On Tue, 29 Dec 2009 15:39:33 -0500, Jerry Avins <jya@ieee.org> wrote:>Muzaffer Kal wrote: >> On Tue, 29 Dec 2009 14:37:29 -0500, Jerry Avins <jya@ieee.org> wrote: >> >>> (I repeat: why are manhole covers round?) >> >> Doesn't that question assume all manhole covers are round? There are >> plenty of mhc which are square or rectangle (and some are hexagonal, >> star shaped etc.) > >Yes. What disadvantage do those have? Are they often found in street >accesses? Why [not]?I think your main reason would be that they can't fall in their own hole no matter how hard one tries. Another reason is that they're much easier to roll than the pointy ones which usually need to be lifted to be carried. -- Muzaffer Kal DSPIA INC. ASIC/FPGA Design Services http://www.dspia.com
Re: Convolution Tutorial
Started by ●December 29, 2009
Reply by ●December 29, 20092009-12-29
On Tue, 29 Dec 2009 15:39:33 -0500, Jerry Avins <jya@ieee.org> wrote:>Muzaffer Kal wrote: >> On Tue, 29 Dec 2009 14:37:29 -0500, Jerry Avins <jya@ieee.org> wrote: >> >>> (I repeat: why are manhole covers round?) >> >> Doesn't that question assume all manhole covers are round? There are >> plenty of mhc which are square or rectangle (and some are hexagonal, >> star shaped etc.) > >Yes. What disadvantage do those have? Are they often found in street >accesses? Why [not]?I think your main reason would be that they can't fall in their own hole no matter how hard one tries. Another reason is that they're much easier to roll than the pointy ones which usually need to be lifted to be carried. -- Muzaffer Kal DSPIA INC. ASIC/FPGA Design Services http://www.dspia.com
Reply by ●December 29, 20092009-12-29
Muzaffer Kal wrote:> On Tue, 29 Dec 2009 15:39:33 -0500, Jerry Avins <jya@ieee.org> wrote: > >> Muzaffer Kal wrote: >>> On Tue, 29 Dec 2009 14:37:29 -0500, Jerry Avins <jya@ieee.org> wrote: >>> >>>> (I repeat: why are manhole covers round?) >>> Doesn't that question assume all manhole covers are round? There are >>> plenty of mhc which are square or rectangle (and some are hexagonal, >>> star shaped etc.) >> Yes. What disadvantage do those have? Are they often found in street >> accesses? Why [not]? > > I think your main reason would be that they can't fall in their own > hole no matter how hard one tries. Another reason is that they're much > easier to roll than the pointy ones which usually need to be lifted to > be carried.Right on both counts. There is a minor manufacturability advantage, especially for the receiving surface. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 29, 20092009-12-29
Muzaffer Kal wrote:> On Tue, 29 Dec 2009 15:39:33 -0500, Jerry Avins <jya@ieee.org> wrote: > >> Muzaffer Kal wrote: >>> On Tue, 29 Dec 2009 14:37:29 -0500, Jerry Avins <jya@ieee.org> wrote: >>> >>>> (I repeat: why are manhole covers round?) >>> Doesn't that question assume all manhole covers are round? There are >>> plenty of mhc which are square or rectangle (and some are hexagonal, >>> star shaped etc.) >> Yes. What disadvantage do those have? Are they often found in street >> accesses? Why [not]? > > I think your main reason would be that they can't fall in their own > hole no matter how hard one tries. Another reason is that they're much > easier to roll than the pointy ones which usually need to be lifted to > be carried.Right on both counts. There is a minor manufacturability advantage, especially for the receiving surface. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 29, 20092009-12-29
Muzaffer Kal wrote:> On Tue, 29 Dec 2009 15:39:33 -0500, Jerry Avins <jya@ieee.org> wrote: > >> Muzaffer Kal wrote: >>> On Tue, 29 Dec 2009 14:37:29 -0500, Jerry Avins <jya@ieee.org> wrote: >>> >>>> (I repeat: why are manhole covers round?) >>> Doesn't that question assume all manhole covers are round? There are >>> plenty of mhc which are square or rectangle (and some are hexagonal, >>> star shaped etc.) >> Yes. What disadvantage do those have? Are they often found in street >> accesses? Why [not]? > > I think your main reason would be that they can't fall in their own > hole no matter how hard one tries. Another reason is that they're much > easier to roll than the pointy ones which usually need to be lifted to > be carried.Right on both counts. There is a minor manufacturability advantage, especially for the receiving surface. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 29, 20092009-12-29
