helpfaqform_template.ui

基于遗传算法的排课软件源码 根据需要安排合理的课程时间等

				activity 3 - preferred on tuesday
				activity 4 - preferred on thursday
				activity 5 - anytime
		The best solution will contain 2 conflicts, and a possible solution would be:
				act 1 - mon
				act 2 - tue
				act 3 - wed
				act 4 - thu
				act 5 - fri
		If you use ConstraintActivityPreferredTimes, you will get only one conflict:
				act 1 - mon
				act 2 - wed
				act 3 - tue
				act 4 - thu
				act 5 - fri
				
-------------------------------------------------------------------------------

Q: What advantages has FET over other applications?
A: 	- It is free software
	- Supports weekly and biweekly activities (my university of Craiova, Romania, needed that);
	- Independent subgroups, overlapping or independent groups, overlapping or independent years (flexible enough to permit any kind of students structure). FET can even be used to manage every individual student, if you really need that;
	- Possibility of optional activities;
	- Many kinds of constraints, possibility to add many more (please suggest!).

-------------------------------------------------------------------------------

Q: What are the disadvantages of FET, compared to other applications?
A:	- Very unfriendly (no help, primitive graphical user interface);
	- Potentially buggy. I do not have enough sample files for testing FET (and I hate testing :-)
	
-------------------------------------------------------------------------------

Q: Does FET compile on other operating systems than GNU/Linux?
A: FET can be compiled easily in operating systems which are similar to GNU/Linux. I will provide help to compile this program on any operating system. In particular, FET can be compiled on Microsoft Windows, if you install Qt from trolltech.com.

-------------------------------------------------------------------------------

Q: Does FET claim to be the best timetabling software in the world, like all the other timetabling applications?
A: I cannot pretend that, because I could not compare FET with other applications (if you could help me, that would be great). All I can say right now is that I did not see any application with as many kinds of constraints and such flexibility as FET, and besides being free software.

Is FET the first free timetabling software (GNU/GPL)? Hmmm... the first one was Tablix, as I found out after finishing FET. You can see links to this software if you look in the LINKS file or if you search it on the internet.

-------------------------------------------------------------------------------

Q: What is the difference between unallocated and random initialization? Which one is better?
A: This means the method of initializing the population of solution candidates. It seems (practical results) that unallocated initialization is better. I have not read about unallocated initialization anywhere, but it seems to me more natural and I have an empirical explanation somewhere on my thesis.

-------------------------------------------------------------------------------

Q: Help on ConstraintMinNDaysBetweenActivities.
A: It refers to a set of activities and involves a constant, N. For every pair of activities in the set, it does not allow the distance(in days) between them to be less than N. If you specify N=1, then this constraint means that no two activities can be scheduled in the same day. N=2 means that each two subactivities must be separated by at least one day
Example: 3 activities and N=2. Then, one can place them on Monday, Wednesday and Friday (5 days week).
Example2: 2 activities, N=3. Then, one can place them on Monday and Thursday, on Monday and Friday, then on Tuesday andFriday (5 days week).

-------------------------------------------------------------------------------

Q: Is it easy to add new constraints to FET?
A: It is very easy. I can say that I am able to implement a new constraint in a matter of hours. You can find a description of this procedure in file /.../fet-x.x.x/doc/how-to-implement-new-constraints

-------------------------------------------------------------------------------

Q: Help on ConstraintStudentsEarly.
A: It is a constraint that imposes the condition that all the students must begin their courses as early as possible. You have to be careful with this constraint: if any set of students	begins the classes later than the first hour in a certain day, you
will get a conflict.

-------------------------------------------------------------------------------

Q: FET fails to solve my timetable.
A: Please try to use a greater population size. Then, try more simulations. If that does not solve your problem, please try to relax the conditions on the timetable. You can accomplish that by deleting compulsory constraints or by making them non-compulsory

-------------------------------------------------------------------------------

Q: Do the weights have any importance? What is the best way to choose them?
	---The comment below was written when FET used only mutation which randomized an activity's starting time.
A: Yes, the weights are important, but unfortunately I cannot answer to the second question.
	I can justify the first affirmation by an example: the considered file is named (for the moment) sample4. As it is right now, it is a good example of a very constraint timetable, difficult to schedule by FET. The weights are chosen such that the basic constraints have a smaller weight than the constraint avoiding the gaps for the students. I think that after about 4 tries, FET manages to find a clash-free timetable (I am only referring to compulsory constraints). There was no trial in which FET failed with more than 3 compulsory constraints conflicts (usually 1).
I wanted to impose the more important basic constraints, so I raised their importance (weight) and lowered the weight of the gaps constraints. The results came as a very unpleasant surprise for me: I never obtained less than 3 conflicts, with an average of 6. What conclusions can be derived: I am currently thinking and analysing this issue. Until someone will come up with a plausible explanation, I think that: the weights of the constraints are influencing the conflicts function. The function can have more or less local minima (which are a headache for genetic algorithms designers). You are encouraged to play with different weights.

