Final evaluation of Introduction to Sound and Vibration Evaluation compiled by Patrik Andersson, Mars 17, 2007.

Transcription

1 Final evaluation of Introduction to Sound and Vibration Evaluation compiled by Patrik Andersson, Mars 17, The evaluation questionnaire was handed out the last lecture and 11 questionnaires were returned. The answers to the questionnaire are compiled and discussed below. Thereafter some comments from the exam is given and finally the halftime evaluation is appended at the end. Short background Year 2007, the course Introduction to Sound and Vibrations (ISV) was given for the first time. The course partly a combination of the previous courses Akustik, hus (AH) and Maskinakustik (MA), and partly completely new elements were added (Lars lectures on vehicle acoustics and the project work). Patrik Andersson developed the lecture notes based on Wolfgang Kropp s lectures notes previously used in AH and MA. All notes where updated with respect to structure and language and was transferred to LaTeX. Major updates, new explanations, and new parts were included in some of the lecture notes. In addition Lars Ivarsson held 2 times 2 h of lectures related to vehicle acoustics. Lars developed Power Point presentations that are available for the students. The project work was developed by Patrik Andersson with aid from Lars Ivarsson. The reports were reviewed and graded by Patrik. Patrick Sabiniarz held a laboratory work where the students under about 2 hours worked with basic measurements on a passenger car. The reports of the laboratory work is under review by Patrick. The course consist of 1. About 14 times 2 hours lectures where the students learn basic knowledge and understanding of sound and vibration phenomena and engineering approaches to solve problems in sound and vibration. 2. A quite extensive project work divided into 4 parts where the students learn to apply their knowledge and understanding on problems in sound and vibration. There is also a strong focus on writing good reports to explain their problems, solution, results and interpretation. The reports are graded U,3,4,5 both wrt performed tasks, contents and structure/layout. 3. Exercises and supervision 7 time 2h (2 h a week). 4. About 2 hours of practical laboratory work per occasion, where two groups of two students (4 individuals in alles). Was held Lv6. 5. A written exam evaluating knowledge and understanding of phenomena in sound and vibration. Graded U,3,4,5. 22 students participated in the course: 8 from Civil Engineering (Väg och Vatten) 4 form Building Services/Architecture (English speaking) 3 from Engineering Mechanics (M) 3 Doctoral students from Vehicle Safty 1 from Automation and Mechatronics 1 from Computer Science (D) 1 form (Specialutformat program) 1 from Physics at Göteborg University that only follows the lectures. 20 students participated in the written exam.

2 My suggestions for improvement based on the answers of the final evaluation questionnaire: Evaluation of project work: The students think that the project work is interesting, that they learned from the work, and most understand the grade they got. It is clear that especially project work 2 (and maybe 3) was not easy and very time consuming for the students. Project work 1 and 3, 4 will be kept pretty much as they are. I will next year look into reducing the amount of tasks in project work 2, while still trying to cover the same contents, and eventually creating a building acoustics version of it (ventilation duct). Project work 4 can be transferred into a building acoustics task (double wall in a building). See also the comments in the half-time evaluation below. Evaluation of laboratory work (The students had not got the review of the reports when this evaluation was handed out.) Most of the students appreciated the laboratory work. Despite the positive reactions of the laboratory work, I suggest that it is changed substantially to next year. I suggest that the lab. work comes rather early (study week 2) and to let the students investigate a lot of different typical sounds ( sound hunting ): Computer fan with tonal components, road traffic noise, reduction of sound through a wall (HiFi booming noise), vacuum cleaner, transients (speech), impulses (handclap), etc. The intension is to give the students to get a good feeling for typical levels, frequency content, and relations between time records and frequency spectrum. It is important that they get this feeling early. Patrik and Patrick will look into this until next year. Self evaluation I will try to skip more of the derivation parts next year and focus on the basic relations and final results. I will also show more application examples and what typical requirements look like (use data in Lagerlöf, Vigran and Bies). Other comments: The lecture notes will be kept and I will try to update them with some more some application examples next year. We will try to get a little more clear connection between the lectures and Friday demonstrations. MATLAB was a problem for many students I will provide them with a tutorial (Is there one already in the Masters Programme (IPC course) that we can use?) instead of booking computer halls. Regarding the need for more supervision: In my opinion, most students asked for very little supervision/questions so more time is really not needed? We have to make clearer that supervision giving discussions is a vital part in the learning process and repeatedly tell the students to use the opportunity for supervision. Maybe the questions have been to detailed and too much like precipices? Could more general questions give more active discussions? I will look into the project work as stated above and below, i.e. reduce repeating questions of the same kind and transfer some of the tasks to building acoustics equivalents.

