Count Definition and 168 Threads

hi guys, I did some reading into dioxin in light of recent incident in Ohio. I'm not sure how to count the carbon in this compound, if i start counting from top left or top right, I comes with carbon 2, 3, 8, 9 that bounds with Chlorine atom. https://www.epa.gov/dioxin/learn-about-dioxin

Hello, In the context of categorical variables, a frequency table which gives us the count (aka frequency) for each level of the categorical variable. Count is a number telling us how many times a specific level occurs. A bar-chart handles a single categorical variable (nominal or ordinal) with...

Hello everyone, I am trying to measure the dark count from a measurement a SPDC source. Although I collected data from the signal generator, I do not know how to obtain dark count rates per second. I only know the following definition Dark counts refer to the tiny amount of DC current in the...

I have a deck of 60 cards. I draw 7 cards. Among the 60 cards are 21 cards in category "A", 4 cards in category "B" and 8 cards in category "C". The categories are mutually exclusive. I want to the probability that my 7 cards contain at least 2 from category A, 1 from category B and 1 from...

In Mathematica, how can we have "M" levels of nested loops, with each loop (level) going from 1 to Counts=##\{N_1, N_2, ... N_M\}## respectively, where the value of M and the elements of Counts are computed beforehand?

I know that least count is the smallest measurement that is possible with a measuring device. But I fail to understand the exact meaning of least count error. According to my textbook, the following is the definition of least count error. "Least count error is the error associated with the...

Hello, I watched MIT course on Nuclear physics (13. Practical Radiation Counting Experiments on ytb) and I do not understand why 2*sigma (standard deviation) = 0.05* countRate. As far as I know, integral of normal distribution from -2sigma to 2 sigma gives 95 % probability, but how can 2*sigma...

Is it healthy for said individual to ruminate about how nothing of great significance has transpired ever since leaving college? Is it healthy for said individual to mentally place his college days on a metaphorical pedestal, and claiming that that period of his life was the one during which he...

At the end of the measurement I made with a detector, I only have the energy and count values as in the attached excel file. How can I find the peak values with the data I have and calculate the efficiency?

Summary:: Count characterers in a string and display it in hexadecimal [New user has been reminded to show their work on schoolwork problems] Hi, how can I do this in MIPS? Given a string of characters, the program has to count the number of characters in the string, and display it in...

Hi hi, I was thinking about this, all of this starts playing a game, I'll show a simplification: We ca win several times. We have a count ##n##, where is the max number of rolls until you win, let's say we can win a ##m## amount. In every roll we can win ##m## with a probability of ##p##. If...

Let x1, ..., x25 be such positive integers that x1⋅x2⋅ ... ⋅x25 = x1 + x2 + ... + x25. What is the maximum possible value of the largest of numbers x1, x2, ..., x25?

Find the count of multiples of 2;or 7, for all natural numbers less than or equal to 999.

Homework Statement The count-rate from a gamma source is measured to be 1000 counts per minute. When 1.0 cm of lead is placed between the source and the detector, the count rate is reduced to 100 counts per minute. What additional thickness of lead would have reduced the count-rate to 50 counts...

Preface: I also posted this question on mathoverflow(link: https://mathoverflow.net/questions/324110). A bit surprising for me that it has gotten votes to close. Mostly because all the dozen or so questions (after my very first one) that I have asked there have been received positively. But...

Taking the Earth orbiting the sun as an example, when I consider the angular momentum of the Earth about the sun, should the spin angular momentum be counted? I'm confused that if it's counted, the spin angular momentum, Lcm=Icm×ωspin, is different from other angular momentum regarding the...

Hey. * How many ways we can insert 16 similar balls to 4 drawers such that in every drawer we have at least 3 balls? So I know we have to insert at first 3 balls to every drawer and the remainder is 4 balls. But how can I calculate the amount of possibilities to insert 4 balls to 4 drawers...

This i a test question and we are not allowed to use a calculator, so I was wondering whether I did everything correctly, since the I1 = - 1/7. I am supposed to find out I3, but stopped at I1, since the result is a bit tricky. 1. Homework Statement R1 = 10 ohm, R2 = 20 ohm, R3 = 40 ohm I3 = ...

Homework Statement Is the least count constant for Vernier scale like 0.1 mm or variables? 2. The attempt at a solution If the main scale readings are 10 mm and the vernier scale readings are 9 mm, the least count is MSD/VSD = 9/10 = 0.9 So the least count is 0.1 mm for every count in the...

I was just looking at indeterminate statics problems where you have a beam, three elastic wires (left, centre, and right that are holding it up), and some extra mass. (Just like example 5 in the notes below: http://fast10.vsb.cz/lausova/indeterm_all.pdf). I understand the method that was used to...

I have seen that typically most 110Kv and 330Kv lines around my place have not 4 wires on them (3 phases and one neutral) but rather 7 wires on them, which I suppose is 3 phases x2 which probably means two cables for each phase and a common neutral wire at the top of each post. Now is my...

Setting up a test stand that will need a controller to cycles a device ON and OFF at an adjustable time interval (allows me to make the ON duration and OFF duration whatever I want). It will also need to keep a count, so I can track the cycles count and also set a limit on cycles so it will stop...

<< Mentor Note -- thread moved from the technical forums, so no Homework Help Template is shown >> Let's say you have a laser cavity with two mirrors at either end, one is considered 100% reflective, the other 99.9%, so that a wave beam is emitted through this lower reflectivity mirror. I know...

Homework Statement a) Given x1+x2+x3=20, for all positive integers, how many solutions are there? b) For x > 3? Homework Equations Multichooose The Attempt at a Solution At first I computed "20 multi-choose 3" and got 231, but I believe that is counting zeros as part of the solutions. So for...

