Domain: uct.ac.za
Stories and comments across the archive that link to uct.ac.za.
Comments · 42
-
Re: News for nerds
Cumulative rainfall in Cape Town for the past 3 years (2015, 2016, 2017) is below the 20th percentile of the past 40 years, see http://www.csag.uct.ac.za/curr...
As a result, the dams haven't been able to recover during the winter as they usually do, you can explore the details here: http://niwis.dws.gov.za/niwis2...
The national government (run by the ANC which is largely seen to be corrupt, including the Dept of Water and Sanitatiom which over-spends their budget and has high levels of irregulat expenditure) has however not been cooperative with the provincial government and City of Caoe Town (both run by the DA, which has been highly critical of the corruption in the ANC).
National government has built desalination plants in ANC-run cities that are less affected by the drought (e.g. Richard's Bay), but in Cape Town, the city has even had to foot the bill for the only major dam to be constructed in the Western Cape in the past 20 years (the Berg River dam).
-
Re:How do some people use so much?
You each use only 16 gallons per month? Less than half a gallon a day? Is Saturday bath day in your house? Is the last person to bathe the one who drains the tub? I must be misunderstanding what you're saying.
No, he said:
My water bill for a family of 4 is at the 2K gallon rate which is about 16 gallons each for a month
2000 gallons
/month/family
* 1/4 family/person = 500 gallons / person / month
* 1/30 month/day = 16.66 gallons / person / day
* 3.785 gallons / litre
= 63 litre/person/dayThat's not too bad.
We live in Cape Town, our household (comprising 2 adults, 3 kids aged 3-8) uses 5kl/month, or 33.3 litres / person / day, well below the 87l limit (but there isn't much more we can do to save water in our house). This includes:
- All personal hygeine (toilet, shower etc.) except obviously anything at work/school (we don't shower at a gym or anything like that)
- All washing (dishes, laundry etc.) and cleaning in the house
- All drinking water and food preparation
- We use grey water (e.g. collect bath and shower water) for our small vegetable garden, but haven't used any water for the rest of the garden since they started water restrictions.
- The kids share one small plastic bath tub inside the normal bath tub, adults show with a 20l container in the shower, and don't use more than that, and don't shower every day (2-3 times a week).
- We haven't washed our cars in a year.Lots of people have installed rain collection tanks and complete grey-water systems, and some have had boreholes/wells drilled (but there are long waiting lists with all contractors who install all of these).
I don't know why they haven't reduced the limit further, as it really isn't difficult to use less. 50l/person/day is probably achievable and still relatively fair.
The city has also imposed a 10.5kl limit per household per month, and any household that needs more because they have more than 4 occupants must apply for a higher allocation, but since we are way below we don't apply.
We know of other people who used didn't abide by the restrictions when they were more lenient, they have been forced to pay to have water restriction devices installed, which limit their daily water use (unused daily water accumulates for the rest of the month, but unused monthly water doesn't accumulate/roll over).
There are a lot more issues at play here than described in the BBC article, as the majority (60%0 of the water available in the dams in the Western Cape was allocated by the national government to agriculture. That is understandable, as even that allocation is too little for them (with the amount of rain over the past year), with many farmers having to choose between killing their livestock and taking loans to buy feed (and still possibly have to kill the livestock later anyway).
For some detail on how bad the drought is, see some rainfall stats for Cape Town. The past 3 years we have had less than the 20th percentile of annual rainfall over the last 40 years.
You can also see the trend of water storage in the dams here
We really hope some of the short-term mitigation plans (small-scale desalination plants that can be completed before we run out of water, ground-water extraction etc.) are sufficient to get us to Winter (and rain), but we if the trend of the last 3 years continues, we may not make it to Dec.
-
Re:Not only that...
Wikipedia has a significant problem with content related to this part of the world. Read How pro-fascist ideologues are rewriting Croatia's history. There are similar problems in Indonesia – see Don’t Trust Wikipedia on Indonesia – and in South Africa: The political economy of wikiality: a South African inquiry into knowledge.
It's all got to do with why people contribute to Wikipedia. -
Re:It sounds like London's logic
I first thought of the city and could not understand the reference.
I suspect you are referring to Professor Leslie London and his "Affirmative Action and the invisibility of white privilege," article.
