Submitted by brad on Wed, 2013-05-08 13:37.
You’ve probably noticed that with many of our portable devices, especially phones and tablets, a large fraction of the size and weight are the battery. Battery technology keeps improving, and costs go down, and there are dreams of fancy new chemistries and even ultracapacitors, but this has become a dominant issue.
Every device seems to have a different battery. Industrial designers work very hard on the design of their devices, and they don’t want to be constrained by having to standardize the battery space. In many devices, they are even giving up the replaceable battery in the interests of good design. The existing standard battery sizes, such as the AA, AAA and even the AAAA and other less common sizes are just not suitable for a lot of our devices, and while cylindrical form factors make the most sense for many cell designs they don’t fit well in the design of small devices.
So what’s holding back a new generation of standardization in batteries? Is it the factors named above, the fact that tech is changing rapidly, or something else?
I would propose a small, thin modular battery that I would call the EStick, for energy stick. The smaller EStick sizes would be thin enough for cell phones. The goal would be to have more than one b-stick, or at least more than one battery in a typical device. Because of the packaging and connections, that would mean a modest reduction in battery capacity — normally a horrible idea — but some of the advantages might make it worth it.
There are several reasons to have multiple sticks or batteries in a device. In particular, you want the ability to quickly and easily swap at least one stick while the device is still operating, though it might switch to a lower power mode during the swap. The stick slot would have a spring loaded snap, as is common in many devices like cameras, though there may be desire for a door in addition.
Swapping presents the issue that not all the cells are at the same charge level and voltage. This is generally a bad thing, but modern voltage control electronics has reached the level where this should be possible with smaller and smaller electronics. It is possible with some devices to simply use one stick at a time, as long as that provides enough current. This uses up the battery lifetime faster, and means less capacity, but is simpler.
The quick hot swap offers the potential for indefinite battery life. In particular, it means that very small devices, such as wearable computers (watches, glasses and the like) could run a long time. They might run only 3-4 hours on a single stick, but a user could keep a supply of sticks in a pocket or bag to get arbitrary lifetime. Tiny devices that nobody would ever use because “that would only last 2 hours” could become practical.
While 2 or more sticks would be best for swap, a single stick and an internal battery or capacitor, combined with a sleep mode that can survive for 20-30 seconds without a battery could be OK. read more »
Submitted by brad on Thu, 2011-07-28 21:05.
This is a challenge to blog readers to come up with (or find examples in practice) of good systems to allocate students to parallel sessions based on their preferences. I’ve just concluded one round of this, and the bidding system I built worked OK, but is not perfect.
The problem: Around 80 students. On 10 days over 4 weeks they will be split into 3-5 different parallel sessions on those days. Many sessions have a cap on the number of students, and more students will have them as a 1st choice than can fit. Some sessions can take many students and won’t fill up. The students can express their preference as ranking, or with numeric values.
This is known in the literature as the Allocation problem, and there are various approaches, though none I found seemed to fit just right, either being easy to code or having existing running code. But I am keen on pointers.
- Maximize student satisfaction/minimize disappointment. Giving a student their 1st choice is good. Giving 3rd or 4th choices is bad.
- The system must be easy for the students to understand and use.
- Fairness. This has many meanings, but ideally mismatches that can’t be avoided should be distributed. If somebody gets a 4th choice one day, they perhaps should have a better shot at a 1st choice on another day.
- It’s nice if there’s a means of applying penalties to students who violate rules, sneak into sessions etc. Academic violations can result in less chance at getting your 1st choice.
- It should be flexible. Sessions may have to be changed or many not fully finalize until a week before the session.
- It is nice to handle quirks, like duplicated sessions a student takes only once, but where the student might have preferences for one of the instances over another. There may also be pre-requisites, so only students who take one session can have the sequel.
- Things change and manual tweaking can be advised.
Rank sessions in order, 1st come, 1st served
This was used in the prior year. Much like a traditional sign-up sheet in some ways, students could indicate their choices in order. If more students had a session as 1st choice than would fit, the ones who filled out their form first got in. This gave priority over all 10 days and so it was changed to rotate each week to distribute who was first in line. read more »
Submitted by brad on Mon, 2011-04-25 12:57.
I have written before about letting passengers pay for an empty middle seat next to them and recently about ANZ’s cuddle class and related programs which partially implement this.
While I believe airlines could sell the empty middle for somewhere in the range of 30-40% of a regular ticket, this still has issues. In particular, are they really going to bump a poor standby passenger who had a cancelled flight and make them stay another night so that people can get a more comfortable seat?
One idea is to allow the sale of empty middles by dutch auction. In effect this would say, “If there are going to be empty middles on this plane, those who bid the most will get to sit next to them.” If this can be done, it’s a goldmine of extra revenue for the airline. What they sell costs them nothing — they are just selling the distribution of passengers on the plane. If the plane fills up, however, they sell it all and nobody is charged.
The dutch auction approach would let each passenger make an offer. If there are 5 empty middles, then the 10 people who sit next to them win, but they all pay the 10th highest bid price. If only 9 passengers bid, the 10th highest price is zero, and everybody pays zero — which is what happens today, except it’s semi-random. While this may seem like a loss for the airline, many game theory tests suggest that dutch auctions often bring the best result, as they make both sides happy, and people bid more, knowing they will actually pay the fair price if they win.
(On the other hand, airlines are masters at having two people pay vastly different prices for exactly the same thing and have managed to avoid too much resentment over it.)
There is one huge problem to solve: How do you arrange that matched bidders are sitting together to share the empty middle? Each empty middle benefits two passengers. read more »
Submitted by brad on Tue, 2011-03-22 19:35.
