跳到主要內容

發表文章

目前顯示的是 4月, 2012的文章

unmanned space vehicle for delivery

NASA / ISS is now trying out SpaceX's Dragon. It's one of ways to replace the role of space shuttle, which were now retired. They use the robotic arm CanadARM to "catch" the Dragon, when it is within 2 km range of the space station. It's a very KISS approach to solve the problem. When compared with China's ShenZhou 8 type of head-to-head dockiing method, this "catch" method is safer, when there's some mishappenings. ??? ( is it real ?) It's also low tech enough for commercialisation too. SpaceX successfully kicked off the rocket called Falcon 9 on 22 May, 2012 and attached to ISS ( International Space Station) on 25 May animation  soyuz docking explained   german instruments onboard   shenzhou 8 launch and docking

Security updates for Debian / Ubuntu

In view that now malware threats is extending to other non-Windows platform, like recently on MAC OS X, the flashback trojan, it should be on higher alert to linuxes too. For Ubuntu, besides using Update Manager to do it for you, one of the way is to get security updates, eg from Debian Security . >>> This won't work. As you couldn't get trust certificates so that the patch be applied to Ubuntu. You need to use Ubuntu Security Update Simply add a line like this to your apt: deb http://security.debian.org/ squeeze/updates main contrib non-free You can use apt to easily get the latest security updates. This requires a line such as deb http://security.debian.org/ squeeze/updates main contrib non-free in your /etc/apt/sources.list file. Then execute apt-get update && apt-get upgrade to download and apply the pending updates.  instead, get automatic security update for Ubuntu Go to Update Manager,...

Ngong Ping 360 investigation report

This haul-rope transport system is one of the most challenging project in the world, in terms of scale, length, and shape of travel. The investigation from EMSD pinpoints it is 1) a mechanical failure 2) abnormal vibration at bullwheel No. 3 and No. 4 3) this abnormal vibration triggers the vibration sensor, and cause emergency stop of the system cause of failure wear and tear of linings ( rubber ) at the bullwheel upper raceway of inner bearings : spalling             pits and dents in running element : lower raceway - outer bearing : corroded metal fragments ( Hmmm, may have been running without lubrication and high temperature....) high moisture content of lubricant The remedial actions include: 1) replace all bull-wheel bearings 2) enhance the vibration monitoring system of all bull-wheel bearings to capture data on an ongoing basis, 3) increase scrutinising frequency to fortnightly. Frankly speaking, ...