Monthly Archives: April 2005

Zeroconf for seamless networking…

Internet, Networking, Python

I have HP's all in one device which is ethernet enabled. So all computers on the LAN can print to it/scan from it etc. The printer seems to use DHCP server to acquire the IP address and did not provide any name to the DHCP server. The windows version of software managed to detect the printer correctly and also everytime the address is changed. Then after the obligatory nmap port scan I discovered that it runs something called rendezvous protocol for autodiscovery. This is now standardized by IETF Zeroconf working group and is promoted by apple for seamless network configuration, autodiscovery etc. for SoHo users (and used by iPod, is built into MacOSX etc.) This also seems to be supported by HP, IBM.

There is ofcourse a competitive proposal called uPnP
 (universal plug and pray play) which is endorsed by Microsoft.

Anyway, found some interesting links on zeroconf:
A very good article on O'Reilly network about zeroconf.

An interview with Stuart Cheshire (now with Apple) who authored zeroconf IETF RFC's.

An interesting thread on linux mailing list about adding this stuff to linux and politics behind such a thing!

Python and its implementation of zeroconf.

Amazon’s “Statistically Improbable Phrases”

Internet

Amazon.com has quitely introduced this concept of "Statistically Improbably Phrases" (SIP's). They scan the entire books (with the permission of publisher/authors) for users to be able to "search inside" the book. During this they do some analysis of some phrases that occur frequently in the book, which otherwise does not occur outside of that book. So for the book: WCDMA for UMTS : Radio Access for Third Generation Mobile Communications, they list the following SIP's:

mobile transmission power, time division scheduling, power control signalling, uplink transmission power, more multipath diversity, cell interference ratio, own cell interference, air interface load, power control headroom, allocated bit rates, physical layer procedures section, kbps real time data, cell change order, uplink loading, radio resource management algorithms, adjacent channel interference problems, soft handover base stations, enhanced access channel, outer loop power control, fast power control, uplink coverage, downlink orthogonal codes, macro diversity gain, admission control strategy, system information blocks

Now using these SIP's you can search other books having them. I think this is a very clever idea of word frequency analysis to artificially gain knowledge about keywords in the book. So by searching for the SIP "mobile transmission power" they generate the following books:

10 references in WCDMA for UMTS: Radio Access for Third Generation Mobile Communications, Revised Edition by Harri Holma (Editor), Antti Toskala (Editor)

7 references in WCDMA for UMTS, 2nd Edition by Harri Holma (Editor), Antti Toskala (Editor)

5 references in WCDMA: Towards IP Mobility and Mobile Internet by Tero Ojanpera (Editor), Ramjee Prasad (Editor)

1 reference in Adaptive Blind Signal and Image Processing by Andrzej Cichocki, Shun-ichi Amari

1 reference in Wireless Networks by P. Nicopolitidis, et al

BTW, here is what amazon.com says about SIP's

Update: (2005/05/05) There is an wired article on this topic: Judging a Book by Its Contents which talks about SIP's

Greasemonkey: Control your web!

Internet, Programming, Scripting

Greasemonkey is a plugin for Firefox browser that lets you assign DHTML scripts to various domains. What's the big deal you ask ? This lets you correct some annoying problems some websites have or even add some nice features to your regular websites.

There are tons of user contributed scripts for doing fun things, like Adding waypoints to google maps., Remove ads from indiatimes.com etc.

The disadvantages of this are 1. this is firefox specific and 2. This works only on the computer that you installed the extension and scripts on. But hey! it's still way cool...

Update: 02/22/05
Here is a very nice application of this: Let's say you are browsing amazon.com for some books, how about checking out your local public library's catalogue for the same book and displaying that information right next to amazon book title ? This has been done by Jon Udel (but looks like he has taken down his script) and Bill Stilwell. I managed to tweak his script to search San Diego Public Library. Hurray! Contact me if you are interested. I will polish the script and put it here in a few days anyway...