3 Detailed summary of the answers Evaluation of project work: Mark with an X in the fields below where you want to state your opinion on to what extent you dis or to the following statements of the different parts in the project work. Part 1 Completely dis dis Fully It was interesting for me It was easy for me It took to much time for me I learned from the work 5 6 I could understand the grading (Sound pressure levels / A weighting / Summation of pressure from manifold) Part 2 Completely dis dis Fully It was interesting for me It was easy for me It took to much time for me I learned from the work 5 5 I could understand the grading (Exhaust system: Acoustic components (mufflers) / Estimation of contribution from the exhaust pipe termination to sound pressure in the passenger compartment) Part 3 Completely dis dis Fully It was interesting for me It was easy for me 5 7 It took to much time for me I learned from the work 5 6 I could understand the grading (Road traffic noise The Nordic Prediction Method) Part 4 Completely dis dis Fully It was interesting for me 6 5 It was easy for me 5 6 It took to much time for me I learned from the work 6 4 (Sound insulation (reduction index) of separating wall)

4 Evaluation of laboratory work It was interesting/boring? You learned something? You got sufficient with help (lab. description/supervision)? Etc. Positive * Good design of laboratory work. * Good with discussion about theory before the laboratory work. * Good with a discussion of the work after the measurements. * We got sufficient with help form the lecturer and tutor. * I got sufficient with help in both description and supervision. * Good, interesting to measure on a real car. * We got to learn the fundamentals of measurement techniques. * Fun to be allowed something practical that couples theory and reality. * Good try of practical application * It was quite interesting. I learned more about acoustics. * It was very interesting and we learned more about acoustics. * It is interesting. I learned the order of engine, and the skills of calibrating the signals. * I really learned from the lab. work. * The laboratory work was good. Negative *...but I did not learn much (right now). * We did not do much our self; the computer did most, so a little bit boring. Did not learn much. * Un-necessary, the same as project work part 1. Suggestions: * Should maybe have been a week earlier. * I would have liked to have it at least one week earlier so you do not have to write the report during the exam week. * I really learned from the lab. work, so I suggest more lab. work than project work. * I suggest that there can be a lab. work about room acoustics or the reduction index of double and single walls as I think a lab. work can raise my interest on studying these topics. Self evaluation An important step in you learning process is to reflect on it... What have you learned during the course (in general terms)? What was most interesting for you? What was most surprising for you? I have learned: * I learned most from the project work. * I have learned much more about where formulas that we have used in previous courses on acoustics come from. I.e. a more fundamental knowledge about why things are like they are. * We have learned how to decrease the noise in real life. * How to design the system to reduce SPL. * I have got the opportunity to see that there are a lot of formulas/equations for calculations of sound. I would have learned the meaning of all these calculations of we got more examples on applications. There was often only one example I would have liked to see more examples and more relations. * I learned most from the project work the derivations at the lectures felt abstract.

5 * New area, learned a lot. Interesting * Engine mounts. Firewall. Transfer functions. Double wall construction. * The laboratory work I could not imagine that it would be a real car for us the we could measure on. * The car engine acoustic problem is the most interesting. * The most interesting part for me is the application part on the project work, for instance, the sound pressure levels of road traffic, reduction index for wall of a car. Surprising: * How one calculates road traffic noise. * New area, everything interesting. Other comments: Comments on lectures, lecture notes, contents, supporting exercises, course organisation, additional comments on project work, etc. can be made here: Positive: * Very good and interesting course! * Good course. * Very well written lecture notes. * Good lecture notes * Good with lecture notes instead of textbook. * Both Patrik and Partick are formulating themselves very well English which makes it easy to follow. * The supporting lectures (on friday) provided me a full understanding of the lecture content. I appreciated it a lot! * Quick answers and help from Patrik via . * Good course web page * Good with review of the project work. * I though first that is would be a more general overview course in acoustics. But it has been more focused on fundamentals which is good. * Understood most of the building acoustics project as it is there I have my interest. Negative: * MATLAB is challenging * It was a pity that it was so focused on vehicle acoustics. These projects were much harder to understand, as I do not even know how an engine looks like. On the other hand, I have learned about engines. * I did not understand what project work 2 had to do with V. It was hard to understand when it was about the exhaust system of a car I do not even know how the car works. * Sometimes a little bit unclear questions in the project work. * Too much to read in lecture notes. * Project work took a lot of energy. * Introductory course in MATLAB auth to be compulsory. * The project work tasks were sometimes hard to understand. Just to interpret the questions took a lot of unnecessary time. Suggestions: * Be more specific in the questions of the project work.

