|Ken Novak's Weblog
Purpose of this blog: to retain annotated bookmarks for my future reference, and to offer others my filter technology and other news. Note that this blog is categorized. Use the category links to find items that match your interests.
Subscribe to get this blog by e-mail.
New: Read what I'm reading on Bloglines.
Ken Novak's Weblog
Saturday, October 25, 2003
Winning the War on spam: Comparison of 2 Bayesian spam filters: "
- SpamBayes is currently the best solution to the spam problem. In fact, after I started using it I hardly notice there is a spam problem at all.
- POPFiles' support for multiple buckets can actually be a very useful feature for sorting your normal mail.
- both function as POP3 proxies "
Can Aliens Find Us?: "they could spectroscopically sample the light reflected from our atmosphere, and learn that it has large quantities of oxygen and methane, tell-tale markers of biology. In other words, aliens -- even relatively distant aliens -- could make straightforward astronomical observations that would prove that the third planet from the Sun hosts life. .. [But intelligent life? The easiest way] would be to detect our military radars. The bigger ones typically boast a megawatt of power, and are focused into beams that are a degree or two across. There are enough such radars that, at any given time, they cover a percent of the sky or so. The signal from the most powerful of these could be found at 50 light-years distance in a few minutes time with a receiving antenna 1,000 feet in diameter. Indeed, these military radars are the only signals routinely transmitted from Earth that are intense enough to be detectable at interstellar distances with setups equivalent to our own SETI experiments.
Bottom line? With radio technology slightly more advanced than our own, Homo sapiens is detectable out to a distance of roughly 50 light-years. Within that distance are about 5,000 stars, all of which have had the enviable pleasure of receiving terrestrial television. And each day, a fresh stellar system is exposed to signals from Earth.
But even if you believe in highly optimistic estimates regarding the prevalence of cosmic intelligence, its unlikely that another civilization exists within 50 light-years. Thats too small a distance. Were no doubt listed in some alien grad students data tables as a world with life, but without the footnote indicating intelligent life. We are the new kids on the block, and so far its a safe bet that none of the other kids know were here." 9:44:49 AM
Uganda to Make Solar Panels
: "Construction is expected to start by the end of the year on the $500,000 plant to be located in Kyambogo near Kampala. It is funded by the Danish Development Agency (Danida) as a joint venture between a Ugandan company, RAcell Uganda and a Danish company RAcell Denmark. Mr George Sizoomu, Executive director RAcell Uganda told BusinessWeek that the panels will be made using raw material imported from Europe. "We have to invest quite a lot to be able to produce. In about three months time, the factory will be operational and with the production in place, prices will definitely go down," he said." 9:30:46 AM
Friday, October 24, 2003
The full text
of Rumsfeld's memo on the war on terror. 11:50:54 PM
al-Qaida planned to attack U.S. embassy in Kenya
: "Al-Qaida operatives planned to destroy the U.S. Embassy in Nairobi in June with a truck bomb and a hijacked plane loaded with explosives, a plot described in a Kenya police report seen by The Associated Press on Friday. The report, based on an interrogation of a terror suspect, could explain why the U.S. Embassy was closed June 20-24 and why Kenyan officials banned flights from June 20-July 8 to and from Somalia, a lawless neighbor and suspected haven for terrorists." 11:33:18 PM
Carrots and Fuel Rods
: "A news article in the Lebanese Daily Star
titled "Iran nuclear pledge is victory over Washington" shed
more pragmatic light on the details of the new agreement. According to the Star
, Iran does not recognize the Oct. 31st
deadline for proving that its nuclear program is "entirely peaceful," though it has now turned in documents to prove that point. Moreover, Iran has said nothing about how long it will suspend its uranium enrichment program or what might cause it to resume the process. The article quoted Israel's military intelligence chief ominously asserting that "if Iran completed its uranium enrichment program, it would be able to produce nuclear weapons without outside help within one year."" 9:31:49 PM
Trusted Email Open Standard