In 2004, I described a system that would allow secure voting over an insecure internet and PC. Of late, I have been pondering the question of how to build a “turn-key democracy kit” — a suite of tools and services that could be used by a newly born democracy to smoothly create a new state. We’ve seen a surprising number of new states and revolutions in the last few years, and I expect we’ll see more.
One likely goal after any revolution is to quickly hold some sort of meaningful election so that it’s clear the new regime has popular support and is not just another autocracy replacing the old one. You don’t have time to elect a full government (and may not want to due to passions) but at some point you need some sort of government that is accountable to the people to oversee the transition to a stable democracy.
This may create a need for a quick, cheap, simple and reliable election. Even though I am generally quite opposed to the use of voting machines, particularly voting machines which only record results in digital form, there are a number of advantages to digital voting over cell phones and PCs in a new country, at least in a country that has a digital or mobile phone infrastructure established enough so that everybody, even if they don’t have a phone, knows someone who has one.
- In a new country, fresh out of autocracy, powerful forces will oppose the election. They will often try to prevent it or block voters.
- A common technique is intimidation, scaring people away from voting with threats of violence around polling places.
- The attacks against digital voting systems tend to require both sophistication and advanced planning.
- For a revolutionary election, the digital voting systems may well be brought in and operated by disinterested foreign parties, backed by the U.N. or other agencies.
- An electronic system is also immune to problems like boxes of ballots disappearing or being stuffed or altered.
It may be judged that the risks of corruption of a digital or partially digital election may be less than the risks of a traditional polling place election in a volatile area. It may also be hard to build and operate trustable polling places in remote locations, and do it quickly.
The big issue I see is maintaining secret ballot. It is difficult to protect secret ballot with remote voting, and much easier in polling-station voting. If secret ballot is not adequately protected, forces could use intimidation to make sure people vote the right way, or in some cases to buy votes. I am not sure I have a really good solution to this and welcome input; this is an idea in the making. read more »
Submitted by brad on Sat, 2010-11-20 13:58.
You’re driving down the road. You see another car on the road with you that has a problem. The lights are off and it’s dusk. There is something loose that may break off. There’s something left on the roof or the trunk is not closed — any number of things. How do you tell the driver that they need to stop and check? I’ve tried sometimes and they mostly think you are some sort of crazy, driving to close to them, waving at them, honking or shouting. Perhaps after a few people do it they figure it out.
We have a few signals. Oncoming cars flash lights on and off to warn you your lights are off. (Sometimes they are also warning of a speed trap.) High beams means, “I want to pass and you’re impeding the lane” and while many think that’s rude it’s better than tailgating.
We need a signal for “There is a problem with your car, you should check it out.” This signal should be taught in driving schools, and even be on the driving test. A publicity campaign should educate existing drivers.
One proposal that might make sense is the SCUBA signal for “I have a problem.” This is holding your hand flat, palm down, and wiggling it side to side (ie. rotating your wrist.) Then you point to the source of the problem, like your regulator or whatever. (There are specific SCUBA signals for well known problems, like being low on air, nitrogen narcosis etc.)
For this signal you would waggle the hand and then point at the place on the other person’s car. To those untrained, the signal often mean’s “dicey” or uncertain. Shaking of the head could also strengthen the signal.
Anybody have a better signal to propose?
Submitted by brad on Sun, 2010-11-14 16:47.
For many years I have had a popular article on what lenses to buy for a Canon DSLR. I shoot with Canon, but much of the advice is universal, so I am translating the article into Nikon.
If you shoot Nikon and are familiar with a variety of lenses for them, I would appreciate your comments. At the start of the article I indicate the main questions I would like people’s opinions on, such as moderately priced wide angle lenses, as well as regular zooms.
If you “got a Nikon camera and love to take photographs” please read the article on what lens to buy for your Nikon DSLR and leave comments here or send them by email to firstname.lastname@example.org. I’m also interested in lists of “what’s in your kit” today.
Submitted by brad on Sat, 2010-01-02 14:10.
I have the photo archives of a theatre company I was involved with for 12 years. It is coming upon its 50th anniversary. I have a high speed automatic scanner, so I am going to generate scans of many of the photos — that part is not too hard.
Even easier for modern groups in the digital age, where the photos are already digital and date-tagged.
But now I want members of the group to be able to rotate the photos, tag them with the names of people in them and other tags, group them into folders where needed, and add comments. I can’t do this on my own, it is a collaborative project.
Lots of photo sharing sites let other people add comments. Few sites let you add tags or let trusted other people do things like rotations. Flickr lets others draw annotations and add tags/people which would make it a likely choice, but they can’t rotate.
Facebook has an interesting set of features. It’s easy to tag photos with friends’ names, and they get notified of it and the photos appear on their page, which is both good and bad. (The need for the owner to approve is a burden here.) Tagging non-friends is annoying because when somebody adds a real friend tag you must delete the old one, and the old ones may be spelled differently. However, the real deal-breaker on facebook is that the resolution is unacceptably small.
The recent killer feature I really want is face recognition, which makes tagging with people’s names vastly easier. Even the fact that it auto-draws boxes around the faces for you to tag is a win even without the recognition feature. The algorithms are far from perfect but they speed up the task a great deal. As such, right now an obvious choice is Picasa and Picasa Web Albums. however, while PWA lets you allow others to upload photos to your albums and tag their own photos, they can’t tag yours.
There is also face recognition in iPhoto, but I am not a Mac user so I don’t know if that can meet this need.
So right now two choices seem to be Flickr (but I must do all rotates) or a newly created Picasa account to which the password is shared. That’s a bit of a kludge but it seems to be the only way to get shared face recognition tagging.
Facebook can be integrated with a face recognizer called “Polar Rose” which also works with the 23hq photo sharing site. However, Facebook’s resolution is way, way too small and you need to approve tags.
