I’ve purchased headphones in a foreign country and declared them when coming back. Do I have to re-declare them on subsequent trips?

A few months back I’ve purchased a set of expensive headphones in the US and dutifully declared them when coming back to Canada. Now I would like to travel to the US again and carry the same headphones in my backpack. When coming back to Canada, would I need to re-declare the item as technically it wasn’t purchased in Canada? If not, how do I prove that the headphones have already been imported to Canada and I don’t need to pay duty on them any longer?

If it matters, in the first trip I’ve verbally declared that I’m carrying the headphones when re-entering Canada by car and thus didn’t have to fill out a customs declaration. I did not pay any duty as I was below the duty free limit at that time.

In determining shape from line, what is special about the lines I’ve shown in these drawings by Ken Reid? [closed]

I’m interested in the way artists use lines to indicate shape in drawings. Strictly speaking, my question is about human vision — how our brains interpret certain lines — but I’m asking it here because those working in shape perception might be able to suggest an answer. It concerns what my visual system thinks it’s seeing in the arrowed parts of drawings such as these, and how this relates to the geometrical properties of the objects and their projection onto two dimensions:

Frame 2, row 2       Frame 1, row 3

Before continuing with the question, I should add that after I posted it, “D.W.” put it on hold without consulting me, on the grounds that it’s not about computer science. I refer him or her to http: //gfx.cs.princeton.edu/proj/ld3d/ , “Line Drawings of 3D Shapes”. To quote from the top of that page:

This site describes recent research on line drawings of 3D shapes, including studies on how artists create drawings and how people interpret drawings.

So far, this work involves two studies. The first, “Where Do People Draw Lines?,” investigates how artists’ drawings of 3D shapes correlate with the mathematical properties of the shapes, and known computer graphics line drawing techniques. The second, “How Well Do Line Drawings Depict Shape?,” examines how people interpret line drawings, both hand-drawn and computer-generated, and when depiction succeeds and fails.

Note the bit about how drawings correlate with the mathematical properties of the shapes drawn. This is related to the cues that humans and programs use to infer 3-d shape from 2-d projections, which in turn are related to the way that 3-d shapes look when projected onto 2-d surfaces. An excellent writeup of the latter topic is given in http: //www.gestaltrevision.be/pdfs/koenderink/Shape.pdf , “Shadows of Shape” by Jan Koenderink, a mathematician and psychologist known for his researches on visual perception, computer vision, and geometry. I hope what I’ve said in bold shows that my question is relevant to computing, but if not, D.W., please ask a computer-vision expert.

The drawings are by Ken Reid. He drew for the Beano and other comics, and was known for strips such as Frankie Stein, Queen of the Seas, and The Nervs. His faces were often grotesque, with protrusions such as chins and Adam’s apples standing out clearly despite being drawn with very few lines. There are examples of his work on Lew Stringer’s blog at http://lewstringer.blogspot.co.uk/2012/07/ken-reid-genius.html , and a copy of a The Nervs strip at http://1.bp.blogspot.com/_448y6kVhntg/RhIjT_1lF0I/AAAAAAAAA3I/KtvcxEIE3F8/s1600-h/nervs_pg1.jpg . What interests me is why the lines he drew are so effective. What is the visual system interpreting them as?

The images above are from the above-linked strip. In the first image, the back of the knee, there’s an upward-curving line above a short vertical above two downward-curving lines. The higher downward-curving line is presumably the contour of the lower leg. It’s less obvious what the downward-curving line below it is, or whether it corresponds to any physical feature. Nevertheless, it certainly helps in giving a sense of three-dimensional form.

Similarly, in the second image, some of the three upward-curving lines could be folds where the chin presses back against itself. But is the visual system interpreting them all as folds? I don’t know, but again, they readily give a sense of form. Another example is here, from the very first frame in that strip:

Frame 1, row 1

As I said at the start, those working in shape perception might have an answer. I’d also be interested to hear from anyone whose vision programs happen to fit Reid’s conventions so well that they can actually deduce from those drawings the shapes he intended.

