Issues Definition and 407 Threads

The question might be a bit silly.. (asking for advice regarding the theory of machines content, not a homework). I'm enrolled in the mechanical engineering bachelor's. I applied for several internships however I couldn't pass because of a particular type of questions. The interviewer shows me...

I am trying for the first time in 5 years, to make a n- layer, m-width backprop neural network from scratch, My issue is, I've tried training it on XOR, where it returns 0.48 for any of the inputs instead of 1 for half of them and 0 for the other half, if you give it a dataset where the outputs...

Hello. I am creating a boost circuit and there is a lot of problems while testing. Before creating circuit i have simulated circuit in modelsim. Problems. 1. Sudden voltage rise from 40% to 50 % dury cycle. ( i am checking each duty cycle ) 2. When applying a gate voltage to mosfet the the...

I am not sure what the next step is: Linux kernel 4.18.0-425.3.1.el8.x86_64 work s fine. 4.18.0-425.10.1.el8_7.x86_64 works on two of my five machines. On the other two, I get the screen messages "CPU Stall" but nothing obvious in the log files. The troubled machines have older CPUs (Haswell)...

Hello - We are building a backyard tow rope for my course. All of the electrical components are working as designed; however, the pulley can't consitently grip the rope when only placed around the rim. When looped around 1.5 times the rope continually shifts underneath itself causing the motor...

I am using 2 lenses in a 4f configuration. The input is a large collimated beam (632nm). After passage through the 2 lenses the beams vertical dimension remains constant, however, the horizontal dimension get smaller, as if it is being focused only in the horizontal direction. Does anyone have...

I - A point divides a line into two parts; II - A line divides a plane into two parts; III - Does a smaller sphere divide a larger sphere into two parts, like layers of an onion? Note that the first two statements, the question of infinity must be considered. For the third statement, is the...

About a month or two ago I started doing simulations of light physics around black holes and yesterday I got a fast Christoffel symbols function for the Schwarzschild metric in cartesian coordinates, but now the photon ring appears flipped. I feel as though it is wrong. But as I am still pretty...

Hello! I am having some issues with a bow-tie cavity I am aligning and I would really appreciate any help. The cavity is not locked, so it does have some vibrations (it is on damping legs), and I want to lock a laser to it. I am seeing some peaks, but the output power is lower than expected...

Any idea what I'm doing wrong in the code below? It seems lines 15-16 are the problem. I thought ptr2 was a pointer. What am I missing? #include <memory> #include <iostream> class c1 { public: void f1() { std::cout<<"im a class \n"; } }; int main() { c1*...

Popular article: https://www.cambridge-news.co.uk/news/uk-world-news/seven-ten-people-long-covid-23442293 Research article: https://www.frontiersin.org/articles/10.3389/fnagi.2022.804937/full Well, that's not particularly good news. ☹️ Tom

[Mentor Note -- Two similar thread starts merged into one] Hey all, I have been working on this project for a while now, which features suspending an object midair through the use of magnetic levitation principles. Cool right? And so I have been researching and trying, even finding ground...

So I have this problem to solve, I was thinking that for k=2, the threshold value is too low and inefficient, but I'm not sure when k is at logn or more. If 2 sorting algorithms have the same complexity, won’t merging them be pointless in terms of running time? For b), i think the merged...

The only thing I could think of was using Q=sqrt(6000/50)-1 = 10.9, which then gets me XL=545 and XC=550, or 96.4nH, and 0.32pF at resonance of 900Mhz. I tried seeing if Zin=Zout equation would bring me close, so I tried Z=545+(50-550)=45, then XL for 38.5nH was 217.7, and XC for 2.4pF was 74...

Hi guys i have some concept issues about flux. My book says flux is proportional to the number of lines passing through that area. so my question is: first i am thinking that a 2D circle which has a 2r diameter and it is enclosing a 2q charge so its flux should be 2q/Epsilon.then i am thinking a...

Just wanted to drop this here because you guys were helping me with a few projects and I bugged out for a while without leaving much notice. Nothing life threatening, but it was pretty time consuming. Now on the mend, but slowly.