I have not tried all the photo sharing sites so I wonder if people know of one that can do what I want?
Submitted by brad on Sat, 2009-12-12 22:18.
It’s now becoming common to kludge a conference “backchannel” onto Twitter. I am quite ambivalent about this. I don’t think Twitter works nearly as well as an internal backchannel, even though there are some very nice and fancy twitter clients to help make this look nicer.
But the real problem comes from the public/private confusion. Tweets are (generally) public, and even if tagged by a hashtag to be seen by those tracking an event, they are also seen by your regular followers. This has the following consequences, good and bad.
- Some people tweet a lot while in a conference. They use it as a backchannel. That’s overwhelming to their followers who are not at the conference, and it fills up the feed.
- When multiple people do it, it’s almost like a spam. I believe that conferences like using Twitter as backchannel because it causes constant mentions of their conference to be broadcast out into the world.
- While you can filter out a hashtag in many twitter clients, it’s work to do so, and the general flooding of the feed is annoying to many.
- People tweeting at a conference are never sure about who they are talking to. Some tweets will clearly be aimed at fellow conference attendees. But many are just repeats of salient lines said on stage, aimed only at the outsiders.
- While you can use multiple tags and filters to divide up different concurrent sessions of a conference, this doesn’t work well.
- The interface on Twitter is kludged on, and poor.
- Twitter’s 140 character limit is a burden on backchannel. Backchannel comments are inherently short, and no fixed limit is needed on them. Sure, sometimes you go longer but never much longer.
- The Twitter limit forces URLs to be put into URL shorteners, which obscure where they go and are generally a bane of the world.
Dedicated backchannels are better, I think. They don’t reach the outside world unless the outsiders decide to subscribe to them, but I think that’s a plus. I think the right answer is a dedicated, internal-only backchannel, combined with a minimal amount of tweeting to the public (not the meeting audience) for those who want to give their followers some snippets of the conferences their friends are going to. The public tweets may not use a hashtag at all, or a different one from the “official” backchannel as they are not meant for people at the conference.
The most common dedicated backchannel tool is IRC. While IRC has its flaws, it is much better at many things than any of the web applications I have seen for backchannel. It’s faster and has a wide variety of clients available to use with it. While this is rarely done, it is also possible for conferences to put an IRC server on their own LAN so the backchannel is entirely local, and even keeps working when the connection to the outside world gets congested, as is common on conference LANs. I’m not saying IRC is ideal, but until something better comes along, it works. Due to the speed, IRC backchannels tend to be much more rapid fire, with dialog, jokes, questions and answers. Some might view this as a bug, and there are arguments that slowing things down is good, but Twitter is not the way to attain that.
However, we won’t stop those who like to do it via Twitter. As noted, conferences like it because it spams the tweetsphere with mentions of their event.
I would love to see an IRC Bot designed to gateway with the Twitter world. Here are some of the features it might have. read more »
Submitted by brad on Wed, 2009-09-16 13:05.
Two years ago, I discussed solutions for Burning Man Exodus. The problem: Get 45,000 people off the playa in 2 days, 95% of them taking a single highway south which goes through a small town which has a chokepoint capacity of about 450 cars/hour. Quite often wait times to get onto the road are 4 hours or more, though this year things were smoother (perhaps due to a lower attendance) and the number of people with 4 hour waits was lower. In a bad year, we might imagine that 25,000 people wait an average of 3 hours, or 75,000 person hours, almost 40 man-years of human labour.
Some judge my prior solution, with appointments, as too complex. Let’s try something which is perhaps simpler, at least at its base, though I have also thought up some complexities that may have value.
When you are ready to leave, drive to the gate. There, as was tried in 2,000, you would be directed into a waiting lot, shaped with cones at the front. The lot would have perhaps 20 rows of 10 cars (around 150 vehicles as there are so many trailers and RVs.) The lot would have a big number displayed. There you would park. You would then have three options:
- Stay in the lot and party with the other people in the lot, or sit in your car. This is in fact what you would do in the current situation, except there you start your engine and go forward 30 feet every minute. Share leftover food. Give donations to DPW crew. Have a good time.
- Go to the exodus station near the parking lots. Get a padded envelope and write your address on it, and your plate number, DL number and car description. Put your spare set of keys in the envelope. Get on your bike, or walk back to the city, and have a good time there. Listen to Exodus Radio. They will give reports on when your lot is going to move, in particular a 30 minute warning. When you get it, go back, pick up your keys and get ready.
- Volunteer to help with city cleanup. Do that by driving to the premium section of the waiting lot. Park there, wait a bit, and then get on a bus which takes you somewhere to do an hour shift of clean-up. You moop check the playa, clean, take down infrastructure, or spend an hour doing Exodus work which you trained for earlier. At the end of your shift, you are free to take a bus back to the lot, or wait in the city with friends. Listen to Exodus Radio. They will call your premium lot. It will be called well before the regular lot. Ideally give an hour, gain an hour! Get there and be ready.
When your lot is called, the Exodus worker pulls back the cones and the lanes stream out, non-stop (but still 10mph) off the playa. The road does not have to be lengthened to hold more cars. At the blacktop entrance, an Exodus worker with a temporary traffic light has it set to a green left arrow except when other traffic is coming, when it’s red. You turn without hesitation (people do that on green arrows, but slow down for flag workers.) Off you go.