Jerry Avins <jya@ieee.org> writes:> Randy Yates wrote: >> Jerry Avins <jya@ieee.org> writes: >> >>> Muzaffer Kal wrote: >>>> On Tue, 29 Dec 2009 15:39:33 -0500, Jerry Avins <jya@ieee.org> wrote: >>>> >>>>> Muzaffer Kal wrote: >>>>>> On Tue, 29 Dec 2009 14:37:29 -0500, Jerry Avins <jya@ieee.org> wrote: >>>>>> >>>>>>> (I repeat: why are manhole covers round?) >>>>>> Doesn't that question assume all manhole covers are round? There are >>>>>> plenty of mhc which are square or rectangle (and some are hexagonal, >>>>>> star shaped etc.) >>>>> Yes. What disadvantage do those have? Are they often found in >>>>> street accesses? Why [not]? >>>> I think your main reason would be that they can't fall in their own >>>> hole no matter how hard one tries. Another reason is that they're much >>>> easier to roll than the pointy ones which usually need to be lifted to >>>> be carried. >>> Right on both counts. There is a minor manufacturability advantage, >>> especially for the receiving surface. >> >> Doesn't a manhole cover have to have a lip? You can make a square cover >> that can't fall into its own hole: set >> >> L > ((sqrt(2) - 1) / 2) * d >> >> where d is the inside distance and L is the lip size. > > Cast iron is too brittle to allow large lips with reasonable > thickness.Well what about unreasonable thicknesses? The point is, it's not really the "can't fall through" argument, is it? The constraint is something else, like "too heavy" or "too expensive." -- Randy Yates % "She's sweet on Wagner-I think she'd die for Beethoven. Digital Signal Labs % She love the way Puccini lays down a tune, and mailto://yates@ieee.org % Verdi's always creepin' from her room." http://www.digitalsignallabs.com % "Rockaria", *A New World Record*, ELO
Reply by ●December 31, 20092009-12-31
Randy Yates wrote:> Jerry Avins <jya@ieee.org> writes: >> [...] >> Relying on a large brittle flange extending out from a stress raiser >> (abrupt change in section) is an engineering sin you wouldn't commit. > > So when you asked the question, "Why are manhole covers round?", you > expected the answer to be based on such knowledge of materials?The expected answer is "So they don't fall through." Knowledge of materials is needed only to deal with nitpicking. :-) This was dealt with here before. What I intended as an allusion became instead a discussion. Happy New Year! Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 31, 20092009-12-31
On Dec 31, 8:48�am, Jerry Avins <j...@ieee.org> wrote:>...> What I intended as an allusion became instead a discussion.that's what happened to this whole friggin' thread. note the Subject: header.> Happy New Year!i dunno. instead of seeing an Old Man 2009 going out and the Baby 2010 coming in, i think what i see is the Old Man holding a condom with attached label "2010". such as it is. Happy New Year (i'll be accompanying my kids to "Burlington First Night", also, coincidentally, i turn 54 tomorrow, big fat hairy deal.) r b-j
Reply by ●December 31, 20092009-12-31
Jerry Avins <jya@ieee.org> writes:> Randy Yates wrote: >> Jerry Avins <jya@ieee.org> writes: >>> [...] >>> Relying on a large brittle flange extending out from a stress raiser >>> (abrupt change in section) is an engineering sin you wouldn't commit. >> >> So when you asked the question, "Why are manhole covers round?", you >> expected the answer to be based on such knowledge of materials? > > The expected answer is "So they don't fall through." Knowledge of > materials is needed only to deal with nitpicking. :-) > > This was dealt with here before.I don't think it has yet been dealt with properly until now. See my recent (like, 2 minutes ago) post to Muzaffer Kal. -- Randy Yates % "She has an IQ of 1001, she has a jumpsuit Digital Signal Labs % on, and she's also a telephone." mailto://yates@ieee.org % http://www.digitalsignallabs.com % 'Yours Truly, 2095', *Time*, ELO
Reply by ●December 31, 20092009-12-31
On 12/31/2009 10:13 AM, robert bristow-johnson wrote:> On Dec 31, 8:48 am, Jerry Avins<j...@ieee.org> wrote: > ... >> What I intended as an allusion became instead a discussion. > > that's what happened to this whole friggin' thread. note the Subject: > header.It has, in fact, become convoluted.>> Happy New Year!Likewise to everybody!> i dunno. instead of seeing an Old Man 2009 going out and the Baby > 2010 coming in, i think what i see is the Old Man holding a condom > with attached label "2010". > > such as it is. Happy New Year (i'll be accompanying my kids to > "Burlington First Night", also, coincidentally, i turn 54 tomorrow, > big fat hairy deal.) > > r b-jHappy b-day, dood! -- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com