Some more blog posts on greasemonkey:
http://taint.org/2005/03/16/201734a.html
http://javascript.weblogsinc.com/entry/1234000273026520/

**Update: 05/05/12**
Hmmm... [Dive into Greasemonkey](http://diveintogreasemonkey.org/ "Dive into Greasemonkey")

**Update: 05/18/05**
Wow this monkey is getting bigger and bigger.

[Here is](http://www.wired.com/news/technology/0,1282,67527,00.html "Firefox Users Monkey With the Web") a link to a recent wired article on greasemonkey.

wordpress themes

Misc

Interesting wordpress themes from www.alexking.org
:

Clasikue
Connections
Dark Maple
Elvgren
Fasttrack
Greenwood
Head (3 column layout)
Jakarta (Cool javascript hacks for align, smaller/bigger font etc.)
Neuron (Collapsible menus)
rdc*Theme
Red Train
Rin
Sharepoint Like

Currently reading…

Books

Currently the following books are on my reading shelf:

  • How To Make Money In Stocks: A Winning System in Good Times or Bad, 3rd EditionHow To Make Money In Stocks: A Winning System in Good Times or Bad is written by William J. O'Neil, who is the founder of Investor's Business Daily. In addition to pitching IBD (which is good BTW), he outlines his method of picking the winning stocks to the acronym CAN-SLIM.
    C = Current Quarterly Earnings per Share. (The absoulute number not the growth percentage) The more the better. The earnings should be consistently increasing on log scale year-over-year and they should increase with the sales growth.

    Current quarterly earnings per share should be up a major percentage-at least 25% to 50% or more-over the same quarter the previous year. The best companies might show earnings up 100% to 500% or more!

    A=Annual Earnings Increases 25-50% or more growth rate. Check earning stability in past three years. Ignore P/E ratio.

    Concentrate on stocks with proven records of significant earnings growth in each of the last three years plus strong recent quarterly improvements.

    N=New Products/Management/Highs.

    Search for companies that have developed important new products/services, or benefited from new management or new industry conditions. Then buy their stcks when they are emerging from price consolidation patterns and are close to, or actually making, new price highs.

    S=Supply and Demand. Look for companies with less number of outstanding shares, enterpreneurial management rather than caretakers, no excessive stock splits, companies buying back shares in open market, low corporate debt/equity ratio.

    Any size capitalization stock can be bought under the CANSLIM method, but small-cap stocks will be substantially more volatile, both on upside and downside. From time to time, the market will shift its emphasis from small to large caps and vice versa. Companies buying back their stock in the open market and companies showing stock ownership by management are preferred.

    L=Leader or Laggard. Buy among top two or three stocks in a group. Use relative strength to seperate leaders (>80) from laggards.

    It seldom pays to invest in laggard stocks, even if they look tantalizing cheap. Look for, and confine your purchase to, market leaders.

    I=Institutional Sponsorship: Follow the leaders. Look for >10 quality institutional owners. (IBD sponsorship rating A). Avoid "overowned by institutions" stocks.

    Only buy stocks that have at least a few institutional sponsors with better-than-average recent performance records, and invest in stocks showing an increasing total number of institutional owners in recent quarters.

    M=Market Direction. Even good quality stocks will go down when overall market direction is downwards. Look for movement in S&P 500, DJIA, Nasdaq Composite indices. Don't be blinded by the myth surrounding "Long-Term Investing".

    The key to staying on top of the stock market is not predicting or knowing what the market is going to do, but knowing what the market has actually done recently and what it is currently doing.

  • Collapse: How Societies Choose to Fail or SucceedCollapse: How Societies Choose to Fail or Succeed
  • Using Your Brain--For a ChangeUsing Your Brain--For a Change

Rebate tracker use cases

Programming, Python
  • Adding a new rebate:
    Step 1 Enter zip code for mailing address (zip+ext)
    Step 2 A list of rebates with same submission zip code is displayed
    Step 3
    Case 1 - Click on one of the links to prepopulate rebate form with entered information.
    (Display Submission address, Contact information, rebate validity, postmark date, expect check date)
    OR
    Case 2 - Enter new rebate and capture all information:
    (Product Name*), (Rebate amount*), (Rebate Description*), (Purchase valid from*), (Purchase valid until*), (Must postmark by*), (Expect check in*), (to ) weeks, (Submission address*), (City*), (State*), (Zip*), (Zipext), (Product Website), (Rebate Form URL), (Enquiry Phone), (Enquiry Email), (Inquiry Website)
    Display info as in Case 1.

    Step 4 Get (Purchase Location), (Purchase Date), (Purchase Price), (Date Mailed), (Postage), (Status: one of Mailed, Processing, Approved, Declined, Received, Void), (date Completed)
    Allow user to save/cancel data

  • Change Status of a rebate
    Currently active (status != Declined, Received, Void) rebates are displayed. One of them is selected, display the same data as in Step 4. and allow user to change and save data.
  • Periodic run
    Go through currently active rebates and email reminder for all rebates falling after (mail date + Expect check low)