As noted, it seems a good idea that people who want to leave the lot leave a set of keys. Not their only set — it is foolish to bring only one set to the playa anyway, and if you read the instructions you knew this. This allows exodus workers to easily move vehicles for people who don’t return, and there will be some. Even so the lots should be designed so it’s not hard to get around them. If the first lane has a spare lane to the other direction that works. It does require somebody to hand back the keys. If you read the instructions, they will say to bring photos of yourself (and alternate drivers.) Tape that photo to the key envelope and it makes it very quick and easy for the key wrangler to hand you the right keys. Don’t bring a photo and they must confirm a DL number, which they won’t have time to do if time is short — so get there in plenty of time.
If you don’t get there in time to get your keys, you can wait, or you can pay $10 (or whatever it costs) and the BM Org will mail you the keys after the event. Of course with rental vehicles this is not an option, so be there early.
However, it may also be simpler to not do the key system, and tow people who don’t show up, and charge them a fat fee for that. Or tow those who don’t leave a key. People might leave a fake key, which would result in a tow and an even larger fine, perhaps. As such I am not wedded to the key desk idea and it may be simpler to first see if no-shows are a big problem. No-shows can be punished in lots of ways if they signed a contract before leaving.
There is an issue for people who do volunteer work and then head for the city. They need to have left keys before the volunteer shift, or return to the lot to leave them, or not leave them and risk a tow.
Volunteers would get a leader who directs them what they will be doing. A common task will be doing a playa walk/MOOP sweep. The leader will listen to Exodus Radio and know if things move quickly and the volunteers must return. Normally, however, volunteer shifts would be taken only when the line is very long, much longer than a volunteer shift. People can of course offer to do more than one shift when the line is long but in that case they should bring their own portable radio, just as people who leave the lot should bring one or be near one. The shift leaders could also have a radio on loud enough for all to hear, hopefully the DJ will be doing something fun between exodus lot announcements.
As noted, one of the things people can volunteer for is exodus work itself. The offer of early exodus in exchange for an hour of exodus work assures there can never be a shortage of workers as long as there is a base of workers that does it without that reward. You’re helping the people ahead of you in line get out earlier. However, regular (non-leaving) volunteers are needed for when the line is short and first bunches up, and for when it shortens again.
To do exodus work you would have to attend training in advance, and be certified as able to do it. Probably done in SF, but possibly on-playa. Some other volunteer jobs (such as cleanup crew leader) would require some training and approval.
Staff needed are
- An exodus DJ (in a tower overlooking the line and the lots) with assistant or two who are controlling the whole operation.
- Flag worker controlling the traffic light at the blacktop. Possibly others in Gerlach.
- 2 crews of 1-2 workers directing cars into the lot currently filling up. They also prepare the lot, replacing the exit cones and possibly moving no-show cars to the side. May have a golf cart.
- 1-2 workers diverting cars from the main exit lane merge (the “fallopian tubes”) to the staging lots when needed. A cop would be very handy here.
- 1 worker to remove the cones at the lot being emptied and wave cars out of it. (The Exodus DJ is also telling those people to get going.) When only one lane is left, this person moves to the next lot. Worker probably has a scooter or golf cart.
- 1-2 workers to man the key desk.
The police come in huge numbers and spend a lot of time on victimless crimes. Managing traffic is a a great way to make really effective use of their police powers. Police can be there to deal with people who ignore signs, bypass or cut out of lots, or who leave their car without doing a key drop or contract.
How to start the lots
It is an interesting problem how to start the lots close to the city. Initially the volume is low and people exit directly, and will tend to go in multiple
lanes without a lot of work, eager as faster vehicles will be to pass slow ones. Eventually they will bunch up at the forced merge, and then the bunch up will spread backwards, traffic-jam style. However, this is taking place three miles from the city, at least 15 minutes drive at 10mph. There is a magic amount of back-up at which point you should start holding cars, and then a point at which you should release a lot full of them. Fortunately any short gaps you put in the stream are not wasted as they are re-smoothed on the blacktop before Gerlach-Empire, which is believed to be the primary choke point. However, it will take experience to learn the exact right times, so the first year will not do as well as later years. Data has been kept on car counts from the past, presumably broken down by hour, which could help.
Submitted by brad on Fri, 2008-02-15 02:12.
I’ve read studies that say that “chocolate” is the world’s favourite flavour. That’s not too surprising. Coming from central America after the Spanish conquest, the candy at least quickly was adopted all over Europe and to a lesser degree elsewhere. So did many other new world ingredients, such as corn, beans, squash, chiles, potatoes, vanilla, tomatoes, peanuts and many others. And we’ve seen many of these become common, and even essential ingredients in many overseas cuisines. (I often wonder what Italian meals were like before pasta came from China and tomatoes from the americas!)
But oddly, the tastiest and most complex of the ingredients never got exported in any significant way for savoury cooking. You can find excellent cocao based mole sauces in Mexican and southwest cuisine, but this is to be expected, as the ingredients come from there. Those dishes are centuries old. And if they didn’t exist one might conclude that chocolate only works as a sweet. But it doesn’t. So why did the talented chefs of Europe, India, China, Japan and other places never develop a popular dish with this ingredient, when they did so much with the other new ingredients? I say popular because there certainly are dishes, but they are by and large obscure. Just about every culture has a range of well known potato and tomato dishes, for example.
I’ll presume it’s different. But modern fusion chefs, with fancy tools, knowledge of chemistry and the world’s ingredients should be able to do it. Not just come up with dishes, but come up with something both tasty and simple enough to spread as a popular choice. Though for now we won’t feel too bad having to limit ourselves to French hot chocolate and Belgian truffles.
Submitted by brad on Wed, 2007-11-07 12:20.
I’ve accumulated tons of paper, and automated scanner technology keeps getting better and better. I’m thinking about creating a “Scanner club.” This club would purchase a high-end document scanner, ideally used on eBay. This would be combined with other needed tools such as a paper cutter able to remove the spines off bound documents (and even less-loved books) and possibly a dedicated computer. Then members of the club would each get a week with the scanner to do their documents, and at the end of that period, it would be re-sold on eBay, ie. a “ReBay.” The cost, divided up among members, should be modest. Alternately the scanner could be kept and time-shared among members from then on.