By the way, I and other readers have noticed that Reid’s drawings seem very “intense”. As one reader commented in a blog, “they seem to enter the subconscious and stick there for the rest of your life”. Why? That’s probably outside the scope of computer vision, but not necessarily. It might be that some classes of line, e.g. closely-spaced lines curving around a cylinder, happen to affect us particularly strongly. So it would be useful to know if there’s something special about the geometry of Reid’s lines.

I’ve suddenly lost all my Gmail notes on my iMac Pro

I’ve suddenly lost all my Gmail notes on my iMac Pro. By lost, I mean I open the Apple notes app and see no items.

  • I lost them on my iPhone last week and was unable to find a good documented process to follow to fix – so the notes do not sync with my iPhone today.
  • I could still see them on my iMac Pro.

I decided to go and forward them to iCloud Note so I would never lose them again, [Here is the process I used to “forward them – please describe what you did or better – link to an online article explaining what process you followed]

Usually, they are in my email files (mail.app? A screenshot might help us help you here) and also show in the notes app.

How do I retrieve my critical Gmail notes?

[ Civic Participation ] Open Question : Among the prospective 2020 presidential candidates I’ve listed, who are you most likely to support and which ones would you approve of?

Joe Biden Michael Bloomberg Richard Blumenthal Cory Booker Sherrod Brown Steve Bullock Peter Buttigieg Julian Castro Mark Cuban Andrew Cuomo John Delaney Jeff Flake Tulsi Gabbard Eric Garcetti Kirsten Gillibrand Kamala Harris John Hickenlooper Eric Holder Jay Inslee Dwayne Johnson Tim Kaine John Kasich Joseph P. Kennedy III Amy Klobuchar Mitch Landrieu Terry McAuliffe Jeff Merkley Seth Moulton Richard Ojeda Martin O’Malley Beto O’Rourke Deval Patrick Tim Ryan Sheryl Sandberg Bernie Sanders Howard Schultz Tom Steyer Eric Swalwell Donald Trump Mark Warner Elizabeth Warren Mark Zuckerberg

How do I find a specific app’s location on my iPhone screen when I forget where I’ve put it?

I guess most people may have this question:

I have installed a LOT of apps on my iPhone. And I have put some of them in groups.

I can find any app by searching, but that’s only for using this app.

I would like to find the location of a specific app. It’s something like:

your “Facebook” app is located in the Group “Social” of your 5th screen.

Entering UK on Canadian passport when I’ve forgotten my EU passport

I am currently visiting my family in Canada. Normally I bring both my Italian and Canadian passports with me when I travel outside the EU, but this time I wasn’t thinking straight and brought only my Canadian passport with me. So when I re-enter the UK, I will only have my Canadian passport; when it comes time to explain to border control that I am re-entering the UK to continue my full-time job, I will not have my Italian passport with me to prove that I have the right to live and work in the UK.

What should I do? Should I explain to border control that I am an Italian citizen at the border, even though I don’t have the passport to prove it, or will this cause issues? I could see if I have any other documentation that indicates I am an Italian citizen. Also, I have a picture of my Italian passport photo page that I could show.

Shipping is calculated in checkout no postcode. I think I’ve figured out why

My shipping module is getting a postcode even though postcode is not set in the cart.

  • This is for a new cart created from an guest customer.
  • Magento 2.3/Ubuntu Server
  • All Magento Default Shipping Modules Disabled, Running Custom Module.

In my shipping module, using xdebug, I saw that:

$ request->getDestPostcode(); // Defaults to value from Tax Calculation in admin backend.

I’ve isolated this value to be from:

http://Base_url/admin/admin/system_config/edit/section/tax/ postcode set here

Can someone confirm/reproduce this? Github Issue #18630

Can I improve a suit of Adamantine Armor I’ve found to have a +2 AC magic bonus?

Is it possible to add extra AC onto “Adamantine Armor” that we find as treasure? As the Adamantine is uncommon, I would assume that the highest magical increase could be +2, making it Legendary.

I haven’t found much about how to craft magical items in 5e (I do understand why that is) or whether it’s possible to alter enchantments on existing items, so I thought I’d ask.