As a follow up from my other thread, where I consider popular media describe entanglement sort of as: and I think this may be wrong. As a follow up question I want to put forward this: A singlet state of entangled particles is notated in a superposition of product states as: ##|up, down...

In recent years, I found that many cars, I don't know if their headlamps are original or customized, the light is very bright or sharp, sometimes causing me to see temporary shadow in the eye like camera flash or even a little bit faint. In addition to yellow and white light there are also many...

I have a 3 phase problem that I think might be applicable to this forum. The setup is equipment which contains 5 resistive heaters (A through E). The unit is powered by 208V 3 phase and each of the heaters are hooked up line to line in an unbalanced configuration as follows: L1-L2: Heater D...

My father has some sort of elderly, age-related cognitive decline and/or disease (possibly dementia or Alzheimer's) that we haven't officially diagnosed yet (beyond his primary care physician simply saying that some cognitive decline is natural with age). One thing that puzzles me is why he...

Hello! According to recent studies, gold nanoparticles play a negative role on male fertility (reducing the motility of sperm cells, among other things), So, the question is, is the amount of gold absorded from donning gold jewerly enough to have noticeable spermatotoxic effects?

Its is podcast #138, guest = Daryl Morey, analytics inclined GM of the Philly team. Apple Podcasts: https://podcasts.apple.com/us/podcast/sean-carrolls-mindscape-science-society-philosophy/id1406534739?i=1000513079530 It covers higher level issues like: how good's your data? Balance between...

"The characteristics and extent of food industry involvement in peer-reviewed research articles from 10 leading nutrition-related journals in 2018" G Sachs et al. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0243144#sec012 Popular science version...

I have the problem with checking solution in calculators. For example wolfram doesn't give result of this equation. Have you any idea what is going on? Maybe should I simplyfy something. The equation is placed in photo.

Consider a purely inductive circuit with an inductor of self-inductance ##L## and sinusoidally varying AC source of peak voltage ##V_{m}##. First of all, Why is ##V_{ac} = ε_{ind}## (where ##ε_{ind}## is the back emf)? Now, at ## t=0 ##, voltage is increasing at a fast rate. Hence, due to the...

So essentially I followed pretty much what is in the picture here in this solution. https://www.slader.com/textbook/9780134162430-chemistry-a-molecular-approach-4th-edition/242/exercises/79/ My question is essentially why does he do the 0.07XXX mol f2 * 2mol clf3/3mol f2 * 92xx g/2mol f2 =...

http://www.chemroc.com/programs/NEC2Test.zip I don't understand what has happened with newer versions of GFORTRAN/MinGW64 . This is a very old FORTRAN program that I had edited years ago to compile and run with GFORTRAN. It doesn't work with newer versions. Can anyone help? I included link to...

Hello, I'm trying to solve a material placement issue at work and I'm exploring the idea of using static electricity to solve it. We currently combine two materials together using a heat activated glue that's sandwiched between the two materials and pressed together using a heat press...

Hi, I gave my friend a proof that the set of pairs ##\ mathbb N \times \mathbb N \times...\mathbb N ## (Finite product) is countable. I gave an injection : ##(a_1, a_2,...,a_n) \right arrow p_1_^{a_1} p_2^{a_2}...p_n^{a_n}## Where the ##p_i## are distinct primes. My friend is telling me this...

ok, setting the force issues aside (for now), Id like to use what I know about triangles to figure how to position my linear actuator in order to open and close this door correctly: The vertical side is 84cm, the door is 92cm. The measured stroke of the AL is 25cm. I would need to lower the...

https://www.sciencemag.org/news/2020/03/mathematics-life-and-death-how-disease-models-shape-national-shutdowns-and-other This shows how policy can be informed about differing effects of control policies in different environments. One of the bleak aspects of UK choices is shown as a graph...

Dear FEA experts, I’m trying to analyse* some finite elements model of a thin walled cylinder with variable cross-section, but I’m observing four weird issues in the buckling modes. The structure is vertically (along z-axis) and horizontally (along y-axis) loaded on top. Would you help me to...

Hi guys. Recently I've been assigned to know / calculate the capacity of the racks in our section. Our racks has layered steel pipes that are carrying the loads. After actual testing it can carry a load around 25 tons after yielding or having a bend. So my next step was to calculate for its...