Google led me to: http://www.uct.ac.za/mondaypaper/archives/?id=6412 -
Voronoi diagrams
They're really cool when done using gradients.
http://en.wikipedia.org/wiki/Voronoi_diagram
Code for generating them...
http://www.perlmonks.org/?node_id=190245
Example...
http://people.cs.uct.ac.za/~chultqui/houdini/images/heightfield_voronoi_part.png -
Re:no post-grad center on the whole continent?
And if we're talking about stuff like LHC and Fermilab, there's iThemba Labs. Not on the grand scale of the major European and American facilities, of course.
The High-Energy Physics section at UCT's physics department (the one sayfawa linked above) is actually involved in one of the components of the LHC.
The University of Cape Town offers as full a range of undergraduate and postgraduate study as what you would find at a good American or European university, and was listed as one of the top 200 universities in the THES-QS rankings. There are several other universities in South Africa with a similar range and quality of research. -
Re:no post-grad center on the whole continent?
And if we're talking about stuff like LHC and Fermilab, there's iThemba Labs. Not on the grand scale of the major European and American facilities, of course.
The High-Energy Physics section at UCT's physics department (the one sayfawa linked above) is actually involved in one of the components of the LHC.
The University of Cape Town offers as full a range of undergraduate and postgraduate study as what you would find at a good American or European university, and was listed as one of the top 200 universities in the THES-QS rankings. There are several other universities in South Africa with a similar range and quality of research. -
Re:no post-grad center on the whole continent?
If TFA (which I haven't read) suggested that there's no post-grad physics or math department in Africa, it's wrong. I have personally visited several physics departments in various African countries that had Ph.D programs. For example, here's a math program and here's a physics one.
-
Silly
It's a silly thing to say, really. This falls in the same category as computer predictions made over the years that were based on current trends and technology. The funny thing about technology is that it tends to progress. What he's describing are current limitations, and while accurate, hopefully things will progressand we'll try to come up with solutions to those problems.
-
Re:Argh, bad science reporting.Seven sequences does not a genome make.
Three chromosomes for the maths-kings under the sky,
Seven for the Dinosaur-lords in their halls of chicken,
Nine for polyglutamine doomed to die,
One for the pneumolysin on his dark throne
In the Land of Slashdot where the Firehoses lie.
One Sequence to rule them all, One Sequence to find them,
One Sequence to bring them all and in the darkness bind them
In the Land of Slashdot where the Firehoses lie. -
Re:HERVs: 8% of Human GenomeEbright might say it, but does that make it right?
The researchers weren't sure about the infectivity of the virus...they weren't sure it would be infective at all. This is a virus that was beaten by evolution and became a pet:
In addition, the researchers showed that Phoenix could form particles capable of infecting mammalian cells in culture. Infectivity was very low, presumably because host cells have evolved mechanisms to resist uncontrolled virus propagation, as has been repeatedly observed for retroviruses from experimental animals. -- ScienceDaily
Now, taking the components of this retrovirus and mixing them with, say a pig retrovirus that is known to infect human cells (this is called superinfection)...that's a bit scarier. Unfortunately, it's called "pig farming." Last I checked, pig farming was not a Biosafety Level 4 activity. It's these porcine retroviruses that are holding up using genetically engineered pig body parts as human replacement parts for transplant. Still, think of all the people who get pig heart valves each year...
Why haven't we all died from some strange porcine-HERV virus combination? Human retroviruses (HTLV1, HTLV2, HIV1, HIV2) are all Biosafety Level 2. The hallmark of these retroviruses is that they aren't very good at propagating. By bumping up to Level 3 the virus that is probably recreated naturally every once in a while, and throwing in the disabling trick to permit it to only reproduce once, they took more than sufficiently reasonable precautions.
Biosafety 4 is reserved for viral hemorrhagic fever viruses (Ebola, Marburg, etc.) and stuff like that. If Phoenix were deserving a Biosafety Level 4, humanity would have been long dead and no one would be alive to conduct the experiments. Think of it as the biologist's version of the Anthropic principle.