6 * The project work should be presented in more detail as the task sometimes where hard to interpret. Many assumptions must be made, which leads to that the students mistrust their results. * The lecture notes could be clearer. *Lars lecture notes: Would be good with more explaining text or make them available before the lecture so one can make own comments. * Some more examples, like the ones with the modes in the lecture hall, and less derivations. Should be enough to show the beginning and the end of the derivation and tell that the rest is in the lecture notes. * More examples from reality, e.g. how different NVH problems have been solved. Maybe with oscillation dampers, double wall constructions, etc. * The most complicated was to get MATLAB to calculate in the correct way. It would have been good with one additional lecture/week in a computer room where the students could get direct supervision with problems with MATLAB. Some of the results of the project work were hard to comment as we were unsure. A supervisor would have been good at these occasions. * The lectures are sometimes about the project work that was discussed the previous week, it would have been better it the lecture was before the project work. The following was written in the end of the exam. Evaluation of exam Feel free to write any comments about the exam here and hand it in: * Questions 6a and 6b is very much connected and hard to treat separately. * Tickets to Metaltown are released! * Good layout with project work and only theory on the written exam! One understands so much more in the work and this makes also the theory easier. * The exam was good! To trying to get out understanding from us how are writing it instead of learning to repeat must be hard but I thing you succeeded completely ok. * Thanks for a good course! My comment: I have to get tickets to Metaltown...

7 Half-time evaluation of Introduction to Sound and Vibration Evaluation compiled by Patrik Andersson, Feb 23, questionnaires were returned. Lecture notes = Course literature: Contents? Structure? Language? etc. Positive: * It is good that it is more compact not pages after pages with no info nor just mathematical equations. * Good that the teacher writes them only what is important to focus on is included. * Compact and easy to overview. * 3 x Very good or good lecture notes. * One can follow the notes during the lecture. Negative: * A lot of documents to keep track of. * It had been good if Lars s lectures would be put on the course web page. My suggestions for improvements: The lecture notes are generally appreciated no changes during the course this year. I will keep them pretty much as they are also next year with some minor updates (e.g. some additional pictures, updating the hand-written figures to MATLAB once, some different explanations, and correcting a few errors in formulas). Next year everything will be posted at the course start so the students can download it once and for all maybe also a master document containing all chapters. Lectures: Structure? Tempo? Content? Pedagogic skills? Patrick s complementary demonstrations? etc. Positive: * Good that one can follow the lecture notes and thus can concentrate on listening instead of writing. * Good with sound examples, figures and animations that describes sound phenomena. * 4 x The tempo is good or ok. * The lectures cover the course literature well. * No problems to follow structure. * Lars lectures are interesting. * Patrik explains very well... Negative: * It is bad that the lectures are a bit behind/or problem solving a little bit to quick. * Patrick s exercises could be more connected to the lectures.

8 * Maybe high tempo on the exercises for those who have not at all studied acoustics before but on the other hand nobody ever complains when it is to fast... * Sometimes a little bit high tempo. * Sometimes too many equations. * A lot of formulas, more concrete examples to explain how one uses the information in practical situations are needed for better understanding. Suggestions: * Maybe focus more on theory during the lectures. * Are we in phase with the schedule? If not, is something going to be cancelled? That is good to know beforehand. * More basics! My suggestions for improvements: Both more theory and more practical stuff are asked for. More theory are covered in later courses in the Masters programme Sound and Vibrations, hence I will still in the future treat some parts very briefly, i.e. only the physical effects are discussed and not so much theory and equations. The intension of the course is to get a broad overview of the complexity in sound and vibrations in general plus a detailed understanding of selected parts. I will try to include more practical demonstrations however, it might be hard do a lot this year, as I also have to write the lecture notes at least a few demonstration should be feasible, e.g. I will take the students in a tour de division anechoic, transmission suit, ANC-ventilation duct, etc. Patrick s examples will probably be more in phase to the course next year when I know better the amount of time each lecture requires. Project work descriptions: Content? Structure? Language? Content? Layout? etc. Positive: * Good descriptive text with informative images. * Good description of formulas, but can anyhow sometimes be hard to follow. * OK. * Good. * Very good so far. * Language is ok. * Part 1 was good and rather easy to understand. Negative/Suggestions: * Maybe good to have a short presentation of each part when they are handed out, to get an overview understanding. * Could contain more MATLAB info. * Extensive work. The first part could have been less extensive so that the students do not give up directly. * The description could have been more clear, we have to assume a lot by our self. * Sometimes hard to understand what one should do. * A through presentation of the project work is needed for each part not everybody has worked with automotive engines. * Hard to get the questions sometimes.

