I red something interesting about geotechnical sw:
The application of finite element analysis to the design of embedded retaining walls
PhD RICHARD IAN WOODS, 2003
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
http://forum.civilea.com/thread-27464.html
***************************************
It's old stuff but pdf page 23, 24, 25 (doc. pages I- 6-8) really got my attention:
Quote:Anomalies and unexpected results had cropped up in the analysis of a variety of geotechnical problems ... due to:
a) bugs within the code itself (program not working as stated)
b) user errors in the input data (program not solving the problem intended)
C) inappropriate use or misunderstanding of finite elements (program not being used as envisaged)
d) genuine though unanticipated response (program behaving correctly but not as expected)
It applies to other engineering software as well. I encourage you to read it when you have some spare time.
Software hides it's bugs by using disclaimers. Open your favorite and read.
Those typically encourage users to check the output. Easy for a simply restrained beam for which no software is required and hard for a multistory building for which a software justifies it's price. Check by comparing, but with what if the structure is uncommon, a different software and even design team, who will pay, and why pay twice?
For products too like let's say corrugated sheet:
Quote:The tables are not a substitute for the structural analyses required for the building design.
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
http://forum.civilea.com/thread-27464.html
***************************************
So I'm supposed to learn two design software, make the same model in both, compare results, find why are different, find and read/buy some literature for every uncommon structure, check the products technical data, make drawings, print and after check drawings (problem with plotstyle, bad plotter, wrong version of reader), do by hand material lists and compare with software, not excel because it might have bugs
....
To check some corrugated metal sheet acc. to EC it takes about week the first time, if you have all the data. Maybe another week to build an excel which might be used for the same shape type.
I wander when design codes will start having disclaimers too. Many eurocodes advice to use in design experimental study.
Enough off topic
Patching:
A software developer commonly places license checks in various places in code and so in program parts. Most have a from time to time check which triggers at fixed or even variable time intervals. Some look first if the software is monitored by some hacker tool. Some checks are silent other raise a message like License not valid.
A cracker typically searches for checks which are somehow related to license validation. The depth of it's search is based on experience, talent, money, enthusiasm, a human like everyone else.
Some of the license checks trigger when you click some button, an important one like run analysis, or a not so important one like make drawings or output report.
A good (well paid and innovative) software developer will embed more than one type of check (completely different and independent) to deceive a cracker.
Protecting software takes time and money and testing and bug checking and it's a part of the sw price.
If let's say an error occurs when a license check fails, that part of the code will not run, if the error is silent or hidden the cracker might not see it, if that part of code was required to let's say change some property of material, it can be skipped. So the software can run apparently flawlessly but because of some internal error or skipped code will provide wrong results. The cracker might even accidentally jumped over some instructions.
Fake license:
A fake license, dongle, without altering the software will yield the same product you pay for. No difference between as long as cloning or replica is well done.
Most likely no software developer wishes for users to know that it's product has bugs. Including pirated versions. And it seems that pirating software is tolerated. If you draw the line it's all about money, image, advertising, brand, habit. Altering results if crack is detected will never improve his image or increase the number of clients.
Tekla has used a tag to mark drawings, also it is said that the model contains license information.
Code:
***************************************
Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:
http://forum.civilea.com/thread-27464.html
***************************************
To draw a conclusion, based on disclaimers with or without license you still have to analyze problems with more than one software and have some expert advice&review.