-
Re:I was just reading this creationist articleThe best arguement against a young earth is not decay rates or deposition rates, or salinity rates but things you can walk up and see. The best arguement I have come up with is the geological angular unconformity with takes several unavoidable long time period sequential steps such as
- Deposition
- Lithofication
- Uplift
- Erosion
- Deposition (again)
- Lithofication (again)
- Uplift (again)
- Etc.
Great examples abound and there is even one at the bottom of the grand canyon. Some fine examples 1, 2, 3 and 4 -
Re:A point of clarification
>> Like quarks
... where's the objective verificationIn the Large Hadron Collider you will find the answer. Here or here or a more wider search
>>What about the hadron boot-strap? Branes?
Not sure what you mean about boot-strap, but as for the Hadron family, look for..."Large Hadron Collider"
You may not SEE them, but evidences are conclusive enough. When experiences match theory closely, it holds proof of existence.
>Branes
Branes..ah! Branes...Wait for the next version of the LHC. We'll know if it's just theory or not in a few years, so hold your breath! Even more! The Higgs boson might give up to the LHC and show up at last (he's the one supposedly responsible for giving its mass to a particle - so it's somewhat a big deal). And the nice thing is that, since it's theory (again), we'll soon be fixed on wherever it exists or not. If not, other theories will try to explain mass and will be tested. Until we find out.
>>I think we take a lot on faith without realising it. Much of that is based on someone elses faith too!
That is where your mistake is. Science is not faith-based but fact-based. Faith has no room in the scientific process. Confidence in one's experiments or theory is only confidence and has to be tested to be considered valid.
>>And I don't see Occam's razor as being a logical method.
The Occam's razor is not a method for conducting science, it is a simple thought and a guidance as to where to look at: the most simplest explanation is the first you should consider. It assumes (generally rightfully) that nature takes the shortest paths. As do humans. But again, it is not a method - at all.
-
ECE: long term solution, or short?
An alternative to using RSA, DSA, or other encryption methods which rely on the difficulty of factoring is Elliptic Curve Encryption. As far as I know, nobody has come up with a theory for how quantum computing might be used to crack ECE. What I do not know is how hard it might be to come up with such a thing, or how long it might take to become available once the theory is mapped out.
RSA-oriented solutions are going to get the lion's share of the attention and development for a while, because it is so popular. Unless ECE catches on in a big way, and/or RSA is widely viewed as useless, there won't be much market incentive to develop an ECE-oriented solution. At least, that's my opinion. So in the meantime, ECE-encrypted data might be safer than RSA/DSA-encrypted data.
-- TTK
-
Re:Fractal compression
fractal image compression is a separate and distinct technique from wavelet transforms. I do recall that there was a company called Iterated Systems that had a browser plugin for viewing their proprietary image filetype. It looks like they've dropped off the face of the planet. Anyway, here's a nice bibliography on the subject.
-
Re:12" Powebook noise level reduction
Oh, that's easy. Just shove your universal Macintosh disk eject tool in there and the noise should stop immediately.
-
Creative quoting?
Funny how that site gives you a definition for the noun and a definition for the adjective and you decided to quote the wrong one, eh? Creative quoting, I guess.
Here's the other one (for the noun, from the very same page):
"A work, such as a film or television program, presenting political, social, or historical subject matter in a factual and informative manner and often consisting of actual news films or interviews accompanied by narration" (fits Fahrenheit 9/11 like a glove, more so than any of Moore's previous documentaries, in fact).
But let's see what specialised sites have to say about it:
[1] "an interpretation of theoretical, factual, political, social or historical events or issues presented either objectively or with a specific point of view"
[2] "a nonfiction motion picture film having a theme or viewpoint but drawing its material from actual events and using editing and sound to enhance the theme"
[3] "a non-fiction film which usually, although not always, has a particular point of view regarding its subject matter"
[4] "an eligible documentary film is defined as a theatrically released non-fiction motion picture dealing creatively with cultural, artistic, historical, social, scientific, economic or other subjects"
[5] "factual footage arranged in such a way that it informs and expresses a point of view"
I've been working on (and watching) documentaries for a couple of decades, and these are the definitions employed and accepted by the authors, the industry, the critics, the festivals and the viewers. If you think a documentary is something else, you can either a) correct yourself or b) try to convice every filmmaker, film institute, film festival, cinema historian, etc., that they are wrong.