A number of people I have spoken to are interested, so recruiting enough members is no issue. The question is, what scanner to get? Document scanners can range from $500 for a “workgroup” scanner to anywhere from $1,500 to $10,000 for a “production” scanner. (There are also $100,000 scanning-house scanners that are beyond the budget. The $500 units are not worth sharing and are more modest in ability.
My question is, what scanner to get? As you go up in price, the main thing that changes is speed in pages per minute. That’s useful, but for private users not the most important attribute. (What may make it important is that if you need to monitor the scanning job to fix jams or re-feed. Then speed makes a big difference.)
To my mind the most important feature is how automatic the process is — can you put in a big stack of papers and come back later? This means a scanner which is very good at not jamming or double-feeding, and which handles papers of different sizes and thicknesses, and can tolerate papers that have been folded. My readings of reviews and spec sheets show many scanners that are good at detecting double feeds (the scanner grabs two sheets) as well as detecting staples, but the result is to stop and fix by hand. But what scanners require the least fixing-by-hand in the first place?
All the higher end units scan both sides in the same pass. Older ones may not do colour. Other things you get as you pay more will be:
- Bigger input hoppers — up to around 500 sheets at a time. This seems very useful.
- Higher daily duty cycles, for all-day scanning.
- Staple detectors (stops scan) and ultrasonic double feed detectors (also stop scan.)
- Better, fancier OCR (generating searchable PDFs) including OCR right in the hardware.
- Automatic orientation detection
- Ability to handle business cards. Stack up all those old business cards!
- The VRS software system, a high end tool which figures out if the document needs colour, grayscale or threshold, discards blank pages or blank backs and so on.
- In a few cases, a CD-burner so can be used without computer.
- Buttons to label “who” a document is being scanned for (can double as classification buttons.)
- Ability to scan larger documents. (Most high-end seem to do 11” wide which is enough for me.)
One thing I haven’t seen a lot of talk about is easy tools to classify documents, notably if you put several documents in a stack. At a minimum if would be nice if the units recognized a “divider page” which could be a piece of coloured paper or a piece of paper with a special symbol on it which means “start new document.” One could then handwrite text on this page to have it as a cover page for later classification at the computer, or if neatly printed, OCR is not out of the question. But even just a sure-fire way to divide up the documents makes sense here. Comments suggest such tools are common.
It may be that the most workable solution is to hire teen-agers or similar to operate the scanner, fix jams and feed and classify documents. At the speeds of these scanners (as much as 100 pages/minute for the higher end) it seems there will be something to do very often.
Anyway, anybody have experience with some of the major models and comments on which are best? The major vendors include Canon, Xerox Documate/Visioneer, Fujitsu, Kodak, Bell and Howell and Panasonic.
Submitted by brad on Mon, 2007-10-15 16:59.
You may have heard about a technique which makes ice in an otherwise warm desert when the skies are clear at night. Dig a pit, insulate it (in olden days this was done with straw by Romans and other biblical folk) and expose it to the open, clear sky at night. During the day, cover it with reflective and insulating material. The open night sky is very cold, and energy will radiate out to it. In addition, in the low humidity, evaporation chills the water. It need not be a pit, it can be an insulated tube with high walls.
I haven't had a lot of luck finding articles about the numbers on this process, and I presume it's not particularly efficient. But I started asking, could you do it with seawater? Seawater freezes at a few degrees colder than fresh, but most importantly, the ice itself is fresh, and if extracted will have minimal salt. Ice of course floats on brine as it does on fresh water, and if the brine tank is deep enough, you won't increase the concentration of salt a great deal before you remove the ice and replace the brine (though a heat exchanger, of course.)
Most people are interested in the ice because it's cold, but it may be just as valuable because it's not brine, in areas of the world where fresh water is scarce but arid land and clear night skies are plentiful. In these areas, desalination is done with power-intensive means such as distillation and reverse osmosis, so this method need only be more efficient than these to work. The "cost" of this method, if it works, would be the insulated pits themselves, with plumbing, pumping the brine around from the sea, and mechanisms for covering the pits and extracting the ice. The infrastructure cost is high but the energy cost may be low, if we don't have to move the brine very far.
As for the ice, it could of course be sold as ice first, to be used for refrigeration, and then as irrigation water once melted. Or it could be melted in a heat exchanger with incoming brine to keep the brine pits ice-cold and working well. Then, after melting it could be used for irrigation or depending on circumstances, for washing or even drinking.
What I don't know is whether this even works OK on brine, and if it's so inefficient that you use an acre to only get a modest number of gallons, or that even the modest pumping and mechanical needs don't justify the water you get. Should it work, it could be very useful. After all, it seems we get a lot of wars caused by people fighting over water in the desert.
Submitted by brad on Fri, 2007-10-05 19:14.
The growing social network systems, notably Facebook and LinkedIn, have become better and better places to find old friends. And we're also seeing people search engines, such as zabasearch and the new spock.com to look through databases. If you're determined, you can find many folks.
Facebook lets users develop applications, but one I have in mind would not work as a developed app, since it requires access to people who have not installed the app. Right now on Facebook, you can type in a name and see all the people with that name (and variants) as well as their picture. You see their networks which sometimes tells you where they live, what school they went to and perhaps where they work. In theory you can't see anything else, including useful stuff like their age. You can, however, see their list of friends in most cases.