Hello, long time lurker here on PF. I was wondering if there is anyway that I could make self-study/teaching count in any way as credentials for future jobs? I have a masters degree already but I'm hesitant to jump into a PhD since it would require that I attend part time while I work full time...

Hello there Im really stucked with my model in ansys Maxwell. it has an important error saying the following : [error] Separate operation failed due to lump count inconsistancy. Found 1 lumps instead of expected 20 and I don't really know what does it mean! I have searched all over the...

Mentor note: Moved thread to homework section ok So I'm doing supposedly easy trigonometry problems. i did the easiest ones. now I have no idea how to solve 2. first one is count sin+cos When tg - (1/tg) = -(7/12) what i figured is that i probably need to use...

Does anyone know of a simple relation between dark current and dark count in photon collection devices?

Hi, I am setting the accelerometer (BMA250E) on the bicycle wheel hub. I want to count the wheel revolutions(each sine wave) but the Speed over 20km the x-axis(a) data will increase. My question is: How to count the sine wave when x-axis sine wave position move to high or low. Thanks.

I have a project and in that project I'll count the wild life animals from a drone. I need to find a drone that doesn't make much sound also (maximum 60-70 dB), it must capable of a flight time 30 min and also can carry a IR camera. I find a drone callled Phantom 4 (Advanced or Pro)...

Hello! How is the count rate of a detector defined (I need for a scintillator)? It is just the number of particle hitting the detector per second times the efficiency of the detector at that energy?

Star Wars has destroyed six planets full of people, and the city of Jedah. Anyone with a higher body count?

Is there a general average number of neurotransmitters a given cell would "work with"?

Hi. I have a simple circuit with a third-part model. As far as I can tell using info from the internet I have everything correct, but I still get this problem. Please help me clear this log-jam, thanks!

Post count. "Like" count. What are your best explanations about what they say about you (and other PF members)? This isn't serious, it's just a silly little game. Anything goes. I'll start: Multiply your like count by 100 and then divide it by your post count. This is the number of lovers...

Homework Statement Homework EquationsThe Attempt at a Solution I am guessing P is a noble gas and Q is in group I. Therefore A, B, C and E can be canceled out. S is a transition metal. It is a metal lattice structure. But I guess it could be described as a giant structure, so would you say D...

I want to know whether the following the counts as a proof that infimum of the set $S = \left\{2(-1)^n+\frac{5}{n^2+2}: n \in \mathbb{N}^{+} \right\}$ is $\text{inf}(S) = -2$. Let $A \subseteq X$, where $X$ is some ordered field. Then $\text{inf}(A)$ is $m \in X$ such that for any $x \in A$...

I want to know how admission committee counts the number of words in an applicant's statement of purpose, because usually they put limitation on the number of words in this essay. I want to know this because in my statement of purpose there are "words" that actually comprise of two words, for...

Count the number of strings of length $8$ over $A = \{w, x, y, z\}$ that begins with either $w$ or $y$ and have at least one $x$ I don't understand this question at all. First of all, this is a set A that contains 4 elements $w,x,y,z$ correct? They are asking me to count the number of strings...

We all know the coordination number is an important characteristic of a system consisting of many particles. But in experiments,except CT,do we have any easier and cheaper way to know it? Thanks for help.

Homework Statement I'm trying to show that ##\Sigma_j(\vec a_j \cdot \vec B)=\vec B\cdot\Sigma_j(\vec a_j)## (I need this to be true to derive some angular momentum properties.) 2. The attempt at a solution Let's say that in some coordinate system we can express the vectors as ##\vec...

I am using Renishaw confocal Raman microscope to do photoluminescence spectroscopy of some polymer inside microchannel. When I fix the laser power and exposure time, the absolute count of intensity will change from time to time even for the same sample. I was hoping the intensity should linearly...

Hello Ladies and Gents,I am look for some help with designing the gear trains for an orrery (a mechanical model of the solar system) I am planning. I need some advice on how to go about calculating the specification of the gears in the mechanism which I will machine. I will use cycloidal teeth I...

Good morning everyone, I would really be pleased with a quick answer because I am very soon going to school. I have been asked to plot a graph, for that I am given a table with time in minutes from 0 to 6 on the first row. On the second row I was given activity in counts per minute with values...

In Gaus's law when the integral is set up, we don't account for the charge outside the closed area. Why is this? How does this law work when the charges outside are not accounted for and only the charges enclosed is in the equation? I need an explanation why Gaus's law still works for...

Homework Statement I have a data table and I am doing a query on some of the attributes.[/B]Homework EquationsThe Attempt at a Solution I think I need to use ## \Sigma ## in the menu bar, but that has not worked. I know how to return all other query values, but not how to do a count. Thanks.[/B]

< Mentor Note -- thread moved to HH from the technical forums, so no HH Template is shown > I have a file Aggregation.dat ######################################################################################## 6.999e+04 4.50000e+01 2.22222e+00 4.94813e+00 2.50000e+01 1.00000e+00 7.004e+04...

Hi, I'm using an Altera DE2 Development Board. I'm creating a counter that counts the number of times a user pushes a button. I'm using 74163 counter since I need to count 0-9 and I think it's easier to control. I must have it running on an internal clock. However, my counter didn't seem to be...

Hi! (Smile) Given the following algorithm, I want to find how many times the command t+=8 is executed. Function Fun(int m){ int j,k,t=1; for (j=0; j<=4n^2; j+=4){ for (k=j; k<=4*sqrt(n); k+=4){ t+=8; } } } The outer loop is executed $\lfloor \frac{4n^2}{4}...