Either way, good luck, it's not going to be easy.
RMN
~~~ -
Re:You don't know the half of it....1) The Soviet Union did all the heavy lifting when it came to defeating the Nazis in WW2. That's not to say that the Western allies didn't contribute AT ALL, but the Soviets bore the brunt of it and did the lions share of destroying the German army.
True, the Soviets paid a high price in casualties to beat back the Nazis. However, a big reason for the high number of Soviet casualties was Hitler's invasion of the USSR (which Stalin, at least, wasn't expecting quite so soon) in violation of the 1939 Molotov/von Ribbentrop nonagression pact, at a time when the USSR wasn't fully prepared for war, partially because Stalin had just brutally purged the USSR in general and the Red Army in particular of those he feared were disloyal. One of the primary Soviet motivations for signing the pact with the Nazis, instead of joining an alliance against them with France and Britain, was the USSR's general unreadiness for war and Stalin's belief that he could build up his army while Hitler was busy in the west.
Thus, in the attempt to buy some time at the expense of France and Britain (and Poland, which Hitler and Stalin agreed to divide between themselves) to rebuild the army that he was responsible for decimating in the first place, Stalin made the mistake of trusting Hitler and got burned. So if you're trying to drum up some sympathy for the Soviets, you'll get precious little from me =)
Also, a slight nitpick: the phrase "the lion's share" means all of something, not just the majority of it. The reference is to one of Aesop's fables.
-
Useful resource
If anyone (like me) needs a refresher on what the Higgs Boson entails from the perspective of physics, there's a nice collection of one-page explanations at http://www.phy.uct.ac.za/courses/phy400w/particle
/ higgs.htm. -
RSA vs ECCFor those of you who are suprised at the number of bits needed to secure data using ECC compared to RSA, a good discussion can be found here
http://www.cs.uct.ac.za/courses/CS400W/NIS/papers
0 0/mlesaoan/paper.html -
OpenTextMe and a few friends are currently making an 'Opentext' book for highschools, aimed at teaching physics, maths and chemistry to south african schools (where we are based).
if anyone is keen, the link (probably slow if you are not in SA) is
unfortunately, we haven't got anonymous cvs access... but if anyone wants to read what we have, just send one of us a mail! try
fommil AT yahoo DOT ie
and we are looking for writers
:-DUniveristy Physics, Maths or Chemistry is necessary if you want to help out however.
-
not that bad...
Give him a break.. He's got some points. And at least he's thinking about real and genuine problems. I see a lot of people commenting with the 'who needs 10 million lines of code?' shtick. Sounds familiar.
We're going to need to do things in a decade or two that would require 10 million lines of code (measured by current languages), just as the things we do now would require 10 million lines of code in 1960's languages.
The new languages and techniques that we have now provided ways for us to reduce the apparent complexity of programs. This guy is just looking for a way to do that again. Certainly there is room to disagree with his techniques for accomplishing this, but it is shortsighted to deny the problem. -
Re:Correct me if I'm wrong
here's a link that talks about how much the shuttle damages the ozone now:
http://www.egs.uct.ac.za/csag/faq/ozone-depletion/ intro/faq-doc-26.html
-
Re:More jokes
IIRC the divisors *do* need to be distinct. Eitherway, here is a link to people smarter then me arguing about it.
-
Re:77 Million Years?
-
Tying In The Higgs Boson
I have yet to see ANYBODY in this field tie the Pokletnov claims to the mainstream theory of gravity believed by most particle physicists, which is that it is caused by a particle called the Higgs Boson. What's interesting is that these mainstream physicists share many traits with Pokletnov to the untrained eye - they haven't really found the Higgs particle yet, they just think it's there because it ought to be, and without understanding of some really DEEP math the Higgs at first blush seems to be just as much handwaving as anti-gravity. Some of the best public-consumption stuff on the Higgs is to be found here, something about the (so far unsuccessful) search here, and an audio discussion with the inventor of the whole concept, Dr. Higgs himself, here. If you want to get into the serious math of the Higgs (good luck) one place to start is the bottom of the web page here.
-
Re:Good to see HP commit further.NO, I do not think that it is too much to ask for.