Often you will find many people with the same name, and this will only get worse as the systems get bigger. If a name is common it can make the search very difficult. Facebook uses an algorithm to put your likely hit near the top (it seems to be people with things in common with you, like locations, hometowns, etc.) which is a very good idea, but even so, you can still be in the dark, especially if the picture thumbnail makes it hard to see the face, or it's been 20 years.
You don't learn things like their age or hometown directly, which would be a privacy violation. You can often guess it by looking at the list of friends -- if they have only young friends still in school, they are probably young. If many of their friends are older, they probably are too. If many of their friends are from a town, they probably lived in that town or still do.
So you may end up sending a blind E-mail saying, "Are you the Fred Jones who went to Valley High?" But if the number of matches are too high that doesn't work either.
What would be nice would be a way to specify you are looking for a person with a given name, and to provide other data like their age and perhaps school. Then, all the people who match that would get a notification with the brief query. This would not be a full blown e-mail, they would just see a notice that somebody is looking for "the Fred Jones born around 1965 who went to Comdex." and if they were that Jones they could follow-up on it (or ignore) and if they weren't they would not see it again and could block seeing any further notes like this.
However, the real gold would come if the query could be stored, so that every new Fred Jones who joins sees that, and perhaps finds people already waiting to reconnect.
Key here is that while it would be a privacy violation to let me search for "The Fred Jones born around 1965" because multiple queries would let you pull out the person's age (which they have hidden from strangers or even friends) it is not so much a problem to present the searches to the people and let them decide if they want to respond.
You tune it so you would hopefully be less bothered by these queries than you would be the direct "are you the..." queries you would get. Of course, the more tuning information both parties give, the fewer people to get a notice. In fact, you could require the searcher to come up with something that only notifies fewer than some set number of people. So if there are 300 Fred Jones, you can't bug them all, but you could make the query of the 10 who are closest in age to a given year, for example. There are ways to game this a bit to search for private info, but it's harder, and users who respond can be notified about what they will be confirming by responding.
The "search for new users matching a name" query could be a Facebook app, but the above could not be, unless it were an app only for those who want enough to be found this way that they install it. But the main goal is to find people who don't realize they are being looked for.
LinkedIn is better at qualified queries, but doesn't let you email the people who match, except for money.
Submitted by brad on Wed, 2007-09-05 15:20.
I’ve created a new blog category “Burning Man” to track my posts on the event. I was using a simpler tag before.
Today I want to talk about the Burning Man Exodus problem, a problem you might find interesting even if you don’t come to Burning Man. This year, even at 8pm Monday there was a long line and a 2 hour wait to get off the playa. Normally by about 5pm there is no wait. With 45,000 or more this year, and I presume at least 15,000 to 20,000 vehicles, and various chokepoints limiting traffic to 450 cars/hour, how do you drain the playa when everybody wants to go Sunday and Monday. (In addition, with so many now leaving Sunday, it makes Monday less interesting driving some who could leave Monday to leave earlier.)
It has now been routine to see waits of 5 hours or more at the peak times. I believe a solution should be possible involving some sort of appointment system, where cars are given a set time to leave, and they leave then. If they want to go at a peak time, instead of waiting 5 hours in line, they spend 5 hours in the city, or doing more cleanup, instead of idling their car in a giant line. Not that the line doesn’t become a little bit of a party, but it’s still not like being in camp. And for my exodus on Monday night there as the worst dust storm ever for Exodus, you could not see the car in front of you, or the fence beside you.
However, a good system to hand out appointments is hard to design. First of all, we have a mostly volunteer crew, and they don’t have much law enforcement power to stop violators or ticket them. (More participation by the police in this, when the city truly needs them, instead of having them be there for pot busts that nobody wants would be a great thing.)
Here are some of the constraints: read more »
Submitted by brad on Sat, 2007-06-23 14:16.
At the recent Supernova 2007 conference, they did a session where startups presented, and to mix things up, at the end they told us that one of the companies was fake. Most people clued in, because the presentation had been funny, and had a few obvious business mistakes, but at the same time many commented that it was chosen well, because they would like it to exist. The fake company, ZapMeals claimed it would let you order delivered food from quality at-home chefs and caterers, with a reputation system that helped you choose them by quality. GPS-enabled delivery companies would show you where your meal was as it drove to your home. read more »
Submitted by brad on Thu, 2007-01-18 20:19.
(Note I have a simpler article for those just looking for advice on how to get their Widescreen TV to display properly.)
Very commonly today I see widescreen TVs being installed, both HDTV and normal. Flat panel TVs are a big win in public places since they don’t have the bulk and weight of the older ones, so this is no surprise, even in SDTV. And they are usually made widescreen, which is great.
Yet almost all the time, I see them configured so they take standard def TV programs, which are made for a 4:3 aspect ratio, and stretch them to fill the 16:9 screen. As a result everybody looks a bit fat. The last few hotel rooms I have stayed in have had widescreen TVs configured like this. Hotel TVs disable you from getting at the setup mode, offering a remote control which includes the special hotel menus and pay-per-view movie rentals. So you can’t change it. I’ve called down to the desk to get somebody to fix the TV and they often don’t know what I’m talking about, or if somebody comes it takes quite a while to get somebody who understands it.
This is probably because I routinely meet people who claim they want to set their TV this way. They just “don’t like” having the blank bars on either side of the 4:3 picture that you get on a widescreen TV. They say they would rather see a distorted picture than see those bars. Perhaps they feel cheated that they aren’t getting to use all of their screen. (Do they feel cheated with a letterbox movie on a 4:3 TV?)
