FAAL, P. Teorie celkového výstupu (nastoupané výšky) [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2024.

Posudek vedoucího

Pavlík, Jan

The thesis deals with the problem of elevantion gain of a terrain path. Although this is often considered a quantity directly assigned to the path, one can observe that to determine it one has to overcome several issues. One of them is the definition. If we have a path defined as a curve in a space with well defined elevation (a continuous function), then the elevation gain can be, on a theoretical level, defined rigorously in a certain integral form. One problem is that the terrain can be almost infinitesimally jagged. i.e., it admits "teeth" of arbitrarily small size (width and height). Even if the height is somehow constrained, it still can lead to huge numbers (possibly infinite). It is undesired since the the main motivation is that elevation gain reflects the difficulty of passing along the path w.r.t. the vertical movement. Moreover, if a person moves along this path, the corresponding trajectory (of the center of body mass) can be even more jagged, since the oscilation produced by human gait is involved. This is why the desired quantity may be affected not only by the path itself but also by biometrical data of the individual. All of these problems were a matter to deal with for the student. Writing a thesis in a restricted time with a need to overcome several issues connected to an international study was neither easy for him nor for me as a superviser. Hence my role was mainly as an advisor on what to do rather than on how to present the results in the written form of thesis. Although there has been a significant progress from its early stages, it may still seem the thesis is written a nonstandard way which may not be easy for a reader to follow and some decissions do not seem wright at all (such as presenting graph not matching the preceding calculations, posting formulas without their justification and others). For the research, the student needed to acquire the data, this was done by several trips in Brno and surroundings where the measurments on the devices lent by CESA was done. Unfortunately, the data was were too heterogeneous so that the were hardly comparable as such. It may have included significant information needed for the research but I was not sure whether the accuracy of the measuring devices was sufficient to confirm our conjectures that the smaller the stride the larger the elevationg gain is, which is one of the student's presented achievements. Several methods were used to process the data, some concepts were only mentioned within the thesis and not employed in the research. I leave out on the reviewer to list the errors contained in thesis. Since there was still some contribution to the topic (such as the idea of classification of 5 types of paths (although it is involving mistakes in the definition and in the choice of the type of correlation) or fractal dimension approach) and with respect to the shortened time for the masters thesis, I suggest the grade D.  

Posudek oponenta

Štoudková Růžičková, Viera

The thesis works with data obtained on three trips. These data are processed and analyzed, and conclusions are drawn about how is EG affected by stride length and other parameters of a person and by the type of terrain. The author made some trips, got some data and did something with them, but the presented work did not convince me that he did it right. I have the impression that he does not always understand what he is doing and what he is writing. A large part of the work consists of text that describes unimportant things. It seems like generated by AI. Some things are repeated in several parts, many are not used later in the work. (Section 2.1; section 3.5 (unfinished); P, T notation introduced on p. 18; section 2.5 (R factor); Richardson's method on p. 34 and 55; etc.). Definitions, theorems and proofs are hidden in text. Proofs are sometimes missing or incomplete. (The properties of EG on p. 24, etc.) The formula given on p. 25 is not true. Conclusion on p. 29 bottom is nonsense. Formulas are not numbered, if the author needs them later, he always writes them again. The calculations use simple math, even so there are errors (e.g. m_k, n_k on p. 21, 23) The list of cited literature is chaotic. The same thing is under number 15 and 20, also 9 and 18. Probably the only mathematical publication cited is Čermák, Hlavička (Numerical methods). Several publications on fractal dimension are listed, but not cited in the text. Literature from the specification is not mentioned at all. There is missing information about the data used, especially the number of points. The author claims that he standardized all data to 20 points for each track and device. This would mean, for tracks about 1 kilometer long, measuring only every 50 meters, thus losing information about the terrain (rocky, flat) and the stride length. So, all his later conclusions could not come out at all! Question 1: How many data (points) did you have in the beginning, how many did you work with after standardization? Trip 2 was supposed to compare deviations for devices, but was not repeated, so the measurement error cannot be determined. Obtained percentage deviations were used for corrections of the measurements of the 1st trip. Similarly, 3rd trip was supposed to determine deviations on flat terrain, but it seems that these were not used later at all. In tab. 4.6, the average EG for different terrains is illustrated, but the formula is not given. The overall slope should somehow be considered there, the type of terrain will only show on an otherwise horizontal surface. Question 2: What is the formula for the average EG in tab. 4.6? On p. 48 the fractal dimension is calculated, but it is not clear what profiles were used for the calculation (average of all corresponding tracks?). Figure 4.6 does not match the previous calculations at all. There is no way to check the results in tab. 4.7. Question 3: Explain what is in Fig. 4.6 and how you obtained the values in tab. 4.7. On p. 58 the author states an interesting relationship between EG and stride length, but without any proof. Tab. 7.1 compares EG estimates from “theoretical model” with values obtained from Mapy.cz and Google maps, but it is not stated, how these values were obtained. The work only describes how to determine EG for a specific set of 20 points. Question 4: How exactly did you get the EG’s for tracks in tab. 7.1?

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