: 10-point summary of TEOS, which includes extensions to SMTP to verify identities, make assertions about message contents, and allow multiple authorities to certify the correctness of assertions. ".[Messages] that come from senders who are prepared to identify themselves are more likely to be legitimate than those that don't.. [Assertions will be useful because] it is a lot riskier to lie about messages when people know who you are". More details here 12:44:20 PM
Thursday, October 23, 2003
Carbon Finance at the World Bank: July 2003 presentation at a workshop on "Carbon Credits from Flare Reduction Activities" sponsored by the Global Gas Flaring Reduction Partnership (GGFR). Notable:
- greenhouse gas credits already purchased or under negotiation total approximately US$250 million
- shift into renewables and not just efficiency in last 2 years (breakdowns by region, type, and purchaser of carbon credits)
- carbon prices currently running $3-$4/tonne CO2e
- carbon finance helps solid waste management which saves on more powerful greenhouse gases
Author: Chandra Shekhar Sinha, Portfolio Manager, Carbon Finance Group The World Bank. 9:13:35 AM
Wednesday, October 22, 2003
CSIR Launches New Open Source Centre
: "The Council for Scientific and Industrial Research (CSIR) on Friday launched an Open Source Centre as part of broader endeavors aimed at stimulating the adoption of Open Sources Software Technologies in Africa. The center will be operating from CSIR in Pretoria. The CSIR, the largest scientific and technological research, development and implementation organisation in Africa, has been operating for more than 50 years." 11:52:39 PM
Tata Energy Research Institute TeriScope newsletters carry interesting stories. In this recent issue:
- The GNESD (Global Network on Energy for Sustainable Development), launched by UNEP at the World Summit on Sustainable Development in Johannesburg, is a network of centres of excellence in the developing world working on energy, development, and environmental issues. Related institution: South Africa’s EDRC
(Energy and Development Research Centre),
- TERI has worked with the Pembina Institute for Appropriate Development (Canada) in developing potential CDM projects in Bangladesh, China, India, and Indonesia. Other related organizations included the Prototype Carbon Fund, International Emissions Trading Association, Asian Development Bank, EDRC, and Natsource.
Record Heat Wave in Europe Takes 35,000 Lives: "A record heat wave scorched Europe in August 2003, claiming an estimated 35,000 lives. In France alone, 14,802 people died from the searing temperatures—more than 19 times the death toll from the SARS epidemic worldwide. .. Though heat waves rarely are given adequate attention, they claim more lives each year than floods, tornadoes, and hurricanes combined. Heat waves are a silent killer, mostly affecting the elderly, the very young, or the chronically ill."
Health risks are magnified when humidity is high, the heat lasts 2 or more days, in cities where night cooling is less than rural areas (esp. "heat islands"), and where the air is polluted. Other killer waves in the US with over 700 deaths each were in LA in 1955, NYC 1972, Chicago 1995. "Over the last 25 years the average global temperature rose by 1 degree Fahrenheit, or 0.6 degrees Celsius. The IPCC's projected rise in temperature for this century is a global average, but the temperature is expected to rise more over land, where people live, than over sea. .. The World Meteorological Organization estimates that the number of heat-related fatalities could double in less than 20 years." 9:35:06 AM
Tuesday, October 21, 2003
UNEP Launches New Initiative to Shift Investment to Sustainable Energy
: "Noting that large centralized fossil-fuelled power stations supported by large centralized distribution systems will continue to be vulnerable, Mr. Toepfer launched the UNEP Sustainable Energy Finance Initiative (SEFI) aimed at engaging the finance sector to invest in renewable energy and energy efficiency. Although sustainable energy technologies such as solar cells and wind generators have advanced rapidly, Mr. Toepfer said the transaction costs and market uncertainty of many renewable energy projects has lead most financiers to adopt a "wait-and-see" attitude, which is compounded by an overall lack of information, experience and the tools needed to quantify, mitigate and hedge project and financial product risks. With support from the United Nations Foundation (UNF), SEFI will help mainstream financiers overcome these barriers and consider renewable energy and energy efficiency as not just niche investments, but key components of secure energy systems based on truly sustainable forms of energy." 10:35:47 AM
Monday, October 20, 2003
The End of Spectrum: "There are two basic problems with the rules governing the radio spectrum: there is no such thing as spectrum, and we don't need any rules."