It is presumably for those people that the TVs are set this way. For broadcast signals, a TV should be able to figure out the aspect ratio. NTSC broadcasts are all in 4:3, though some are letterboxed inside the 4:3 which may call for doing a “zoom” to expand the inner box to fill the screen, but never a “stretch” which makes everybody fat. HDTV broadcasts are all natively in widescreen, and just about all TVs will detect that and handle it. (All U.S. stations that are HD always broadcast in the same resolution, and “upconvert” their standard 4:3 programs to the HD resolution, placing black “pillarbox” bars on the left and right. Sometimes you will see a program made for SDTV letterbox on such a channel, and in that case a zoom is called for.)
The only purpose the “stretch” function has is for special video sources like DVD players. Today, almost all widescreen DVDs use the superior “anamorphic” widescreen method, where the full DVD frame is used, as it is for 4:3 or “full frame” DVDs. Because TVs have no way to tell DVD players what shape they are, and DVD players have no way to tell TVs whether the movie is widescreen or 4:3, you need to tell one or both of them about the arrangement. That’s a bit messy. If you tell a modern DVD player what shape TV you have, it will do OK because it knows what type of DVD it is. DVD players, presented with a widescreen movie and a 4:3 TV will letterbox the movie. However, if you have a DVD player that doesn’t know what type of TV it is connected to, and you play a DVD, you have to tell the TV to stretch or pillarbox. This is why the option to stretch is there in the first place.
However, now that it’s there, people are using it in really crazy ways. I would personally disable stretch mode when playing from a source known not to be a direct video input video player, but as I said people are actually asking for the image to be incorrectly stretched to avoid seeing the bars.
So what can we do to stop this, and to get the hotels and public TVs to be set right, aside from complaining? Would it make sense to create “cute” pillarbars perhaps with the image of an old CRT TV’s sides in them? Since HDTVs have tons of resolution, they could even draw the top and bottom at a slight cost of screen size, but not of resolution. Some TVs offer the option of gray, black and white pillars, but perhaps they can make pillars that somehow match the TV’s frame in a convincing way, and the frame could even be designed to blend with the pillars.
Would putting up fake drapes do the job? In the old days of the cinema, movies came in different widths sometimes, and the drapes would be drawn in to cover the left and right of the screen if the image was going to be 4:3 or something not as wide. They were presumably trying to deal with the psychological problem people have with pillarbars.
Or do we have to go so far as to offer physical drapes or slats which are pulled in by motors, or even manually? The whole point of flatscreen TVs is we don’t have a lot of room to do something like this, which is why it’s better if virtual. And of course it’s crazy to spend the money such things would cost, especially if motorized, to make people feel better about pillarbars.
I should also note that most TVs have a “zoom” mode, designed to take shows that end up both letterboxed and pillarbarred and zoom them to properly fit the screen. That’s a useful feature to have — but I also see it being used on 4:3 content to get rid of the pillarbars. In this case at least the image isn’t stretched, but it does crop off the top and bottom of the image. Some programs can tolerate this fine (most TV broadcasts expect significant overscan, meaning that the edges will
be behind the frame of the TV) but of course on others it’s just as crazy as stretching. I welcome other ideas.
Update: Is it getting worse, rather than better? I recently flew on Virgin America airlines, which has widescreen displays on the back of each seat. They offer you movies (for $8) and live satellite TV. The TV is stretched! No setting box to change it, though if you go to their “TV chat room” you will see it in proper aspect, at 1/3 the size. I presume the movies are widescreen at least.
Submitted by brad on Fri, 2006-11-17 16:43.
Differential pricing occurs when a company attempts to charge different prices to two different customers for what is essentially the same product. One place we all encounter it a lot is air travel, where it seems no two passengers paid the same price for their tickets on any given flight. You also see it in things like one of my phones, which has 4 line buttons but only 2 work — I must pay $30 for a code to enable the other 2 buttons.
The public tends to hate differential pricing, though in truth we should only hate it when it makes us pay more. Clearly some of the time we’re paying less than we might pay if differential pricing were not possible or illegal.
So even if differential pricing is neutral, one can rail if it punishes/overcharges the wrong thing. There might be a better way to get at the vendor’s goal of charging each customer the most they will tolerate — hopefully subject to competition. Competition makes differential pricing complex, as it’s only stable if all competitors use roughly the same strategy.
In air travel, the prevailing wisdom has been that business travellers will tolerate higher ticket prices than vacation travellers, and so most of the very complex pricing rules in that field are based on that philosophy. Business travellers don’t want to stay over weekends, they like to change their flights, they want to fly a combination of one-way trips and they want to book flights at short notice. (They also like to fly business class.) All these things cost a lot more in the current regime.
Because of this, almost all the travel industry has put a giant surcharge on flexibility. It makes sense that it might cost a bit more — it’s much easier to schedule your airline or hotel if people will book well in advance and keep to their booking — but it seems as though the surcharge has gotten immense, where flexible travel can cost 2 to 4 times what rigidly scheduled travel costs.
Missing the last flight of the day can be wallet-breaking. Indeed, there are many arguments that since an empty seat or hotel room is largely wasted, vendors might be encouraged to provide cheaper tickets to those coming in at the last minute, rather than the most expensive. (And sometimes they do. In the old days flying standby was the cheapest way to fly, suitable only for students or the poor. There are vendors that sell cheap last minute trips.)
Vendors have shied away from selling cheap last-minute travel because they don’t want customers to find it reliable enough to depend on. But otherwise it makes a lot of sense.
So my “Solve this” problem is to come up with schemes that still charge people as much as they will tolerate, but don’t punish travel flexiblity as much.
One idea is to come up with negative features for cheap tickets that flexible, non-business travellers will tolerate but serious business travellers and wealthy travellers will not. For example, tickets might come with a significant (perhaps 10-20%) chance of being bumped, ideally with sufficient advance notice by cell phone that you don’t waste time going to the airport. For example, the airline might sell a cheap ticket but effectively treat the seat as available for sale again to a higher-paying passenger if they should come along. You might learn the morning of your trip that somebody else bought your seat, and that you’ll be going on a different flight or even the next day. They would put a cap on how much they could delay you, and that cap might change the price of your ticket.