What you will probably find is that as time goes on, this might become the Linux company's competitive advantage.
I remember when I was in university, our varsity prided itself in employing the highest number of A rated scientists in any educational institution on the continent... or some similar claim.
Why employ your Co. instead of Co. B would therefore be answered by "we employ 7 of the 10 name-the-program-here core developers!"
Capitalism at work and benefiting the open source community. -
He is funding research too..
Shutleworth is funding three research projects around his trips. One of the projects will involve University of Cape Town, Physiologists. The universities monday paper has the story
-
Pictures off cnn
I have taken pictures off cnn. They can be accessed at: http://edge.smuts.uct.ac.za/~smorar/cnn/
-
Re:And the point is?Harsh but true.
Racist and false.
You haven't the foggiest idea what you're talking about. None. You are a typical uneducated spoiled pampered suburban neoliberal slob with no knowledge of history other than the occasional tidbits you manage to pick up from Hollywood movies.
Here's a bibliography for you. Go read some of the works cited, if you can find any that don't exceed your reading level. Then come back and express an informed opinion.
-
Old news
I never heard of this guy before but I found a old news item from the University of Cape Town.
-
Previous workAbout a year ago there was an effort to write a peer reviewed online journal. It made it as far as a quick and dirty prototype implementation, but then got abandonded due to lack of interest.
If anybody is interested in rescuing it from its abandoned state: The GPLed source is here.
Its architecture is wacky: It uses a journalling filesystem instead of a database, does aggressive caching and on the fly compression. All written in C, so probably needs an audit.
-
Re:Could be useful.
Being able to kill off cancer cells and other types of viruses(maybe) this could have huge value to people.
IANAB, but I as far as I know, viruses are not cells. From this article on viruses structure, here are the components of a virus:
- The CAPSID denotes the protein shell that encloses the nucleic acid. It is built of structure units.
- STRUCTURE UNITS are the smallest functional equivalent building units of the capsid.
- CAPSOMERS are morphological units seen on the surface of particles and represent clusters of structure units.
- The capsid together with its enclosed nucleic acid is called the NUCLEOCAPSID.
- The nucleocapsid may be invested in an ENVELOPE which may contain material of host cell as well as viral origin.
- The VIRION is the complete infective virus particle
The bottom line is: this cell killer gene will not help fighting the flu.
-- .sig under construction... -
Java isn't Javascript
All I have to say is that if you think Java is insecure
Java is rather secure as can be seen by reading any of the numerous articles on the web about it. Javascript on the other hand is a disaster which was foisted on us by Netscape and excarberated by Microsoft.
PS: You do realize that the NY Times article is discussing a Javascript exploit and not a Java one, right?
Grabel's Law -
Re:O' the irony!
Actually this is from the University of Cape Town, a South African university.
With the limited bandwidth they have (~2-4 Mbps last count), and the limited space in the various labs, it doesn't take much porn-surfing and mp3-downloading for everything to start working pretty slowly. Some of the labs already had time-limited access for non-UCT sites (ie no access during work hours). Of course, not all of the labs have 24hr access.
Specifically filtering the site because it is a porn site seems a bit rash, especially given that other sites can chew up much more bandwidth (mp3s, mpgs/DivX, etc). And there is the issue of UCT now having taken it upon themselves to filter the network content: They could now be responsible if any illegal content is found (this argument has been put forward on
/. before).There is more information available at the URL mentioned above.
Of course, there is also the whole definition of "public universities". Attending UCT is not free. They do, however, receive certain government funding. I do not if this could force them to suspend the filtering. They do classify the traffic according to academic relevance, sorta.
- Al
-
Re:O' the irony!
Actually this is from the University of Cape Town, a South African university.
With the limited bandwidth they have (~2-4 Mbps last count), and the limited space in the various labs, it doesn't take much porn-surfing and mp3-downloading for everything to start working pretty slowly. Some of the labs already had time-limited access for non-UCT sites (ie no access during work hours). Of course, not all of the labs have 24hr access.
Specifically filtering the site because it is a porn site seems a bit rash, especially given that other sites can chew up much more bandwidth (mp3s, mpgs/DivX, etc). And there is the issue of UCT now having taken it upon themselves to filter the network content: They could now be responsible if any illegal content is found (this argument has been put forward on
/. before).There is more information available at the URL mentioned above.
