello. I cannot see new menu in my sd card. I can see it when I right click on desktop, but something has happened to my sd card. I have also realized that card gives "disk is write-protected". I think this cause not to create folder or file. I cannot find a link that explains it. Would...
  4. dgsfbandeira

    I How to 'reverse' derive correct value when given MEAN + SD

    I have a scatterplot that I'm trying to extract. I found 54 values out of 55. There is one "missing" value, probably because it is overlapped and I can't actually see. I have the MEAN and Stand Dev of the 55 values. Is there a way to reverse find the one that is missing? I mean, is there a...
  5. DaveC426913

    Dashcam is leaving file artifacts on SD card

    My Dashcam is telling me the memory card is full. It has done this a couple of times now over the last month or two. The SD card is a Class (10) 16Gb NEXXTech MicroSD (The class 10 relates to how fast it can record; the Dashcam requires at least a 6 or 8 or something. A 4 is too slow and it...
  6. fluidistic

    A Monte Carlo to compute uncertainties, why report the mean and SD?

    I am learning about the use of Monte Carlo to calculate/estimate uncertainties. If I take the example of a single measurement (i.e. I measure several quantities required to get an estimate of some physical property, but I do this only once), I can use Monte Carlo and some common sense for the...
  7. F

    Micro SD card - preloaded or not?

    Hello, I have a raspberry pi with a camera and would like to take some pictures with. Online, there are preloaded and not preloaded cards...What is the difference? Preloaded in what sense? For example: https://www.amazon.com/dp/B01LXR6EOA/?tag=pfamazon01-20 Not sure about the NOOBs either...
  8. Wrichik Basu

    Where to find app data on SD card (Android)?

    In my phone, a large number of apps have been moved to sd card. Where do I find the app data if I view the sd card via windows explorer? The reason I want this is, my phone is creating a lot of problems, and tomorrow I'm taking it to the service centre. They might want to factory reset the...
  9. M

    How can I fix a corrupted SD card and restore my files?

    When I was taking a backup my sd card has broken down. How could I restored my files in it? Does trying a live linux work and what about chkdsk option? Does chkdsk recover my files or does it only format the disk...
  10. M

    Problem of having no more than one SD slot

    I like using SD instead of USB. But even though my PC has 3 USB slot there is only one SD slot. This makes the things more complicated. Without copying files to the desktop and without using USB technology how can I make a back up from one SD card to another SD card? Thank you.
  11. M

    An SD card ejection problem -- Why is svchost.exe using the card?

    I try to eject my sd card in my PC but I take this notification. How can I reject it? Why is svchost.exe using the card? Thank you.
  12. Y

    Male Micro SD to Male USB Cable?

    Does such a thing exist. I have a device that only has a slot to write data to a micro sd card. I have an external USB hard drive. Is it possible to hook up my external hard drive to the micro sd slot in my device? Like a male USB cable into the external hard drive that has a male micro sd...
  13. N

    Question about free damped vibration in an SD

    Homework Statement "If a horizontal force of F = 299kN is applied to the right at the girder level by a hydraulic jack and then the force is removed suddenly, find the equation of motion of the girder. Consider 5% critical damping. Find the displacement and velocity of the girder at 0.2 seconds...
  14. phosgene

    Comparing SD of data with RMSE of regression line

    Homework Statement I'm being asked to compare the standard deviation of a data set with the root mean square error of the regression line used to model the data, in order to determine the reliability of the regression line. Homework Equations Mean squared error = variance + bias squared The...
  15. oilyardm

    How to recover deleted files from Android SD card?

    Anyone has the suggestion on this? I deleted a couple of photos stored on SD card and i heard it's highly possible get back them. Actually, I tried a few 'so-called' data recovery apps, none of them work. Do you guys have any recommendation on this? thanks in advance
  16. T

    MHB Probability question (mean, SD)

    Scores on an examination are assumed to be normally distributed with a mean of 58 and a standard deviation of 18. (a) What is the probability that a person taking the examination scores higher than 72? (b) Suppose that students scoring in the top 10% of this distribution are to receive an A...
  17. J

    SD Card Module Slot Socket Reader to USB - Help please

    Hi I want to use the SD Card Module Slot Socket Reader Module (Link attached) as a micro sd card reader DIRECTLY to my PC. Is it possible to connect to this Module a USB Male connector and use it as a normal sd-card reader? The Module...
  18. M

    Hypothesis testing for std. deviation (SD)