Nice technical summary, listing spectrum sharing methods other than frequency division: "Wireless technology has come a long way since Marconi's day. For example, many systems now use spread-spectrum as an alternative to frequency division. WiFi and CDMA cellular networks are two examples. In both cases, devices share the "same" frequencies, using computational intelligence to distinguish one signal from another. The ultimate form of spread-spectrum is ultra-wideband (UWB). UWB systems can transmit at extremely low power, so low that they appear invisible to licensed systems operating in the same bands. .. Other novel forms of wireless sharing include angle-of-arrival (for example, distinguishing a satellite transmission coming from overhead and a terrestrial wireless signal moving horizontally); mesh networking (relaying signals from other users); and cognitive radio (sensing the environment to find temporarily open "holes," and moving out of the way once another signal appears)." 10:25:23 PM
: Flash demo of a better way to do long scrolling lists. 9:59:04 PM
Water sparks new power source
: "A new way to generate electricity from water which could be used to power small electronic devices in the future has been developed by Canadian scientists. .. The research by Professor Kostiuk and colleague Professor Daniel Kwok is published by an Institute of Physics journal. It is said to be the first new method of generating electricity in over 150 years. The work is all to do with charge separation, and what happens to ions in liquids when they come into contact with a non-conducting solid." Bottom line: pressurized water can generate power when passed through a device with hundreds of thousands of microchannels in a block of glass . 12:08:32 PM
Sunday, October 19, 2003
Smart InFlow Power: "In commercial and industrial pipes where gases, liquids, or solids exert enough extra pressure to turn a small turbine, renewable electric power can be generated allowing utility companies, manufacturers, even owners of high-rise buildings to produce their own electricity or sell the power and create an additional source of revenue. These new smart turbine devices called Flow-to-Wire(sm) are a compact and more efficient version of much larger hydropower equipment used successfully around the world. The surplus power created by Flow-to-Wire(sm) can be a byproduct of a chemical reaction, occur during the release of stored compressed gas, or result from gravity pulling material from an elevated physical position to a lower one...
The power will qualify for renewable status in most states. To maximize efficiencies and safeguard water supplies against homeland security threats, Rentricity has built integrated sensors into the devices to provide data that will enable water utilities to track flow, pressure, and vault intrusion. Individually, a Flow-to-Wire(sm) system will produce on average 30 kilowatts (KW) to 50 KW -- enough to meet the usual demand of up to 50 homes or a portion of an industrial facility. Rentricity expects to install its devices in thousands of locations worldwide.. Rentricity is part of the Rensselaer Incubator Program" 10:48:36 PM
America Must Let Iraq Rebuild Itself: The current president of the Iraqi Governing Council writes in the NYT: "it is vital to call up the Iraqi Army and the national police force, at least up to mid-officer level. The coalition's early decision to abolish the army and police was well intended, but it unfortunately resulted in a security vacuum that let criminals, die-hards of the former regime and international terrorists flourish. .. Most of these soldiers are Iraqi patriots who chose not to fight for Saddam Hussein. Americans should not confuse the Iraqi Army with the hated Republican Guard, which Saddam Hussein created precisely because he distrusted the legitimate military. .. The coalition and the Iraqi Interior Ministry can vet officers to remove those who committed crimes under the old regime, and then rapidly redeploy the most capable units to work with, and progressively relieve, American troops of security duties. Iraqi Army units have an established chain of command and esprit de corps. Not only can they be recalled to barracks immediately, but it would be much easier and quicker to retrain and re-equip them within their existing organizational structure than to start from scratch.
.. In addition, the Iraqi national police must also be recalled. Most Iraqi policemen — as opposed to Saddam Hussein's feared intelligence and security organs — are dedicated to law and order. The United States does not have the time or money to create a police force from the ground up, nor is it necessary, because we have a large, organized force that is ready and willing to serve." 4:06:36 PM
High-Performance Photovoltaic Project: Entech 440x concentrator
: "Project Objective: Develop a new 440X, 27%-efficient photovoltaic concentrator module which is a "plug-and-play" replacement for ENTECH's existing, field-proven 21X, 13%-efficient module. The new module will use advanced multi-junction cell technology to be provided by lower-tier subcontractor Spectrolab, to replace the silicon cell technology used in the existing module. New color-mixing Fresnel lenses will be required to provide the primary 21X concentration and the secondary 21X concentration, together yielding a 440X overall concentration. The new module will fit into existing field-proven sun-tracking arrays, including the SunLine
2-module array for small power applications and the SolarRow
72-module array for large power applications. Due to the anticipated doubling of module and array efficiency, the delivered energy economics for the new systems are expected to be much better than for the existing systems." Longer paper available
. 10:35:15 AM