Of course, there is also the whole definition of "public universities". Attending UCT is not free. They do, however, receive certain government funding. I do not if this could force them to suspend the filtering. They do classify the traffic according to academic relevance, sorta.
- Al
-
O' the irony!I attempt to check out SmartFilterWhere and get the following message from our proxy:
ERROR: Site Access Denied
I nearly fell off my chair I was laughing so hard. The best part is that the list of sites blocked is shared amongst quite a few universities in here. Talk about poetic justice.If you are seeing this message, then you are trying to access a porn site.
Please read this document for clarification on why this site is restricted.
Access is restricted from 07:00 to 19:00 on weekdays.
Please contact the helpdesk if you feel the site you are trying to access is needed during these times or is not a porn site, please include the URL of the site in your report.
UCT Cache Administrator
Generated Fri, 08 Dec 2000 09:09:40 GMT by cache.uct.ac.za (Squid/2.3.STABLE3)
Of course, any filter company would block their rivals' sites.
-
Flexi time interferes with play
For a long time I've really enjoyed working when I feel like it. Basically since it allows me to get out of bed at 10:00 instead of 7:00, but I've finally come to notice the greatest disadvantage of flexi-time (we use the British terminology in South Africa) is that I'm never quite sure when the jobs done. When and when my private life starts and my job finishes is quite important to my mental health and working fixed time puts all this resposibility on my employer and leaves me free to work hard when I work, and play hard when I play. (Maybe I should rather be doing psych than math...;)
-
Re:Okay... but why not?
I deserve (-1, Flamebait) for my previous post, looking at it again. I flew off the handle for no good reason and I apologize. (Moderators, do your duty.)
It'd be possible to use sampling to get it within a decent margin of error, possibly saving a boat load of money while still getting good enough (+/- 1%? 5%? 10%?) results to fairly apportion representatives, federal money, etc.
There is a tradeoff between sample size and error--it is intuitive that as sample size increases, the probability of the sample being like the population increases. It won't be dead on--100% confidence would require sampling the whole population. (Apologies to mathematicians everywhere, but I think this sums up sampling.)
However, I don't believe we get it dead on now, either--slammed doors, lost forms, data entry errors, (hopefully few) derelict enumerators . . . (And it won't get any better with U.S. Representatives saying things like Dan Miller did.)
I think the biggest problem with using sampling would be ensuring the data were good and that the administration wasn't pushing an agenda--it wouldn't take falsifying nearly as many census forms to change the outcome when a sample is being used as it would when it wasn't.
And, while some would still indeed be "selected" to fill out the forms, identifying data could be eliminated from the form (what value would sampled identifying data be?), rather than kept to be released in 72 years (or when the Census Bureau just gives it up anyway). This alone might be enough incentive to get better data. A blind signature voting protocol could be used--tickets could be assigned to those selected, those selected could be known. But the responses of those selected could not be associated with an individual who has responded. (This could be used with a full count approach, as well--the hard part is implementing the protocol in a way that every person could easily perform it.)
I definitely agree with those here that say the census will be useless in the future if this data is misused now. There are already plenty of good reasons not to trust the government, but this would be a serious and unforgiveable breach of the people's trust. -
Pamela the Penguin is Missing!
Take a look at the satellite track. Pamela (the yellow track) has aparently gotten lost.
Are they going to send out search planes?
Whose idea was it to drop off htess penguins 800 kms from home anyway?
Why wasn't there an appeal for those really cute baby penguin sweaters, like they had for the Australian penguins caught in an oil spill?
-
Similar Projects - which already work
There is grouplens which does co-operative usenet rating, and there is prol which does a co-operative slashdot (don't like that article - vote it down) and then there was some overhyped stuff from some media wired woman which did co-operative movie reviews and got sold out to the Borg Empire IIRC, so I am not going to mention their URL.
-
CachingIf you anticipate a lot of hits, you might want to precompute/cache most of your database access, if at all possible.
There are a couple of experimental systems about which do this kind of thing. For example prol does aggressive caching (but is not db-backed). I once heard somebody say that Roxen also does caching, but I have not investigated that.