9 * Some tasks in Part 2 were much harder to understand. My suggestions for improvements: I will in the future present the project work in about 10 min at the Friday lecture. Next year I will provide the student with an info script about the MATLAB syntax needed to solve the problems. Regarding the questions I think it is better that the students ask for supervision than explaining even more more explanations tend to be just recipes. Project work: Useful? Interesting? Challenging? To easy/to hard? Using Matlab/Octave? Enough time? Supervision? Etc. Positive: * Good, interesting. * Patrik is very helpful when we have questions. * Good but a little bit to extensive. * Interesting tasks that are not to abstract Calculations on the exhaust system of a car is a realistic and interesting task, good! * Good level. * Interesting topics that are easy to get into. * MATLAB is good. Negative: * Little bit hard to understand the questions. * Feels unnecessary to do a proper report of everything for each report. * Some tasks are really hard in both theory and with MATLAB. * I had no knowledge in MATLAB, pure luck that my work-mate had it! * Hard when one cannot MATLAB and it is this that takes time. * Too large projects - especially of one do not know MATLAB so good = takes a lot of time. * Not enough time. * Hard tasks that do not follow the lectures. * The second part needs more background and explanations. Much harder and more to do than the first one. Suggestions: * Maybe some fewer parts of project work. * The project work can be reduced without learning less, i.e. take away similar tasks so you don t have to do about the same twice. * More times for supervision. My suggested improvements: Next year there will be a more detailed MATLAB guide available It is probably to late this year, the students have already gained the basic knowledge, and I don t have time anyhow... A good MATLAB guide will probably reduce the amount of time spent on the project work considerably. Regarding the amount of tasks it is already reduced compared to the indented amount, and I will keep it on a rather challenging levels (the project work is after all replacing all exercises on the written exam). I will however look into the work and see if some similar task can be taken away or added

10 by others. Regarding the time for supervision: It is surprisingly that a major part of the students do not actively ask for supervision both during scheduled time and nonschedule time only a few students took the full opportunity to use the supervision to gain additional knowledge. Maybe the project task descriptions are too detailed and do not promote the students to ask for supervision. Other comments: Course information? Lecture hall? Course organisation? or whatever... Positive * Good organised course web page! * Good course web page. * Good lecture hall. * Interesting course. Negative * The lecture hall is small and the white board is too low hard to see the lower part. * No presentation of goals, aims, etc. of the course. * Seams like the course is holding a high physical level that not everybody seams to have enough of from before. It should be an introductory course after-all. * Sometimes a little bit hard to follow Lars lectures and project work due to my lack of knowledge about passenger cars and engines. Suggestions: * The structure of the course is 100% theoretical. The sound laboratory rooms should be used better, to give the students a more practical view on sound. It is an introductory course? Right? * More practical experiments, e.g. testing how different material are damping differently etc. So that the students can examine by themselves now we get ready formulas for everything... * It would have been good to have introductory tasks so one understands what one should know, what kind of understanding it is about, etc. * How will the exam be? A real example exam would be good. A lot of calculations or mostly theory questions. Suggestions of improvements: The goals and aims were, at least briefly, discussed during the first lecture. Regarding the use of laboratory rooms, it is rather hard to take the full class to the rooms. The laboratory work is covering some practical aspects. I will offer a tour of the division after next lecture. Maybe we should put the laboratory work earlier next year, e.g. Lv2 to give the students practical experience already at the start of the course. Example questions for the written exam are now available on the web page.