    Hi, What I know: In a hypothesis test for the mean, we compare a sample mean with a hypothetical sampling distribution of means. And depending on how far it is away from the mean of the sampling distribution, we attribute it the probability of getting that value purely by chance. What I...
  19. N

    Mean and SD of the inverse of a population

    If one has the mean and standard deviation of a population, is it possible to calculate (or estimate) the mean and standard deviation of the inverse population (ie. 1/(every value in the original population)? Thank you!
  20. H

    TMS320F28035 bootloading to SD card

    I'm using a TMS320F28035 (TI -piccolo series) microcontroller and it came to my attention that the chip only has about 128KB of flash memory and the binaries for my main program are easily 150KB or larger. So that's where my SD dilemma comes in. The documentation (section 2.1)...
  21. S

    Is it possible to find the SD without the data?

    I have the mean and I have the value at a percentile (99th percentile to be specific). I am just wondering if it's possible to find the SD. Actually, what I am trying to find is the value at the 90th percentile (I think I need the SD to do it, but maybe just maybe there's another method...)...
  22. P

    Normal distribution, find mean and SD

    Homework Statement Suppose X is a normally distributed random variable. Suppose also that P ( X > 44.7 ) = 0.33 and P ( X < 46 ) = 0.7123. What is the mean and standard deviation of X ? Homework Equations The Attempt at a Solution P(X<44.7) = 1-P(X>44.7) = 1-.33 = .67 P(X<44.7)...
  23. T

    Can an SD Card be Used for Booting and Program Storage on a New Computer?

    I'm finally getting a new computer that actually has an SD slot. What I'm wondering is: are SD/flash cards are faster than a 5400rpm hard drive? And, is it possible to boot from a SD card? Basically, I'm thinking it would be a poor man's SSD. Also, is there a way to set windows to use a...
  24. I

    Calculators How read text files on CASIO fx-9860GII SD?

    Hi to all. I'm sorry for my english, but I come from Italy. My CASIO fx-9860GII SD calculator see the text files who I put near its SD, and I can copy they on main memory, but I can't open they to read! How can I read the text files by the calculator? Must I use a particular software to...
  25. M

    Defining SD from a set of errors

    Hi, I never took stats so maybe this doesn't make sense or is really simple, either way any help is appreciated. I have a series of data, say Xi (i=1,...1000) and a series of true values of that data, say Ti. Each true value is different and independent. Is it possible to get some kind of...
  26. S

    P(5 sets of twins in the SD state football tournament)

    All, I'm guessing that I'm vastly over- or under-thinking this one, but here it is. Question: In the South Dakota State High School Football Tournament, there are 12 teams competing with a total across all 12 teams of 555 players. Among the 555 players there are 5 sets of twins (i.e., 10...
  27. J

    Updating the mean and sd of a set efficiently

    I am trying to work out the most efficient way of updating the mean and standard deviation of a 1 dimensional set of data. The data points change frequently and by a small amount each time, but I do not want to do a complete recalculation of the mean and sd after each change, as this is...
  28. L

    How get the significant difference from arithmetic means and SD?

    The raw data are lost, I have only final outputs (arithmetic means and standard deviations) for equally long measurement series. How I can compare results (calculate results) for the purpose to see significant statistic difference (significant difference, p<0.05)? Thank you in advance.
  29. R

    Finding the mean, midpoint and sd

    Homework Statement The Acme Chocolate Factory produces 40 different types of chocolate candies. An individual sample of each candy was weighed tot he nearest gram. weight - Types of candies 0-4 - 7 5-9 - 14 10-14 - 10 15-19 - 4 20-24 - 2 25-29 - 3 The Attempt at a Solution The...
  30. M

    Using SPI mode to interface msp430 with RF transciever and SD card

    Hi, I am planning to use SPI mode to interface a eZ430-RF2500 with a Sandisk Secure Digital Card. The eZ430-RF2500 includes a MSP430 microcontroller and a CC2500 RF transceiver. According to the schematic, the RF transceiver interfaces the MSP430 utilizing the SPI mode, using the SOMI, SIMO...
  31. M

    How to caculate the needed capacity of the SD flash memory card

    Hi, I going to interface a microcontroller with SD flash memory card for data log. How to caculate the needed memory capacity? Thanks
  32. J

    Optimizing PCB Design: Choosing Between SD and MicroSD Connectors

    Hello, If vias are covered with soldermask is it OK to mount an SD card connector with a metal frame over the top of them? Thanks
  33. T