New comment: FET-s algorithm favorises the one-mutation transitions, that is, from a candidate solution you obtain a new candidate solution with a single activity rescheduled. The old candidate solution and the new one must have a good fitness, to be preferred in the evolutionary process. Basic constraints are more likely to be respected by this mutation, whereas gaps constraints require more mutations and the intermediary candidate solutions are not so fit and therefore the chances are lower of finding the good solution.

	---The comment below was written after I chosed to introduce also the second kind of mutation, a swapping of two random activities. This swapping was very benefical, and now the results are the same, regardless of the weights (I am only referring to the above example). The reason is that this random swap helps FET transform a candidate solution which does break gaps constraints into a candidate solution which does not.

-------------------------------------------------------------------------------

Q: Can I use FET to do interactive timetabling?
A: Yes, but this is not easy. All the part regarding data representation and gradually construction of the solution is working, only the interface has to be updated.
	Anyway, when you add a compulsory ConstraintActivityPreferredTime, it means that you fixed that activity. You can use this feature for a semi-automatic or even manual timetabling, but it is not so convenient.

-------------------------------------------------------------------------------

Q: Help on ConstraintActivityPreferredTimes.
A: You can specify a set of time slots when this activity can be scheduled (a kind of OR of more ConstraintActivityPreferredTime).

Important: For only one non-compulsory preferred time, ConstraintActivityPreferredTimes might behave better than ConstraintActivityPreferredTime, depending on whether you are interested in minimizing the distance to this preferred time or only in reaching the exact preferred time. Please see the detailed observation in the explanation of ConstraintActivityPreferredTime

-------------------------------------------------------------------------------

Q: Help on ConstraintStudentsSetIntervalMaxDaysPerWeek.
A: Quite a difficult and long name. A user needed a constraint to disallow more than 2 afternoons per week for a students set. This constraint is more general. You can specify an interval (by the start and end hour), a students set and the maximum number of days in a week when it is permitted to have activities in this time interval.

-------------------------------------------------------------------------------

Q: Help on Constraint2ActivitiesConsecutive.
A: A user needed a timetable to respect the requirement that 2 activities follow one after the other (order is important). For compulsory and non-compulsory, normal error reporting is done. The conflicts are a difference in days + a difference in hours. The number of conflicts is multiplied with 2 if the first activity is weekly (not bi-weekly) and again multiplied with 2 if the second activity is weekly.
	
	->added - 15 May 2004.
	->modified - 20 February 2005.

-------------------------------------------------------------------------------

Q: Help on Constraint2ActivitiesGrouped.
A: A user needed a timetable to respect the requirement that 2 activities follow one after the other (order is not important).For compulsory and non-compulsory, normal error reporting is done. The conflicts reported are: the difference in days+:		- the difference in hours if the activities are too far from each other
	- a constant number if the activities overlap
	- 0 if the hours are OK.
The number of conflicts is multiplied with 2 if the first activity is weekly (not bi-weekly) and again multiplied with 2 if the second activity is weekly.

	->added - 15 May 2004.

-------------------------------------------------------------------------------

Q: Help on ConstraintActivitiesPreferredTimes.
A: A user suggested that ConstraintActivityPreferredTimes should be more general. Now, you can specify a teacher, the students and a subject as a filter to a set of activities that must be scheduled in certain intervals.

	->added - 15 May 2004.

-------------------------------------------------------------------------------

Q: After finding the timetable of our school, suppose that a single teacher needs to modify his timetable and the rest would like to keep their timetable unchanged. Thus, it is needed to fix all the activities of the rest of the teachers and re-allocate the hours. Can FET deal with such a situation?
A: Yes, FET can deal with that. Just add many compulsory ConstraintActivityPreferredTime-s, one for each activity that you would like to be fixed (the preferred time will be the one from the previous allocation). This will not slow down the allocation,
because compulsory constraints of this type are dealt with in a special way (repairing of the chromosomes, to be more specific).

	->added - 17 November 2004.

-------------------------------------------------------------------------------

Q: What about introducing duplicate constraints in the timetable data?
A: It will slow down the automatic allocation, so please don't.

	-> added - 12 February 2005.

-------------------------------------------------------------------------------

Q: What about the one phase and 2 phases automatic allocation?
A: If FET fails to solve your timetable in 2 phases (it has many broken space constraints), try a single phase allocation
	
	-> added - 14 February 2005.


this documentation by Liviu Lalescu</string>
            </property>
        </widget>
    </grid>
</widget>
<connections>
    <connection>
        <sender>closePushButton</sender>
        <signal>clicked()</signal>
        <receiver>HelpFaqForm_template</receiver>
        <slot>close()</slot>
    </connection>
</connections>
<layoutdefaults spacing="6" margin="11"/>
</UI>