Follow Slashdot stories on Twitter

 


Forgot your password?
Close
typodupeerror

Comment Re:No shit (Score 2) 90

by dv82 (#65666470) Attached to: OpenAI Says Models Programmed To Make Stuff Up Instead of Admitting Ignorance

I recently gave AI's a paradox. When an ideal 10uF cap is charged to 100V, it has x charge, when an uncharged cap of 100uF is placed in parallel, the voltage goes to about 9.1V and the total energy is about 0.1x. If energy is neither destroyed nor created, where did the energy go? The AI kind of forgets that I specified an "ideal" capacitor, and makes shit up. If a human can explain this to me, I am all ears. Please keep in mind: "Ideal capacitor", and "equations show this", don't make shit up.

Consider the moment just before the two caps are connected to each other. One is charged to a nonzero voltage and the other is at zero. As the conductor attached to one capacitor top plate approaches the conductor attached to the other capacitor top plate (the bottom plates already sharing a common connection), the E field between them will at some point be high enough to exceed the breakdown field of the medium in between (even if it is free space). Then an arc occurs. That arc is observable, maybe even visibly. The "lost" energy radiates away as the electromagnetic energy associated with this arc.

Comment the role of a university? (Score 5, Insightful) 93

by dv82 (#64587513) Attached to: ChatGPT Outperforms Undergrads In Intro-Level Courses, Falls Short Later
"He said the role of a modern university is to prepare the students for their professional careers..." How sad. A university professor believes the university is a trade school, not a place to learn critical thinking and become educated enough to understand something of the ways of the world and one's place in it. So go ahead and simply teach the sheep AI so they can earn money and become good consumers.

Comment Re:the only people who thought that were (Score 1) 170

by dv82 (#62631018) Attached to: The Argument That Video Games Spur Mass Shootings Is Losing Steam
Isn't the type of gun to which young people have access more important than the absolute number of guns? Maybe kids 50 years ago had greater access to guns, but I doubt they had ready access to weapons that could fire so much ammunition so quickly. It's the number of rounds of ammunition, not the number of guns, that enables mass shootings.

Comment Re:Source to noise... (Score 1) 129

by dv82 (#59730912) Attached to: Activate this 'Bracelet of Silence,' and Alexa Can't Eavesdrop

The original article http://sandlab.cs.uchicago.edu... has some interesting graphs showing efficacy under certain situations. Looks like sometimes it can be fairly effective. What's missing are the frequency (ies) and sound energy the bracelet (transducers) puts out. Normal conversation is about 60 dB in amplitude. If you can get an SPL out of the transducers exceeding this, then the source (conversation) to noise (jamming) ratio will be low enough that the level will swamp the input of the listening device. The signal has to go through an A/D converter on the front end, and if you can get enough volume out of the jammer, that's all it will pick up. No amount of post filtering will make the signal intelligible.

Why is the mic picking up ultrasonics? In any case, to defeat this they could just put an analog low pass before the ADC. There should be one there already (the anti-aliasing filter for the ADC). Band-limiting the input to around 4kHz like POTS should do the trick. Not that I want this jammer to be defeated...

Comment Is this a technical forum? (Score 4, Insightful) 86

by dv82 (#53824657) Attached to: Sony's Latest Smartphone Camera Sensor Can Shoot At 1,000fps
"4-tier construction on the circuit section used to convert analog video signals to digital signals" ... Really, posting marketing non-information on Slashdot? Perhaps it's a parallel/pipelined A/D, judging form the application, performance and use of "tier". In any case, A/D converters have common specs, and if this one is special those specs would be of interest. Nerds don't have to be protected from "fancy camera talk".

Comment Shannon turning in his grave (Score 1) 146

by dv82 (#53822667) Attached to: Google Brain Creates Technology That Can Zoom In, Enhance Pixelated Images
The only reason this works as well as it does (poorly - 10% to 28% according to the post) is that humans are hard-wired to find faces among images. We'll accept anything with two small ovals on the same line with another shape roughly in the middle, below. Nose optional. Try the equivalent with random images or music, and I'll bet the success rate would drop to nil.

Comment Engineering Depts Subsidize the University (Score 1) 537

At a research universities, the overhead charged by the university on engineering research grants goes into a general fund that supports the other disciplines, directly or indirectly. The flow of cash is from engineering to the other programs, not vice versa. The university engineering school often also must pay the university liberal arts college based on enrollment of engineering undergrads in required courses taught in the liberal arts college (such as some basic math and science courses). The suggested tuition differential, if justified on the basis of costs to the various departments, would have to take into account these facts of university finance. It's not nearly as simple as suggested.
Education

Improving Education Through Social Gaming 44

Posted by Soulskill from the i'd-play-a-number-munchers-mmo dept.
A piece up at Mashable explores how some schools and universities are finding success at integrating social gaming into their education curriculum. Various game-related programs are getting assistance these days from sources like the government and the Bill & Melinda Gates Foundation. "For the less well-to-do educator, the Federation of American Scientists has developed a first-person shooter-inspired cellular biology curriculum. Gamers explore the fully-interactive 3D world of an ill patient and assist the immune system in fighting back a bacterial infection. Dr. Melanie Ann Stegman has been evaluating the educational impacts of the game and is optimistic about her preliminary findings. 'The amount of detail about proteins, chemical signals and gene regulation that these 15-year-olds were devouring was amazing. Their questions were insightful. I felt like I was having a discussion with scientist colleagues,' said Stegman. Perhaps more importantly, the video game excites students about science. Motivating more youngsters to adopt a science-related career track has became a major education initiative of the Obama administration. So desperate to find a solution that motivates students to become scientists, the government has even enlisted Darpa, the Department of Defense’s 'mad scientist' research organization, to figure out a solution."

Comment Re:LTSpice and SolveElec (Score 2, Insightful) 211

by dv82 (#28915223) Attached to: Cheap, Cross-Platform Electronic Circuit Simulation Software?
Thanks Vario ! I tried LTSpice on all three platforms (using stock WINE on Ubuntu and Crossover on Mac) and it works beautifully. In fact, it is easier to get up and running than OrCad in some ways, it has no net limits, and even does things OrCad can't (like print a schematic directly). The plotting tool accepts mathematical functions of time, node voltages, etc, so ideal and real results can be plotted simultaneously, just like OrCad. I will hand this over to a student for further testing, but from what I have seen, your suggestion has solved my problem.
Education

Submission + - Cross Platform Electronic Circuit Simulation

Submitted by
dv82
dv82 writes: "I teach circuits and electronics at the undergraduate level, and have been using the free student demo version of OrCad for schematic capture and simulation because (a) it comes with the textbook and (b) it's powerful enough for the job. Unfortunately OrCad runs only under Windows, and students increasingly are switching to Mac (and some Linux netbooks). Wine and its variants will not run OrCad, and I don't wish to require students to purchase Windows and run with a VM. The only production-quality cross-platform CAD tool I have found so far is McCad, but its demo version is so limited in total allowed nets that it can't even run a basic opamp circuit with a realistic 741 opamp model. gEDA is friendly to everything BUT Windows, and is nowhere near as refined as OrCad. I would like students to be able to run the software on their laptops without a network connection, which eliminates more options. Any suggestions?"

Slashdot Top Deals

If they can make penicillin out of moldy bread, they can sure make something out of you. -- Muhammad Ali

Close