    Validity SD Logic Homework Question

    Show that the following argument is valid in SD. (I will use "⊃" to show conditional.) (E v (L v M)) & (E ≡ F) L ⊃ D D ⊃ ~ L ---------------------- E v M I'm only allowed to use the basic derivation rules of SD: Reiteration (R) Conjunction Intro. (&I) and Conjunction Elim. (&E)...
  34. T

    SD Logic Homework (Derivability)

    The question is: Show that the following derivability claim holds in SD. (I'll use ">" to stand in for conditional.) {(A > F) & (F > D), ((M v H) v C) > A, ~(M v H) & C} entails D I'm only allowed to use the basic derivation rules of SD: Reiteration (R) Conjunction Intro. (&I) and...
  35. wolram

    SD Card: Baffled by Big & Little Bits

    I just bought an SD card for my camera, talk about things getting smaller i could hardly hold the big bit that the little bit had to be pushed into, now i am baffled is it the big bit that holds the 1 gig memory or the little bit, if it is the little bit why have the big bit, or is that for...
  36. K

    SD Logics Problems: Derivability, Inconsistency, Equivalence, and Validity

    My teacher threw us a couple of questions on SD that I know hardly anything about. The first one one to come up with correct answers receives an additional 10% on our next paper. I would really like to answer them all myself, but I don't have the information about SD to do them as I have never...
  37. K

    Need Help with SD Questions in Phil Course

    My teacher threw us a couple of questions on SD that I know hardly anything about. The first one one to come up with correct answers receives an additional 10% on our next paper. I would really like to answer them all myself, but I don't have the information about SD to do them as I have never...
  38. C

    Passing SD and HD video through a HPF

    Good morning I have been browsing this forum for quite sometime finding very valuable information, but now I have a question of my own. The very basic principles of RC HPF's tell us that all else equal the frequency and the value of the capacitance are inversely related. This suggests that the...
  39. S

    Need help in Mean, Probability & SD

    The placement data of a business school suggest that the percentage of students securing a job with a multinational during the years 1996, 1997 and 1998 are 20%, 30% and 40% respectively. One student is chosen at random from the graduating batch of each year. Let X be the number of students...
  40. W

    How can I derive (G&H)->J using SD rules?

    Ok, so I'm doing some logic review on my own. It's been awhile since I've done derivations, so I'm a little rusty. I'm just trying to use SD rules and not SD+. I'd appreciate any help you all can offer. Thanks in advance. Derive: (G&H)->J 1. E->(F->G) assum. 2. H->(G->I)...
  41. Clausius2

    Historical Meeting: Astro & Clausius in SD

    Historical Meeting: Astro & Clausius in SD! Yeah man! Although it was a very fast meeting, we were talking in my new place at San Diego!. A nice guy!. And yeah, his beard is original (I tried to pull out his beard hair and after some Astro screams I realized is beard is true!). Behind a...
  42. Y

    Proving Theorems in Sentential Logic: SD Derivation Guide

    Hi everyone, I really need help proving a theorem for logic HW. I am allowed to use all the standard derivations in Sentential Logic. Also I do not know how to enter in the symbols so I will use ">" to signify conditional in the problem below. Instructions: Show that each of the...
  43. Y

    How Do You Prove Theorems in Sentential Logic?

    Hi everyone, I really need help proving a theorem for logic HW. I am allowed to use all the standard derivations in Sentential Logic. Also I do not know how to enter in the symbols so I will use ">" to signify conditional in the problem below. Instructions: Show that each of the...
  44. G

    Having Trouble Understanding SD: F > ~G, ~F > ~H & More

    Hi, I am having trouble showing that {F > ~ G. ~ F > ~H, (~ F v G) & H} is inconsistent in SD. Also I don't understand how one can derive: ~ H from: {(R v ~ H), (~ R v ~ H)} I would be grateful to anyone who can help me understand these problems.
  45. M

    Poisson Distribution Mean & SD: Solving for Y

    I am attempting a past paper question from school, i don't have the answer (and it doesn't look like i will anytime soon!) The question: "The Random variable X has a poisson distribution with mean 4. The random variable Y is defined by Y = 4X + 1 Find the mean and standard deviation...
  46. M

    Can SD+ Make Proving Inconsistency Easier Than SD?

    Why is SD+ so difficult? I understand SD, but SD+ is eluding me..
  47. W

    How can you derive (P v ~P) in SD?

    Hello, I am doing some exercises in my symbolic logic text as review and I came across the following question: I am having no trouble in deriving other theorems in SD but this one eludes me. Any help / hints would be appreciated. Thankyou.