For a person with a flexible work schedule (like a consultant) or the retired, they might well not care much about exactly what day they get back home. They might like the option to visit a place until they feel like returning, with the ability to get a ticket then, but the risk that it might not be possible for a day or two more. Few business travellers would buy such a ticket.
Such tickets would be of most value to those with flexible accomodations, who are staying with friends and family, for example, or in flexible hotels. Rental cars tend to be fairly flexible.
Of course, if you’re willing to be bumped right at the airport, that should given you an even cheaper ticket, but that’s quite a burden. And with today’s ubiquitous cell phones and computer systems there’s little reason not to inform people well in advance.
This technique could even provide cheaper first-class. You might buy a ticket at a lower price, a bit above coach, that gets you a first class seat half the time but half the time puts you in coach because somebody willing to pay the real price of first class bought a ticket. (To some extent, the upgrade system, where upgrades are released at boarding time based on how many showed up for first class, does something like this.)
Any other ideas how airlines could provide cheaper flexible tickets without eating into their business flyer market? If only one airline tries a new idea, you get an interesting pattern where everybody who likes the new fare rules switches over to that airline in the competitive market, and the idea is forced to spread.
Added note: In order to maintain most of their differential pricing schemes today, airlines need and want the photo-ID requirement for flying. If tickets (including tickets to half a return trip) could be easily resold on the web to anybody, they could not use the systems they currently use. However, the system I suggest, which requires the passenger be willing to be bumped, inhibits resale without requiring any type of ID. A business traveller might well buy a cheap ticket at the last minute from somebody who bought earlier, but they are going to be less willing to buy a ticket with unacceptable delay risks associated with it.
Submitted by brad on Sun, 2006-09-10 18:18.
As a hirsute individual, I beg the world’s makers of medical tapes and band-aids to work on an adhesive that is decent at sticking to skin, but does not stick well to hair.
Not being versed in the adhesive chemistries of these things, I don’t know how difficult this is, but if one can be found, many people would thank you.
Failing that would be an adhesive with a simple non-toxic solvent that unbinds it, which could be swabbed on while slowly undoing tape.
Submitted by brad on Tue, 2006-05-02 00:03.
Here’s an interesting problem. In the movies we always see scenes where the good guy is fighting the Evil Conspiracy (EvilCon) and he tells them he’s hidden the incriminating evidence with a friend who will release it to the papers if the good guy disappears under mysterious circumstances. Today EvilCon would just quickly mine your social networking platform to find all your friends and shake them down for the evidence.
So here’s the challenge. Design a system so that if you want to escrow some evidence, you can do it quickly, reliably and not too expensively, at a brief stop at an internet terminal while on the run from EvilCon. Assume EvilCon is extremely powerful, like the NSA. Here are some of the challenges:
- You need to be able to pay those who do escrow, as this is risky work. At the same time there must be no way to trace the payment.
- You don’t want the escrow agents to be able to read the data. Instead, you will split the encryption keys among several escrow agents in a way that some subset of them must declare you missing to assemble the key and publish the data.
- You need some way to vet escrow agents to assure they will do their job faithfully, but at the same time you must assume some of them work for EvilCon if there is a large pool.
- They must have some way to check if you are still alive. Regularly searching for you in Google or going to your web site regularly might be traced.
Some thoughts below… read more »
Submitted by brad on Tue, 2006-03-21 00:32.
You may be familiar with Stegonography, the technique for hiding messages in other messages so that not only can the black-hat not read the message, they aren’t even aware it’s there at all. It’s arguably the most secure way to send secret data over an open channel. A classic form of “stego” involves encrypting a message and then hiding it in the low order “noise” bits of a digital photograph. An observer can’t tell the noise from real noise. Only somebody with the key can extract the actual message.
This is great but it has one flaw — the images must be much larger than the hidden text. To get down a significant amount of text, you must download tons of images, which may look suspicious. If your goal is to make a truly hidden path through something like the great firewall of China, not only will it look odd, but you may not have the bandwidth.
Spammers, bless their hearts (how often do you hear that?) have been working hard to develop computer generated text that computers can’t readily tell isn’t real human written text. They do this to bypass the spam filters that are looking for patterns in spam. It’s an arms race.
Can we use these techniques and others, to win another arms race with the national firewalls? I would propose a proxy server which, given the right commands, fetches a desired censored page. It then “encrypts” the page with a cypher that’s a bit more like a code, substituting words for words rather than byte blocks for byte blocks, but doing so under control of a cypher key so only somebody with the key can read it.
Most importantly, the resulting document, while looking like gibberish to a human being, would be structured to look like a plausible innocuous web page to censorware. And while it is rumoured the Chinese have real human beings looking at the pages, even they can’t have enough to track every web fetch.
A plan like this would require lots and lots and lots of free sites to install the special proxy, serving only those in censored countries. Ideally they would only be used on pages known to be blocked, something tools behind the censorware would be measuring and publishing hash tables about.
Of course, there is a risk that the censors would deliberately pretend to join the proxy network to catch people who are using it. And of course with live human beings they could discover use of the network so it would never be risk-free. On the other hand, if use of the proxies were placed in a popular plugin so that so many people used it as to make it impossible to effectively track or punish, it might win the day.
Indeed, one could even make the encrypted pages look like spam, which flows in great volumes in and out of places like China, stegoing the censored web pages in apparent spam!
(Obviously proxying in port 443 is better, but if that became very popular the censors might just limit 443 to a handful of sites that truly need it.)