I've attached a screengrab of the problem (Specifically, Part B, as indicated in the image) and my attempt at a solution. Summarized, my thinking was based on using ##-\Delta U=\frac{Kx_i^2-Kx_f^2}{2}##. After using up all my attempts, the solution, as it turns out, was U2=4.91J. No variation...

Hi everyone. I'm the only physics teacher at my school, so I have nobody to bounce ideas off of. I'm having a problem with students getting confused with direction when calculating net force. I teach an introductory physics course. It's the first time the students have ever seen physics and...

Hello, I'm using a "TQ2SA-1.5V Panasonic 2 Form C AS Single side stable, 1.5VDC 2A DPDT NON-LATCHING SMD Relay" (specifically the coil side of this relay) that is rated for 1.5 volts that is connected in series to this circuit (as the last device in this circuit shown below), which in this...

It looks like sometime in the next few days I'm going to buy a new iPhone to replace my 5S. I've been thinking about this for almost a year, but now it's become somewhat urgent because my wife needs to replace her old Nokia non-smartphone soon. According to our cellular provider (Consumer...

Hi all, I am having #HREF! issues in Excel 2007 when copying formula-based data from one sheet to another. The suggested solutions online are not working. I understand what the issue is: when copying from one sheet to another, Excel is trying to use data from the previous sheet, sheet_j...

Summary: Problems generating industrial clear Ice tube. The ice is cracking and we don't know why. Summary: Problems generating industrial clear Ice tube. The ice is cracking and we don't know why. Hi all! I'm an engineer from Spain and I'm working in a new project (factory ice). We have...

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The recently described hormone Klotho (which I never heard of before) seems to provide relief from some aging and brain problems (like Alzheimer's) and may even enhance brain function (as in a "smart" pill). This NY Times article describes research background and some of the potential issues it...

This thread is a shootoff from this post in the thread Summary of Frauchiger-Renner. The topics are related, but this thread offers a new perspective that diverges from the main subject of that thread. In QM foundations, the sheer amount of interpretations, disagreement among experts about what...

We have a Toyota Etios Liva, four years old, petrol variant. Today, my father took it for annual servicing at the authorised service centre, where the service personnel declared that the battery was "dead". Our car is not used much. Usually on an average, it is driven for around 14km per month...

I designed two geometries (one for beam/line reinforcements and other second for a solid block shown below) in Ansys workbench spaceclaim for static structural analysis. In Ansys workbench Mechanical, I got a weird mesh for the reinforcements which I modeled as beam in Spaceclaim (shown...

One approach that has been proposed to replicate the description of dark matter phenomena in galaxies with a gravity modification that is set forth in a simplified manner in the phenomenological toy model theory MOND is to do so through a variation on Einstein's General Relativity known as...

Hello I'm trying to set up my gaming computer in my 2018 Kenworth T680 but having power issues. Both with the monitor and the tower. But mostly the monitor. I realize the power inverter is likely incompatible with monitor and tower PSU. I need a workaround. Issue: Monitor works interminitly for...

Recently I've been recycling lead from old bullets.But everytime I recast the molten lead to an ingot, its surface is oxidized, therefore I am losing lead every single time I reuse it. Are there simple solutions to this without using an atmosphere of noble gases?

I understand that the evidence for dark matter, although indirect, is quite strong. Yet there are a few things that puzzle me about the dark matter idea. If dark matter is the predominant form of matter in the universe, why does it have no effect on solar system dynamics? The solar system is...

PROS AND CONS OF INSTALLING AN EOT CRANES IN A LIMITED SPACE FACTORY. Capacity of the crane is 10 TON, SPAN is 27.6 meter, 4x10 Ton Cranes for 125 meter bay. The space limit in the factory is 10.5 meters. There is a 9 meter steel post at the center of the factory (part of a machine). The crane...

Hey there! While considering going into foundational issues in QM (reading abou entanglement and Bell's theorems now), I realized I may need a better grasp of QM. I have studied both Griffiths' and Cohen-Tannoudji's (both volumes, excluding the appendices) books. I am not very confident in my...